Describe the Staphylococcus Genus
Gram Positive Cocci in Clusters, Facultative Anaerobe, Catalase Positive, Lipase Positive, Halophile
What differentiates Staphylococcus from Streptococcus?
Staphylococcus's cocci are in clusters and catalase positive; whereas streptococcus gram positive cocci are in pairs or chains, facultative anaerobe with peroxidase, and catalase negative.
Opportunist, ubiquitous on skin, primarily infectious in immune compromised patient (Example: HIV) - Main normal flora of skin
Virulence Factors of S. aureus
1. Coagulase Positive (Hiding in the clot), Kinase, Hyaluronidase (hyaluronic acid - invades deeper), Beta hemolytic - lysis cells; Eats them Up!
2. Protein A - Binds stem of igG preventing opsonizations and complement
3. Slime Layer - Inhibits phagocytes, allows attachment to artificial surfaces (catheters, shunts, heart valves, artificial joints - loves plastic)
4. Beta lactamase - Brakes beta lactam ring of penicillin = resistant to penicillin and other Antibiotics, 90% of strains are resistant