Staphylococcal food poisoning (SFP) is one of the most probably occurring food-borne diseases which cause intoxication from the consumption of food containing preformed staphylococcal enterotoxins (SEs). Staphylococcal enterotoxins are mainly produced by Staphylococcus aureus which is enterotoxigenic strains of coagulase … Read more
Image Source: ASM and Bacteria in Photos. Habitat of Staphylococcus aureus The natural habitat is mammalian body surfaces. They are normal flora of the skin and mucous membrane. Also present in the nose / the anterior nares. They can also be … Read more
Coagulase Test Definition A coagulase test is a biochemical test that is used to differentiate Staphylococcus aureus from other Staphylococci species like S. epidermidis and S. saprophyticus on the basis of the ability to produce the coagulase enzyme. The coagulase … Read more
What is Catalase Test? The catalase test is a biochemical test for aerobic organisms that detects the production of catalase enzyme in the organism. Catalase enzyme is a common enzyme that is found in all living beings that survive in … Read more
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 … Read more
Baird Parker Agar was developed by Baird Parker from the Tellurite-glycine formulation of Zebovitz et al for isolation and enumeration of Staphylococci in food and other material since it allows a good differentiation of coagulase positive strains. Sodium pyruvate was … Read more
MRSA is mediated by the mecA gene; which is chromosomally coded. It alters penicillin-binding protein (PBP) present on S. aureus cell membrane to PBP-2a: PBP is an essential protein needed for the cell wall synthesis of bacteria. β lactam drugs … Read more
Introduction of Mannitol Salt Agar (MSA) Mannitol Salt Agar (MSA) is used as a selective and differential medium for the isolation and identification of Staphylococcus aureus from clinical and non-clinical specimens. It is recommended for the detection and enumeration of coagulase-positive Staphylococci in … Read more
Enterococcus faecalis and Enterococcus faecium Clinical Features Urinary tract infections, peritonitis, bacteremia, endocarditis Virulence Factors Relatively avirulent Staphylococcus aureus Clinical Features Suppurative infections: impetigo, folliculitis, furuncles, carbuncles, wounds Disseminated infections: bacteremia, endocarditis, pneumonia, empyema, osteomyelitis, septic arthritis Toxin-mediated infections: toxic … Read more
Biochemical Test 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 … Read more