Biochemical Test of Bacteria

Biochemical Test of Bacteria

Biochemical Test of Bacteria Biochemical reactions are very important in the identification of bacterial isolates and in the identification of different bacterial species. These tests depend on the presence of certain enzymes, such as catalase, oxidase, urease, gelatinase, etc., produced by the bacteria. Different bacteria produce varying spectra of enzymes. For example, some enzymes are … Read more Biochemical Test of Bacteria

Habitat of Bacillus cereus

Habitat of Bacillus cereus

Habitat of Bacillus cereus Bacillus cereus is isolated from soil, vegetables, milk, cereals, spices, fried rice, cooked poultry and meats, soups and desserts. It is also found in mashed potato, beef stew, apples, hot chocolates sold in vending machines and other improper food handling areas. In 1887, B. cereus was isolated from air in a cowshed … Read more Habitat of Bacillus cereus

Cultural Characteristics of Bacillus cereus

Cultural Characteristics of Bacillus cereus

Cultural Characteristics of Bacillus cereus Some of the characteristics are: Most Bacillus spp grow readily on nutrient agar or peptone media. The optimum temperature for growth varies from 20°C to 40°C, mostly 37°C. B. cereus is mesophilic and is capable of adapting to a wide range of environmental conditions. On Nutrient Agar at 37°C, it … Read more Cultural Characteristics of Bacillus cereus

Morphology of Bacillus cereus

Morphology of Bacillus cereus

Morphology of Bacillus cereus Some of the characteristics are: Bacillus cereus is gram-positive rod-shaped bacilli with square ends. Occasionally may appear gram variable or even gram-negative with age. They are single rod-shaped or appear in short chains. Clear cut junctions between the members of chains are easily visible. Tissue section staining may appear long and … Read more Morphology of Bacillus cereus

Lecithinase Test- Objectives, Principle, Procedure and Results

Result Interpretation of Lecithinase Test

Objective of Lecithinase Test The objective is to determine the ability of microorganisms to produce the enzyme lecithinase and to identify the bacteria which are capable of producing lecithinase enzyme. Principle of Lecithinase Test Lecithinases or phospholipases are enzymes released by bacteria that have the ability to destroy animal tissues and play a role in pathogenecity. Lecithinase, which … Read more Lecithinase Test- Objectives, Principle, Procedure and Results

Biochemical Test of Bacillus cereus

Biochemical Test of Bacillus cereus

Biochemical Test of Bacillus cereus ­Basic Characteristics Properties (Bacillus cereus) Catalase Positive (+ve) Citrate Positive (+ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Positive (+ve) Growth in KCN Positive (+ve) Hemolysis Positive (+ve) Indole Negative (-ve) Motility Positive (+ve) MR (Methyl Red) Negative (-ve) Nitrate Reduction Variable Oxidase Negative (-ve) Pigment Negative (-ve) Shape Rods Spore … Read more Biochemical Test of Bacillus cereus

Laboratory Diagnosis, Treatment and Prevention of Bacillus cereus

Laboratory Diagnosis, Treatment and Prevention of Bacillus cereus

Laboratory Diagnosis of Bacillus cereus SPECIMENS: Faeces, vomitus, remaning food (if any), eye specimen (corneal swab) DIRECT DETECTION METHODS Microscopically the organisms appear as large gram positive rods in singles, pairs, or serpentine with square ends after Gram staining. Endospores formation are seen as unstained oval or round region within centre of cell. Spores are oval … Read more Laboratory Diagnosis, Treatment and Prevention of Bacillus cereus

Clinical manifestation and Pathogenicity of Bacillus cereus

Clinical manifestation and Pathogenicity of Bacillus cereus

Clinical manifestation of Bacillus cereus A. Food poisoning Two forms of food poisoning: vomiting disease (emetic form) and diarrheal disease (diarrheal form). Emetic form The emetic form of disease results from the consumption of contaminated rice. Most bacteria are killed during the initial cooking of the rice, but the heat-resistant spores survive. If the cooked … Read more Clinical manifestation and Pathogenicity of Bacillus cereus