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

Biochemical Test of Listeria monocytogenes

Biochemical Test of Listeria monocytogenes

Biochemical Test of Listeria monocytogenes Basic Characteristics Properties (Listeria monocytogenes) CAMP Positive (+ve) Catalase Positive (+ve) Flagella Flagellated Gas Negative (-ve) Gram Staining Positive (+ve) H2S Negative (-ve) Hemolysis Beta Hemolysis Indole Negative (-ve) Motility Motile MR (Methyl Red) Positive (+ve) Nitrate Reduction Negative (-ve) Oxidase Negative (-ve) Shape Rods Spore Non-Sporing Urease Negative (-ve) … Read more Biochemical Test of Listeria monocytogenes

Virulence factors, Pathogenesis and Clinical manifestations of Listeria monocytogenes

Listeria monocytogenes

Virulence factors of Listeria monocytogenes 1. Adhesion proteins (Ami, Fbp A, flagellin) Mediate bacterial binding to host cell that contribute to virulence. 2. Listeriolysin O A hemolytic and cytotoxic toxin that allows for survival within phagocytes. 3. Internalin Cell surface protein that induces phagocytosis. 4. Act A Induces actin polymerization on the surface of host cells, … Read more Virulence factors, Pathogenesis and Clinical manifestations of Listeria monocytogenes

Laboratory diagnosis of Listeriosis caused by Listeria monocytogenes

Laboratory diagnosis of Listeriosis caused by Listeria monocytogenes

Laboratory diagnosis of Listeriosis caused by Listeria monocytogenes Specimens: Cerebrospinal fluid (CSF), Blood Microscopy Gram-stain preparations of cerebrospinal fluid (CSF) typically show no organisms because the bacteria are generally present in concentrations below the limit of detection (e.g., 10ˆ4 bacteria per milliliter CSF or less). If the Gram stain shows organisms, they are intracellular and extracellular … Read more Laboratory diagnosis of Listeriosis caused by Listeria monocytogenes

Habitat and Morphology of Listeria monocytogenes

Habitat and Morphology of Listeria monocytogenes

Habitat and Morphology of Listeria monocytogenes Habitat of Listeria monocytogenes They are the natural pathogens of wide range of animals, birds, fish, ticks and crustacean. They are saprophytic in soil, water, sewage and plants decaying. They occasionally colonizes the human gastrointestinal tract (1-10%). They can be isolated from foods for human consumption, including raw and … Read more Habitat and Morphology of Listeria monocytogenes

CAMP Test- Principle, Procedure and Result Interpretation

CAMP Test- Principle, Procedure and Result Interpretation

CAMP Test- Principle, Procedure and Result Interpretation Objective of CAMP Test The Christie, Atkins, and Munch-Peterson (CAMP) test is used to differentiate group B streptococci (Streptococcus agalactiae–positive) from other streptococcal species. Listeria monocytogenes also produces a positive CAMP reaction. Principle of CAMP Test Certain organisms (including group B streptococci) produce a diffusible extracellular hemolytic protein … Read more CAMP Test- Principle, Procedure and Result Interpretation