Description of the major classes of antimicrobial drug, resistant mechanisms developed by bacteria to combat the action of antimicrobials, and the control measures needed to limit this horizontal gene transfer.
To study Prevalence, Pre-disposing factors and Prevention of the following MDRO’s – Klebsiella pneumoniae Carbapenemase Producer, Methicillin Resistant Staphylococcus aureus, Multi Drug Resistant Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli.
A short brief on 'Hospital Acquired Infections' (HAI) or 'Nosocomial Infection' (NI) for M Phil, MPH and Advance Course in Hospital Management/ Administration
To study Prevalence, Pre-disposing factors and Prevention of the following MDRO’s – Klebsiella pneumoniae Carbapenemase Producer, Methicillin Resistant Staphylococcus aureus, Multi Drug Resistant Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli.
A short brief on 'Hospital Acquired Infections' (HAI) or 'Nosocomial Infection' (NI) for M Phil, MPH and Advance Course in Hospital Management/ Administration
Antibiotics are most common therapeutic agents used in hospitals across world, however, microbial world is becoming resistant day by day, posing special challenges to clinicians specially working in ICU set ups. There are multiple ways to curb this menace, if approached together in antibiotic stewardship way, can bring about wonders and retain therapeutic potentials of these drugs.
A brief presentation on the efficacy and safety of contact precautions and MRSA, given as a student at Beth Israel-Deaconess Medical Center in Boston, MA
Central-Line-Associated Bloodstream Infections (CLABSI) pause a major health problem in hospitalized patients. This disease is associated with people with a central line/tube inserted through the skin into the large vein, which can be used to give medicines, fluids, nutrients, or blood products to patients in critical conditions. The disease occurs when microbes enter through the central line invading the bloodstream.
Using the Central Line Bundle
Hand Hygiene
Remove Unnecessary Lines
Use of Maximal Barrier Precautions
Chlorhexidine for Skin Antisepsis
Avoid femoral lines
Report CLABSI rates to the units
Celebrate success!!
Infection Control and Antibiotic Stewardship Symposia presented in Milot, Haiti at Hôpital Sacré Coeur.
CRUDEM’s Education Committee (a subcommittee of the Board of Directors) sponsors one-week medical symposia on specific medical topics, i.e. diabetes, infectious disease. The classes are held at Hôpital Sacré Coeur and doctors and nurses come from all over Haiti to attend.
Antibiotics are most common therapeutic agents used in hospitals across world, however, microbial world is becoming resistant day by day, posing special challenges to clinicians specially working in ICU set ups. There are multiple ways to curb this menace, if approached together in antibiotic stewardship way, can bring about wonders and retain therapeutic potentials of these drugs.
A brief presentation on the efficacy and safety of contact precautions and MRSA, given as a student at Beth Israel-Deaconess Medical Center in Boston, MA
Central-Line-Associated Bloodstream Infections (CLABSI) pause a major health problem in hospitalized patients. This disease is associated with people with a central line/tube inserted through the skin into the large vein, which can be used to give medicines, fluids, nutrients, or blood products to patients in critical conditions. The disease occurs when microbes enter through the central line invading the bloodstream.
Using the Central Line Bundle
Hand Hygiene
Remove Unnecessary Lines
Use of Maximal Barrier Precautions
Chlorhexidine for Skin Antisepsis
Avoid femoral lines
Report CLABSI rates to the units
Celebrate success!!
Infection Control and Antibiotic Stewardship Symposia presented in Milot, Haiti at Hôpital Sacré Coeur.
CRUDEM’s Education Committee (a subcommittee of the Board of Directors) sponsors one-week medical symposia on specific medical topics, i.e. diabetes, infectious disease. The classes are held at Hôpital Sacré Coeur and doctors and nurses come from all over Haiti to attend.
abscess advanced trauma life support anterio advanced trauma life support antibiotics apically repositioned flap dental diseases dr dr shabeel drshabeel’s face eye trauma lidocaine anodontia management medical medicine misuse and abuse orthodontics teeth braces pharmacy pn preparation dental students for community based ed presentations s abscess abscess tooth active orthodonti shabeel shabeel"s shabeel’s shabeelpn trends of antimicrobial usage in dental practice View all
’s abscess abscess advanced trauma life support anterio abscess tooth active orthodontics adolescent advanced trauma life support aesthetic dentistry airway management alignment of teeth amalgam anesthesia in dentistry anesthetics in dentistry anterior open bite antibiotic resistanace antibiotics antibiotics and leukopenia aphthous ulcers apically repositioned flap apicoectomy appliances arch dental arch form orthodontics braces arch length orthodontics braces arch wire orthodontist braces ayurvedha baby teeth bloger boil books braces braces teeth cancer canker sore pain cavity preparation children community based learning congenitally missing teeth cosmetic dentistry csf leaks dental dental anesthetics dental restorations dental teeth dento alveolar fractures disease
Antibiotics In Acute Respiratory Failureshabeel pn
abscess advanced trauma life support anterio advanced trauma life support antibiotics apically repositioned flap dental diseases dr dr shabeel drshabeel’s face eye trauma lidocaine anodontia management medical medicine misuse and abuse orthodontics teeth braces pharmacy pn preparation dental students for community based ed presentations s abscess abscess tooth active orthodonti shabeel shabeel"s shabeel’s shabeelpn trends of antimicrobial usage in dental practice View all
’s abscess abscess advanced trauma life support anterio abscess tooth active orthodontics adolescent advanced trauma life support aesthetic dentistry airway management alignment of teeth amalgam anesthesia in dentistry anesthetics in dentistry anterior open bite antibiotic resistanace antibiotics antibiotics and leukopenia aphthous ulcers apically repositioned flap apicoectomy appliances arch dental arch form orthodontics braces arch length orthodontics braces arch wire orthodontist braces ayurvedha baby teeth bloger boil books braces braces teeth cancer canker sore pain cavity preparation children community based learning congenitally missing teeth cosmetic dentistry csf leaks dental dental anesthetics dental restorations dental teeth dento alveolar fractures disease
Nimalox is a non steroidal anti inflammatory drug with
analgesic and antipyretic properties and cox-2
selective inhibition
it's a study to re-branding Nimalox
MBA Cairo University
This presentation is about MRSA which is also known a 'superbug.' It consist of information on MRSA,MRSA infection,its genetics,types,symptoms,prevention,research,etc
The newer antibiotics added to Our Arsenal against resistant bacteria. Know about the upcoming antibiotics and newer antibiotics in use.
Free text at
http://medchrome.com/basic-science/pharmacology/newer-antibiotics-review/
DISPERCAM, Marketing Plan for 2011
Markeiting & IMC plan for pharmaceutical product. using modern and emotional communication concept can be used for direct marketing by medical reps.
now more about me @
http://www.slideshare.net/AbdulrhmanTantawy/atantawy-visual-resume
To understand the mechanisms of antimicrobial action and the classification of antimicrobial drugs.
To explain the process of microbial resistance.
To understand the spread of resistant microbes.
Outlines the prevention of microbial resistance.
Validation of lab instruments and quantitative test methods Mostafa Mahmoud
This lecture shows the procedures applied when going to validate your laboratory instruments and quantitative test methods also either FDA approved or laboratory developed tests.
This presentation describes the key performance indicators to assess the quality of work in microbiology department. The KPIs in common use are mentioned and other indicators are summarized.
The lecture was presented to the students of Saudi board of Community Medicine to help them know about the various serological methods applicable in the diagnosis of infectious diseases in general with attention upon the specificity and sensitivity of various diagnostic modalities. The lecture covers the basic principles of each test and the clinical applications with the advantages and disadvantages of each.
Lab diagnosis of Sexually transmitted Infections (STIs)Mostafa Mahmoud
This lecture was presented to the physicians dealing with the various infectious diseases specially in STIs in Riyadh Region, MOH. The lecture concentrates about the various methodology applied to diagnose STIs in the laboratory with the advantages and disadvantages of each. Hope to make benefits to all.
Conventional methods for bacterial identificationMostafa Mahmoud
this lecture describes the conventional procedures for identification of bacterial colonies using different tests. the lecture is suitable for the medical students, technicians and medical staff.
this lecture describes the various procedures and maintenance steps that should be taken to insure that all lab equipment are working well in a controlled manner for the guarantee of accuracy of microbiological test results.
A simple lecture for the description of the various culture media used for isolation of different bacteria in a pure form for further identification procedures.
The lecture is a simple one describing the various methods that could be applied in small microbiology laboratories where the automated systems are lacking.
The lecture describes the performance and presentation of the antibiograms by the hospitals based upon recommendations of CLSI and shows experience of some of our MOH hospitals with the advantages and pitfalls in them.
The lecture gives concise review about the main four groups of viruses causing hemorrhagic fever i.e. Flavivirues, Filoviruses, Arenaviruses and Bunyaviruses.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
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.
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- 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
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
4. Classification and mechanism of action of antimicrobials
• Antimicrobial agents are substances that kill or inhibit the growth
of microorganisms and are suitable for systemic use.
• If this antimicrobial substance is synthesized in the laboratory it is
named Chemotherapeutic.
• The term “antibiotic” is a substance produced as a secondary
metabolite by a bacterium which inhibits or kills other
microorganisms.
5. Some Naturally Produced Antibiotics
Species Microorganism Antibiotic produced
Gram positive Bacteria Bacillus subtilis Bacitracin
Bacillus polymixa Polymixin
Actinomycetes Micromonospora purpurea Gentamycin
Streptomyces Streptomyces erythreus Erythromycin
Streptomyces griseus Streptomycin
Streptomyces rimosus Tetracycline
Streptomyces orientalis Vancomycin
Fungi Penicillium chrysogenum Penicillin
Cephalosporium acremonium Cephalosporins
Miscellaneous Pseudomonas fluorescens pseudomonic acids*
6. classifications of antimicrobials:
• Several ways according to:
• Mechanism of action: (inhibit cell wall, protein, or NA synthesis
etc).
• Spectrum of activity: (broad or narrow spectrum).
• Killing or inhibitory effect upon microorganism: (Bacteriostatic or
Bactericidal).
• The chemical structure.
8. 1- Inhibition of bacterial cell wall synthesis
Group Examples Spectrum of action
Penicllins: 1-Natural Penicillin G (injection)
Penicillin V (oral)
Gram positive bacteria.
2-Penicillinase-Resistant
Penicillins
Cloxacillin - Dicloxacillin - Methicillin,
Nafcillin - Oxacillin
Antistaphylococcal actions
3- Aminopenicillins Amoxicillin - Ampicillin
Amoxicillin/clavulanate
Ampicllin/sulbactam
bacapicillin
Gram +ve and Gram -ve
bacteria.
4- Carboxypenicillins Carbenicillin - Ticracillin,
Ticracillin/clavulante
Greater activity against gram
negative organisms
5-Ureidopenicillins and
Piperazine
Mezlocillin - Piperacillin
Piperacillin/tazobactam
They have the broadest-
spectrum of all penicillins
especially on Pseudomonas
aeruginosa
9. Group Examples Spectrum of action
2-
Cephalosporins:
1st generation
Cefadroxil - Cefazolin - Cephalexin
Cephalothin - Cephradine
Gram (+ve) & few Gram (–ve) e.g.
E. coli, Klebsiella
2nd generation Cefaclor – Cefamandole - Cefmetazole,
Cefoxitin - Cefoprzil - Cefuroxime
More G (–ve) e.g. Klebsiella,
Proteus, less on (G+ve)
3rd generation Cefixime – Cefoprazone - Cefotaxime,
Ceftazidime - Ceftriaxone
Pseudomonas & Enterobacter.
- TTT of HAIs.
4th generation Cefepime upon G (+ve) & G (-ve)
organisms, including
P. aeruginosa
10. Other cell wall inhibitors:
Group Examples Spectrum of action
3- Carbapenems Imipenem - Meropenem
Etrapenem - Doripenem
broad-spectrum of activity
(MSSA- Pseudomonas).
4- Glycopeptides Vancomycin
Bacitracin
Teicoplanin
MRSA
5- Monobactams Aztreonam Aerobic Gram-negative
microorganisms
N.B. - Beta-Lactam Antimicrobials include: PENICLLINS, CEPHALOSPORINS,
CARBAPENEMS, MONOBACTAMS.
- All Beta-Lactam Antimicrobials are generally Bactericidal on bacteria.
11. 2- Interference with cell membrane function
• This group includes some antibacterial agents e.g. polymyxin B
and colistin, and antifungal agents e.g. amphotricin B, imidazoles
and nystatin.
12. 3-Inhibition of bacterial protein synthesis
Group Examples Mechanism of action Effect bacteria
Aminoglycosides Streptomycin - Neomycin,
Kanamycin - Tobramycin,
Netilimicin - Amkacin
Irreversible binding to 30S
ribosomal subunit
Bactericidal
Tetracyclines Tetracycline - Oxytetracycline
Demeclocycline – Doxycycline
Minocycline
Reversibly bind to 30S
subunit
Bacteriostatic
(Chlamydia &
rickettsia)
Glycocyclines
(30S= TAGG)
Tigecycline Binds to 30S ribosomal
subunit.
Bacteriostatic
(mostly)
(for MRSA, GISA,
ESBL, and VRE)
13. Group Examples Mechanism of action Effect bacteria
Chloramphenicol Chloramphenicol Binds 50S and inhibits
peptidyl transferase
Bacteriostatic
Clindamycin Clindamycin Binds to 50S Bacteriostatic
(Anaerobes)
Macrolides Erythromycin, azithromycin,
clarithromycin Dirthromycin,
Troleandomycin
Bind to the 50S subunit
inhibiting RNA-
dependent protein
synthesis.
Bacteriostatic or
Bactericidal
Ketolides Telithromycin Binds to the 50S subunit. Bacteriostatic or
Bactericidal
Inhibitors of protein synthesis (continue
14. Group Examples Mechanism of action Effect bacteria
Oxazolinones Linezolid Binds to the 50S subunit Bacteriostatic or
Bactericidal
(for VRE, MSSA and
MRSA)
Streptagramins Quinupristin-dalfopristin
(Synercid)
binding to the 50S
ribosomal subunit of
gram + bacteria
Bactericidal
Cyclic lipopeptides Daptomycin Not completely
understood, but alters
cell membrane activity
Bactericidal
Inhibitors of protein synthesis (continue)
15. 4- Inhibition of nucleic acid synthesis
Group Examples Mechanism of
action
Effect on bacteria
Fluoroquinolone (1st) Nalidixic acid
(2nd)–Ciprofloxacin - Levofloxacin
Norfloxacin - Ofloxacin
(3rd)–Gatifloxacin
(4th)–Trovafloxacin
Inhibit DNA gyrase Bactericidal
Sulfonamides Sulfisoxazole - Sulfamethoxazole,
Sulfadiazine - Sulfadoxine,
Sulfasalazine - Sulfapyridine
Inhibit folic acid
(FA) synthesis.
Bacteriostatic
16. Group Examples Mechanism of action Effect on bacteria
Trimethoprim Trimethoprim Inhibit dihydrofolate reductase
enzyme
Bacteriostatic
Bactericidal if combined
with sulfa
Cyclic
lipopeptides
Daptomycin Not clearly understood,
disruption of DNA, RNA and
protein synthesis
Bactericidal
Natural
For MRSA & VRE
Rifamycins Rifampin,
Rifabutin,
Rifapentine.
Inhibiting RNA by binding to
DNA-dependent
RNA polymerase
Bactericidal
(Antibiotics)
TTT of TB
Inhibitors of nucleic acid synthesis (continue).
17. Mechanisms of antimicrobial drug resistance
Classification:
• The resistance of microorganisms to antimicrobials is classified
as being either natural or acquired.
• 2.3.2.1 Natural resistance
• An organism is termed as having natural (intrinsic) resistance
when it has an inherent resistance to the action of an
antibiotic; this pattern of resistance is common to all isolates
of the species, e.g. the resistance of Escherichia coli to
macrolides and the resistance of Pseudomonas aeruginosa to
most drugs.
18. • The intrinsic (natural) resistance of a microorganism to an
antimicrobial is explained by the absence or inaccessibility of
the target of the drug action, e.g. Gram-negative bacteria are
naturally resistant to some antibiotics e.g. erythromycin due to
the non-permeability of the outer membrane
19. Acquired resistance
• Acquired resistance is developed to an antibiotic to which the
microorganism was previously susceptible; it develops within one
or more isolates of the species, i.e. not all strains of a species are
resistant.
• For an antimicrobial to produce its intended action, it has to have
a target for its action (e.g. in the form of an enzyme or protein)
within the bacterial cell, to be able to reach this target, and also
to reach the target in its active form, i.e. not having been
destroyed.
The functional mechanisms of acquired resistance
20. What bacteria can do to combat antimicrobials?
• 1) they may destroy or inactivate the antibiotic;
• 2) bacteria can use an efflux system to exclude the drug from its
interior ;
• 3) bacteria can produce alterations in the target site used by
antimicrobials to act or they may completely prevent this binding;
• 4) bacteria can reduce their cell surface permeability or even
completely block the entrance of the antimicrobial to the cell, so
that the antimicrobial can no longer act; and
• 5) bacteria can produce a bypass mechanism by using alternative
pathways which are different from those inhibited by the antibiotic
21. Different mechanisms of antimicrobial resistance
used by bacteria
Mechanism Examples of affected antimicrobials
1- Destruction, modification, or
inactivation of the antimicrobial.
- β-lactam antibiotics - Chloramphenicol
- Aminoglycosides
2- Multidrug efflux pumps. -Tetracycline
3- Target site alteration. -β-lactam antibiotics - Chloramphenicol
- Streptomycin - Quinolones
- Fusidic acid - Erythromycin
– Glycopeptides - Rifampicin
22. Different mechanisms of antimicrobial resistance
used by bacteria
Mechanism Examples of affected antimicrobials
4- Reduction in the cell surface
permeability or access of the
antimicrobial to the cell interior.
Tetracyclines - Quinolones
β-lactam antibiotics
Aminoglycosides - Chloramphenicol
5- New metabolic bypass
mechanism.
Trimethoprim - Sulphonamides
23. The basis (mechanism) of antimicrobial resistance
• A-Passive (intrinsic or phenotypic) drug resistance:
• bacteria stop multiplying they are not affected by the
antimicrobial; Mycobacterium tuberculosis, where “persister”
• L-form bacteria, which lack the cell wall which is the target for
action by some antimicrobials like penicillins and cephalosporins;
this is sometimes termed “phenotypic tolerance” rather than
resistance
24. B-Active drug resistance:
• Attributed to the emergence or acquisition of a new gene(s) which
controls the process of resistance either following mutation, which
may be spontaneous or induced, or by the transfer of a gene from
another bacterium or another locus within the same bacterium by
the process of transposition
25. 1- Mutation
• Mutation is a heritable change in the structure of the genes which
may arise spontaneously as an error of replication.
• Due to UV light, radiation, or alkylating agents
• Termed chromosomal resistance, as it usually originates in a
chromosome as a spontaneous mutation in a locus responsible for
the antimicrobial drug action.
• May arise by insertion or deletion of nucleotide(s).
26. Examples of Mutations:
1-Mutation producing a single amino acid change in the PBPs
gives low level resistance to penicillins and cephalosporins.
2-Mutations in the 23S ribosomal RNA gene also lead to
linezolid-resistant strains of VRE and MRSA,
27. Mobile Genetic Elements (carriers of antimicrobial
resistance genes (ARGs)) from one species to another??)
• Spread of antimicrobial resistance genes (ARGs) among, human,
animal, and environmental bacteria is mediated through this
mobile genetic elements (MGEs).
• The MGEs include: conjugative plasmids, gene cassettes within
the integrons, plasmids, transposons, and Insertion Sequence (IS)
elements
2- Gene Transfer
28. 1- Conjugative plasmids
• Conjugative plasmids are those having the ability to transfer
themselves and other plasmids from one bacterial cell to
another carrying ARGs present in both Gram positive and Gram
negative bacteria.
• Spread of conjugative plasmids can occur at narrow or wide
range of species.
29. 2- Integrons
• Integrons, which are present naturally as gene expression elements
as they contain open reading frames (ORFs) enabling them to
express the genes it contains, are formed from two conserved
flanking regions which incorporate one or more resistance gene(s)
in-between.
3-Gene cassettes
• The mobile genetic elements (MGEs) within the integrons are
known as the genetic cassettes. Many identified genetic cassettes
are known and have been identified that mediate resistance to
several antimicrobials e.g. penicillins, cephalosporins,
aminoglycosides, chloramphenicol, and trimethoprim.
30. 4- Insertion sequences and transposons
• The simplest transposable DNA sequences are known as the
insertion sequence (IS) elements. They are a heterogeneous class
of MGEs in bacteria, having the ability to promote their own
translocation and do not carry antimicrobial resistance genes
(ARGs).
• Transposons are mobile genetic elements which contain self-
transmissible elements, including transposase and recombination
DNA segments (e.g. ARGs).
31.
32. Slide comment for the figure:
• Transposable DNA elements: a) the insertion sequence (IS) elements which are
the simplest transposable DNA sequences, having reversed identical sequences
(inverted repeats: IR) of 10-40 nucleotides at both ends flanking the
transposase (tnp) gene. The direct repeats formed from 5-9 bp at the
extremities of the structure are the target for the enzyme transposase during
the integration process; b) the simple Tn3 transposons containing the
transposase gene tnpA, regulator sequence (tnpR) and the (res) site to which
the resolvase enzyme binds; c) the composite transposons which are formed
from two IS elements making a frame for a region which is not essential for
transposition e.g. tetracycline resistance gene (tetB); d) represents the
conjugative transposons which have certain segments encoding factors used in
the control of the transfer (Tra) and transposition (Tn) processes
33. Horizontal (lateral) gene transfer (HGT)
• Gene transfer between different bacteria occurs through one of
three mechanisms: conjugation, transformation, or transduction.
Conjugation is the most frequent mechanism mediated in HGT.
1- Conjugation
• Conjugation is the process of gene transfer between bacteria
from the donor to the recipient via intimate contact, termed
“mating through a channel”.
• The transposable DNA elements include the insertion sequences
(IS) and the different forms of tranposons (simple, composite,
and conjugative transposons).
34. Transfer of a conjugative plasmid by the process of conjugation between two bacterial
cells via the sex pili: a) formation of the conjugation channel, b) start of the transfer of
a single strand of the plasmid cleaved by the endonuclease enzyme at a specific point,
c) the cleaved strand entering the recipient cell where d) a complementary strand is
synthesized
35. 2- Transformation
• Bacteria can take exogenous DNA (genes) from the surrounding
environment. This ability to take exogenous genes is called competence
and it is encoded by chromosomal genes within the bacterium, and it is
mostly a time-limited process and occurs in a wide variety of bacteria
e.g. Hemophilus, Helicobacter, Campylobacter, Niesseria, Staphylococci,
and Pseudomonas species.
• Transformation can occur as natural process or can by induced by
certain factors e.g. nutrient access, altered growth conditions, or
starvation.
• Antimicrobial resistant gene (ARG) transfer is the natural one which can
transmit resistance gene among different bacterial strains. The DNA is
up taken as double stranded one which then converted to one strand
while passing the inner membrane.
36. 3- Transduction
• In transduction, the bacterial genes are transferred between
different bacterial strains by the means of bacteriophage, which is
a bacteria infecting virus.
• The phage for transfer must be the temperate (Lysogenic) one and
not the lytic phage.
N.B. Transposition
• In transposition, a DNA segment (mobile genetic element) can
move either to another locus in the same molecule (chromosome
or plasmid) or transfer between them i.e. inside the cell not
involved in HGT.
37. Schematic representation of different gene transfer mechanisms in bacteria: A= transformation, B= Transduction, and C=
Conjugation
38. Source of Resistant Bacteria
• Large amounts of antibiotics are used for human therapy, as well
as for farm animals and even for fish in aquaculture, resulted in
the selection of bacteria resistant to multiple drugs.
• These environmental resistant bacteria carry great harm to human
beings when genes are transferred to clinical isolates by HGT.
• MDROs are those resistant to more than 2 classes of
antimicrobials!!.
• Examples of MDROs include: MRSA, ESBLs, VRE,
• Pan-Resistant organisms are isolated nowadays resistant to all
available antimicrobials.
• Going to the pre-antibiotic era is the actual threat.
41. Example of
MDROs
Resistant to: Treatment
MRSA Penicillins, Cephalosporins, Monobactams,
Carbapenems. (additionally to aminoglycosides,
macrolides, tetracycline, chloramphenicol, and
lincosamides).
Vancomycin,
Linezolid,
ESBLs Penicillins, cephalsporins, Monobactams. Synercid,
Tigecyclines,
VRE, VRSA
& VISA
Penicillins, Cephalosporins, Monobactams,
Carbapenems, Vancomycin.
Linezolid
PDROs All available antimicrobials Colistin ??
CRE imipenem, meropenem, doripenem, or ertapenem
(Escherichia coli, Klebsiella oxytoca, Klebsiella
pneumoniae, or Enterobacter)
42. CDC definitions of MDROs
• MRSA: Includes S. aureus cultured from any specimen that tests
oxacillin-resistant, cefoxitin-resistant, or methicillin-resistant by
standard susceptibility testing methods (AST) OR, positive FDA
approved direct testing from sampling (e.g. PCR) for MecA gene.
• VRE: Enterococcus faecalis, Enterococcus faecium, or Enterococcus
species unspecified that is resistant to vancomycin, by standard
susceptibility testing methods (AST) or by direct testing by FDA
approved test e.g. PCR for genes (VanA, VanB, VanC).
43.
44. • CRE (Carbapenem-Resistant Enterobacteria): Any Escherichia
coli, Klebsiella oxytoca, Klebsiella pneumoniae, or Enterobacter
spp. testing resistant to imipenem, meropenem, doripenem, or
ertapenem by standard susceptibility testing methods (AST). OR
by production of a carbapenemase (i.e., KPC, NDM, VIM, IMP,
OXA-48) genes by PCR.
45. • MDR-Acinetobacter: Any Acinetobacter spp. testing non-
susceptible (i.e., resistant or intermediate) to at least one
agent in at least 3 antimicrobial classes of the following 6
antimicrobial classes:
Antimicrobial
class
β-lactam/β-lactam β-
lactamase inhibitor
combination
Aminoglycosides Carbapenems
Representatives Piperacillin
Piperacillin/tazobactam
Amikacin
Gentamicin
Tobramycin
Imipenem
Meropenem
Doripenem
Antimicrobial
class
Fluoroquinolones Cephalosporins Sulbactam
Representatives Ciprofloxacin
Levofloxacin
Cefepime
Ceftazidime
Ampicillin/sulbact
am
46. Burdens of MDROs Problem
1- Antimicrobial resistance kills (no treatment).
2- Antimicrobial resistance hampers the control of infectious
diseases.
3- Antimicrobial resistance increases the costs of health care.
4- Antimicrobial resistance jeopardizes health care gains to
society.
47. MDRO Prevention and Control
1. Administrative support: (Financial and HR, communication
system, HH facilities, staff levels, adherence to IPC
recommendations).
2. Education: Facility-wide, unit-targeted, and informal, educational
interventions.
3. Judicious use of antimicrobial agents: (antimicrobial stewardship
program). Use narrow spectrum, treat only infections not
contaminant or colonizers, duration limited, restricted Abs
validation).
48. Control of MDROs Spread:
4. MDRO surveillance: (new pathogen, trends, effective
interventions, by either reviewing micro lab results or by Active
Surveillance Culture/Testing (ASC/AST) to detect colonization.
• Antibiograms (simplest for of MDROs surveillance).
• MDRO Infection Rates reviews
• Molecular typing of MDRO isolates.
• Surveillance for MDROs by Detecting Asymptomatic Colonization
(great impact up to 65% reduction of spread ).
49. Methods for obtaining ASC/AST:
• MRSA: Studies suggest that cultures of the nares.
• VRE: Stool, rectal, or perirectal swabs.
• MDR-GNBs: peri-rectal or rectal swabs + oro-pharyngeal,
endotracheal, inguinal, or wound cultures.
• Rapid detection methods: (media containing chromogenic enzyme
substrates – real-time PCR-based tests for MRSA from swabs, vanA
and vanB genes (VRE or VRSA) from rectal swabs).
50. 5. Infection Control Precautions: (Standard and Contact isolation
Precautions for MDROs, Hand hygiene) .
• Cohorting and other MDRO control strategies: (cohorting of
patients, cohorting of staff, use of designated beds or units, unit
closure are necessary for control of transmission.
• Duration of Contact Precautions: controversial. 3 negative swabs,
better for all period of stay in facility.
• Barriers used for contact with patients infected or colonized with
MDROs: (gloves with or without gowns, .
• Impact of Contact Precautions on patient care and well-being:
(adverse effects).
51. 6. Environmental measures e.g. surfaces and medical equipment,
environmental cultures are not recommended routinely, .
• Stick to proper environmental , surfaces, and equipment
cleaning).
7. Decolonization: (treat colonized persons with MRDOs to
eradicate them e.g. MRSA, little success in VRE).
52. Stop the Abuse of Antimicrobials
Follow antimicrobial Policy and
stewardship program in
hospitals.
59. If the world does not cooperate
together fighting microbial
resistance, then all these drugs
will have no value.
Eventually we will go to the pre-
antibiotic era.