Staphylococcus aureus- Lab Diagnosis, Treatment, Prevention

Staphylococcus aureus- Lab Diagnosis, Treatment, Prevention

Staphylococcus aureus are catalase-positive, gram-positive cocci which frequently colonize the skin and mucosa of humans and animals. However, it is a highly successful opportunistic pathogen and thus involved in various diseases including toxin-mediated diseases (food poisoning, toxic shock syndrome, scalded skin syndrome), pyogenic diseases (impetigo, folliculitis, furuncles, carbuncles, wound infections), and other systemic diseases. The … Read moreStaphylococcus aureus- Lab Diagnosis, Treatment, Prevention

Differences between Staphylococcus and Streptococcus

Staphylococcus and Streptococcus Differences

Differences between Staphylococcus and Streptococcus Staphylococcus and Streptococcus are Gram positive and the two most common pathogenic cocci of medical importance. They are both non-motile, non-sporing and facultative anaerobes which can be differentiated on following grounds: S.N. Character Staphylococcus Streptococcus 1.       Cellular Arrangement Spherical cells in clusters (grape like clusters). Spherical or ovoid cells in chains or pairs. 2.       … Read moreDifferences between Staphylococcus and Streptococcus

Biochemical Test of Staphylococcus epidermidis

Biochemical Test of Staphylococcus epidermidis

Biochemical Test of Staphylococcus epidermidis ­Basic Characteristics Properties (Staphylococcus epidermidis) Capsule Mostly Capsulated Catalase Positive (+ve) Citrate Negative (-ve) Coagulase Negative (-ve) Gas Positive (+ve) Gelatin Hydrolysis Negative (-ve) Gram Staining Positive (+ve) H2S Positive (+ve) Hemolysis Negative (-ve) Motility Negative (-ve) MR (Methyl Red) Negative (-ve) Nitrate Reduction Positive (+ve) Oxidase Negative (-ve) Pigment … Read moreBiochemical Test of Staphylococcus epidermidis

Staphylococcus aureus on combined Mannitol Salt Agar and Vogel & Johnson Agar

Staphylococcus aureus on combined Mannitol Salt Agar and Vogel & Johnson Agar

– Staphylococcus aureus on combined Mannitol Salt Agar and Vogel & Johnson Agar. – Photo By: Luis Alberto Pascual Santiago. – It is used for the selective isolation and differentiation of Staphylococcus aureus from clinical samples. – It forms yellow colonies with yellow zones. – Culture Media is still pink because this is combined media … Read moreStaphylococcus aureus on combined Mannitol Salt Agar and Vogel & Johnson Agar

Staphylococcus aureus on Columbia CNA Agar with 5% Sheep Blood

Staphylococcus aureus on Columbia CNA Agar with 5% Sheep Blood

– Staphylococcus aureus on Columbia CNA Agar with 5% Sheep Blood. – Photo By: Marlon Neris from Brasília, Brazil. – Columbia CNA Agar is recommended for use as a selective growth medium for the isolation and differentiation of gram-positive cocci from clinical and non-clinical specimens which contain mixed flora. – Large White to Cream Colonies … Read moreStaphylococcus aureus on Columbia CNA Agar with 5% Sheep Blood

Biochemical Test of Staphylococcus aureus

Biochemical Test of Staphylococcus aureus

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 Negative (-ve) Motility Negative (-ve) MR (Methyl Red) Positive (+ve) Nitrate Reduction Positive (+ve) OF … Read moreBiochemical Test of Staphylococcus aureus

Virulence factors and Clinical manifestation of Staphylococcus aureus

Virulence factors and Clinical manifestation of Staphylococcus aureus

Virulence factors of Staphylococcus aureus A. Cell wall components Polysaccharide Capsule: inhibits phagocytosis Peptidoglycan: activates complement, IL-1, chemotactic to PMNs Teichoic acid: species specific, mediate binding to fibronectin Protein A: It binds to the Fc region of IgG and complement ,exerting an anti-opsonin effect. Fibronectin binding protein(FnBP): promote binding to ,mucosal cells and tissue matrices. … Read moreVirulence factors and Clinical manifestation of Staphylococcus aureus

Cultural and Biochemical characteristics of Staphylococcus aureus

Cultural characteristics of Staphylococcus aureus Staphylococci grow readily on most bacteriologic media under aerobic or microaerophilic conditions. Colonies on solid media are round, smooth, raised, and glistening. S. aureus usually forms gray to deep golden yellow colonies. Mannitol Salt Agar: circular, 2–3 mm in diameter, with a smooth, shiny surface; colonies appear opaque and are often … Read moreCultural and Biochemical characteristics of Staphylococcus aureus

Habitat and Morphology of Staphylococcus aureus

Habitat and Morphology of Staphylococcus aureus

Habitat and Morphology of Staphylococcus aureus Habitat Natural habitat is mammalian body surfaces. They are normal flora of skin and mucous membrane. Also present in nose / the anterior nares. They can also be found in Pharynx. Found in stratified epithelial cells or mucous or serum constituents associated with these cells. Found in skin/nasal passage … Read moreHabitat and Morphology of Staphylococcus aureus

Coagulase Test- Principle, Procedure and Result Interpretation

Coagulase Test- Principle, Procedure and Result Interpretation

Coagulase Test- Principle, Procedure and Result Interpretation Purpose of Coagulase Test The test is used to differentiate Staphylococcus aureus (positive) from coagulase-negative staphylococci (negative). Principle of Coagulase Test S. aureus produces two forms of coagulase, bound and free. Bound coagulase, or “clumping factor,” is bound to the bacterial cell wall and reacts directly with fibrinogen. This … Read moreCoagulase Test- Principle, Procedure and Result Interpretation