The document discusses antimicrobial susceptibility testing (AST), including the reasons it is performed, factors considered in determining if testing is warranted, selecting antimicrobial agents for testing, definitions, methods of testing, quality control, multidrug resistant bacteria (superbugs), and references. AST is performed to guide physician selection of effective antibacterial therapy, and involves testing isolated bacteria against a battery of antimicrobial agents using standardized methods to determine susceptibility. Results are reported as susceptible, intermediate, or resistant based on interpretive criteria. Automated systems have increased reproducibility of AST. Controlling superbugs requires recognizing and reporting resistant isolates, contact precautions, proper antimicrobial use, and hand hygiene.
The use of a machine designed to follow repeatedly and automatically a predetermined sequence of individual operations.
AUTOMATED WASHING
AUTOMATED MEDIA PREPARATORS
AUTOMATED COLLECTION AND
PROCESSING OF SAMPLES
CYTOSPIN
AUTOMATED GRAM STAINING
AUTOMATED STREAKING
SPIRAL PLATER
AUTOMATED ANTIBIOTIC -
SENSITIVITY SYSTEM
AUTOMATIC COLONY COUNTER
AUTOMATED URINE MICROSCOPY -
ANALYSER
beta lactamases : structure , classification and investigationsDr Taoufik Djerboua
this is a simple introduction to the world of beta lactamase enzymes that i had the chance to present during my observership in turkey. it bears some introductive notions necessary to the unverstading of the function fo these enzymes and some tests usually used to invistigate bacteria producing these enzymes. the pictures were taken from Microbe-edu.com Bush et al classification of Beta lactamase, the EUCAST and CLSI recommandation for susceptibility testing documents.
The use of a machine designed to follow repeatedly and automatically a predetermined sequence of individual operations.
AUTOMATED WASHING
AUTOMATED MEDIA PREPARATORS
AUTOMATED COLLECTION AND
PROCESSING OF SAMPLES
CYTOSPIN
AUTOMATED GRAM STAINING
AUTOMATED STREAKING
SPIRAL PLATER
AUTOMATED ANTIBIOTIC -
SENSITIVITY SYSTEM
AUTOMATIC COLONY COUNTER
AUTOMATED URINE MICROSCOPY -
ANALYSER
beta lactamases : structure , classification and investigationsDr Taoufik Djerboua
this is a simple introduction to the world of beta lactamase enzymes that i had the chance to present during my observership in turkey. it bears some introductive notions necessary to the unverstading of the function fo these enzymes and some tests usually used to invistigate bacteria producing these enzymes. the pictures were taken from Microbe-edu.com Bush et al classification of Beta lactamase, the EUCAST and CLSI recommandation for susceptibility testing documents.
definitions and description of the main procedures used for antimicrobial susceptibility testing; to support teaching general medicine students in their second year of study
A study of antibiotic resistance of Extended-Spectrum Beta-Lactamases produci...Premier Publishers
Background: Extended-Spectrum Beta-Lactamases - producing Enterobacteriaceae are common in hospitals. This study aims to describe the antibiotic resistance of these bacteria and their associated demographic and clinical factors. Methods: It was a prospective study of 73 isolates of Extended-Spectrum Beta-Lactamases - producing Enterobacteriaceae for a period of six months from July to December 2019 in the laboratory of Befelatanana. Results: This study showed 73 (6.3%) isolates of Extended-Spectrum Beta-Lactamases- producing Enterobacteriaceae, represented by 25 (34.2%) isolates of Klebsiella spp, 24 (32.9%) isolates of Escherichia coli, 22 (30.1%) isolates of Enterobacter spp and 2 (2.7%) isolates of Proteus spp. The antibiotic resistance of these bacteria varied from 0% to 100% for all of the antibiotics tested. Resistance to aminoglycosides ranged from 0% (amikacin) to 69.9% (gentamycin). Resistance to quinolones ranged from 43.8% (levofloxacin) to 76.7% (nalidixic acid). Similarly, 60 (82.2%) isolates were resistant to cotrimoxazole and 25 (34.2%) isolates to chloramphenicol. Patients under 20 years (57.1%) (p=0.03), men (52.2%)(p=0.11; NS), patients with respiratory samples (83.3%)(p=0.004), with pus (61.9%)(p=0.02) and hospitalized in surgery and intensive care units (68.4%)(p=0.0009) were the most affected by these enterobacteria. Conclusion: Extended-Spectrum Beta-Lactamases - producing Enterobacteriaceae are responsible for severe infections and the majorities are multi-resistant bacteria.
Keywords: Beta-lactamase, Enterobacteriaceae, antibiotic resistance, amikacin, imipenem.
Multidrug Resistance Pattern of Staphylococcus Aureus Isolates in Maiduguri ...Scientific Review SR
Multi drug-resistant (MDR) isolates of Staphylococcus aureus are on rise and are becoming a
challenge for timely and appropriate treatment. The present study was carried out with an objective to isolate
Staphylococcus aureus from clinical samples and determine their sensitivity. Out of 110 samples collected, 44
were shown to contained S. aureus. The isolates were subjected to antibiotic sensitivity tests using 10 different
and commonly used antibiotics by modified Kirby- Bauer disc diffusion technique. Out of the total isolates (42)
tested, only 7.1% were susceptible to all the antibiotics. Multiple resistance was eminent in over 92% with
highest occurrence in 4.8% where the entire antibiotics were resisted. Multiple antibiotic resistance indixes
(MAR index) indicated that 0.6 index occurred most (23.8%) followed by 0.5 (19.0%). On the other hand, 0.1
and 0.8 indexes were the lowest with 0.0% and 1.0% occurrence respectively. Ciprofloxacin was resisted by
most of the organisms (64.3%) while amoxicillin (64.3%) and streptomycin (61.9%) were most efficacious. With
over 90% isolate having MAR index ≥ 0.2, the multiple drug resistance by the S. aureus is quite alarming and
might suggest inappropriate antibiotic usage by the sampled population. Therefore, the need to strategize the
nature of antibiotic treatment against S. aureus and massive campaign on indiscriminate antibiotic use is urgent.
Multidrug Resistance Pattern of Staphylococcus Aureus Isolates in Maiduguri M...Scientific Review
Multi drug-resistant (MDR) isolates of Staphylococcus aureus are on rise and are becoming a challenge for timely and appropriate treatment. The present study was carried out with an objective to isolate Staphylococcus aureus from clinical samples and determine their sensitivity. Out of 110 samples collected, 44 were shown to contained S. aureus. The isolates were subjected to antibiotic sensitivity tests using 10 different and commonly used antibiotics by modified Kirby- Bauer disc diffusion technique. Out of the total isolates (42) tested, only 7.1% were susceptible to all the antibiotics. Multiple resistance was eminent in over 92% with highest occurrence in 4.8% where the entire antibiotics were resisted. Multiple antibiotic resistance indixes (MAR index) indicated that 0.6 index occurred most (23.8%) followed by 0.5 (19.0%). On the other hand, 0.1 and 0.8 indexes were the lowest with 0.0% and 1.0% occurrence respectively. Ciprofloxacin was resisted by most of the organisms (64.3%) while amoxicillin (64.3%) and streptomycin (61.9%) were most efficacious. With over 90% isolate having MAR index ≥ 0.2, the multiple drug resistance by the S. aureus is quite alarming and might suggest inappropriate antibiotic usage by the sampled population. Therefore, the need to strategize the nature of antibiotic treatment against S. aureus and massive campaign on indiscriminate antibiotic use is urgent.
Antibiotic resistance a global concern part iiRohan Jagdale
Bacteria, not humans or animals, become antibiotic-resistant. These bacteria may infect humans and animals, and the infections they cause are harder to treat than those caused by non-resistant bacteria.
Antibiotic resistance leads to higher medical costs, prolonged hospital stays, and increased mortality.
The world urgently needs to change the way it prescribes and uses antibiotics. Even if new medicines are developed, without behaviour change, antibiotic resistance will remain a major threat. Behaviour changes must also include actions to reduce the spread of infections through vaccination, hand washing, practising safer sex, and good food hygiene.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
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.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stockrebeccabio
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stock
Telegram: bmksupplier
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threema: TUD4A6YC
You can contact me on Telegram or Threema
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Free of customs clearance, Double Clearance 100% pass delivery to USA, Canada, Spain, Germany, Netherland, Poland, Italy, Sweden, UK, Czech Republic, Australia, Mexico, Russia, Ukraine, Kazakhstan.Door to door service
Hot Selling Organic intermediates
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
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
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.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
ACT antimicrobial susceptibility testing, inoculation and drug sensitivity
1. Prepared by Dr. Sadaf Konain Ansari
for 2nd
year BDS
AntimicrobialAntimicrobial
Susceptibility TestingSusceptibility Testing
(AST)(AST)
2. Reasons and Indications for
Antimicrobial Susceptibility Testing
(AST)
Goal
Offer guidance to physician in selecting effective
antibacterial therapy for a pathogen in a specific body
site
Performed on bacteria isolated from clinical
specimens if the bacteria’s susceptibility to
particular antimicrobial agents is uncertain
Susceptibilities NOT performed on bacteria that are
predictably susceptible to antimicrobials
Ex. Group A Strep
Dr.Sadaf Konain Ansari
3. Factors to Consider When
Determining Whether Testing is
Warranted
Body site of infection
Susceptibility not performed on bacteria isolated from body
site where they are normal flora
Ex. Susceptibility for E. coli is NOT performed when isolated
from stool, but IS performed when isolated from blood
Dr.Sadaf Konain Ansari
4. Factors to Consider When
Determining Whether Testing is
Warranted (cont’d)
Presence of other bacteria and quality of specimen
Ex. Two or more organisms grown in a urine
specimen
Host status
Immunocompromised patients
Allergies to usual antimicrobials
Dr.Sadaf Konain Ansari
5. Selecting Antimicrobial Agents for
Testing and Reporting
Clinical & Laboratory Standards
Institute (CLSI)
Develop standards, methods, QC parameters,
and interpretive criteria for sensitivity
testing
If necessary, can alter the breakpoints of
the SIR ( susceptible, intermediate,
resistant) based on emerging resistance
Dr.Sadaf Konain Ansari
6. Selecting Antimicrobial Agents
for Testing and Reporting (cont’d)
There are approximately 50 antibacterial agents
Follow CLSI recommendations
Each laboratory should have a battery of
antibiotics ordinarily used for testing
Drug formulary decided by medical staff,
pharmacists, and medical technologists
Dr.Sadaf Konain Ansari
7. Selection of Test Batteries
Generally, labs choose 10-15 antibiotics
to test susceptibility for GP organisms
and another 10-15 for GN organisms
Too many choices can confuse
physicians and be too expensive
Primary objective
Use the least toxic, most cost-effective, and most clinically
appropriate agents
Refrain from more costly, broader-spectrum agents
Dr.Sadaf Konain Ansari
8. Example of Drug Formulary
Drug Enterococcus Staphylococcus spp.
Ampicillin X
Cefazolin X
Clindamycin
Erythromycin X
Linezolid X X
Oxacillin X
Penicillin G X X
Rifampin X
Streptomycin-2000 X
Tetracycline X X
Trimeth/ Sulfa X
Vancomycin X X
Dr.Sadaf Konain Ansari
9. Example of Drug Formulary
Drug Enterobacteriaceae Ps. aeruginosa
Ampicillin X
Piperacillin/ Tazo. X X
Cefepime X X
Imipenem X X
Gentamycin X X
Tobramycin X X
Ciprofoxacin X X
Levofloxacin X X
Nitrofurantoin X
Trimethoprim/Sulfa X
Dr.Sadaf Konain Ansari
10. Definitions (important to remember)
Minimum inhibitory concentration(MIC)
Lowest concentration of an antimicrobial agent that
visibly inhibits the growth of the organism.
Minimum bactericidal concentration (MBC)
Lowest concentration of the antimicrobial agent
that results in the death of the organism.
Dr.Sadaf Konain Ansari
11. Definitions (cont’d)
Susceptible ”S”
Interpretive category that indicates an organism is
inhibited by the recommended dose, at the
infection site, of an antimicrobial agent
Intermediate “I”
Interpretive category that represents an organism
that may require a higher dose of antibiotic for a
longer period of time to be inhibited
Resistant “R”
Interpretive category that indicates an organism is
not inhibited by the recommended dose, at the
infection site, of an antimicrobial agent.
Dr.Sadaf Konain Ansari
13. Methods of Performing AST
Agar dilution method
Broth macrodilution / Tube dilution
Broth microdilution
Disk diffusion method
Gradient diffusion method (E-Test)
Dr.Sadaf Konain Ansari
14. Standardization of Antimicrobial
Susceptibility Testing
Inoculum Preparation
Use 4-5 colonies
NOT just 1 colony
Inoculum Standardization
using 0.5
McFarland
standard
Dr.Sadaf Konain Ansari
15. Methods of Performing AST
Agar Dilution
Dilutions of antimicrobial agent added
to agar
Growth on agar indicates MIC
Broth macrodilution/Tube Dilution Tests
Two-fold serial dilution series, each
with 1-2 mL of antimicrobial
Too expensive and time consuming
Microdilution Tests
plastic trays with dilutions of
antimicrobials
Dr.Sadaf Konain Ansari
16. Disk Diffusion/ Kirby- Bauer
Procedure
Use a well-isolated, 18-24 hour old
organism
Transfer organism to a broth
Either tryptic soy/sterile saline
Ensure a turbidity of 0.5 McFarland
Inoculate MH agar by swabbing in
three different directions “Lawn of
growth”
Place filter paper disks impregnated
with anitmicrobial agents on the agar
Invert and incubate for 16-18 hours
at35 o
C in non-CO2
Dr.Sadaf Konain Ansari
17. Disk Diffusion/ Kirby-Bauer (cont’d)
During incubation, drug
diffuses into agar
Depending on the organism and
drug, areas of no growth form
a zone of inhibition
Zones are measured to
determine whether the
organism is susceptible,
intermediate, or resistant to
the drug
Dr.Sadaf Konain Ansari
18. E- test/ Gradient Diffusion Method
“MIC on a stick”
Plastic strips
impregnated with
antimicrobial on one side
MIC scale on the other
side
Read MIC where zone
of inhibition intersects E
strip scale
Dr.Sadaf Konain Ansari
19. Automated
Antimicrobial Susceptibility Test
Methods
Detect growth in micro volumes of broth with
various dilutions of antimicrobials
Detection via photometric, turbi-dimetric, or
fluoro-metric methods
Types
BD Phoenix
Microscan Walkaway
TREK Sensititre
Vitek 1 and 2
Dr.Sadaf Konain Ansari
20. Automated
Antimicrobial Susceptibility Test Methods
Advantages
Increased reproducibility
Decreased labor costs
Rapid results
Software
Detects multi-drug resistances
ESBLs
Correlates bacterial ID with sensitivity
Disadvantages
Cost
Dr.Sadaf Konain Ansari
21. Quality Control in Susceptibility
Testing
Reflects types of patient isolates & range of
susceptibility
Frequency of quality control depends on
method, CLSI, or manufacturer
Reference strains of QC material
American Type Culture Collection(ATCC)
E. coli ATCC* 25922
S. aureus ATCC* 25923
Dr.Sadaf Konain Ansari
22. The Superbugs (important to remember)
Organisms resistant to previously effective drugs
MRSA
methicillin-resistant Staphylococcus aureus
mecA gene codes for a PBP that does not bind
beta-lactam antibiotics
Resistant to oxacillin
Vancomycin
VRE –Enterococcus species
VISA/VRSA- Staphylococcus aureus
Dr.Sadaf Konain Ansari
23. The Superbugs: The Beta-Lactamases
Gram negative rods that have genes on chromosomes that code for
enzymes against certain antimicrobials
ESBLs-extended spectrum beta lactamase
Resistant to extended spectrum cephalosporins, penicillins,
aztreonam
Examples: E. coli, Klebsiella
Carbapenemases (CRE)
Klebsiella pneumoniae- KPC- Class A
Class B (NDM, VIM, IMP)- metallo beta lactamases
Resistant to penicillins, cephalosporins, carbapenems, and aztreonam
Cephalosporinases
AmpC enzyme
inducible
“SPACE” organisms Dr.Sadaf Konain Ansari
24. Controlling the Superbugs
Lab’s Role
Recognize and report isolates recovered from
clinical specimens
Methods for identification include automated
systems and screening agars
Dr.Sadaf Konain Ansari
25. Controlling the Superbugs
Role of Health Care Workers/Facilities
Hand hygiene with the use of alcohol-based hand
rubs or soap and water after patient care
Contact precautions for patients identified as
colonized or infected with a superbug
Healthcare personnel education about the
methods of transmission, contact precautions,
and proper use of hand hygiene
Minimization of invasive devices (catheters, etc.)
Proper administration of antimicrobial agents
where therapy is selected for susceptible
organisms for the proper duration
Dr.Sadaf Konain Ansari
27. References
http://www.biomerieux-diagnostics.com/servlet/srt/bio/clinical-d
http://www.cdc.gov/std/gonorrhea/lab/diskdiff.htm
http://www.who.int/drugresistance/Antimicrobial_Detection/en/
Kiser, K. M., Payne, W. C., & Taff, T. A. (2011). Clinical
Laboratory Microbiology: A Practical Approach . Upper
Saddle River, NJ: Pearson Education.
Mahon, C. R., Lehman, D. C., & Manuselis, G. (2011).
Textbook of Diagnostic Microbiology (4th ed.).
Maryland Heights, MO: Saunders.
Murray, P. R. (2013, May). Carbapenem-resistant
Enterobacteriaceae: what has happened, and what is
being done. MLO, 45(5), 26-30.
Dr.Sadaf Konain Ansari
29. ESKAPEPathogens of Highest Concern The most serious, life-
threatening infections are caused by a group of drug-
resistant bacteria that the Infectious Diseases Society of
America (IDSA) has labeled the "ESKAPE" pathogens, because
they effectively escape the effects of antibacterial drugs
What are ESKAPE
Dr.Sadaf Konain Ansari
30. Minimum inhibitory concentration(MIC)
Lowest concentration of an antimicrobial agent that
visibly inhibits the growth of the organism.
Minimum bactericidal concentration (MBC)
Lowest concentration of the antimicrobial agent that
results in the death of the organism.
What stand for MIS, and MBC?
Dr.Sadaf Konain Ansari
Common Questions:
31. Susceptible ”S”
Interpretive category that indicates an organism is inhibited by the
recommended dose, at the infection site, of an antimicrobial agent
Intermediate “I”
Interpretive category that represents an organism that may require
a higher dose of antibiotic for a longer period of time to be inhibited
Resistant “R”
Interpretive category that indicates an organism is not inhibited by
the recommended dose, at the infection site, of an antimicrobial
agent.
What stands for S, I and R?
Dr.Sadaf Konain Ansari
Common Questions:
