This document discusses urine culture and sensitivity testing. It describes how microbiological culture is used to multiply microorganisms to determine what types are present in a sample. Sensitivity testing checks the effectiveness of drugs against microorganisms to select the best treatment. Urine culture and sensitivity testing aims to guide treatment selection, control inappropriate drug use, and monitor antimicrobial resistance in a community. It provides details on performing semi-quantitative urine cultures and antibiotic sensitivity testing methods like Kirby-Bauer and Stokes techniques.

1. URINE CULTURE & SENSITIVITY
SUNIL KUMAR.P
Haematology & Transfusion Medicine
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3. MICROBIOLOGY…….
• Microbiology is the study of living organisms
that are invisible to the naked eye, such as ……
• Bacteria
• Virus
• Fungi
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4. Microbiological Culture
• It is a method of multiplying microbial
organisms by letting them reproduce in
predetermined culture media under
controlled laboratory conditions.
• Microbial cultures are used to determine the
type of organisms and its abundance in the
sample being tested or both
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5. Sensitivity Test………
• A laboratory test perform to check the
effectiveness of a drug against microorganisms
to select the best drug regimen that is
effective..
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6. Purpose of culture & sensitivity test
• To guide the clinician selecting the best drug
for an individual patient.
• To control the use of inappropriate drug in
clinical practice.
• To accumulate epidemiological information on
the resistance of microorganism of public
Health importance within the community.
• To overcome the microbial drug resistance.
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7. Culture
• Semi-Quantitative cultures are done…. on
blood agar and Agar with a calibrated loop.
• Colony count of 105/ml is considered
significant.
• Counts between 104/ml and 105 ml are of
doubtful significance.
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8. • Counts less than this are considered
significant if :….
• The patient is on prior antibiotics
• There is obstruction in the urinary tract
• A fungal infection is present
• If pyelonephritis is present
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9. Antibiotic sensitivity Testing….
• If culture is suggestive of infection, an
antibiotic sensitivity test is done.
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10. Types of Antibiotic sensitivity test
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11. Kirby-Bauer
• This is in common use
• In this method a suitable dilution of broth
culture or a broth suspension of the test
bacterium is inoculated on the surface of solid
medium ( MHA- Mueller-Hinton or Nutrient
Agar) as a lawn by spreading with cotton
swab.
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12. • After overnight incubation, the degree of
sensitivity is determined by measuring the
zones of inhibition of growth around the discs.
• Growth will be inhibited around discs
containing antibiotics to which the bacterium
is susceptible but not around those to which it
is resistant.
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14. Stokes method
• This is suitable method for routine diagnostic
use in diagnostic laboratories.
• This technique was originally described by
stokes.
• This incorporates built-in controls against
many variables and therefore provides depend
results.
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15. Dilution tests
• Here, serial dilution of the drug are prepared
and inoculated with the test bacterium.
• This is too laborious for routine use.
• Dilution tests are generally employed when
the therapeutic dose is to be regulated
accurately as in the treatment of bacterial
endocarditis.
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