This document provides an introduction and overview of antibiotics. It defines antibiotics as substances produced by microorganisms that selectively suppress or kill other microorganisms at low concentrations. The document then discusses the history of antibiotic discovery, including early uses of antimicrobial substances by ancient civilizations, Paul Ehrlich's pioneering work in chemotherapy in the early 1900s, the discoveries of Prontosil, penicillin, and streptomycin in the 1930s-1940s, and subsequent generations of antibiotics. It also outlines ideal properties for antibiotic drugs such as potency, selectivity, oral availability, and lack of toxicity or resistance development.
This document discusses antibacterial agents, specifically penicillins. It provides background on penicillins, noting they contain a beta-lactam ring that inhibits bacterial cell wall formation. Examples of penicillins are discussed, including benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin. Resistance via bacterial production of beta-lactamase is also mentioned.
This document provides an overview of chemotherapy and antimicrobial agents. It begins with a brief history of chemotherapy from ancient times to the modern era. Key figures like Fleming, Florey, Chain and Waksman who discovered important antibiotics like penicillin and streptomycin are mentioned. Basic terminology used in chemotherapy is defined, including terms like antimicrobial, antibiotic, spectrum, bactericidal and bacteriostatic. The major classes of chemotherapeutic agents are listed. Gram-positive and gram-negative bacteria are distinguished and examples are given. Ideal properties of antiseptics and disinfectants are outlined. The document concludes with an assignment asking students to describe bacterial cell structure, distinguish between gram-positive and negative bacteria, and
A presentation on Paul Ehrlich developed modern chemotherapy. This was my ppt for the module pharmaceutics 6. It i based on Anti microbial chemo; hope it help others doing relating things.
This document provides a historical overview of antimicrobial use from pre-antibiotic era treatments to the modern timeline of antibiotic discovery. It describes how ancient cultures used molds and plants to treat infections before the germ theory of disease was established. The work of Leeuwenhoek, Pasteur and Koch helped prove that specific microbes cause specific illnesses. Fleming discovered penicillin in 1928 but it was mass produced for medical use starting in the 1940s. The "golden age" of antibiotic discovery occurred from the 1940s-1960s with drugs like streptomycin, chloramphenicol and erythromycin. However, antibiotic resistance emerged soon after each new drug. Now few new classes have been discovered since 1987 and
This document defines various types of anti-infective agents and provides examples of each. It discusses antibiotics such as penicillins, cephalosporins, macrolides, quinolones, tetracyclines, and aminoglycosides. It also covers antiviral drugs, antifungal agents, antiparasitic drugs, and anti-tuberculosis agents. For each class, it provides the definition, examples of drugs, and their mechanisms and uses.
Antimicrobial drugs have evolved greatly since the discoveries of Salvarsan, sulfonamides, penicillin, and streptomycin. Many modern antibiotics are produced by soil bacteria like Streptomyces. Antibiotics can be bacteriostatic or bactericidal, and have narrow or broad spectra of activity. They work via several mechanisms including inhibiting cell wall, protein, DNA, and folate synthesis. Adverse effects include allergic reactions, toxicity, and disruption of normal flora. Selection of antimicrobial therapy requires confirming infection and identifying pathogens. Classes of antimicrobials also exist for viruses, fungi, protozoa, and helminths.
The document discusses chemotherapeutic agents and antibiotics. It describes how Paul Ehrlich pioneered the concept of selective toxicity for targeted treatment of diseases. Key discoveries included arsphenamine for syphilis. Gerhard Domagk later discovered sulfonamides. Characteristics of effective antibiotics include appropriate spectrum of activity, low toxicity, and resistance prevention. Methods to determine antibiotic effectiveness include dilution tests to find minimum inhibitory concentrations.
This document discusses antibacterial agents, specifically penicillins. It provides background on penicillins, noting they contain a beta-lactam ring that inhibits bacterial cell wall formation. Examples of penicillins are discussed, including benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin. Resistance via bacterial production of beta-lactamase is also mentioned.
This document provides an overview of chemotherapy and antimicrobial agents. It begins with a brief history of chemotherapy from ancient times to the modern era. Key figures like Fleming, Florey, Chain and Waksman who discovered important antibiotics like penicillin and streptomycin are mentioned. Basic terminology used in chemotherapy is defined, including terms like antimicrobial, antibiotic, spectrum, bactericidal and bacteriostatic. The major classes of chemotherapeutic agents are listed. Gram-positive and gram-negative bacteria are distinguished and examples are given. Ideal properties of antiseptics and disinfectants are outlined. The document concludes with an assignment asking students to describe bacterial cell structure, distinguish between gram-positive and negative bacteria, and
A presentation on Paul Ehrlich developed modern chemotherapy. This was my ppt for the module pharmaceutics 6. It i based on Anti microbial chemo; hope it help others doing relating things.
This document provides a historical overview of antimicrobial use from pre-antibiotic era treatments to the modern timeline of antibiotic discovery. It describes how ancient cultures used molds and plants to treat infections before the germ theory of disease was established. The work of Leeuwenhoek, Pasteur and Koch helped prove that specific microbes cause specific illnesses. Fleming discovered penicillin in 1928 but it was mass produced for medical use starting in the 1940s. The "golden age" of antibiotic discovery occurred from the 1940s-1960s with drugs like streptomycin, chloramphenicol and erythromycin. However, antibiotic resistance emerged soon after each new drug. Now few new classes have been discovered since 1987 and
This document defines various types of anti-infective agents and provides examples of each. It discusses antibiotics such as penicillins, cephalosporins, macrolides, quinolones, tetracyclines, and aminoglycosides. It also covers antiviral drugs, antifungal agents, antiparasitic drugs, and anti-tuberculosis agents. For each class, it provides the definition, examples of drugs, and their mechanisms and uses.
Antimicrobial drugs have evolved greatly since the discoveries of Salvarsan, sulfonamides, penicillin, and streptomycin. Many modern antibiotics are produced by soil bacteria like Streptomyces. Antibiotics can be bacteriostatic or bactericidal, and have narrow or broad spectra of activity. They work via several mechanisms including inhibiting cell wall, protein, DNA, and folate synthesis. Adverse effects include allergic reactions, toxicity, and disruption of normal flora. Selection of antimicrobial therapy requires confirming infection and identifying pathogens. Classes of antimicrobials also exist for viruses, fungi, protozoa, and helminths.
The document discusses chemotherapeutic agents and antibiotics. It describes how Paul Ehrlich pioneered the concept of selective toxicity for targeted treatment of diseases. Key discoveries included arsphenamine for syphilis. Gerhard Domagk later discovered sulfonamides. Characteristics of effective antibiotics include appropriate spectrum of activity, low toxicity, and resistance prevention. Methods to determine antibiotic effectiveness include dilution tests to find minimum inhibitory concentrations.
This document provides an overview of antibiotics. It begins with definitions of antibiotics and their history. Alexander Fleming discovered penicillin in 1929 from the Penicillium mold, but it was not until the 1940s that Howard Florey and Ernst Chain discovered its therapeutic properties. The document classifies antibiotics based on their spectrum of activity (narrow vs broad), mechanism of action (bacteriostatic vs bactericidal), source (natural, semisynthetic, synthetic), and chemical nature. Key requirements for antibiotics are that they selectively kill microbes without host toxicity, are eliminated from the body, are stable for formulation, and are highly effective at low concentrations.
Microorganisms can be either helpful or harmful to humans. They are tiny living organisms too small to be seen without a microscope. Some microbes help with important processes like decomposition, while others cause infectious diseases. However, scientists have also learned to use microbes beneficially in areas like food production, medicine development like antibiotics and vaccines, waste treatment, and more. The document discusses in detail various types of microbes, their roles in different processes, and how humans have harnessed them for industrial and medical applications.
Antibiotics were discovered accidentally through the work of Alexander Fleming and others studying microbes. Penicillin was the first widely used antibiotic, discovered when Fleming noticed bacteria-free zones around a contaminated mold. Since then, scientists have discovered many classes of antibiotics through soil sampling and culturing microbes, including streptomycin, cephalosporins, chloramphenicol, and gentamicin. However, overprescription and misuse have contributed to increased antibiotic resistance, highlighting the need for appropriate usage and new antibiotic development.
This document provides an overview of chemotherapy and antimicrobial drugs. It begins by discussing the history and development of antimicrobial drugs from 1910 onward. It then defines key terms related to chemotherapy and antimicrobial classification. The document discusses various classes of antimicrobial drugs like penicillins, cephalosporins, and beta-lactam inhibitors in detail. It covers the mechanisms of action, spectra of activity, pharmacokinetics and clinical uses of these drug classes. Adverse effects and resistance to penicillins are also summarized. The document provides classifications of antimicrobials and concludes by noting that cefotaxime and ceftriaxone effectively cross the blood-brain barrier to treat meningitis.
This document provides an overview of antibiotics. It begins by defining antibiotics as substances produced by microorganisms or synthesized that selectively kill or inhibit the growth of other microorganisms. Antibiotics can be classified in several ways, including by their mechanism of action, spectrum of activity, chemical structure, and types of organisms treated. Common mechanisms of action include inhibition of cell wall synthesis, protein synthesis, and nucleic acid synthesis. The document then discusses the history of antibiotic discovery, including early pioneers like Fleming who discovered penicillin, and Waksman who discovered streptomycin through systematic soil screening. It covers the development of important classes of antibiotics like penicillins, cephalosporins, and aminoglycosides. In summary
This document provides an introduction to medical microbiology for second year public health students. It defines key microbiology terms and outlines the history and development of the field. The document discusses the classification and morphology of microorganisms and provides information on bacterial structures and functions. It also summarizes the important contributions of scientists such as Pasteur, Koch, and others to establishing microbiology as a science.
1. Antibiotics are chemical substances produced by microorganisms like fungi, actinomycetes and bacteria that suppress or destroy other microorganisms.
2. Alexander Fleming discovered penicillin in 1929 after noticing that a mold growing in one of his petri dishes had prevented bacteria from growing nearby. Penicillin revolutionized medicine as the first widely used antibiotic.
3. Antibiotic resistance has become a major problem as bacteria have increasingly developed resistance, even to formerly powerful antibiotics like penicillin. Proper antibiotic stewardship including only using antibiotics when necessary and completing prescribed treatment courses can help address this growing threat.
development of antimicrobial agents which can overcome the antimicrobial resi...Arijit Goswami
as the microorganisms are increasingly becoming resistant to conventional antibiotics therefore there is a need of some new antimicrobial gents which can overcome the resistance and also helps to stop the overuse and mishandling of antibiotics
AS MICROORGANISIMS ARE INCREASINGLY BECOMING RESISTANT TO CONVENTIONAL ANTIBIOTICS,SO THERE IS ANEED OF NEW ANTIMICROBIAL AGENTS WHICH CAN OVERCOME THE RESISTANCE AND HELPS IN REDUCING THE OVERUSE AND MISHANDLING OF ANTIBIOTICS
Lec no 2. antibiotics, antiseptic, antipyreticsParameswari266
Drugs contain carbon and hydrogen with some oxygen, nitrogen or sulfur. They are classified based on their effects on microorganisms and modes of action. Common drug classes include antipyretics to reduce fever, analgesics for pain relief, antimalarials for treating malaria, antibiotics to inhibit germ growth causing disease, and antiseptics to prevent germ growth near wounds. The first antibiotic, penicillin, was accidentally discovered in 1928 by Alexander Fleming through observation of a fungus contaminating a bacterial plate and creating a zone of inhibited growth.
Chemotherapy is a type of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent, or it may aim to prolong life or to reduce symptom
This document discusses broad spectrum antibiotics. It begins with definitions of key terms like antibiotic, pharmacokinetics, and pharmacodynamics. It then covers the history of antibiotics from traditional empirical uses to the modern era including the discoveries of penicillin and other drugs. The document categorizes antibiotics based on their spectrum of activity, mechanism of action, source, and susceptible organisms. It also addresses principles of antibiotic therapy such as selection, combinations, prophylaxis, resistance, and misuse.
The document outlines principles of anti-microbial therapy and summarizes various classes of anti-bacterial drugs. It discusses the definitions and principles of anti-microbial therapy including host-pathogen-drug interactions and features of anti-microbial drugs. It then focuses on different classes of antibiotics including penicillins, describing their mechanisms of action, types, uses and pharmacological properties. Penicillins are discussed in depth, from the discovery of penicillin to the various generations including natural, penicillinase-resistant, aminopenicillins and extended-spectrum penicillins.
This document summarizes research that isolated and characterized antibiotic-producing microorganisms from waste soil samples collected from various industrial areas in India. Soil samples were collected and microbes were isolated using serial dilution and spread plating techniques. Isolates were screened for antibiotic production against other microbes using agar streak and plug methods. Two Bacillus isolates (R29 and B81) showed strong antifungal activity and were selected for further characterization. Biochemical and genetic tests identified R29 as Bacillus subtilis and B81 as likely Bacillus subtilis or Bacillus licheniformis. The research aims to discover new antibiotics and contributes to understanding antibiotic-producing microbes isolated from industrial waste soils.
“Isolation and Biochemical Characterization of Antibiotic Producing Microorga...IOSR Journals
The search for new antibiotics continues in a rather overlooked hunting ground. In the course of screening for new antibiotic-producing microorganisms, isolates showing antimicrobial activity were isolated from waste soil samples from various habitats in the Industrial Areas in Dheradun, Uttarakhand, India. Existing methods of screening for antibiotic producers together with some novel procedures were reviewed. Both modified agar-streak and agar-plug methods were used in the primary screens. The use of selective isolation media, with or without antibiotic incorporation and/or heat pretreatment, enhanced the development of certain actinomycete colonies on the isolation plates. Antibiotics have long been considered the “magic bullet” that would end infectious disease. Although they have improved the health of countless numbers of humans and animals, many antibiotics have also been losing their effectiveness since the beginning of the antibiotic era. Bacteria have adapted defenses against these antibiotics and continue to develop new resistances, even as we develop new antibiotics. In recent years, much attention has been given to the increase in antibiotic resistance. As more microbial species and strains become resistant, many diseases have become difficult to treat, a phenomenon frequently ascribed to both indiscriminate and inappropriate use of antibiotics in human medicine. However, the use of antibiotics and antimicrobials in raising food animals has also contributed significantly to the pool of antibiotic resistant organisms globally and antibiotic resistant bacteria are now found in large numbers in virtually every ecosystem on earth. Dual culture bioassays were used to screen seven selected Bacillus isolates for activity against four plant pathogenic fungi in vitro. All isolates were able to inhibit the pathogens to varying degrees. Two isolates, R29 and B81, were selected for further testing and characterization. Further bioassays were performed on five complex nutrient media which were adjusted to pH S.S and 7, and both incubated at 2SoC and 30°C" respectively. It was found that pH and media composition showed significant influences on the antifungal activities of the isolates tested, but that a SoC temperature difference in incubation temperature did not. Tryptone soy agar was found to give rise to the largest inhibition zones. Both isolates were tentatively identified using standard biochemical and morphological tests. Based on its phenotypic characteristics, R29 was identified as a strain of B. subtilis. B81 proved to be more difficult to assign to a specific group or species of Bacillus, though B. subtilis and B. licheniformis were considered to be the nearest candidates. Genomic DNA was extracted from both isolates and a portion of each of their 16s rDNA genes were amplified and sequenced for homology testing against the GeneBank database. Homology testing confirmed that both isolates were members of the genus Bacillus and most
This document summarizes the discovery of antibiotics. It states that antibiotics were discovered starting in the early 20th century, with Alexander Fleming discovering penicillin in 1928 after observing that mold killed bacteria. It was not until the 1940s that Howard Florey and Ernst Chain were able to produce penicillin in quantity and demonstrate its effectiveness in treating bacterial infections in animals. The widespread clinical use of antibiotics then revolutionized medicine in the 20th century by making many infectious diseases no longer a major cause of death.
The document discusses the production of antibiotics and antitumor agents through industrial microbiology. It defines antibiotics as substances produced by microorganisms that inhibit or kill other microorganisms. Antibiotics are produced through the fermentation of microorganisms like Streptomyces. The production process involves growing the culture in large tanks, isolating the antibiotic, and purifying it into final products through various chemical processes. Quality control ensures antibiotics meet standards before distribution. Some antibiotics like anthracyclines also have antitumor properties and are used to treat cancer.
This document outlines a research project on the effects of antibiotics. It will discuss topics like overuse of antibiotics, antibiotic resistance, and use of antibiotics in agriculture. The document provides background on the history of antibiotics, including the discovery of penicillin in 1928 and its widespread medical use starting in 1942. It lists sources that will be referenced and poses questions about why new antibiotics take so long to develop and what alternatives exist to antibiotics for bacterial infections. An opposing viewpoint that antibiotics are always beneficial will also be addressed.
Rational Use of Antibiotics. Infection was a major cause of morbidity and mortality, before the development of antibiotics.
The treatment of infections faced a great challenge during those periods.
Later in 1928, the discovery of Penicillin, a beta-lactam antibiotic, by Alexander Fleming opened up the golden era of antibiotics.
It marked a revolution in the treatment of infectious diseases and stimulated new efforts to synthesize newer antibiotics.
The period between the 1950s and 1970s is considered the golden era of discovery of novel antibiotic classes, with very few classes discovered since then.
Glycogen is a polymer of glucose residues stored predominantly in liver and muscle cells. Glycogenesis is the synthesis of glycogen from glucose-6-phosphate after a meal when blood glucose levels are high, while glycogenolysis is the breakdown of glycogen into glucose-1-phosphate during fasting or exercise. Both processes are regulated by insulin, glucagon, and epinephrine to maintain blood glucose homeostasis. Deficiencies of enzymes involved in glycogen metabolism can result in glycogen storage diseases.
Antihelminthic and antiprotozoal drugs work by killing or expelling parasitic worms and protozoa. Common antihelminthics discussed include mebendazole, albendazole, pyrantel, and levamisole which are used to treat nematode, cestode, and trematode infections. Their mechanisms of action involve inhibiting microtubule assembly, inducing paralysis, or activating nicotinic receptors in the parasites. Common antiprotozoals discussed include metronidazole for amebiasis, giardiasis and trichomoniasis, and drugs for malaria such as chloroquine, primaquine, and antifol combinations. Adverse
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This document provides an overview of antibiotics. It begins with definitions of antibiotics and their history. Alexander Fleming discovered penicillin in 1929 from the Penicillium mold, but it was not until the 1940s that Howard Florey and Ernst Chain discovered its therapeutic properties. The document classifies antibiotics based on their spectrum of activity (narrow vs broad), mechanism of action (bacteriostatic vs bactericidal), source (natural, semisynthetic, synthetic), and chemical nature. Key requirements for antibiotics are that they selectively kill microbes without host toxicity, are eliminated from the body, are stable for formulation, and are highly effective at low concentrations.
Microorganisms can be either helpful or harmful to humans. They are tiny living organisms too small to be seen without a microscope. Some microbes help with important processes like decomposition, while others cause infectious diseases. However, scientists have also learned to use microbes beneficially in areas like food production, medicine development like antibiotics and vaccines, waste treatment, and more. The document discusses in detail various types of microbes, their roles in different processes, and how humans have harnessed them for industrial and medical applications.
Antibiotics were discovered accidentally through the work of Alexander Fleming and others studying microbes. Penicillin was the first widely used antibiotic, discovered when Fleming noticed bacteria-free zones around a contaminated mold. Since then, scientists have discovered many classes of antibiotics through soil sampling and culturing microbes, including streptomycin, cephalosporins, chloramphenicol, and gentamicin. However, overprescription and misuse have contributed to increased antibiotic resistance, highlighting the need for appropriate usage and new antibiotic development.
This document provides an overview of chemotherapy and antimicrobial drugs. It begins by discussing the history and development of antimicrobial drugs from 1910 onward. It then defines key terms related to chemotherapy and antimicrobial classification. The document discusses various classes of antimicrobial drugs like penicillins, cephalosporins, and beta-lactam inhibitors in detail. It covers the mechanisms of action, spectra of activity, pharmacokinetics and clinical uses of these drug classes. Adverse effects and resistance to penicillins are also summarized. The document provides classifications of antimicrobials and concludes by noting that cefotaxime and ceftriaxone effectively cross the blood-brain barrier to treat meningitis.
This document provides an overview of antibiotics. It begins by defining antibiotics as substances produced by microorganisms or synthesized that selectively kill or inhibit the growth of other microorganisms. Antibiotics can be classified in several ways, including by their mechanism of action, spectrum of activity, chemical structure, and types of organisms treated. Common mechanisms of action include inhibition of cell wall synthesis, protein synthesis, and nucleic acid synthesis. The document then discusses the history of antibiotic discovery, including early pioneers like Fleming who discovered penicillin, and Waksman who discovered streptomycin through systematic soil screening. It covers the development of important classes of antibiotics like penicillins, cephalosporins, and aminoglycosides. In summary
This document provides an introduction to medical microbiology for second year public health students. It defines key microbiology terms and outlines the history and development of the field. The document discusses the classification and morphology of microorganisms and provides information on bacterial structures and functions. It also summarizes the important contributions of scientists such as Pasteur, Koch, and others to establishing microbiology as a science.
1. Antibiotics are chemical substances produced by microorganisms like fungi, actinomycetes and bacteria that suppress or destroy other microorganisms.
2. Alexander Fleming discovered penicillin in 1929 after noticing that a mold growing in one of his petri dishes had prevented bacteria from growing nearby. Penicillin revolutionized medicine as the first widely used antibiotic.
3. Antibiotic resistance has become a major problem as bacteria have increasingly developed resistance, even to formerly powerful antibiotics like penicillin. Proper antibiotic stewardship including only using antibiotics when necessary and completing prescribed treatment courses can help address this growing threat.
development of antimicrobial agents which can overcome the antimicrobial resi...Arijit Goswami
as the microorganisms are increasingly becoming resistant to conventional antibiotics therefore there is a need of some new antimicrobial gents which can overcome the resistance and also helps to stop the overuse and mishandling of antibiotics
AS MICROORGANISIMS ARE INCREASINGLY BECOMING RESISTANT TO CONVENTIONAL ANTIBIOTICS,SO THERE IS ANEED OF NEW ANTIMICROBIAL AGENTS WHICH CAN OVERCOME THE RESISTANCE AND HELPS IN REDUCING THE OVERUSE AND MISHANDLING OF ANTIBIOTICS
Lec no 2. antibiotics, antiseptic, antipyreticsParameswari266
Drugs contain carbon and hydrogen with some oxygen, nitrogen or sulfur. They are classified based on their effects on microorganisms and modes of action. Common drug classes include antipyretics to reduce fever, analgesics for pain relief, antimalarials for treating malaria, antibiotics to inhibit germ growth causing disease, and antiseptics to prevent germ growth near wounds. The first antibiotic, penicillin, was accidentally discovered in 1928 by Alexander Fleming through observation of a fungus contaminating a bacterial plate and creating a zone of inhibited growth.
Chemotherapy is a type of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent, or it may aim to prolong life or to reduce symptom
This document discusses broad spectrum antibiotics. It begins with definitions of key terms like antibiotic, pharmacokinetics, and pharmacodynamics. It then covers the history of antibiotics from traditional empirical uses to the modern era including the discoveries of penicillin and other drugs. The document categorizes antibiotics based on their spectrum of activity, mechanism of action, source, and susceptible organisms. It also addresses principles of antibiotic therapy such as selection, combinations, prophylaxis, resistance, and misuse.
The document outlines principles of anti-microbial therapy and summarizes various classes of anti-bacterial drugs. It discusses the definitions and principles of anti-microbial therapy including host-pathogen-drug interactions and features of anti-microbial drugs. It then focuses on different classes of antibiotics including penicillins, describing their mechanisms of action, types, uses and pharmacological properties. Penicillins are discussed in depth, from the discovery of penicillin to the various generations including natural, penicillinase-resistant, aminopenicillins and extended-spectrum penicillins.
This document summarizes research that isolated and characterized antibiotic-producing microorganisms from waste soil samples collected from various industrial areas in India. Soil samples were collected and microbes were isolated using serial dilution and spread plating techniques. Isolates were screened for antibiotic production against other microbes using agar streak and plug methods. Two Bacillus isolates (R29 and B81) showed strong antifungal activity and were selected for further characterization. Biochemical and genetic tests identified R29 as Bacillus subtilis and B81 as likely Bacillus subtilis or Bacillus licheniformis. The research aims to discover new antibiotics and contributes to understanding antibiotic-producing microbes isolated from industrial waste soils.
“Isolation and Biochemical Characterization of Antibiotic Producing Microorga...IOSR Journals
The search for new antibiotics continues in a rather overlooked hunting ground. In the course of screening for new antibiotic-producing microorganisms, isolates showing antimicrobial activity were isolated from waste soil samples from various habitats in the Industrial Areas in Dheradun, Uttarakhand, India. Existing methods of screening for antibiotic producers together with some novel procedures were reviewed. Both modified agar-streak and agar-plug methods were used in the primary screens. The use of selective isolation media, with or without antibiotic incorporation and/or heat pretreatment, enhanced the development of certain actinomycete colonies on the isolation plates. Antibiotics have long been considered the “magic bullet” that would end infectious disease. Although they have improved the health of countless numbers of humans and animals, many antibiotics have also been losing their effectiveness since the beginning of the antibiotic era. Bacteria have adapted defenses against these antibiotics and continue to develop new resistances, even as we develop new antibiotics. In recent years, much attention has been given to the increase in antibiotic resistance. As more microbial species and strains become resistant, many diseases have become difficult to treat, a phenomenon frequently ascribed to both indiscriminate and inappropriate use of antibiotics in human medicine. However, the use of antibiotics and antimicrobials in raising food animals has also contributed significantly to the pool of antibiotic resistant organisms globally and antibiotic resistant bacteria are now found in large numbers in virtually every ecosystem on earth. Dual culture bioassays were used to screen seven selected Bacillus isolates for activity against four plant pathogenic fungi in vitro. All isolates were able to inhibit the pathogens to varying degrees. Two isolates, R29 and B81, were selected for further testing and characterization. Further bioassays were performed on five complex nutrient media which were adjusted to pH S.S and 7, and both incubated at 2SoC and 30°C" respectively. It was found that pH and media composition showed significant influences on the antifungal activities of the isolates tested, but that a SoC temperature difference in incubation temperature did not. Tryptone soy agar was found to give rise to the largest inhibition zones. Both isolates were tentatively identified using standard biochemical and morphological tests. Based on its phenotypic characteristics, R29 was identified as a strain of B. subtilis. B81 proved to be more difficult to assign to a specific group or species of Bacillus, though B. subtilis and B. licheniformis were considered to be the nearest candidates. Genomic DNA was extracted from both isolates and a portion of each of their 16s rDNA genes were amplified and sequenced for homology testing against the GeneBank database. Homology testing confirmed that both isolates were members of the genus Bacillus and most
This document summarizes the discovery of antibiotics. It states that antibiotics were discovered starting in the early 20th century, with Alexander Fleming discovering penicillin in 1928 after observing that mold killed bacteria. It was not until the 1940s that Howard Florey and Ernst Chain were able to produce penicillin in quantity and demonstrate its effectiveness in treating bacterial infections in animals. The widespread clinical use of antibiotics then revolutionized medicine in the 20th century by making many infectious diseases no longer a major cause of death.
The document discusses the production of antibiotics and antitumor agents through industrial microbiology. It defines antibiotics as substances produced by microorganisms that inhibit or kill other microorganisms. Antibiotics are produced through the fermentation of microorganisms like Streptomyces. The production process involves growing the culture in large tanks, isolating the antibiotic, and purifying it into final products through various chemical processes. Quality control ensures antibiotics meet standards before distribution. Some antibiotics like anthracyclines also have antitumor properties and are used to treat cancer.
This document outlines a research project on the effects of antibiotics. It will discuss topics like overuse of antibiotics, antibiotic resistance, and use of antibiotics in agriculture. The document provides background on the history of antibiotics, including the discovery of penicillin in 1928 and its widespread medical use starting in 1942. It lists sources that will be referenced and poses questions about why new antibiotics take so long to develop and what alternatives exist to antibiotics for bacterial infections. An opposing viewpoint that antibiotics are always beneficial will also be addressed.
Rational Use of Antibiotics. Infection was a major cause of morbidity and mortality, before the development of antibiotics.
The treatment of infections faced a great challenge during those periods.
Later in 1928, the discovery of Penicillin, a beta-lactam antibiotic, by Alexander Fleming opened up the golden era of antibiotics.
It marked a revolution in the treatment of infectious diseases and stimulated new efforts to synthesize newer antibiotics.
The period between the 1950s and 1970s is considered the golden era of discovery of novel antibiotic classes, with very few classes discovered since then.
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Glycogen is a polymer of glucose residues stored predominantly in liver and muscle cells. Glycogenesis is the synthesis of glycogen from glucose-6-phosphate after a meal when blood glucose levels are high, while glycogenolysis is the breakdown of glycogen into glucose-1-phosphate during fasting or exercise. Both processes are regulated by insulin, glucagon, and epinephrine to maintain blood glucose homeostasis. Deficiencies of enzymes involved in glycogen metabolism can result in glycogen storage diseases.
Antihelminthic and antiprotozoal drugs work by killing or expelling parasitic worms and protozoa. Common antihelminthics discussed include mebendazole, albendazole, pyrantel, and levamisole which are used to treat nematode, cestode, and trematode infections. Their mechanisms of action involve inhibiting microtubule assembly, inducing paralysis, or activating nicotinic receptors in the parasites. Common antiprotozoals discussed include metronidazole for amebiasis, giardiasis and trichomoniasis, and drugs for malaria such as chloroquine, primaquine, and antifol combinations. Adverse
This document discusses drugs used to treat cough. It begins by defining cough and classifying it based on duration and characteristics. Nonspecific therapies for cough include demulcents to soothe the throat, expectorants to enhance mucus secretion or reduce viscosity, and antitussives to suppress the cough center. Demulcents include lozenges and cough drops. Expectorants include bronchial secretagogues like guaifenesin and mucolytics like bromhexine that break down mucus. Antitussives include opioids like codeine, nonopioids like dextromethorphan, and antihistamines. Specific treatments depend on the underlying cause of cough such as antibiotics for infection
This document discusses antitussive drugs, which are used to suppress coughing. It defines antitussives and expectorants, and describes the mechanism of cough production involving cough receptors in the lungs and the cough center in the medulla. It classifies cough and antitussives, and discusses the mechanisms of action and indications of centrally- and peripherally-acting antitussives. Common antitussive drugs like codeine, hydrocodone, and dextromethorphan are described along with their effects and side effects. Various animal models used to screen for antitussive effects are outlined, including methods using guinea pigs, cats, and dogs exposed to irritants to induce coughing.
- A dose response relationship describes how the magnitude of a drug's effect varies with increasing or decreasing doses. Dose response curves plot this relationship, with dose on the x-axis and response on the y-axis.
- There are two main types of dose response curves: graded/quantitative curves where response increases continuously with dose, and quantal/all-or-none curves where responses are binary above a threshold dose.
- The shape, slope, efficacy and potency of a dose response curve provide information about a drug's effects, safety, and relative potencies of similar drugs. Steep curves indicate higher potency while flatter curves suggest a drug has less impact over a range of doses.
Antihelminthic and antiprotozoal drugs work by killing or expelling parasitic worms and protozoa. Common antihelminthics discussed include mebendazole, albendazole, pyrantel, and levamisole which are used to treat nematode, cestode, and trematode infections. Their mechanisms of action involve inhibiting microtubule assembly, inducing paralysis, or activating nicotinic receptors in the parasites. Common antiprotozoals discussed include metronidazole for amebiasis, giardiasis and trichomoniasis, and drugs for malaria such as chloroquine, primaquine, and antifol combinations. Adverse
This document discusses antitussive drugs, which are used to suppress coughing. It defines antitussives and expectorants, and describes the mechanism of cough production involving cough receptors in the lungs and the cough center in the medulla. It classifies cough and antitussives, and discusses the mechanisms of action and indications of centrally- and peripherally-acting antitussives. Common antitussives discussed include codeine, hydrocodone, dextromethorphan, and benzonatate. The document also describes several animal models used to screen for antitussive effects, such as measuring coughs induced by irritants in guinea pigs and mechanical stimulation in anesthetized guinea pigs and cats.
Antitussives are drugs that suppress coughing by reducing activity in the brain's cough center. Codeine is the most commonly used antitussive and works by raising the threshold for cough reflexes. It has antitussive effects at doses of 15-60mg and has a plasma half-life of 3-4 hours. Codeine is converted to morphine in some individuals, explaining its analgesic effects as an opioid receptor agonist. Common side effects include nausea, vomiting, constipation, drowsiness, and dry mouth.
Scabies is a skin infection caused by mites that burrow into the skin. It is transmitted through direct skin-to-skin contact with an infected person. Symptoms include an itchy rash. Diagnosis is usually made based on symptoms and history of contact with infected individuals. Treatment involves applying prescription topical creams or lotions to kill the mites. Proper treatment of all infected individuals and environmental cleaning is important to prevent outbreaks. Treatment may need to be repeated if symptoms persist or new burrows appear.
Antihelminthic and antiprotozoal drugs are used to treat infections caused by helminths (worms) and protozoa. The major classes of antihelminthics discussed are mebendazole, albendazole, pyrantel, levamisole, and piperazine which are used against nematodes, trematodes, and cestodes. Antiprotozoal drugs discussed include metronidazole for amoebiasis, giardiasis, and trichomoniasis. Drugs for malaria discussed are quinine, chloroquine, antifolates, primaquine, and nitrofurans. Melarsoprol
This document provides an overview of commonly used antibiotics, including their classification, mechanisms of action, spectra of activity, clinical uses, and pharmacokinetic properties. It discusses six major classes of antibiotics: beta-lactams, aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and glycopeptides. For each class, it summarizes the antibiotic names, mechanisms, spectra, uses, and considerations for optimizing treatment such as dosing principles and preventing toxicity. Key messages emphasize the importance of early sepsis diagnosis/treatment and selecting antibiotics based on the infection site and tissue penetration properties.
The document summarizes the axial skeleton, which includes the skull, vertebral column, and thoracic cage. It describes the three regions of the axial skeleton and provides figures and descriptions of the individual bones that make up each region, including the skull, vertebrae, ribs, and sternum. Key functions of the axial skeleton are also summarized, such as protecting internal organs and serving as attachment sites for muscles involved in posture, respiration, and limb movement.
Antihelminthic and antiprotozoal drugs are used to treat infections caused by parasites. The major classes of antihelminthics discussed target nematodes, trematodes, and cestodes. Specific drugs mentioned include mebendazole, albendazole, pyrantel, levamisole, and praziquantel. These drugs work through various mechanisms including disrupting microtubule assembly, inducing muscle paralysis, or causing calcium leakage. Common side effects include abdominal pain, diarrhea, and allergic reactions. Antiprotozoal drugs discussed treat infections caused by protozoa like Entamoeba histolytica, Giardia lamblia, and Plasmodium
Antihelminthic and antiprotozoal drugs are used to treat infections caused by parasites. The major classes of antihelminthics discussed target nematodes, trematodes, and cestodes. Specific drugs mentioned include mebendazole, albendazole, pyrantel, levamisole, and praziquantel. These drugs work through various mechanisms including disrupting microtubule assembly, inducing muscle paralysis, or causing calcium leakage. Common side effects include abdominal pain, diarrhea, and allergic reactions. Antiprotozoal drugs discussed treat infections caused by protozoa like Entamoeba histolytica, Giardia lamblia, and Plasmodium
Heart failure is the inability of the heart to pump enough blood to meet the body's needs. There are two main types - left-sided and right-sided failure. Symptoms include breathlessness and swelling. Treatment focuses on reducing preload and afterload through medications like ACE inhibitors, diuretics, vasodilators, and positive inotropes. Digoxin increases cardiac contractility by inhibiting the sodium-potassium pump, allowing more calcium to enter heart cells and strengthen contractions. While improving cardiac output, it can also decrease heart rate through vagal stimulation.
This lecture discusses opioid analgesics including natural, semisynthetic, and synthetic opioids. It defines opioids as substances that produce morphine-like effects by binding to opioid receptors in the brain. Natural opioids discussed include morphine and codeine, which are extracted from the poppy plant. Semisynthetic opioids are derived from natural opioids through chemical modification, such as heroin from acetylation of morphine. Synthetic opioids include agonists like fentanyl, antagonists like naloxone that block opioid receptors, and mixed agonist-antagonists. The lecture covers pharmacological properties, therapeutic uses, and adverse effects of various opioid analgesics.
This document provides definitions and information about seizures, epilepsy, and antiepileptic drugs. It defines seizures as a temporary change in brain function due to high-frequency neuronal impulses in the brain. Epilepsy is characterized by recurrent seizures. Several types of seizures are described, including focal onset seizures which start in one brain area and generalized onset seizures which affect large brain regions. Causes of epilepsy include genetic and acquired factors like brain damage. Antiepileptic drugs work via mechanisms like enhancing GABA inhibition, blocking sodium channels, or inhibiting excitatory neurotransmitters. First and second generation antiepileptic drugs are outlined with their mechanisms of action and adverse effect profiles.
This document discusses dose-response relationships and toxicity studies. It provides details on:
- Acute and chronic toxicity studies which determine lethal doses, target organs, and appropriate doses for further studies.
- Factors that influence toxicity like dose, exposure route, chemical properties, and individual variability in things like genetics, age and sex.
- Dose-response curves which illustrate the relationship between dose and effect and are used to determine safe exposure levels.
- Various terms used in toxicity assessments like NOAEL, LOAEL, BMD, RfD, and ADI.
Pharmacology is the study of drugs and their actions within the body. It deals with how drugs are absorbed, distributed, metabolized and excreted by the body, as well as their physiological effects. The document provides a brief historical overview of pharmacology and important discoveries. It discusses the development process for new drugs, which includes preclinical testing in animals followed by clinical trials in humans in four phases. Stringent regulations and guidelines govern the development and approval of new drugs to ensure safety and efficacy.
This document provides an introduction to the field of pharmacology. It defines pharmacology as dealing with all aspects of drugs, including their sources, effects, side effects, metabolism, and elimination in the body. It then discusses key terms in pharmacology like pharmacokinetics, pharmacodynamics, and toxicology. The document also covers drug nomenclature, essential drug concepts, orphan drugs, factors governing drug administration routes, and special features of transdermal drug delivery systems. Finally, it discusses pharmacokinetic effects of drugs including absorption, distribution to tissues, metabolism, and excretion.
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Osteoporosis - Definition , Evaluation and Management .pdfJim Jacob Roy
Osteoporosis is an increasing cause of morbidity among the elderly.
In this document , a brief outline of osteoporosis is given , including the risk factors of osteoporosis fractures , the indications for testing bone mineral density and the management of osteoporosis
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
1. Antibiotics: An Introduction
Dr Ravi Kant Agrawal, MVSc, PhD,
Senior Scientist (Veterinary Microbiology)
Food Microbiology Laboratory
Division of Livestock Products Technology
ICAR-Indian Veterinary Research Institute
Izatnagar 243122 (UP) India
2. Antibiotics and Antimicrobials
• Antibiotics: Greek words anti (against) and biotikos (concerning
life) refers to substances produced by microorganisms, which
selectively suppress the growth of or kill other microorganisms
at very low concentration.
• Chemotherapeutic agents: The use of drugs (chemical entity)
with selective toxicity against infections/ viruses, bacteria,
protozoa, fungi and helminthes.
• Antimicrobials: derived from the Greek words anti (against),
mikros (little) and bios (life) and refers to all agents of natural,
synthetic or semi-synthetic origin which at low concentrations
kill or inhibits the growth of microorganisms but causes little or
no host damage. Antimicrobials include both chemotherapeutic
agent + Antibiotics.
3. Antibiotics
• OLD: An antibiotic is a chemical substance produced by various
species of microorganisms that is capable in small
concentrations of inhibiting the growth of other
microorganisms.
• NEW: An antibiotic is a product produced by a microorganism
or a similar substance produced wholly or partially by chemical
synthesis, which in low concentrations, inhibits the growth of
other microorganisms.
• An antibiotic is a selective poison.
• It has been chosen so that it will kill the desired bacteria, but
not the cells in your body. Each different type of antibiotic
affects different bacteria in different ways.
4. History
Use of substances with antimicrobial properties is known to have been
common practice for at least 2000 years.
Ancient Egyptians and ancient Greeks used specific molds and plant extracts
to treat infection.
Although, for centuries preparations derived from living matter were applied
to wounds to destroy infection, the fact that a microorganism is capable of
destroying one of another species was not established until the latter half of
the 19th cent when Pasteur noted the antagonistic effect of other bacteria
on the anthrax organism and pointed out that this action might be put to
therapeutic use.
Microbiologists such as Louis Pasteur and Jules Francois Joubert observed
antagonism between some bacteria and discussed the merits of controlling
these interactions in medicine.
Before Ehrlich Period:
Chaulmoogra oil by hindus in leprosy.
Cinchona bark for fever.
Mouldy curd by chinese for boils.
Chinese used artemisia for malaria treatment (1970-isolated Artemisinin).
Mercury by Paracelsus for syphilis.
Jordan people- used red soils to treat skin infections- isolated Actinomycetes
and many other antibiotic producing bacteria.
5. History……
Paul Ehrlich (Ehrlich Period – 1900-1930)
• The German chemist Paul Ehrlich developed the idea of selective
toxicity: that certain chemicals that would be toxic to some
organisms, e.g., infectious bacteria, would be harmless to other
organisms, e.g., humans.
• Paul Ehrlich - derived from finding that dyes used in
histochemistry became bound to cell-specific receptors. He
asked “Why can’t such dyes be toxic for specific organisms?”
• Paul Ehrlich, Alfred Bertheim and Sahachiro Hata (1910) looking
for something to target Treponema pallidum, developed
hundreds of organo-arsenic compounds from highly toxic drug
Atoxyl and 606th
compound tested was effective against syphilis.
• Hoechst - Salvarsan (Arsphenamine).
• First documented case of a chemical that could selectively kill
pathogens w/o permanently harming the human host.
• The concept of chemotherapy to treat microbial diseases was
born.
• Coined the term ‘CHEMOTHERAPY’
• NOBEL: 1908
• FATHER OF CHEMOTHERAPY
• He used the term ‘MAGIC BULLETS’
• MOA- still not known.
6. Post Ehrlich Period: 1930- till date
• Over the next 20 years, progress was made against a variety of
protozoal diseases, but little progress was made in finding
antibacterial agents untill introduction of Proflavine in 1934.
• Proflavine is a yellow coloured amino-acridine structure which
is particularly effective against deep wound bacterial infections.
• Used in world war II.
• Interesting drug as it targets bacterial DNA rather than protein.
• Despite success of this drug, it was not effective against
infections in Bloodstream and there was urgent need for agents
which could fight systemic infections.
History……
Proflavine
7. Post Ehrlich Period: 1930- till date
• Ehrlich approach of systematic screening of compounds became
the cornerstone of the pharma industry.
• This approach led to the discovery of Sulfonamidochrysoidine
(KI-730) – synthesized by Bayer chemists Josef Klarer and Fritz
Mietzsch and tested by Gerhard Domagk for antibacterial
activity.
• Marketed under the brand name Prontosil.
• Effective against streptococcal infections invivo.
• Prontosil was a prodrug and its active compound sulfanilamide
was not patentable as had been in use in dye industry.
• Cheap to produce, off-patent and easy to modify – many
companies started producing sulfonamide derivatives.
• NOBEL: 1939
History……
8. History….
Alexander Fleming
• In 1928, Sir Alexander Fleming, a Scottish
biologist, observed that Penicillium
notatum, a common mold, had destroyed
staphylococcus bacteria in culture.
• Fleming unable to purify compound
• NOBEL: 1945
• Penicillin was isolated in 1939 by Oxford
chemists Howard Florey and Ernst Chain.
• 1940: first clinical trials of penicillin were
performed.
• Mass production of penicillin started from
1945 and used during WWII.
9. Selman Waksman
• Soil Streptomyces make antibiotics
• Comes up with definition of antibiotic
• In 1944, Selman Waksman and Albert Schatz,
American microbiologists, isolated
streptomycin and a number of other
antibiotics from Streptomyces griseus.
• NOBEL: 1952
History……
10. • In 1947, Chloramphenicol was
first used clinically to treat
Typhus.
• G. Brotzu discovered
Cephalosporins.
• Benjamin M. Duggar isolated
Chlortetracycline from a mud
sample obtained from a river in
Missouri.
• 1960 onwards second
generation antibiotics like
Methicillin were discovered.
• Following this, semi synthetic
derivatives of older antibiotics
with more desirable properties
and different spectrum of
activity were produced e.g.
Fluoroquinolones,
Oxazolidinones etc.
11. 1900 1920 1940 1960 1980 2015
1900- Paul
Ehrilich
Chemotherapy
Animal model
developed
1908- Discovery
of Arsphenamine
1932- Prontosil-
First sulfonamide-
Bayer’s Laboratory
Gerhard Domagk 1939-
Sulfonamidochrysoidine
(Prontosil)
Alexander Fleming 1928-
Penicillin
1943- Nitrogen
mustard in
lymphomas
1948- Anitfolates
1951- Thiopurines
1958- Methotrexate
1957- 5-Fluorouracil
1959- Antitumor
antibiotics
1963 to 1970-
Treatment for
Hodgkin’s disease
1962- nalidixic acid
1997- Monoclonal
antibody approved
for the treatment of
tumor.
2005- Tyrosine kinase
inhibitors
2007- Target specific
screens
1996- Imatinib
Paul
Ehrilich
Father of
Chemotherapy
Timeline history of chemotherapy development
1944- Waksman et
al., discovered
streptomycin.
1963-
Vinca alkaloids
12. Between 1962 and 2000, no major classes of
antibiotics were introduced
Fischbach MA and Walsh CT, Science 2009
Methicillin
13. Timeline of antibiotic resistance
Penicillin
Penicillin resistant
S.aureus
Methicillin
MRSA
VRE VRSA
Vancomycin
Pencillin:1943, Resistance in 1947
within 4 years
Methicillin: 1959, resistance in 1961
Vancomycin: 1958
VRE:1987
VRSA:2002
14. The Ideal Drug*
1. Should have powerful action against MOs.
2. Selectively kill or inhibit the growth of pathogens - cause no damage to
the host - greater harm to microbes than host, done by interfering with
essential biological processes common in bacteria but not human cells.
3. Therapeutic index (the lowest dose toxic to the patient divided by the
dose typically used for therapy). High TI are less toxic to the patient.
4. Should not be inactivated rapidly by tissue enzymes or GI microflora
5. Should have good oral bio-availability
6. Should penetrate efficiently to various body tissues and fluids - reach
target site in body with effective concentration remain in specific tissues
in the body long enough to be effective
7. Favorable pharmacokinetics - drug interactions, how drug is distributed,
metabolized and excreted in body (unstable in acid, can it cross the
Blood-brain barrier, etc)
• Drugs differ in how they are distributed, metabolized and excreted
• Important factor for consideration when prescribing
• Rate of elimination of drug from body expressed in half-life -Time it
takes for the body to eliminate one half the original dose in serum
• Half-life dictates frequency of dosage
• Patients with liver or kidney damage tend to excrete drugs more slowly
15. 8. Desired Spectrum of activity: broad vs. narrow
• broad spectrum – wide
• Narrow spectrum - narrow range (pathogen must be ID’d)
9. Bactericidal vs. bacteriostatic
• Bacteriostatic drugs rely on host immunity to eliminate pathogen
• Bacteriocidal drugs are useful in situations when host defenses cannot be
relied upon to control pathogen
10. Should have a long elimination half life and not rapidly excreted by kidney
or bile
11. Should not interfere the host immune mechanism
12. Should not show adverse drug interactions with other antimicrobial drugs
Combination some times used to treat infections
When action of one drug enhances another, effect is synergistic
When action of one drug interferes with another, effect is antagonistic
When effect of combination is neither synergistic or antagonistic, effect said
to be additive
13. Should have no/short withdrawl time in food producing animals.
14. Little resistance development- Should not favour bacterial resistance and
show cross resistance with other antimicrobial agents
15. Stable when stored in solid or liquid form
16. Affordable and easily available
17. Lack of “side effects” allergic, toxic side effects, suppress normal flora
• Allergic reactions: Allergies to penicillin
• Toxic effects: Aplastic anemia- Body cannot make RBC or WBC
• Suppression of normal flora
• Antibiotic associated colitis
* There is no perfect drug
16. Classification of antimicrobials
A. Chemical structure
B. Mechanism of action
C. Type of organisms (against which primarily active)
D. Spectrum of activity
E. Type of action (bacteriostatic and bactericidal)
F. Source of antibiotics
18. B. Mechanism of action
THFA
PABA
Ribosomes
cell
membrane
metabolism
Cell wall synthesis m-RNA code
protein
synthesis
DNA gyrase
19. B. Mechanism of action
THFA
PABA
Ribosomes
Inhibition of
protein
synthesis
Inhibition of DNA
gyrase
Inhibition of
metabolism
Inhibition of
Cell wall synthesis
Sulfonamides
Sulfones
Trimethoprim
PAS
Pyrimethamine
Ethumbutol
Beta-lactams
Cephalosporins
Vancomycin
Tetracyclines
Aminoglycosides
Macrolides
Clindamycin
Chloramphenicol
Fluoroquinolones
Inhibition of Cell
Membrane
Leakage form cell
membrane
Polypeptides - Polymyxines,
colistin.
Polyenes- Amphotericin B,
Nystatin, Hamycin
Fluoroquinolones
Rifampin
Misreading of
m-RNA code
Aminoglycosides-
Streptomycin,
Gentamicin
20. C. Type of organisms (against which primarily active)
• Antibacterial: Penicillins, Aminoglycosides, Erythromycin, etc.
• Antiviral: Acyclovir, Amantadine B, Zidovudine, etc.
• Antifungal: Griseofulvin, Amphotericin B, Ketoconazole, etc.
• Antiprotozoal: Chloroquine, Pyrimethamine, Metronidazole,
etc.
• Anthelminthic: Mebendazole, Niclosamide, Diethyl
carbamazine, etc.
21. D. Spectrum of activity
Narrow-spectrum
Penicillin G, Streptomycin,
Erythromycin
Broad-spectrum
Tetracyclines,
Chloramphenicol
effective against specific
type of bacteria
either gram-positive or
gram-negative
effective against a wide
range of bacteria,
both gram-positive and
gram-negative
22. D. Type of action
(bacteriostatic and bactericidal)
Bacteriostatic:
Inhibit the growth of Bacteria.
E.g.: Sulfonamides, Tetracyclines,
Chloramphenicol, Erythromycin,
Ethambutol
Bactericidal:
Kill the microbes.
E.g.: Penicillins, Aminoglycosides,
Polypeptides, Rifampin, Isoniazid,
Vancomycin, Ciprofloxacin, Metronidazole,
Cotrimoxazole
Note: Some b’static drugs may act as
bactericidal at high concentration
(Sulfonamides, nitrofurantion)
24. Principles of antimicrobial therapy
• Diagnosis: Site of infection, responsible organism,
sensitivity of drug
• Decide- chemotherapy is necessary: Acute
infection require chemotherapy whilst chronic infections
may not. The chronic abscess respond poorly, although
chemotherapy cover is essential if surgery is undertaken
to avoid a flare-up of infection.
• Select the drug: Specificity (spectrum of activity,
antimicrobial activity of drug), pharmacokinetic factors
(physiochemical properties of the drug) , patient related
factors (allergy, renal disease)
25. Principles of antimicrobial therapy
Cont.,
• Frequency and duration of drug administration: Inadequate dose
may develop resistance, intermediate dose may not cure infection,
optimize dose should be used for therapy.
• Continue therapy: Acute infection treated for 5-10 days. But some of
the bacterial infection exceptions to this. E.g.: Typhoid fever, tuberculosis
and infective endocarditis (after clinical cure, the therapy is continued to
avoid relapse).
• Test for cure: After therapy, symptoms and signs may disappear before
pathogen eradicated.
• Prophylactic chemotherapy: To avoid surgical site infections.
26. Choice of an antimicrobial agents
Patient related factors
Drug factors
Organism-related considerations
27. Choice of an antimicrobial agents
Patient related factors:
• Patient age (chloramphenicol produce gray baby syndrome in
newborn; Tetracyclines deposition in teeth and bone-below the
age of 6 years)
• Renal and hepatic function (aminoglycoside, vancomycin- renal
failure; erythromycin, tetracycline- liver failure)
• Drug allergy (History of known AMAs allergy should be obtained) .
– Syphilis patient allergic to penicillin – drug of choice is tetracycline
– Fluoroquinolones cause erythema multiforme
• Impaired host defense
28. Choice of an antimicrobial agents
Cont.,
Drug factor:
• Pregnancy
– All AMAs should be avoided in the pregnant
– many cephalosporins and erythromycin are safe, while safety data on
most others is not available.
• Genetic factors
– Primaquine, sulfonamide, fluoroquinolones likely to produce haemolysis
in G-6-PD deficient patient)
• Spectrum of activity (Narrow/ broad spectrum)
• Type of activity (bactericidal/ bacteriostatic)
• Sensitivity of the organism (MIC)
• Relative toxicity
• Pharmacokinetic profile
• Route of administration
• Cost
29. Choice of an antimicrobial agents
Cont.,
Organism-related considerations:
• A clinical diagnosis should first be made, and the choice of the
AMAs selected
• Clinical diagnosis itself directs choice of the AMA
• Choice to be based on bacteriological examination (Bacteriological
sensitivity testing)
31. Toxicity
Local irritancy:
• exerted site of administration e.g. Gastric irritation, pain and abscess formation at the
site of i.m. inection, thrombo-phlebitis of injected vein.
Systemic toxicity:
• Dose related organ damage.
– High therapeutic index agents may not damage host cells, E.g.: penicillin,
erythromycin.
– The agent which have low therapeutic index exhibits more toxicity.
– Very low therapeutic index drug is used when no suitable alternative AMAs
available. E.g.: Vancomycin - hearing loss, kidney damage, “red man’ syndrome;
polymyxin B - neurological and renal toxicity
aminoglycosides
(renal and CNS toxicity)
tetracycline
(liver and renal toxicity)
chloramphenicol
(bone marrow depression)
32. Hypersensitivity reaction
• All AMAs are capable to causing hypersensitive reaction, and
this this reactions are unpredictable and unrelated to dose. E.g.:
Penicillin induced anaphylactic shock (prick skin testing)
Inj. Penicillin induced
anaphylactic shock
To avoid
Perform sensitivity test before
administering penicillin Inj.
33. Drug Tolerance
• Loss of affinity of target biomolecule of the microorganism with
particular AMAs, E.g.: Penicillin resistance to Pneumococcal
strain (alteration of penicillin binding proteins)
Drug target site Change in protein
configuration - loss of
affinity
34. Superinfection (Suprainfection)
• A new infection occurring in a patient having a preexisting infection.
• Development of superinfection associated with the use of broad/
extended-spectrum of antibiotics, such as tetracyclines, chloramphenicol,
ampicillin and newer cephalosporins.
• Superinfections are more common when host defense is compromised.
• Superinfections are generally most difficult to treat.
– bacterial superinfection in viral respiratory disease
– infection of a chronic hepatitis B carrier with hepatitis D virus
– Piperacillin-tazobactam may cause superinfection with Candida
35. Superinfection
Cont.,
• Treatment for superinfection
– Candida albicans: Monilial diarrhoea, Candidal vulvovaginitis or vaginal
thrush (an infection of the vagina's mucous membranes) treat with
nystain or clotrimazole
– Resistant Staphylococci: treat with coxacillin or its congeners
– Pseudomonas: Urinary tract infection, treat with carbenicillin, piperacillin
or gentamicin.
• Superinfections minimized by
– using specific (narrow-spectrum) AMA (whenever possible)
– avoid using (do not use) antimicrobials to treat self limiting or
untreatable (viral) infection
– avoid prolong antimicrobial therapy.
36. Resistance
• Unresponsiveness of a microorganism to an AMA, and is similar
to the phenomenon of drug tolerance.
– Natural resistance
– Acquired resistance
• Natural resistance: Some microbes have resistant to certain
AMAs. E.g.: Gram negative bacilli not affected by penicillin G; M.
tuberculosis insensitive to tetracyclines.
• Acquired resistance: Development of resistance by an organism
(which was sensitive before) due to the use of AMA over a period
of time. E.g.: Staphylococci, tubercle bacilli develop resistance to
penicillin (widespread use for >50 yr). Gonococci quickly
developed resistant to sulfonamides in 30 yr.
37. COMMON MODES OF ANTIMICROBIAL RESISTANCE
e.g.
Penicillins
e.g. aminoglycosides
, chloramphenicol &
penicillins
e.g.tetracyclines
e.g. aminoglycosides &
tetracyclines
38. Acquired Resistance
Cont.,
Development of resistance
•Resistance mainly developed by mutation or gene transfer.
•Mutation: Resistance developed by mutation is stable and
heritable genetic changes that occurs spontaneously and randomly
among microorganism (usually on plasmids).
•Mutation resistance may be single step or multistep.
– Single gene mutation may confer high degree of resistance. E.g.:
enterococci to streptomycin
– Multistep mutation may modify the more number of gene that will
decreases the sensitivity of AMAs to pathogens.
39. • Development of resistance
• Gene transfer (Infectious resistance): From one organism to
another organism.
– Conjugation
– Transduction
– Transformation
Transposon
donor
a
b
a a a
b
b b
Plasmid
cointegrate
Transfer of resistance genetic elements within the bacterium
Resistance
Cont.,
40. Gene transfer - Conjugation:
• cell-to-cell contact; transfer of chromosomal or
extrachromosomal DNA from one bacterium to another
through sex pili.
• The gene carrying the resistance or ‘R’ factor is
transferred only if another “resistance transfer factor”
(RTF) is present.
• This will frequently occurs in gram negative bacilli.
• The nonpathogenic organisms may transfer ‘R’ factor to
pathogenic organisms, which may become wide spread by
contamination of food and water.
•The multidrug resistance has occurred by conjugation.
– Chloramphenicol resistance to typhoid bacilli
– Penicillin resistance to Haemophilus, gonococci
– Streptomycin resistance to E. coli
Resistance
Cont.,
41. Development of resistance Gene
transfer - Transduction:
•Transfer resistance gene through
bacteriophage (bacterial virus) to
another bacteria of same species.
– E.g.: Transmission of resistance gene
between strains of staphylococci and
between strains of streptococci.
Resistance
Cont.,
42. Development of resistance
Gene transfer - Transformation:
• It will occur in natural conditions.
• Bacteria taking up naked DNA form its environment and
incorporating it into its genome through the normal cross-over
mechanism.
Resistance
Cont.,
43. Combined use of antimicrobials
• To achieve synergism, Rifampin+ isoniazid for tuberculosis
•
• To reduce severity or incidence of adverse effects, Amphotericin
B + rifampin (rifampin enhance the antifungal activity of
amphotericin B)
• To prevent resistance (Concomitant administration of rifampin
and ciprofloxacin prevents Staph. aureus resistance
ciprofloxacin)
• To broaden the spectrum of antimicrobial action (cotrimoxazole:
Trimethoprim/sulfamethoxazole)
44. Prophylactic use of antimicrobials
• Prophylaxis against specific organisms (Cholera: tetracycline
prophylaxis; Malaria: for travelers to endemic area may take
chloroquine/ mefloquine)
• Prevention of infection in high risk situations
• Prophylaxis of surgical site infection
45. Failure of antimicrobial therapy
• Improper selection of AMAs, dose, route or duration of
treatment.
• Treatment begun too late
• Failure to take necessary adjuvant measures
• Poor host defense
• Trying to treat untreatable (viral) infections
• Presence of dormant or altered organisms which later give risk
to a relapse
46. Why do we need newer antimicrobials
• Bacterial resistance to antimicrobials-health
and economic problem
• Chronic resistant infections contribute to
increasing health care cost
• Increase morbidity & mortality with resistant
microorganisms
47. A Changing Landscape for
Numbers of Approved Antibacterial Agents
Bars represent number of new antimicrobial agents approved by the FDA during the period listed.
0
0
2
4
6
8
10
12
14
16
18
Number
of
agents
approved
1983-87 1988-92 1993-97 1998-02 2003-05 2008
Infectious Diseases Society of America. Bad Bugs, No Drugs. July 2004; Spellberg B et al. Clin Infect Dis. 2004;38:1279-1286;
New antimicrobial agents. Antimicrob Agents Chemother. 2006;50:1912
Resistance
48. Common side effects with
chemotherapeutics agents
Think before dispensing
Thank U
51. Disinfection
Disinfection is the process that reduces the number of
potential pathogens on a material until they no longer
represent a hazard.
• Disinfection is complex of measures that are directed
to prevention spread of microorganisms which can be
agent of disease.
• Disinfection, refers to the use of a physical process or a
chemical agent (a disinfectant) to destroy vegetative
pathogens but not bacterial endospores. It is
important to note that disinfectants are normally used
only on inanimate objects because, in the
concentration required to be effective, they can be
toxic to human and other animal tissue.
52. Asepsis
asepsis refers to any practice that prevents the
entry of infectious agents onto sterile tissues
and thus prevent infection
• Aseptic techniques commonly practiced in
health care range from sterile methods that
exclude all microbes to antisepsis.
53. Antisepsis
is the complex of procedures of growth inhibition and
reproduction potential pathogenic microorganisms
on skin of mucous membrane
• In antisepsis, chemical agents called antiseptics are
applied directly to exposed body surfaces (skin and
mucous membrane), wounds, and surgical incisions
to destroy or inhibit vegetative pathogens. Examples
of antisepsis include preparing the skin before
surgical incision with iodine compounds
56. MECHANISMS OF ACTION
• Inhibitors of cell wall synthesis
• Inhibitors of protein synthesis
• Inhibitors of nucleic acid (replication/transcription/other
mechanism)
• Drugs altering cell membranes
• Anti-metabolites
57. Antibiotics: Mechanisms of Action
Transcription
Translation
Translation
Alteration of
Cell Membrane
Polymyxins
Bacitracin
Neomycin
58. Categories antimicrobial agents based
on their application
Term Description Examples
Disinfec-
tant
Agent that kills microorganisms on
inanimate objects
Hypochlorite,
formaldehyde
Antiseptic Agent that kills of prevents the growth of
microorganisms on lining tissues
Soap, hydrogen
peroxide, iodine,
ethanol
Sanitizer A disinfectant that is used to reduce
numbers of bacteria to levels judged safe
by public health officials
Ethanol
Preserva-
tive
Agents that prevents microbial growth:
often added to products such as foods and
cosmetics to prevent microbial growth
Lactic acid,
benzoic acid,
sodium chloride
Antibiotic Agent produced by microorganisms that
inhibits or kills other microorganisms
Penicillin,
tetracycline
59. The action of antimicrobial agents
Term Action Examples
Bactericide Agent that kills bacteria Chlorhexidine,
ethanol
Biocide Agent that kills living organisms Hypochlorite
Fungicide Agent that kills fungi Ethanol
Germicide
(microbicide)
Chemical agent that specifically
kills pathogenic
microorganisms
Formaldehyde,
silver, mercury
Sporicide Agent that kills bacterial
endospores
Glutaraldehyde
Virucide Inactivates viruses so that they
lose the ability to replicate
Cationic detergents
60. Antimicrobial agents
Disinfectants and
antiseptics
Can kill or inhibit growth and
development majority of
microorganisms in space around
patient, and microorganisms that are
on human body surface
Chemotherapeuti
c medicines
Can kill or inhibit reproduction of
agents of disease in the patient
organism. Have selective influence
upon microorganisms.
61. Classification of disinfectants based on
their mode of action
Mode of action Type of disinfectant
Coagulate proteins Formaldehyde,
glutaraldehyde, alcohols,
dyes, mercurials, acids
Oxidize proteins Halogens: iodine, iodophors,
chlorine, chlorine compoynds
Destroys cell membrane Phenolics, quaternary
ammonium compounds
(surface-active agents)
62. Chemotherapy
is a method of therapy of infectious disease
and cancer with chemical agents –
chemotherapeutic medicines
63. Chemotherapeutic index
Maximal tolerated dose is the most quantity of drug
that not cause harmful effect in a patient.
Minimal curative dose is the least dose of drug that
kill of inhibit reproduction of microorganisms
Maximal tolerated dose
Minimal curative dose
> 3
64. Paul Ehrlich’s principles of chemotherapy
Paul Ehrlich have provided principled of chemotherapy.
Receptor interaction of drug and microorganism
Changing of chemical structure of drug causes change of its
activity
Changing of drug structure can occur in microorganism’s cell,
therapeutic effect can slacken or intensify during it
Microbes can develop drug resistance to medicine
The drug can be used only if its chemotherapeutic index is not
less three.
66. Antagonism (ammensalism)
Antagonism is a form interaction between
organisms when one microorganisms inhibits
development of others
Mechanisms of antagonism:
Competition for nutrient substrate (different spread of
growth)
Excretion of acids, alcohols, ammonia by microorganisms-
antagonist
Excretion antibiotics, bacteriocines by microorganisms-
antagonist
Predation
68. Characteristics of successful
antimicrobial drugs
Great activity against microbes
Selectively toxic to the microbe but nontoxic to host cells
Microbicidal rather than mocrobistatic
Relatively soluble and functions even when highly diluted
in body fluids
Remains potent long enough to act and is not broken down
or excreted prematurely
Not subject to the debelopment of antimicrobial resistance
Complements or assists the activities of the host’s
defenses
Remains active despite the presence of large volumes of
organic materials
It is readily delivered to the site of infection
Does not disrupt the host’s health by causing allergies or
predisposing the host to other infections
69. Classification based on type of
antibiotic action
Microbistatic (bacteriostatic,
fungistatic) agents prevent the growth of
microorganisms (bacteria, fungi)
Microbicidal agent (bactericide,
virucide, fungicide) kills microorganisms
(bacteria, viruses, fungi)
70. Categories based on group of organisms
that produce of antibiotics
Producers Antibiotics
Bacteria Polmyxyn
Fungi Penicillin, cephalosporin
Actinomycetes Streptomycin, tetracycline
Plants Imanin, salvin,
Animals Lysocim
71. Classification of antibiotics based on
spectrum of action
Narrow-spectrum agents are effective against a
limited array of different microbial types (examples:
bacitracin inhibit certain gram-positive bacteria)
Broad-spectrum agents are active against a wider
range of different microbes (example – tetracycline that
affect upon gram-positive and gram-negative bacteria,
rickettsias, mycoplasmas)
74. Classification of antimicrobials
A. Chemical structure
B. Mechanism of action
C. Type of organisms (against which primarily active)
D. Spectrum of activity
E. Type of action (bacteriostatic and bactericidal)
F. Source of antibiotics
77. B. Mechanism of action
THFA
PABA
Ribosomes
cell
membrane
metabolism
Cell wall synthesis m-RNA code
protein
synthesis
DNA gyrase
78. B. Mechanism of action
Cont.,
THFA
PABA
Ribosomes
Inhibition of
protein
synthesis
Inhibition of DNA
gyrase
Inhibition of
metabolism
Inhibition of
Cell wall synthesis
Sulfonamides
Sulfones
Trimethoprim
PAS
Pyrimethamine
Ethumbutol Beta-lactams
Cephalosporins
Vancomycin
Tetracyclines
Aminoglycosides
Macrolides
Clindamycin
Chloramphenicol
Fluoroquinolones
Inhibition of Cell
Membrane
Leakage form
cell membrane
Polypeptides- Polymyxines,
colistin.
Polyenes- Amphotericin B,
Nystatin, Hamycin Fluoroquinolones
Rifampin
Misreading of
m-RNA code
Aminoglycosides-
Streptomycin,
Gentamicin
79. C. Type of organisms (against which primarily active)
• Antibacterial: Penicillins, Aminoglycosides, Erythromycin,
etc.
• Antiviral: Acyclovir, Amantadine B, Zidovudine, etc.
• Antifungal: Griseofulvin, Amphotericin B, Ketoconazole, etc.
• Antiprotozoal: Chloroquine, Pyrimethamine, Metronidazole,
etc.
• Anthelminthic: Mebendazole, Niclosamide, Diethyl
carbamazine, etc.
80. D. Spectrum of activity
Narrow-spectrum
Penicillin G, Streptomycin,
Erythromycin
Broad-spectrum
Tetracyclines,
Chloramphenicol
effective against specific
type of bacteria
either gram-positive or
gram-negative
effective against a wide
range of bacteria,
both gram-positive and
gram-negative
81. D. Type of action
(bacteriostatic and bactericidal)
Bacteriostatic:
Inhibit the growth of Bacteria.
E.g.: Sulfonamides, Tetracyclines,
Chloramphenicol, Erythromycin,
Ethambutol
Bactericidal:
Kill the microbes.
E.g.: Penicillins, Aminoglycosides,
Polypeptides, Rifampin, Isoniazid,
Vancomycin, Ciprofloxacin, Metronidazole,
Cotrimoxazole
Note: Some b’static drugs may act
b’cidal at high concentration
(Sulfonamides, nitrofurantion)
83. Choice of an antimicrobial agents
Patient related factors
Drug factors
Organism-related considerations
84. Choice of an antimicrobial agents
Patient related factors:
•Patient age (chloramphenicol produce gray baby syndrome in
newborn; Tetracyclines deposition in teeth and bone-below the
age of 6 years)
•Renal and hepatic function (aminoglycoside, vancomycin- renal
failure; erythromycin, tetracycline- liver failure)
•Drug allergy (History of known AMAs allergy should be
obtained) .
– Syphilis patient allergic to penicillin – drug of choice is tetracycline
– Fluoroquinolones cause erythema multiforme
•Impaired host defence
85. Choice of an antimicrobial agents
Cont.,
Drug factor:
•Pregnancy
– All AMAs should be avoided in the pregnant
– many cephalosporins and erythromycin are safe, while safety data on
most others is not available.
•Genetic factors
– Primaquine, sulfonamide fluoroquinolones likely to produce
haemolysis in G-6-PD deficient patient)
86. Choice of an antimicrobial agents
Cont.,
Organism-related considerations:
•A clinical diagnosis should first be made, and the choice of the
AMAs selected
•Clinical diagnosis itself directs choice of the AMA
•Choice to be based on bacteriological examination
(Bacteriological sensitivity testing)
87. Choice of an antimicrobial agents
Cont.,
Drug factor:
•Spectrum of activity (Narrow/ broad spectrum)
•Type of activity
•Sensitivity o f the organism (MIC)
•Relative toxicity
•Pharmacokinetic profile
•Route of administration
•Cost