CLINICAL MICROBIOLOGY

BIOCHEMICAL TESTS TO IDENTIFY BACTERIA:

 While several commercial systems for identifying
bacteria are available, these are often difficult to
obtain or too expensive to use in developing countries.
This subunit includes a range of conventional
biochemical tests and tablet identification tests which
most district laboratories will be able to perform.

The following tests are described in this part: 
Test                          Purpose
Beta-glucuronidase  To identify E. coli
Bile solubility:       To differentiate S. pneumoniae from other alpha-haemolytic streptococci
Catalase: To differentiate Staphylococci from  Streptococci
Citrate utilization :To differentiate Enterobacteria

Coagulase: To identify S. aureus
DNA-ase  To help identify S. aureus
Indole  To differentiate Gram
negative rods, particularly
E. coli
Litmus milk  To help identify
decolorization Enterococcus and some
clostridia
Lysine decarboxylase  To assist in the
identification of
salmonellae and shigellae
Oxidase   To help identify Neisseria,
Pasteurella, Vibrio,
Pseudomonas
Urease     To help identify Proteus,
Morganella, Y. enterocolitica, H. pylori



 Catalase Test:  This test is used to differentiate those bacteria that
produce the enzyme catalase, such as staphylococci,
from non-catalase producing bacteria such as streptococci.
Catalase acts as a catalyst in the breakdown of hydrogen
peroxide to oxygen and water. An organism is tested for
catalase production by bringing it into contact with hydrogen
peroxide. Bubbles of oxygen are released if the organism is a
catalase producer. The culture should not be more than 24 hour old culture. 

 Please visit these links: 
en.wikipedia.org/wiki/Catalase
www.microbelibrary.org/library/...test/3226-catalase-test-protocol‎

www.vumicro.com › Home › Reference Books › Biochemical Tests‎
learn.chm.msu.edu/vibl/content/catalase.htm




Cited By Kamal Singh Khadka
Assistant Professor in PU, Regional college Of Science & Technology, PNC, Novel Academy, Pokhara




  

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