An antibiogram is a summary of antimicrobial susceptibility testing results for a specific microorganism against a range of antimicrobial drugs. It provides the percentages of organisms tested that were susceptible to each drug. Antibiograms help clinicians select appropriate empirical antimicrobial treatment and allow healthcare facilities to monitor antimicrobial resistance trends over time. They have limitations as they do not show subtle resistance trends below thresholds or account for synergistic drug combinations.

1. {
ANTI BIOGRAM
U. Monika
I – M.Sc Bio-Chemistry

2. ABOUT ANTIBIOGRAMS
“ ANTI MICROBIAL SUSCEPTIBILITIES OF
SELECTED PATHOGENS “
DEFINITION :
An Antibiogram is an overall profile of
antimicrobial susceptibility testing results of a specific
microorganism to a battery of antimicrobial drugs
Stable typing method, but lacks
discriminatory power.

3.  This profile is generated by the laboratory using
aggregate data from a hospital or health care system.
 Data are summarized periodically and presented
showing percentages of organisms tested that are
susceptible to a particular antimicrobial drug.
 Only results of antimicrobial drugs that are routinely
tested and clinically useful should be presented to
clinicians

4.  An antibiogram is the result of an antibiotic
sensitivity test. It is by definition an in vitro
sensitivity, but the correlation of in vitro to in vivo
sensitivity is often high enough for the test to be
clinically useful.
WHAT DOES ANTI BIOGRAM MEAN
A laboratory procedure in which samples of
bacteria are treated with a variety of antibiotics.

6. MEDICAL DEFINITION OF ANTIBIOGRAM
A collection of data usually in the form
of table summarizing the percent of individual bacterial
pathogens susceptible to different antimicrobial agents.
 An antibiogram is generated after bacteria are
isolated and subjected to laboratory testing.
 Local hospitals offer more directed help to their
physicians by creating antibiograms, or tables that
chart the resistance patterns with a specific facility.

7. ANTIBIOGRAM USES
Antibiogram help to guide the clinician and
pharmacist in selecting the best empiric antimicrobial
treatment in the event of microbiology culture and
susceptibility results.
They are also useful tool for detecting and
monitoring trends in antimicrobial resistance.
When antimicrobial susceptibility testing
data are summarized cumulatively for a hospital,
healthcare system, or other healthcare facility
periodically, trends in resistance can be identified and
investigated.

8. The present study recorded the results of
antibiogram as follows :
1) SAMPLE CLASSIFICATION
2) ISOLATION AND IDENTIFICATION
OF BACTERIA FROM URINE SAMPLE
3) ANTIBIOTIC RESISTANCE STUDIES

9. EXAMPLE OF ANTIBIOGRAM

10. LIMITATIONS OF ANTIBIOGRAM
While the antibiogram is useful it should
not be relied upon as the sole tool for guiding therapy.
 Minimum inhibitory concentrations ( MICs )
are not included; as a result subtle trends below the
resistance threshold (known as “MIC creep”) are
not reflected.
 Can’t distinguish between true infection and
colonization.

11.  Data are the result of single organism –
antimicrobial combinations, therefore do not show
trends in cross – resistance of an organisms to other
drugs , nor do they reveal synergistic properties of
antimicrobials used in combinations.
 Data may not be generalizable to specific
patient populations or locations of a health care
facility if the antibiogram is compiled using hospital
or healthcare system wide data.

12. CONCLUSION
The Clinical and Laboratory
Standards Institute ( formerly NCCLS ) recommend
that antibiogram is compiled mainly by
microbiology laboratories technologists , but may be
a collaborative effort involving the lab , pharmacy ,
infection preventionists , and clinicians
Easy to prepare, easy to disseminate
and easy to use.