This document defines various microbiological terms related to pathogenicity and infection. It discusses how microbes cause disease by penetrating host defenses through several mechanisms: 1) adherence using adhesins and ligands, 2) capsules that prevent phagocytosis, and 3) enzymes that damage tissues. It also describes the two main types of toxins - exotoxins secreted outside bacterial cells and endotoxins in gram-negative cell walls. Exotoxins can be cytotoxins, neurotoxins, or enterotoxins and are inactivated by antitoxins stimulated by toxoids in vaccines.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
Term and Definitions regarding microbiology, Pathogenicity and virulency, acute and chronic infection, primary and secondary infection, opportunistic infection.
The document defines key terms related to bacterial pathogenicity and mechanisms by which bacteria cause disease. It discusses how bacteria penetrate host defenses through adherence, capsules, and enzymes. It also describes the role of toxins, including exotoxins and endotoxins, in bacterial pathogenesis. The summary provides an overview of the main points covered in the document.
infection and inflammation. adult healthDishaThakur53
This document discusses infection and inflammation. It defines infection as the colonization of a host by microbes that seek to use the host's resources to reproduce, often resulting in disease. Infections are classified based on their causative agent and symptoms. Acute inflammation is an immediate response to tissue injury and involves vascular changes like increased blood flow and permeability, resulting in redness and warmth as fluid and cells move into tissues, seen as swelling. This allows migration of leukocytes like neutrophils to the site of infection or injury.
This document discusses host-microbe relationships and microbial pathogenesis. It begins by defining key terms like pathogenicity, virulence, and toxigenicity. It then describes how most microbes do not cause harm, while a few contribute to health or pose threats. Pathogens can establish infections through various mechanisms like toxin production, tissue invasion, or evading host defenses. Toxins are categorized as exotoxins, endotoxins, or exoenzymes. Exotoxins like AB toxins directly damage tissues. Colonization, invasion, and evasion of host defenses allow pathogens to replicate and spread infection. Microbes cause disease through direct damage by toxins or indirect activation of the host immune response.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how microbes cause disease by penetrating host defenses through several mechanisms: 1) adherence using adhesins and ligands, 2) capsules that prevent phagocytosis, and 3) enzymes that damage tissues. It also describes the two main types of toxins - exotoxins secreted outside bacterial cells and endotoxins in gram-negative cell walls. Exotoxins can be cytotoxins, neurotoxins, or enterotoxins and are inactivated by antitoxins stimulated by toxoids in vaccines.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
This document defines various microbiological terms related to pathogenicity and infection. It discusses how pathogens can enter the body through mucous membranes, skin, or parenterally. Once inside the host, pathogens use several mechanisms to penetrate defenses, including adherence via adhesins, capsules to avoid phagocytosis, and enzymes that damage host tissues. Toxins, either exotoxins secreted outside bacterial cells or endotoxins in gram-negative cell walls, are also important virulence factors. Vaccines work by using inactivated toxins or toxoids to stimulate antibody production against pathogenic toxins.
Term and Definitions regarding microbiology, Pathogenicity and virulency, acute and chronic infection, primary and secondary infection, opportunistic infection.
The document defines key terms related to bacterial pathogenicity and mechanisms by which bacteria cause disease. It discusses how bacteria penetrate host defenses through adherence, capsules, and enzymes. It also describes the role of toxins, including exotoxins and endotoxins, in bacterial pathogenesis. The summary provides an overview of the main points covered in the document.
infection and inflammation. adult healthDishaThakur53
This document discusses infection and inflammation. It defines infection as the colonization of a host by microbes that seek to use the host's resources to reproduce, often resulting in disease. Infections are classified based on their causative agent and symptoms. Acute inflammation is an immediate response to tissue injury and involves vascular changes like increased blood flow and permeability, resulting in redness and warmth as fluid and cells move into tissues, seen as swelling. This allows migration of leukocytes like neutrophils to the site of infection or injury.
This document discusses host-microbe relationships and microbial pathogenesis. It begins by defining key terms like pathogenicity, virulence, and toxigenicity. It then describes how most microbes do not cause harm, while a few contribute to health or pose threats. Pathogens can establish infections through various mechanisms like toxin production, tissue invasion, or evading host defenses. Toxins are categorized as exotoxins, endotoxins, or exoenzymes. Exotoxins like AB toxins directly damage tissues. Colonization, invasion, and evasion of host defenses allow pathogens to replicate and spread infection. Microbes cause disease through direct damage by toxins or indirect activation of the host immune response.
host pathogen interaction, Mechanism of pathogenesis rashmi816961
-What is host - pathogen interaction?
-Define terms includes pathogenicity, lethal dose, infection etc.
-Duration of symptom
- Pathogens and steps involved in mechanism of pathogenesis
1. Microbial adherence
2. Invasion
3. Colonization
4. Evasion
5. Damage to host
6. Exiting the host
7. Survival outside the host
8. Transmission
- Host -pathogen interaction in plants and animals
- Defence system in plants and animals
This document provides definitions and information related to infection and infection control in dentistry. It begins with definitions of key terms like infection, disease, virulence, and modes of transmission. It then discusses the normal flora of humans and stages of infection. Virulence factors and toxins are explained. The objectives and types of infection control are outlined, including universal precautions, routes of spread, and measures for pretreatment, chairside, and post-treatment infection control.
General virology 3 - Pathogenesis, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses the pathogenesis of viral infections through several stages:
1. Entry through respiratory tract, skin, eyes, digestive tract or mother-to-child transmission. Viruses breach barriers like mucus or skin.
2. Infection occurs at the primary site where viruses replicate and spread locally or through blood/lymphatics to secondary sites like liver/spleen.
3. Cellular changes include rounding, fusion or death of infected cells. Inclusion bodies containing virus may form inside or outside cells. Host responses fight viruses through immunity and fever.
The document discusses host-microbe interactions and principles of infectious disease. It covers several key points:
1) Anatomical barriers like skin and mucous membranes form ecosystems that support beneficial microbial communities while also protecting from pathogens. Microbes and human hosts often have symbiotic relationships that can be mutualistic, commensal, or parasitic.
2) Normal flora microbes play an important protective role by occupying space, producing antimicrobials, and stimulating the immune system. However, if normal flora is disrupted, pathogens may cause disease.
3) Pathogens can damage the host directly through toxins or invasion, or indirectly by eliciting immune responses. Successful pathogens have developed multiple mechanisms to breach
DR.MRS.BHAVANI.A
NURSING TUTOR, ANNAMALAI UNIVERSITY
INFECTION CONTROL - CHAIN OF INFECTION
INTRODUCTION
A major concern for health practioners is the danger of spreading microorganisms from person to person and from place to place. Microorganisms are naturally present in almost all environments. Some are beneficial; some are not. Some are harmless to most people, and others are harmful to many people. Still others are harmless except in certain circumstances. Prevention of infection is a major focus for nurses. As primary caregivers, nurses are involved in identifying, preventing, controlling, and teaching the patient about infection.
INFECTION
• The word "infection" means something different from "disease," although the two terms sometimes are confused. Disease is a general word that describes any abnormality of the human condition or something that interferes with the normal, healthy functioning of the body.
• Diseases include infections and infestations, among others. Infection is a term that refers specifically to any abnormal condition caused by a microbe, such as a bacterium, virus, or parasite, that has invaded another organism (like a human) and interfered with some aspect of its function. An infestation is similar to an infection. It refers to any abnormal condition caused by an organism larger than a microbe, such as an insect, louse, or worm.
• The phrase "infectious diseases" is used to refer to both infections and infestations, regardless of the severity of the condition. An infection beneath a fingernail and a serious case of hepatitis * C both are considered infectious diseases.
• The hallmark of many infections is inflammation, which is largely a result of the immune system's * response to infection, irritation, or injury.
• The characteristics of inflammation include
• redness,
• warmth,
• swelling, and
• pain.
• Important players in the immune reaction are the white blood cells.
• In response to germs, white cells race to the area of infection to fight off the invader; the word "pus" refers to a thick fluid produced by the body in response to an infection that contains these white cells along with other substances resulting from the reaction.
• Chronic infections are those infections that last a longer time—weeks, months, or even years.
• A chronic infection can develop from an acute infection that does not clear up.
• Some chronic infections continue to have signs and symptoms, causing discomfort and interfering with life for long periods of time.
• Other chronic infections may have few or no signs. People who have a chronic infection may not be aware that they still have an active infection and may still be capable of passing the infectious microbe to others.
• One example is hepatitis C, a disease that can have few symptoms but also can cause cirrhosis, chronic liver disease, or liver cancer. People with hepatitis C may not be aware that they have it without taking an antibody * test that
This document provides an overview of major systemic bacterial and fungal infections. It defines infections and the signs and symptoms of disease. It classifies diseases and discusses how pathogens cause disease through virulence factors. It describes the stages of pathogenesis and examples of acute vs. chronic diseases. Examples of major bacterial infections like streptococcus pneumoniae and gonorrhea are provided. The document discusses how fungi cause disease and classifies fungal infections. It provides examples of major fungal infections in humans like dermatophytosis, coccidioidomycosis, and cryptococcal meningitis. It concludes with the medical applications of understanding these pathogens.
The document outlines key concepts related to infection including definitions, classifications, and principles of infection prevention. It defines infection, disease, and infectious disease and describes acute versus chronic infections. It also covers classifications such as primary/secondary infections and local/systemic infections. The chain of infection and its six links - reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host - are explained. Methods of preventing infection by breaking the chain are also summarized.
This document discusses bacterial pathogenesis and infection. It covers several key topics:
1) Normal flora are microorganisms that normally live in or on the human body without causing disease. Opportunistic pathogens are normal flora that can cause disease under certain conditions if the host's immunity is compromised.
2) Bacterial infection is determined by factors of both the bacterium and host. The number and virulence of bacteria as well as the host's innate and acquired immunity impact whether infection occurs.
3) Bacterial pathogenicity is influenced by virulence factors like toxins, invasiveness, and the portal of entry. Virulence refers to an organism's ability to cause disease and is determined by its inv
INFECTION AND INFECTIOUS PROCEعمللياSS.pptxssuser139631
This document discusses infection and infectious processes. It defines infection and classifications of infections such as primary, secondary, and focal infections. It describes sources of infection in humans such as other humans, animals, insects, soil, water, and food. Methods of transmission include contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, and toxins. The document also discusses types of infectious diseases and stages of infectious disease.
This document discusses infection and infectious processes. It defines infection and classifies different types of infections such as primary, secondary, and nosocomial infections. It describes the sources of infections in humans which can come from other humans, animals, insects, soil, water, and food. It also outlines various methods of transmitting infections like contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, toxigenicity, communicability, and bacterial appendages. The document also differentiates between endemic, epidemic, and pandemic diseases and describes the stages of infectious diseases. Finally, it discusses biofilms, quorum sensing, and characteristics of biofilm formation
fundamental of infection and its preveniton.pptxNarayanNeupane3
The document discusses infection control measures and terminology related to infection prevention. It defines key terms like infection, host, agent, asepsis, antisepsis, cleaning, disinfection, decontamination, sterilization, and nosocomial infection. It also describes the chain of infection and explains the components like infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Finally, it discusses nosocomial infections, their causes, impact, risks, and methods for prevention.
Medical diagnostic Microbiology epidemiology 2024 progress.pdf222101989
This document defines key terms related to epidemiology and the study of diseases. It explains epidemiology as the science evaluating the occurrence, distribution, and control of diseases in populations. Key concepts covered include reservoirs of infection, modes of disease transmission, the chain of infection, and the stages of disease development. Koch's postulates for establishing the causative agent of infectious diseases are also summarized.
This document discusses different types of diseases in microbiology. There are four main types: infectious diseases which are caused by microbes like viruses and bacteria; communicable diseases which spread between people; non-communicable diseases which are chronic like cancer and heart disease; and contagious diseases which spread through direct or indirect contact. Infectious diseases can be infectious, acute, chronic, or subclinical. Diseases spread through stages including a reservoir, exit portal, entry portal, and transmission between hosts.
Epidemiology of infectious diseases dr.ihsan alsaimarydr.Ihsan alsaimary
This document discusses infectious diseases and epidemiology. It defines key terms like infection, infectious disease, communicable disease, and epidemiology. It describes how infectious diseases spread from person to person via contact, droplets, or vehicles. Factors that influence transmission include the infectious agent, host susceptibility, and environment. The document also outlines Koch's postulates for determining the cause of an infectious disease and covers topics like disease reservoirs, modes of transmission, and the differences between endemic, epidemic and pandemic diseases.
Microorganisms can cause disease when they enter the body and find a favorable environment. An infection occurs through a chain of events - a pathogen must have a reservoir, exit the reservoir, be transmitted to a new host, enter through a portal, and find a susceptible host. Breaking any link in the chain can prevent transmission and infection. Common ways to do this include proper hygiene, sterilization, use of antiseptics, vaccination, and strengthening a host's defenses.
This document provides definitions and information about infectious diseases. It begins by defining infection as the invasion of a host's tissues by microorganisms that can cause subsequent injury and disease. An infectious disease is caused by the presence of microorganisms. Pathogenicity refers to a microbe's ability to cause disease, while virulence refers to the degree of pathogenicity. The document then discusses various microorganisms that can cause infections like viruses, bacteria, fungi, and parasites. It also covers the basic principles of infection transmission, prevention, and the nature of microorganisms. The stages of infectious disease are described along with factors that influence pathogenicity.
1. The document discusses microorganisms and infectious diseases. It defines key terms like pathogens, virulence, pathogenesis, and defines the chain of infection.
2. The chain of infection involves a source or reservoir, mode of transmission, portal of entry and exit. Common modes of transmission include direct or indirect contact, droplets, vehicles like food or water, and vectors.
3. The human body has natural defenses against infection like skin, mucous membranes, and immune responses. Maintaining hygiene and sanitation can also help prevent the spread of diseases.
This document provides definitions and explanations related to infections. It discusses what constitutes an infection, the types of microorganisms that can cause infections, and how infections are classified. It also describes the normal flora of the human body, how infections develop and spread, methods of diagnosis, and approaches for preventing and treating infections. Key points covered include the difference between acute and chronic infections, the stages of infection including incubation and prodromal periods, and the importance of hygiene, sanitation, and antimicrobial treatments in infection control.
This document summarizes different types and stages of tuberculosis infection and disease. It describes primary tuberculosis occurring in previously unexposed individuals, which may lead to fibrosis and healing or progressive primary disease. It also describes secondary or reactivation tuberculosis occurring in sensitized hosts, which typically involves the lung apices and may progress to cavitary lesions if not treated properly. The document discusses the pathology, microbiology, immunology and clinical manifestations of tuberculosis at different stages.
host pathogen interaction, Mechanism of pathogenesis rashmi816961
-What is host - pathogen interaction?
-Define terms includes pathogenicity, lethal dose, infection etc.
-Duration of symptom
- Pathogens and steps involved in mechanism of pathogenesis
1. Microbial adherence
2. Invasion
3. Colonization
4. Evasion
5. Damage to host
6. Exiting the host
7. Survival outside the host
8. Transmission
- Host -pathogen interaction in plants and animals
- Defence system in plants and animals
This document provides definitions and information related to infection and infection control in dentistry. It begins with definitions of key terms like infection, disease, virulence, and modes of transmission. It then discusses the normal flora of humans and stages of infection. Virulence factors and toxins are explained. The objectives and types of infection control are outlined, including universal precautions, routes of spread, and measures for pretreatment, chairside, and post-treatment infection control.
General virology 3 - Pathogenesis, by Dr. Himanshu KhatriDrHimanshuKhatri
This document discusses the pathogenesis of viral infections through several stages:
1. Entry through respiratory tract, skin, eyes, digestive tract or mother-to-child transmission. Viruses breach barriers like mucus or skin.
2. Infection occurs at the primary site where viruses replicate and spread locally or through blood/lymphatics to secondary sites like liver/spleen.
3. Cellular changes include rounding, fusion or death of infected cells. Inclusion bodies containing virus may form inside or outside cells. Host responses fight viruses through immunity and fever.
The document discusses host-microbe interactions and principles of infectious disease. It covers several key points:
1) Anatomical barriers like skin and mucous membranes form ecosystems that support beneficial microbial communities while also protecting from pathogens. Microbes and human hosts often have symbiotic relationships that can be mutualistic, commensal, or parasitic.
2) Normal flora microbes play an important protective role by occupying space, producing antimicrobials, and stimulating the immune system. However, if normal flora is disrupted, pathogens may cause disease.
3) Pathogens can damage the host directly through toxins or invasion, or indirectly by eliciting immune responses. Successful pathogens have developed multiple mechanisms to breach
DR.MRS.BHAVANI.A
NURSING TUTOR, ANNAMALAI UNIVERSITY
INFECTION CONTROL - CHAIN OF INFECTION
INTRODUCTION
A major concern for health practioners is the danger of spreading microorganisms from person to person and from place to place. Microorganisms are naturally present in almost all environments. Some are beneficial; some are not. Some are harmless to most people, and others are harmful to many people. Still others are harmless except in certain circumstances. Prevention of infection is a major focus for nurses. As primary caregivers, nurses are involved in identifying, preventing, controlling, and teaching the patient about infection.
INFECTION
• The word "infection" means something different from "disease," although the two terms sometimes are confused. Disease is a general word that describes any abnormality of the human condition or something that interferes with the normal, healthy functioning of the body.
• Diseases include infections and infestations, among others. Infection is a term that refers specifically to any abnormal condition caused by a microbe, such as a bacterium, virus, or parasite, that has invaded another organism (like a human) and interfered with some aspect of its function. An infestation is similar to an infection. It refers to any abnormal condition caused by an organism larger than a microbe, such as an insect, louse, or worm.
• The phrase "infectious diseases" is used to refer to both infections and infestations, regardless of the severity of the condition. An infection beneath a fingernail and a serious case of hepatitis * C both are considered infectious diseases.
• The hallmark of many infections is inflammation, which is largely a result of the immune system's * response to infection, irritation, or injury.
• The characteristics of inflammation include
• redness,
• warmth,
• swelling, and
• pain.
• Important players in the immune reaction are the white blood cells.
• In response to germs, white cells race to the area of infection to fight off the invader; the word "pus" refers to a thick fluid produced by the body in response to an infection that contains these white cells along with other substances resulting from the reaction.
• Chronic infections are those infections that last a longer time—weeks, months, or even years.
• A chronic infection can develop from an acute infection that does not clear up.
• Some chronic infections continue to have signs and symptoms, causing discomfort and interfering with life for long periods of time.
• Other chronic infections may have few or no signs. People who have a chronic infection may not be aware that they still have an active infection and may still be capable of passing the infectious microbe to others.
• One example is hepatitis C, a disease that can have few symptoms but also can cause cirrhosis, chronic liver disease, or liver cancer. People with hepatitis C may not be aware that they have it without taking an antibody * test that
This document provides an overview of major systemic bacterial and fungal infections. It defines infections and the signs and symptoms of disease. It classifies diseases and discusses how pathogens cause disease through virulence factors. It describes the stages of pathogenesis and examples of acute vs. chronic diseases. Examples of major bacterial infections like streptococcus pneumoniae and gonorrhea are provided. The document discusses how fungi cause disease and classifies fungal infections. It provides examples of major fungal infections in humans like dermatophytosis, coccidioidomycosis, and cryptococcal meningitis. It concludes with the medical applications of understanding these pathogens.
The document outlines key concepts related to infection including definitions, classifications, and principles of infection prevention. It defines infection, disease, and infectious disease and describes acute versus chronic infections. It also covers classifications such as primary/secondary infections and local/systemic infections. The chain of infection and its six links - reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host - are explained. Methods of preventing infection by breaking the chain are also summarized.
This document discusses bacterial pathogenesis and infection. It covers several key topics:
1) Normal flora are microorganisms that normally live in or on the human body without causing disease. Opportunistic pathogens are normal flora that can cause disease under certain conditions if the host's immunity is compromised.
2) Bacterial infection is determined by factors of both the bacterium and host. The number and virulence of bacteria as well as the host's innate and acquired immunity impact whether infection occurs.
3) Bacterial pathogenicity is influenced by virulence factors like toxins, invasiveness, and the portal of entry. Virulence refers to an organism's ability to cause disease and is determined by its inv
INFECTION AND INFECTIOUS PROCEعمللياSS.pptxssuser139631
This document discusses infection and infectious processes. It defines infection and classifications of infections such as primary, secondary, and focal infections. It describes sources of infection in humans such as other humans, animals, insects, soil, water, and food. Methods of transmission include contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, and toxins. The document also discusses types of infectious diseases and stages of infectious disease.
This document discusses infection and infectious processes. It defines infection and classifies different types of infections such as primary, secondary, and nosocomial infections. It describes the sources of infections in humans which can come from other humans, animals, insects, soil, water, and food. It also outlines various methods of transmitting infections like contact, inhalation, ingestion, inoculation, and congenitally. Factors that contribute to microbial pathogenicity include adhesion, invasiveness, toxigenicity, communicability, and bacterial appendages. The document also differentiates between endemic, epidemic, and pandemic diseases and describes the stages of infectious diseases. Finally, it discusses biofilms, quorum sensing, and characteristics of biofilm formation
fundamental of infection and its preveniton.pptxNarayanNeupane3
The document discusses infection control measures and terminology related to infection prevention. It defines key terms like infection, host, agent, asepsis, antisepsis, cleaning, disinfection, decontamination, sterilization, and nosocomial infection. It also describes the chain of infection and explains the components like infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Finally, it discusses nosocomial infections, their causes, impact, risks, and methods for prevention.
Medical diagnostic Microbiology epidemiology 2024 progress.pdf222101989
This document defines key terms related to epidemiology and the study of diseases. It explains epidemiology as the science evaluating the occurrence, distribution, and control of diseases in populations. Key concepts covered include reservoirs of infection, modes of disease transmission, the chain of infection, and the stages of disease development. Koch's postulates for establishing the causative agent of infectious diseases are also summarized.
This document discusses different types of diseases in microbiology. There are four main types: infectious diseases which are caused by microbes like viruses and bacteria; communicable diseases which spread between people; non-communicable diseases which are chronic like cancer and heart disease; and contagious diseases which spread through direct or indirect contact. Infectious diseases can be infectious, acute, chronic, or subclinical. Diseases spread through stages including a reservoir, exit portal, entry portal, and transmission between hosts.
Epidemiology of infectious diseases dr.ihsan alsaimarydr.Ihsan alsaimary
This document discusses infectious diseases and epidemiology. It defines key terms like infection, infectious disease, communicable disease, and epidemiology. It describes how infectious diseases spread from person to person via contact, droplets, or vehicles. Factors that influence transmission include the infectious agent, host susceptibility, and environment. The document also outlines Koch's postulates for determining the cause of an infectious disease and covers topics like disease reservoirs, modes of transmission, and the differences between endemic, epidemic and pandemic diseases.
Microorganisms can cause disease when they enter the body and find a favorable environment. An infection occurs through a chain of events - a pathogen must have a reservoir, exit the reservoir, be transmitted to a new host, enter through a portal, and find a susceptible host. Breaking any link in the chain can prevent transmission and infection. Common ways to do this include proper hygiene, sterilization, use of antiseptics, vaccination, and strengthening a host's defenses.
This document provides definitions and information about infectious diseases. It begins by defining infection as the invasion of a host's tissues by microorganisms that can cause subsequent injury and disease. An infectious disease is caused by the presence of microorganisms. Pathogenicity refers to a microbe's ability to cause disease, while virulence refers to the degree of pathogenicity. The document then discusses various microorganisms that can cause infections like viruses, bacteria, fungi, and parasites. It also covers the basic principles of infection transmission, prevention, and the nature of microorganisms. The stages of infectious disease are described along with factors that influence pathogenicity.
1. The document discusses microorganisms and infectious diseases. It defines key terms like pathogens, virulence, pathogenesis, and defines the chain of infection.
2. The chain of infection involves a source or reservoir, mode of transmission, portal of entry and exit. Common modes of transmission include direct or indirect contact, droplets, vehicles like food or water, and vectors.
3. The human body has natural defenses against infection like skin, mucous membranes, and immune responses. Maintaining hygiene and sanitation can also help prevent the spread of diseases.
This document provides definitions and explanations related to infections. It discusses what constitutes an infection, the types of microorganisms that can cause infections, and how infections are classified. It also describes the normal flora of the human body, how infections develop and spread, methods of diagnosis, and approaches for preventing and treating infections. Key points covered include the difference between acute and chronic infections, the stages of infection including incubation and prodromal periods, and the importance of hygiene, sanitation, and antimicrobial treatments in infection control.
This document summarizes different types and stages of tuberculosis infection and disease. It describes primary tuberculosis occurring in previously unexposed individuals, which may lead to fibrosis and healing or progressive primary disease. It also describes secondary or reactivation tuberculosis occurring in sensitized hosts, which typically involves the lung apices and may progress to cavitary lesions if not treated properly. The document discusses the pathology, microbiology, immunology and clinical manifestations of tuberculosis at different stages.
Similar to Lecture 6- Bacteria- Pathathogenesis.ppt (20)
Azolla is a free-floating aquatic fern that grows in fresh water. It has a triangular shape and roots that remain suspended in water. Azolla contains a symbiotic relationship with cyanobacteria that can fix nitrogen from the air. It grows best in temperatures between 20-30°C, partial shade, high humidity, and slightly acidic soil between pH 5.2-5.8. Azolla is cultivated by growing it in ponds and supplying nutrients. It can be harvested after 2-3 weeks and fed to livestock as a source of nitrogen. A 6x4 foot pond can yield 800-900g of Azolla per day, providing economic and environmental benefits.
The document discusses microbial fuel cells (MFCs), which use bacteria to convert biomass, bacteria or organic matter into electricity. MFCs consist of an anode where bacteria live and degrade organic matter, producing electrons and protons. A membrane allows protons to pass through while preventing electron transport. At the cathode, oxygen accepts electrons and protons to form water. While MFCs can simultaneously treat waste and produce electricity, their power density remains low and costs are currently high, limiting widespread commercial use. Further research aims to improve performance and reduce costs.
Respiratory tract infections are caused by viruses and bacteria that infect the upper or lower respiratory tract. The document defines respiratory tract infections and lists common types such as cold, flu, pneumonia. It describes symptoms, causes, and treatments for each type of infection. Risk factors include age, environment, and underlying health conditions. Treatment involves antibiotics, antivirals, and other drugs depending on whether the infection is bacterial or viral.
Microbial lipases are enzymes produced by microorganisms that catalyze the hydrolysis of fats. Microbial lipases are widely used in biotechnology and are commonly produced via fermentation using bacteria, yeasts, or molds. Key parameters that influence microbial lipase production include nutrient components, temperature, pH, and agitation. Purification techniques for microbial lipases involve aqueous biphasic systems or reversed micellar systems to separate the lipase from other biomolecules. Purified microbial lipases have various applications in industries such as food, detergent, leather, and pharmaceutical.
10- Funnnnngi and Their Pathogenesis.pptDiptiPriya6
This lecture introduces fungi and their pathogenesis. The objectives are to describe fungi characteristics, terminology, classification, reproduction and identification. Mycology is the study of fungi, which are eukaryotic, heterotrophic organisms lacking chlorophyll. Fungi can be saprobic, symbiotic, or parasitic. Morphologically, fungi include yeasts, filamentous fungi consisting of hyphae and mycelium, and dimorphic fungi that change form depending on environment. Fungi reproduce asexually through budding, fragmentation or spore formation, and sexually through fusion and meiosis. Spores disseminate fungi in the air. While usually saprobic, some fungi can cause diseases by being thermotol
bbbbbbbbBiosynthesis of amino acids.pptxDiptiPriya6
The carbon skeletons of some amino acids can be synthesized in humans through central metabolic pathways, making them non-essential, while others cannot and must be obtained through diet. There are ten essential amino acids that humans cannot synthesize and must consume. Amino acids are synthesized from intermediates in glycolysis, the pentose phosphate pathway, and the citric acid cycle. Transamination reactions add amino groups to form non-essential amino acids. Aromatic amino acids begin synthesis from chorismate and include phenylalanine, tryptophan, tyrosine, and histidine.
- Cyanobacteria are a primitive group of blue-green algae that can be found in almost any environment. They are prokaryotic organisms that can exist as individual cells or form colonies.
- Cyanobacteria play an important ecological role in nutrient cycling and carbon fixation. Some cyanobacteria can fix atmospheric nitrogen. They are also used commercially for applications such as fertilizer production.
- Large scale cultivation of cyanobacteria is possible using photobioreactors like tubular reactors which maximize sunlight exposure while protecting the culture. Proper design of photobioreactors is important for scaling up cyanobacteria production.
This document provides an overview of microbial fuel cells (MFCs). MFCs use bacteria to convert the chemical energy in organic and inorganic matter into electricity. The document describes the components of an MFC, including the anode where bacteria live and degrade substrate, producing electrons and protons, a cathode where oxygen is reduced, and a proton exchange membrane. It explains that protons flow through the membrane while electrons flow an external circuit, powering a load. The document also discusses applications like wastewater treatment and power generation, advantages such as producing renewable energy from waste, and limitations such as low power densities.
The document summarizes the normal microbial flora that inhabit various sites of the human body. It describes the resident and transient flora of the skin, respiratory tract, oral cavity, gastrointestinal tract, and genitourinary tract. The flora vary between sites and help protect against pathogens through competition, production of antimicrobial substances, and stimulation of the immune system. Disruptions to the flora can allow overgrowth of opportunistic microbes.
Microbial metabolites can be used as natural flavouring agents. Microorganisms produce various compounds through fermentation that contribute desirable aromas and tastes to foods. These include alcohols, aldehydes, esters, lactones, methyl ketones, and sulphur compounds. Common microbial flavours include diacetyl from Lactococcus lactis to produce buttery flavours, esters from Saccharomyces cerevisiae and other yeasts for fruity flavours, and vanillin from Aspergillus niger or Pseudomonas putida for vanilla flavours. Solid state fermentation uses agricultural byproducts as substrates and has advantages of lower costs and pollution compared to liquid fermentation.
This document discusses bacterial nutrition and modes of nutrition in bacteria. It explains that bacteria require carbon, nitrogen, phosphorus, iron and other molecules as nutrients. Bacteria can be classified based on their energy source as phototrophs which use light, or chemotrophs which use chemical compounds. They can also be classified based on their electron source as lithotrophs which use inorganic compounds or organotrophs which use organic compounds. The document then discusses autotrophic and heterotrophic bacteria and their carbon sources, as well as their physical requirements for growth such as temperature, oxygen, pH, water activity, and other conditions.
2,3-Butanediol fermentation is an anaerobic fermentation process carried out by facultative anaerobes like Klebsiella and Enterobacter where glucose is converted to 2,3-butanediol. This fermentation produces less acid than mixed acid fermentation, with end products including 2,3-butanediol, ethanol, CO2 and H2. 2,3-Butanediol provides a neutral product that is less inhibitory than other acids produced. There are important industrial applications for 2,3-butanediol including use as an antifreeze, in food additives, and in pharmaceuticals.
Cyanobacteria are a phylum of bacteria that obtain their energy through photosynthesis. They have several distinguishing characteristics:
- They were some of the first organisms to evolve photosynthesis, appearing over 3.5 billion years ago.
- Morphologically, they can be unicellular, colonial, or filamentous. Filaments are surrounded by a mucilaginous sheath.
- They contain chlorophyll a and can fix atmospheric nitrogen like some bacteria. Some are used as biofertilizers or to remediate soil and water.
- Cyanobacteria play important ecological roles as primary producers and can form harmful algal blooms, but also have economic uses including as nutritional supplements, sources of
Microbial metabolism involves a series of biochemical reactions that allow microbes to obtain energy and nutrients through catabolic pathways that break down molecules, and anabolic pathways that use this energy to construct new molecules. Primary metabolism produces essential compounds for growth, while secondary metabolism generates non-essential metabolites that provide competitive advantages. Key molecules like ATP, NADH, and acetyl CoA store and transfer energy to drive the construction of cellular components through anabolic reactions utilizing precursor metabolites.
Evolving Lifecycles with High Resolution Site Characterization (HRSC) and 3-D...Joshua Orris
The incorporation of a 3DCSM and completion of HRSC provided a tool for enhanced, data-driven, decisions to support a change in remediation closure strategies. Currently, an approved pilot study has been obtained to shut-down the remediation systems (ISCO, P&T) and conduct a hydraulic study under non-pumping conditions. A separate micro-biological bench scale treatability study was competed that yielded positive results for an emerging innovative technology. As a result, a field pilot study has commenced with results expected in nine-twelve months. With the results of the hydraulic study, field pilot studies and an updated risk assessment leading site monitoring optimization cost lifecycle savings upwards of $15MM towards an alternatively evolved best available technology remediation closure strategy.
ENVIRONMENT~ Renewable Energy Sources and their future prospects.tiwarimanvi3129
This presentation is for us to know that how our Environment need Attention for protection of our natural resources which are depleted day by day that's why we need to take time and shift our attention to renewable energy sources instead of non-renewable sources which are better and Eco-friendly for our environment. these renewable energy sources are so helpful for our planet and for every living organism which depends on environment.
Optimizing Post Remediation Groundwater Performance with Enhanced Microbiolog...Joshua Orris
Results of geophysics and pneumatic injection pilot tests during 2003 – 2007 yielded significant positive results for injection delivery design and contaminant mass treatment, resulting in permanent shut-down of an existing groundwater Pump & Treat system.
Accessible source areas were subsequently removed (2011) by soil excavation and treated with the placement of Emulsified Vegetable Oil EVO and zero-valent iron ZVI to accelerate treatment of impacted groundwater in overburden and weathered fractured bedrock. Post pilot test and post remediation groundwater monitoring has included analyses of CVOCs, organic fatty acids, dissolved gases and QuantArray® -Chlor to quantify key microorganisms (e.g., Dehalococcoides, Dehalobacter, etc.) and functional genes (e.g., vinyl chloride reductase, methane monooxygenase, etc.) to assess potential for reductive dechlorination and aerobic cometabolism of CVOCs.
In 2022, the first commercial application of MetaArray™ was performed at the site. MetaArray™ utilizes statistical analysis, such as principal component analysis and multivariate analysis to provide evidence that reductive dechlorination is active or even that it is slowing. This creates actionable data allowing users to save money by making important site management decisions earlier.
The results of the MetaArray™ analysis’ support vector machine (SVM) identified groundwater monitoring wells with a 80% confidence that were characterized as either Limited for Reductive Decholorination or had a High Reductive Reduction Dechlorination potential. The results of MetaArray™ will be used to further optimize the site’s post remediation monitoring program for monitored natural attenuation.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
Kinetic studies on malachite green dye adsorption from aqueous solutions by A...Open Access Research Paper
Water polluted by dyestuffs compounds is a global threat to health and the environment; accordingly, we prepared a green novel sorbent chemical and Physical system from an algae, chitosan and chitosan nanoparticle and impregnated with algae with chitosan nanocomposite for the sorption of Malachite green dye from water. The algae with chitosan nanocomposite by a simple method and used as a recyclable and effective adsorbent for the removal of malachite green dye from aqueous solutions. Algae, chitosan, chitosan nanoparticle and algae with chitosan nanocomposite were characterized using different physicochemical methods. The functional groups and chemical compounds found in algae, chitosan, chitosan algae, chitosan nanoparticle, and chitosan nanoparticle with algae were identified using FTIR, SEM, and TGADTA/DTG techniques. The optimal adsorption conditions, different dosages, pH and Temperature the amount of algae with chitosan nanocomposite were determined. At optimized conditions and the batch equilibrium studies more than 99% of the dye was removed. The adsorption process data matched well kinetics showed that the reaction order for dye varied with pseudo-first order and pseudo-second order. Furthermore, the maximum adsorption capacity of the algae with chitosan nanocomposite toward malachite green dye reached as high as 15.5mg/g, respectively. Finally, multiple times reusing of algae with chitosan nanocomposite and removing dye from a real wastewater has made it a promising and attractive option for further practical applications.
Improving the viability of probiotics by encapsulation methods for developmen...Open Access Research Paper
The popularity of functional foods among scientists and common people has been increasing day by day. Awareness and modernization make the consumer think better regarding food and nutrition. Now a day’s individual knows very well about the relation between food consumption and disease prevalence. Humans have a diversity of microbes in the gut that together form the gut microflora. Probiotics are the health-promoting live microbial cells improve host health through gut and brain connection and fighting against harmful bacteria. Bifidobacterium and Lactobacillus are the two bacterial genera which are considered to be probiotic. These good bacteria are facing challenges of viability. There are so many factors such as sensitivity to heat, pH, acidity, osmotic effect, mechanical shear, chemical components, freezing and storage time as well which affects the viability of probiotics in the dairy food matrix as well as in the gut. Multiple efforts have been done in the past and ongoing in present for these beneficial microbial population stability until their destination in the gut. One of a useful technique known as microencapsulation makes the probiotic effective in the diversified conditions and maintain these microbe’s community to the optimum level for achieving targeted benefits. Dairy products are found to be an ideal vehicle for probiotic incorporation. It has been seen that the encapsulated microbial cells show higher viability than the free cells in different processing and storage conditions as well as against bile salts in the gut. They make the food functional when incorporated, without affecting the product sensory characteristics.
Microbial characterisation and identification, and potability of River Kuywa ...Open Access Research Paper
Water contamination is one of the major causes of water borne diseases worldwide. In Kenya, approximately 43% of people lack access to potable water due to human contamination. River Kuywa water is currently experiencing contamination due to human activities. Its water is widely used for domestic, agricultural, industrial and recreational purposes. This study aimed at characterizing bacteria and fungi in river Kuywa water. Water samples were randomly collected from four sites of the river: site A (Matisi), site B (Ngwelo), site C (Nzoia water pump) and site D (Chalicha), during the dry season (January-March 2018) and wet season (April-July 2018) and were transported to Maseno University Microbiology and plant pathology laboratory for analysis. The characterization and identification of bacteria and fungi were carried out using standard microbiological techniques. Nine bacterial genera and three fungi were identified from Kuywa river water. Clostridium spp., Staphylococcus spp., Enterobacter spp., Streptococcus spp., E. coli, Klebsiella spp., Shigella spp., Proteus spp. and Salmonella spp. Fungi were Fusarium oxysporum, Aspergillus flavus complex and Penicillium species. Wet season recorded highest bacterial and fungal counts (6.61-7.66 and 3.83-6.75cfu/ml) respectively. The results indicated that the river Kuywa water is polluted and therefore unsafe for human consumption before treatment. It is therefore recommended that the communities to ensure that they boil water especially for drinking.
Recycling and Disposal on SWM Raymond Einyu pptxRayLetai1
Increasing urbanization, rural–urban migration, rising standards of living, and rapid development associated with population growth have resulted in increased solid waste generation by industrial, domestic and other activities in Nairobi City. It has been noted in other contexts too that increasing population, changing consumption patterns, economic development, changing income, urbanization and industrialization all contribute to the increased generation of waste.
With the increasing urban population in Kenya, which is estimated to be growing at a rate higher than that of the country’s general population, waste generation and management is already a major challenge. The industrialization and urbanization process in the country, dominated by one major city – Nairobi, which has around four times the population of the next largest urban centre (Mombasa) – has witnessed an exponential increase in the generation of solid waste. It is projected that by 2030, about 50 per cent of the Kenyan population will be urban.
Aim:
A healthy, safe, secure and sustainable solid waste management system fit for a world – class city.
Improve and protect the public health of Nairobi residents and visitors.
Ecological health, diversity and productivity and maximize resource recovery through the participatory approach.
Goals:
Build awareness and capacity for source separation as essential components of sustainable waste management.
Build new environmentally sound infrastructure and systems for safe disposal of residual waste and replacing current dumpsites which should be commissioned.
Current solid waste management situation:
The status.
Solid waste generation rate is at 2240 tones / day
collection efficiently is at about 50%.
Actors i.e. city authorities, CBO’s , private firms and self-disposal
Current SWM Situation in Nairobi City:
Solid waste generation – collection – dumping
Good Practices:
• Separation – recycling – marketing.
• Open dumpsite dandora dump site through public education on source separation of waste, of which the situation can be reversed.
• Nairobi is one of the C40 cities in this respect , various actors in the solid waste management space have adopted a variety of technologies to reduce short lived climate pollutants including source separation , recycling , marketing of the recycled products.
• Through the network, it should expect to benefit from expertise of the different actors in the network in terms of applicable technologies and practices in reducing the short-lived climate pollutants.
Good practices:
Despite the dismal collection of solid waste in Nairobi city, there are practices and activities of informal actors (CBOs, CBO-SACCOs and yard shop operators) and other formal industrial actors on solid waste collection, recycling and waste reduction.
Practices and activities of these actor groups are viewed as innovations with the potential to change the way solid waste is handled.
CHALLENGES:
• Resource Allocation.
Presented by The Global Peatlands Assessment: Mapping, Policy, and Action at GLF Peatlands 2024 - The Global Peatlands Assessment: Mapping, Policy, and Action
Epcon is One of the World's leading Manufacturing Companies.EpconLP
Epcon is One of the World's leading Manufacturing Companies. With over 4000 installations worldwide, EPCON has been pioneering new techniques since 1977 that have become industry standards now. Founded in 1977, Epcon has grown from a one-man operation to a global leader in developing and manufacturing innovative air pollution control technology and industrial heating equipment.
2. Infection and Disease
A. Definitions
B. Generalized Stages of Infection
C. Virulence Factors and Toxins
3. A. Definitions
Disease and Infectious Disease
• Disease
• Any deviation from a condition of good
health and well-being
• Infectious Disease
A disease condition caused by the presence
or growth of infectious microorganisms or
parasites
4. A. Definitions
Pathogenicity and Virulence
• Pathogenicity
• The ability of a microbe to cause disease
• This term is often used to describe or compare
species
• Virulence
• The degree of pathogenicity in a microorganism
• This term is often used to describe or compare
strains within a species
5. Definitions
Acute infection vs. chronic infection
• Acute Infection
• An infection characterized by sudden onset,
rapid progression, and often with severe
symptoms
• Chronic Infection
• An infection characterized by delayed onset
and slow progression
6. Definitions
Primary infection vs. secondary infection
• Primary Infection
• An infection that develops in an otherwise
healthy individual
• Secondary Infection
• An infection that develops in an individual
who is already infected with a different
pathogen
7. Definitions
Localized infection vs. systemic infection
• Localized Infection
• An infection that is restricted to a specific
location or region within the body of the host
• Systemic Infection
• An infection that has spread to several
regions or areas in the body of the host
8. Definitions
Clinical infection vs. subclinical infection
• Clinical Infection
• An infection with obvious observable or
detectable symptoms
• Subclinical Infection
• An infection with few or no obvious
symptoms
9. Definitions
Opportunistic infection
• An infection caused by microorganisms that are
commonly found in the host’s environment.
This term is often used to refer to infections
caused by organisms in the normal flora.
10. Definitions
The suffix “-emia”
• A suffix meaning “presence of an infectious agent”
• Bacteremia = Presence of infectious bacteria
• Viremia = Presence of infectious virus
• Fungemia = Presence of infectious fungus
• Septicemia = Presence of an infectious agent in
the bloodstream
11. Definitions
The suffix “-itis”
• A suffix meaning “inflammation of”
• Examples:
–Pharyngitis = Inflammation of the pharynx
–Endocarditis = Inflammation of the heart
chambers
–Gastroenteritis = Inflammation of the
gastointestinal tract
12. Definitions
Epidemiology
• The study of the transmission of disease
Communicable Disease
• A disease that can be transmitted from one
individual to another
Noncommunicable Disease
• A disease that is not transmitted from one
individual to another
13. Definitions
Endemic Disease
• A disease condition that is normally found in a
certain percentage of a population
Epidemic Disease
• A disease condition present in a greater than
usual percentage of a specific population
Pandemic Disease
• An epidemic affecting a large geographical
area; often on a global scale
14. Definitions
Reservoir of Infection
• The source of an infectious agent
Carrier
• An individual who carries an infectious agent
without manifesting symptoms, yet who can
transmit the agent to another individual
Fomites
• Any inanimate object capable of being an
intermediate in the indirect transmission of an
infectious agent
15. Definitions
• Animal Vectors
• An animal (nonhuman) that can transmit an
infectious agent to humans
• Two types: mechanical and biological
• Mechanical animal vectors: The infectious agent is
physically transmitted by the animal vector, but the agent
does not incubate or grow in the animal; e.g, the
transmission of bacteria sticking to the feet of flies
• Biological animal vectors: The infectious agent must
incubate in the animal host as part of the agent’s
developmental cycle; e.g, the transmission of malaria
by infected mosquitoes
16. Definitions
Direct Mechanisms of Disease Transmission
• Directly From Person to Person
• Examples:
Direct Skin Contact
Airborne (Aerosols)
19. Pathogenicity - ability to cause disease
Virulence - degree of pathogenicity
Many properties that determine a microbe’s
pathogenicity or virulence are unclear or
unknown
But, when a microbe overpowers the hosts
defenses, infectious disease results!
20. Molecular Determinants of Pathogenicity
Production
and delivery
of various
factors
Attachment
to host
tissues
Replication
and evasion
of immunity
Damage to
host tissues
23. 1. Mucus Membranes
A. Respiratory Tract
• microbes inhaled into
mouth or nose in
droplets of moisture or
dust particles
• Easiest and most
frequently traveled
portal of entry
24. Common Diseases contracted via
the Respiratory Tract
Common cold
Flu
Tuberculosis
Whooping cough
Pneumonia
Measles
Diphtheria
25. Mucus Membranes
B. Gastrointestinal Tract
• microbes gain entrance thru
contaminated food & water
or fingers & hands
• most microbes that enter the
G.I. Tract are destroyed by
HCL & enzymes of stomach
or bile & enzymes of small
intestine
27. Fecal - Oral Diseases
These pathogens enter the G.I. Tract at one
end and exit at the other end.
Spread by contaminated hands & fingers or
contaminated food & water
Poor personal hygiene.
28. Mucus Membranes of the Genitourinary System - STD’s
Gonorrhea
Neisseria gonorrhoeae
Syphilis
Treponema pallidum
Chlamydia
Chlamydia trachomatis
HIV
Herpes Simplex II
29. Mucus Membranes
D. Conjunctiva –
• mucus membranes that
cover the eyeball and lines
the eyelid
Trachoma
• Chlamydia trachomatis
30. 2nd Portal of Entry: Skin
Skin - the largest organ of the body. When
unbroken is an effective barrier for most
microorganisms.
Some microbes can gain entrance through
openings in the skin: hair follicles and sweat
glands, wound …etc
31.
32. 3rd Portal of Entry: Parentarel
Microorganisms are deposited into the
tissues below the skin or mucus membranes
Punctures and scratches
injections
bites
surgery
33. Preferred Portal of Entry
Just because a pathogen enters your body it
does not mean it’s going to cause disease.
pathogens - preferred portal of entry
34. Preferred Portal of Entry
Streptococcus pneumoniae
• if inhaled can cause pneumonia
• if enters the G.I. Tract, no disease
Salmonella typhi
• if enters the G.I. Tract can cause Typhoid Fever
• if on skin, no disease
35. Number of Invading Microbes
LD50 - Lethal Dose of a microbes toxin that
will kill 50% of experimentally inoculated
test animal
ID50 - infectious dose required to cause
disease in 50% of inoculated test animals
• Example: ID50 for Vibrio cholerea 108 cells
(100,000,000 cells)
• ID50 for Inhalation Anthrax - 5,000 to 10,000
spores ????
36. How do Bacterial Pathogens
penetrate Host Defenses?
1. Adherence - almost
all pathogens have a
means to attach to host
tissue
Binding Sites
adhesins
ligands
37. Some cells use fimbriae to
adhere.
Fimbriae can play
a role in tissue
tropism. Example -
attachment of Candida
to vaginal epithelial
cells
38. Adhesins and ligands are usually
on Fimbriae
Neisseria gonorrhoeae
ETEC
(Entertoxigenic E. coli)
Bordetello pertussis
39. Bacteria typically employ proteins known as Adhesins to
attach to host tissues, which usually are located on ends of
fimbriae.
Alternatively, adhesins can consist of glycocalyx.
42. Cell Wall Components
M protein: Found on cell surface and
fimbriae of Streptococcus pyogenes.
Mediates attachment and helps resist
phagocytosis. M-protein is heat and
acid resistant
Waxes [ Mycolic Acid]: In cell wall
of Mycobacterium tuberculosis helps
resist digestion after phagocytosis and
can multiply inside WBC.
43. 3. Enzymes
Many pathogens secrete enzymes that
contribute to their pathogenicity
45. A. Leukocidins
Attack certain types of WBC’s
1. Kills WBC’s which prevents phagocytosis
2. Releases & ruptures lysosomes
• lysosomes - contain powerful hydrolytic
enzymes which then cause more tissue damage
47. 1. Alpha (α) Hemolytic Streptococci
- secrete hemolysins that cause the incomplete
lysis or RBC’s
Incomplete
Lysis of RBC
48. 2. Beta (β) Hemolytic Streptococci
- secrete hemolysins that cause the complete lysis
of RBC’s
Complete
Lysis of RBC
49. 3. Gamma (γ) Hemolytic Streptococci
- do not secrete any hemolysins
50. C. Coagulase - cause blood to
coagulate
Blood clots protect bacteria from
phagocytosis from WBC’s and other host
defenses
Staphylococcus aureus - are often coagulase
positive
Fibrinogen ----------------- Fibrin ( Clot)
51. D. Kinases - enzymes that dissolve
blood clots
1. Streptokinase - Streptococci
2. Staphylokinase - Staphylococci
Helps to spread bacteria - Bacteremia
Streptokinase - used to dissolve blood clots in the
Heart (Heart Attacks due to obstructed coronary blood
vessels)
52. E. Hyaluronidase
Breaks down Hyaluronic acid (found in
connective tissues)
“Spreading Factor”
mixed with a drug to help spread the drug
through a body tissue
Streptococci, Staphylococci, Clostridia and
pneumococci.
53. F. Collagenase
Breaks down collagen (found in many connective
tissues)
Clostridium perfringens - Gas Gangrene
• uses this to spread through muscle tissue
54. Severe gangrene caused by Clostridium perfringens.
Source: Tropical Medicine and Parasitology, 1997
Tissue Damage Caused by Microbial
Enzymes of Clostridium perfringens
55. G. Necrotizing Factor
- causes death (necrosis) to tissue cells
“Flesh Eating Bacteria”
Necrotizing fasciitis
56. H. Lecithinase
Destroys lecithin ( phosphatidylcholine)
component of plasma membrane.
Allowing pathogen to spread
Clostridium perfringens
57. Summary of How Bacterial
Pathogens Penetrate Host Defenses
1. Adherence
2. Capsule
3. Enzymes
• A. leukocidins B. Hemolysins
• C. Coagulase D. Kinases
• E. Hyaluronidase F. Collagenase
• G. Necrotizing Factor H. Lecithinase
58. 4. Toxins
Poisonous substances produced by
microorganisms
toxins - primary factor - pathogenicity
220 known bacterial toxins
• 40% cause disease by damaging the Eukaryotic
cell membrane
Toxemia
• Toxins in the bloodstream
• Toxigenicity: Capacity of microorganisms to
produce toxins.
59. Two Types of Toxins
1. Exotoxins
• secreted outside the bacterial cell
2. Endotoxins
• part of the outer cell wall of Gram (-) bacteria.
??
62. I- Exotoxins
Mostly seen in Gram (+) Bacteria
Most gene that code for exotoxins are
located on plasmids or phages
63. Three Types of Exotoxins
1. Cytotoxins
• kill cells e.g. Diphtheria toxin
2. Neurotoxins
• interfere with normal nerve impulses.e.g.
Botulinum Toxin
3. Enterotoxins
• effect cells lining the G.I. Tract. e.g. Cholera
toxin or choleragen.
64. Response to Toxins
If exposed to exotoxins: antibodies against the
toxin (antitoxins)
Exotoxins inactivated ( heat, formalin or phenol)
no longer cause disease, but stimulate the
production of antitoxin
• altered exotoxins - Toxoids
Toxoids - modified toxin by heat, chemical,
radiation, that have lost their toxicity. Injected to
stimulate the production of antitoxins and provide
immunity.
67. Most genes that code for exotoxins - plasmids
or phages
Lysogenic convergence
Diphtheria
Cytotoxin inhibits
protein synthesis -
resulting in cell death
Pseudomembrane
• fibrin, dead tissue,
bacterial cells
68. Lysogenic Convergence
Scarlet Fever
Streptococcus pyogenes
• lysogenic convergence
cytotoxin - damages blood capillaries and results in a
skin rash
• Strep Thoat with a rash
69. Rash of Scarlet Fever Caused by Erythrogenic
Toxins of Streptococcus pyogenes
71. Diseases caused by Neurotoxins
Botulism
• Clostridium botulinum
• Gram (+), anaerobic, spore-forming rod, found in
soil
• works at the neuromuscular junction
• prevents impulse from nerve cell to muscle cell
• results in muscle paralysis
72. Tetanus (Lock Jaw)
Clostridium tetani
Gram (+), spore-forming, anaerobic rod
neurotoxin acts on nerves, resulting in the
inhibition of muscle relaxation
tetanospasmin - “spasms” or “Lock Jaw”
73. Neonatal Tetanus (Wrinkled brow and risus sardonicus)
Source: Color Guide to Infectious Diseases, 1992
Muscle Spasms of Tetanus are Caused by
Neurotoxin of Clostridium tetani
75. Cholera toxin
Converts ATP into cAMP
causes cells to excrete Cl- ions and inhibits
absorption of Na+ ions
Electrolyte imbalance
H2O leaves by osmosis
H2O Loss (Diarrhea)
Two polypeptides: A (active) and B (binding).
The A subunit of enterotoxin causes epithelial
cells to discharge large amounts of fluids and
electrolytes.
76. Severe cases, 12 - 20 liters of liquid lost
in a day
Untreated cases - Mortality Rate about 50%
Mortality may be reduced to about 1%
• administering fluids and electrolytes
77. Rice-water stool of cholera. The A subunit of enterotoxin causes
epithelial cells to discharge large amounts of fluids and electrolytes.
Source: Tropical Medicine and Parasitology, 1995
Vibrio Enterotoxin Causes Profuse Watery Diarrhea
78. EHEC (Enterohemorrhagic E. coli)
E. coli (0157:H7)
enterotoxin causes a hemolytic inflammation
of the intestines
results in bloody diarrhea
• Toxin
• alters the 60S ribosomal subunit
• inhibits Protein Synthesis
• Results in cell death
• lining of intestine is “shed”
• Bloody Diarrhea (Dysentary)
80. II- Endotoxins
• Part of outer membrane surrounding gram-negative
bacteria.
• Endotoxin is lipid portion of lipopolysaccharides (LPS),
called lipid A.
• Effect exerted when gram-negative cells die and cell
walls undergo lysis, liberating endotoxin.
• All produce the same signs and symptoms:
• Chills, fever, weakness, general aches, blood clotting
and tissue death, shock, and even death. Can also
induce miscarriage.
• Fever: Pyrogenic response is caused by endotoxins.
83. Endotoxins (Continued)
• Endotoxins do not promote the formation of
effective antibodies.
• Organisms that produce endotoxins include:
• Salmonella typhi
• Proteus spp.
• Pseudomonas spp.
• Neisseria spp.
• Medical equipment that has been sterilized may
still contain endotoxins.
• Limulus amoebocyte assay (LAL) is a test used to
detect tiny amounts of endotoxin.
84. Events leading to fever:
• Gram-negative bacteria are digested by
phagocytes.
• LPS is released by digestion in vacuoles, causing
macrophages to release interleukin-1 (IL-1).
• IL-1 is carried via blood to hypothalamus, which
controls body temperature.
• IL-1 induces hypothalamus to release
prostaglandins, which reset the body’s
thermostat to higher temperature.
86. III. B. The Normal Flora of
Humans
Types of Symbiosis
• Mutualism
• A symbiotic relationship in which both
species benefit
• Commensalism
• A symbiotic relationship in which one
species benefits, and the other species is
neither helped nor harmed
87. III. B. The Normal Flora of
Humans
Types of Symbiosis (cont.)
• Parasitism
• A symbiotic relationship in which one
species benefits, and the other species is
harmed
• Generally, the species that benefits (the
parasite) is much smaller than the species
that is harmed (the host)
88. III. B. The Normal Flora of
Humans
Normal flora is present in
• skin
• upper respiratory tract
• oral cavity
• intestine, especially large intestine
• vaginal tract
Very little normal flora in eyes & stomach
89. III. B. The Normal Flora of
Humans
Notably absent in most all internal organs
• Absent in:
• lower respiratory tract
• muscle tissue
• blood & tissue fluid
• cerebrospinal fluid
• peritoneum
• pericardium
• meninges
90. III. B. The Normal Flora of
Humans
Benefits of the normal flora
• Nutrient production/processing
eg Vitamin K production by E. coli
• Competition with pathogenic microbes
• Normal development of the immune system
Normal flora and opportunistic infections
91. III. C. Generalized Stages of
Infection
1. Entry of Pathogen
• Portal of Entry
2. Colonization
• Usually at the site of entry
3. Incubation Period
• Asymptomatic period
• Between the initial contact with the microbe
and the appearance of the first symptoms
92. III. C. Generalized Stages of
Infection
4. Prodromal Symptoms
• Initial Symptoms
5. Invasive period
• Increasing Severity of Symptoms
• Fever
• Inflammation and Swelling
• Tissue Damage
• Infection May Spread to Other Sites
93. III. C. Generalized Stages of
Infection
6. Decline of Infection
5. Convalescence
94. Course of Infectious Disease
Incubation period is
the interval between
exposure and
illness onset.
Convalescence is
a time of
recuperation and
recovery from
illness.
Depending on various
factors an individual may
still be infectious during
either incubation or
convalescence.
