Bacterial Identification

Biochemical Test and Identification of Pseudomonas aeruginosa

Characteristics Pseudomonas aeruginosa Gram Staining Negative Shape (Cocci/Diplococci/Rods) Rods Motility (Motile / Non-Motile) Motile (Unipolar) Capsule (Capsulated/Non-Capsulated) Non-Capsulated Spore (Sporing/Non-Sporing) Non-Sporing Flagella (Flagellated/Non-Flagellated) Single Flagella Catalase Positive (+ve) Oxidase Positive (+ve) MR Negative (-ve) VP Negative (-ve) OF (Oxidative/Fermentative) Oxidative Indole Negative (-ve) Citrate Positive (+ve) Urease Negative (-ve) Nitrate Reduction Positive (+ve) H2S Negative …

Urease Test- Principle, Media, Procedure and Result

Urea Agar was developed by Christensen in 1946 for the differentiation of enteric bacilli. The urease test is used to determine the ability of an organism to split urea, through the production of the enzyme urease. Principle of Urease Test Urea is the product of decarboxylation of amino acids. Hydrolysis of urea produces ammonia and CO2. The formation …

Cetrimide Agar- Composition, Principle, Uses, Preparation and Colony Morphology

Cetrimide Agar is a selective and differential medium used for the isolation and identification of Pseudomonas aeruginosa from clinical and non-clinical specimens. Cetrimide is the selective agent and inhibits most bacteria by acting as a detergent ( Cetyltrimethylammonium bromide, a quaternary ammonium, cationic detergent). It is also known as Pseudomonas Cetrimide Agar or Pseudosel Agar. Composition of Cetrimide Agar Ingredients In …

Biochemical Test and Identification of Enterococcus faecalis

Characteristics Enterococcus faecalis Gram Staining Positive Shape (Cocci/Diplococci/Rods) Cocci Motility (Motile / Non-Motile) Non-Motile Capsule (Capsulated/Non-Capsulated) – Spore (Sporing/Non-Sporing) Non-Sporing Flagella (Flagellated/Non-Flagellated) – Catalase Negative (-ve) Oxidase Negative (-ve) MR – VP Positive (+ve) OF (Oxidative/Fermentative) – Indole Negative (-ve) Citrate Negative (-ve) Urease Negative (-ve) Nitrate Reduction Positive (+ve) H2S Negative (-ve) Gas – …

String test for the identification of Vibrio cholerae

Vibrio cholerae is a gram-negative bacilli bacteria with a “comma” shaped body and a flagella for the movement. V. cholerae and V. mimicus are the only Vibrio spp. that do not require salt for growth. The string test may be performed on a glass microscope slide or plastic petri dish by suspending 18 to 24 hour growth …

Optochin Susceptibility Test for the identification of Streptococcus pneumoniae

Result Interpretaion of Optochin Susceptibility Test

Differentiation of Streptococcus pneumoniae from other viridans streptococci depends on demonstrating optochin susceptibility, bile solubility, reaction with a specific DNA probe, or detection of species-specific capsular polysaccharides. Most clinical microbiology laboratories today depend on the optochin susceptibility test. Although optochin susceptibility was first described for differentiating pneumococci from other α-hemolytic streptococci in 1915, the test …

Biochemical Test and Identification of Staphylococcus aureus

Basic Characteristics Properties (Staphylococcus aureus) Capsule Non-Capsulated Catalase Positive (+ve) Citrate Positive (+ve) Coagulase Positive (+ve) Gas Negative (-ve) Gelatin Hydrolysis Positive (+ve) Gram Staining Positive (+ve) H2S Negative (-ve) Hemolysis Positive (+ve)- Beta Indole Negative (-ve) Motility Negative (-ve) MR (Methyl Red) Positive (+ve) Nitrate Reduction Positive (+ve) OF (Oxidative-Fermentative) Fermentative Oxidase Negative (-ve) Pigment …

Biochemical Test and Identification of E. coli

Characteristics E. coli Gram Staining Negative Shape (Cocci/Diplococci/Rods) Rods Motility (Motile / Non-Motile) Motile Capsule (Capsulated/Non-Capsulated) Variable Spore (Sporing/Non-Sporing) Non-Sporing Flagella (Flagellated/Non-Flagellated) Flagellated Catalase Positive (+ve) Oxidase Negative (-ve) MR Positive (+ve) VP Negative (-ve) OF (Oxidative/Fermentative) Fermentative Indole Positive (+ve) Citrate Negative (-ve) Urease Negative (-ve) Nitrate Reduction Positive (+ve) H2S Negative (-ve) Gas …

Widal Test- Introduction, Principle, Procedure, Interpretation and Limitation

Interpretation of Widal Test- Tube Method

Introduction of Widal Test Widal Test is an agglutination test which detects the presence of serum agglutinins (H and O) in patients serum with typhoid and paratyphoid fever. When facilities for culturing are not available, the Widal test is the reliable and can be of value in the diagnosis of typhoid fevers in endemic areas. …

Biochemical test for Vibrio cholerae

Basic Characteristics Properties (Vibrio cholerae) Capsule Non-Capsulated Citrate +ve Flagella Flagellated Gas -ve Gelatin Hydrolysis +ve Gram Staining -ve H2S -ve Hemolysis Beta Hemolysis Indole +ve Motility Motile MR (Methyl Red) -ve Nitrate Reduction +ve Oxidase +ve Shape Rods Spore Non-Sporing String Test +ve Urease -ve VP (Voges Proskauer) Variable Fermentation of Adonitol -ve Arabinose …