OF (Oxidation-Fermentation) test is a biochemical test used to find out how a bacterium utilize carbohydrate (mainly glucose). It was developed by Hugh and Leifson (1953). It differentiates organisms into fermentative type and oxidative type based on acid production in anaerobic and aerobic condition. It is done in a semi-solid OF medium having high carbohydrate … Read more
Pyruvate Broth Test is a biochemical test used to determine the ability of a bacterium to utilize pyruvate as a carbon and energy source. It is done in a carbohydrate-free broth medium containing sodium pyruvate. The medium contains an indicator (bromothymol blue) which gives greenish-blue colour initially. If the organism metabolizes pyruvate, organic acids are … Read more
Phenylalanine Deaminase Test (PDA test) is a biochemical test used to detect the enzyme phenylalanine deaminase produced by some bacteria. It is used to identify and differentiate gram-negative enteric bacteria, mainly the Proteeae group from other Enterobacteriaceae. In this test, the organism is grown on a medium containing phenylalanine. If the enzyme is present, phenylalanine … Read more
The Bacitracin susceptibility test is one of the antimicrobial disc tests used to distinguish between group A and other -hemolytic Streptococci.
Streptococcus pneumoniae can be distinguished from other viridans streptococci by showing that it is sensitive to optochin, dissolves in bile, reacts with a specific DNA probe, or has species-specific capsular polysaccharides.
The SXT (sulfamethoxazole-trimethoprim) susceptibility test tells the difference between group A and B streptococci and other hemolytic streptococci.
illon’s test can be described as an analytical test for the identification that the amino acid tyrosine which is the sole amino acid with the phenolic group.
Bial’s test is a chemical test used for detection of pentoses (5-carbon sugars) and it is used to distinguish pentoses from hexoses. It was developed by German physician Manfred Bial. It is also used in laboratory for estimation of RNA because RNA contains pentose sugar ribose. It works on principle of acid dehydration of sugars. … Read more
Many bacteria produce a group of enzymes known as beta-lactamases that are mediated through genes in plasmids or the chromosomes. Beta-lactamase can be a constant process or it may be triggered through contact with antimicrobials. Beta-lactamases hydrolyze (and consequently inhibit) the beta-lactam ring of many Cephalosporins as well as penicillins. Beta-Lactamase Test is a rapid test to determine the presence of beta-lactamase , an enzyme that is produced by the strains from Staphylococcus aureus Neisseria gonorrhoeae, Branhamella catarrhalis as well as Haemophilus influenzae.
The nitrocefin biochemical test is a sensitive technique for detecting beta-lactamase-producing strains of N. gonorrhoeae, H. influenzae, Staphylococcus spp, Enterococcus spp, and Moraxella (Branhamella) catarrhalis. Nitrocefin is the only reliable test for detecting beta-lactamase-producing Enterococcus spp.
