Coagulase positive Staphylococcus aureus Human pathogen Coagulase negative Staphylococcus epidermidis Normal flora, disease under special circumstances Staphylococcus saprophyticus UTI in young females Aerobic Facultative anaerobic Catalase positive Non motile Non sporulating Pigment – white, golden yellow

1. Staphylococcus

2. Gram stain - Microscopy

3. What is the likely organism?
Staphylococcus

4. Important Species
Coagulase positive
• Staphylococcus aureus
• Human pathogen
Coagulase negative
• Staphylococcus epidermidis
• Normal flora, disease
under special
circumstances
• Staphylococcus
saprophyticus
• UTI in young females

5. What is the shape of the colony?
Grape like/ cluster like

6. Features
• Aerobic
• Facultative anaerobic
• Catalase positive
• Non motile
• Non sporulating
• Pigment – white, golden yellow
• Grow readily on standard lab. Media- blood agar
• Optochin resistant

7. Gram stain

8. Blood agar

9. Blood agar

10. Blood agar

11. Blood agar

12. Chocolate agar

13. MacConkey agar

14. Golden yellow colonies

15. What are the virulence factors?
Cell wall
• Peptidoglycan
• Teichoic acid
Cell surface
proteins
• Protein A
• Coagulase
Enzymes
• Hyaluronidase
• DNAse
• Haemoxylin
and leucocidin
• Catalase
• Lipase
Toxins
• Toxin shock
syndrome
• Enterotoxin
• Exofoliative
toxin

16. Infections
Invasive infections
Local
Disseminated
Toxin mediated infections
Toxic shock syndrome
Food poisoning
Scalded skin syndrome

17. Local infections
• Folliculitis
• Furuncle
• Carbuncle
• Abscess
• Impetigo
• Cellulitis

21. Folliculitis

22. Furuncle

23. Carbuncle

24. Abscess

25. Cellulitis

26. Impetigo – Bullous

27. Disseminated Infections
• Septicaemia
• Osteomyelitis – most common cause
• Meningitis
• Pneumonia
• Endocarditis
• Pyelonephritis

28. Toxin-mediated
• Toxic shock syndrome
• Food poisoning
• Scalded skin syndrome

29. Scalded Skin Syndrome

30. Toxic shock syndrome

31. Risk factors
• Viral upper respiratory tract infection (Influenza)
• Skin disease
• Neoplasia
• Diabetes
• Foreign body
• Liver disease
• Renal failure
• Trauma
• Broad spectrum antibiotic use

32. Antibiotics
1st line
• Cloxacillin
• Flucloxacillin / methicillin / nafcillin
• Erthromycin/ gentamicin/ cotrimazole
2nd line
• Fusidic acid/ rifampicin/ clindamycin
• Quinolones - ciprofloxacin
• Aminoglycosides – amikacin/ netimycin
• Vancomycin - MRSA

33. Thank
You