Pyruvate Broth Test

Pyruvate Broth Test

Pyruvate Broth Test Objectives To determine the ability of an organism to utilize pyruvate. It aids in the differentiation between Enterococcus faecalis and Enterococcus faecium. Principle In the identification of microorganisms, the widely used method is the ability of bacteria to form organic compounds by metabolizing certain carbohydrates and related compounds. Pyruvate broth is a carbohydrate-free, … Read more Pyruvate Broth Test

Leucine Amino Peptidase (LAP) Test

Leucine Amino Peptidase (LAP) Test

Leucine Amino Peptidase (LAP) Test Objective To detect the presence of the enzyme leucine aminopeptidase for the preliminary characterization of catalase-negative, gram-positive cocci, especially non-beta-hemolytic cocci. Principle of Leucine Amino Peptidase (LAP) Test Leucine aminopeptidase (LAP) test is a rapid test for the detection of enzyme leucine aminopeptidase. In general, Streptococcus pneumoniae and Streptococcus pyogenes, … Read more Leucine Amino Peptidase (LAP) Test

Sulfur Reduction Test

Sulfur Reduction Test

Objectives To determine the ability of the organism to reduce sulfur for the production of hydrogen sulfide. To differentiate members of Enterobacteriaceae, especially the sulfur-reducing Salmonella and Proteus from the non-reducing Morganella morganii and Providencia rettgeri. Principle The Sulfur Reduction Test is performed using the SIM medium. SIM medium also tests for indole production and … Read more Sulfur Reduction Test

Salt Tolerance Test

Salt Tolerance Test

Salt Tolerance Test Objectives To determine the ability of an organism to grow in high concentrations of salt. It is used for the differentiation of Enterococci from Non-Enterococci. Principle Salt acts as a selective agent and interferes with membrane permeability and osmotic equilibrium. The salt tolerance medium is a selective and differential medium in which … Read more Salt Tolerance Test

Kligler Iron Agar Test

Kligler Iron Agar Test

Kligler Iron Agar Test Objective To differentiate the enteric gram-negative bacilli based on the production of hydrogen sulfide and fermentation of dextrose and lactose. Principle Kligler Iron Agar (KIA) test is used in differentiating certain members of the Enterobacteriaceae by demonstrating hydrogen sulfide production and the fermentation of dextrose and lactose. Kligler agar used for … Read more Kligler Iron Agar Test

Potassium hydroxide (KOH) test

Potassium hydroxide (KOH) test

Potassium hydroxide (KOH) test Objective To visualize the fungal element in the clinical specimens. To examine skin scrapings or flakes and hair for the presence of hyphae and arthroconidia in suspected dermatophyte infections. Principle Potassium hydroxide (KOH) can be used on clinical specimens to clear cellular material and for better visualization of fungal elements. KOH … Read more Potassium hydroxide (KOH) test

Nitrite Reduction Test

Nitrite Reduction Test

Nitrite Reduction Test Objective To determine the ability of an organism to reduce nitrites to gaseous nitrogen or to other compounds containing nitrogen. Principle Nitrate reduction by bacteria is mediated by nitrate reductase and indicates that the organism can use NO3– as an electron acceptor during anaerobic respiration and reduce nitrate to nitrite. Nitrite, on the … Read more Nitrite Reduction Test

Phenylalanine Deaminase Test

Result Interpretation of Phenylalanine Deaminase Test

Phenylalanine Deaminase Test Objectives of Phenylalanine Deaminase Test To determine the ability of an organism to oxidatively deaminate phenylalanine to phenylpyruvic acid. To differentiate enteric Gram-nega­tive bacilli on the basis of their ability to produce phenylpyruvic acid from phenylalanine. Principle of Phenylalanine Deaminase Test Phenylalanine deaminase medium tests the ability of an organism to produce the enzyme … Read more Phenylalanine Deaminase Test

Triple Sugar Iron Agar (TSIA) Test

Result Interpretation of TSIA Test

Triple Sugar Iron Agar (TSIA) Test Objectives of TSIA Test To determine whether a gram negative bacilli ferments glucose and lactose or sucrose and forms hydrogen sulfide (H2S). To differentiate members of the Enterobacteriaceae family from other gram-negative rods. Principle of TSIA Test The Triple Sugar Iron agar (TSIA) test is designed to differentiate among … Read more Triple Sugar Iron Agar (TSIA) Test

Casein Hydrolysis Test

Result of Casein Hydrolysis Test

Casein Hydrolysis Test Objectives of Casein Hydrolysis Test To determine the ability of the organism to degrade the casein protein. To differentiate the organism on the basis of production of exoenzyme proteinase (caseinase) Principle of Casein Hydrolysis Test Casein is a macromolecule composed of amino acids linked together by peptide bonds, CO-NH. Some microorganism have the ability … Read more Casein Hydrolysis Test

Bile Esculin Test

Bile Esculin Test

Bile Esculin Test Objectives of Bile Esculin Test To identify Enterococci and group D Streptococci based on the ability of an organism to hydrolyze esculin in presence of bile. To differentiates enterococci and group D streptococci from non–group D viridans streptococci. Principle of Bile Esculin Test Esculin is a glycoside (a sugar molecule bonded by an acetyl linkage … Read more Bile Esculin Test

Beta (β)-Lactamase Test- Objectives, Principle, Procedure and Results

Result Interpretation of Beta (β)-Lactamase Test

Objective of Beta (β)-Lactamase Test To detect the enzyme beta-lactamase, which confers penicillin resistance to various bacterial organisms. Principle of Beta (β)-Lactamase Test Various bacteria produce a class of enzymes called beta-lactamases, which may be mediated by genes on plasmids or chromosomes. Production of beta-lactamase may be constitutive or induced by exposure to antimicrobials. Beta-lactamases hydrolyze (and thereby inactivate) … Read more Beta (β)-Lactamase Test- Objectives, Principle, Procedure and Results

X and V Factor Test for Haemophilus

X and V Factor Test for Haemophilus

Objective of X and V Factor Test To differentiate among Haemophilus species based on X and V factor required for growth. Principle of X and V Factor Test Haemophilus spp. have varying requirements for X and V growth factors. X factor indicates hemin and V factor indicates nicotinamide-adenine-dinucleotide, NAD. Consequently, the significant differences in growth factor … Read more X and V Factor Test for Haemophilus