Staphylococcus

1. Staphylococcus

2. Staphylococceae family
 Low G + C
 Cocci (spheres)
 Grapelike clusters
3 planes
1 micrometer diameter
 FA
 Nonmotile, NSF
 Halotoerant
 Catalase (+)
 Oxidase (-)
 +/- fermentation

3. Staphylococcus species
 61 species
 Important
 S. aureus
 S. epidermidis
 S. saprophyticus
 S. pseudointermedius
 Others
 S. haemolyticus
 S. capitus
 S. hominis
 S. xylosis
 S. warneri

4. Cell Wall

5. Location
 Ubiquitous
 Normal flora
Skin
Mouth
Nose
Throat
 Predisposing factors
Immunosuppression
Concurrent disease
AB resistance

6. Epidemiology
 Normal microbiotica
 Direct transmission
 Portal of Entry
Hair follicle
Break in skin
Respiratory
 Complications
Bacteremia
Septicemia
Abscess

7. Cytological Sample

8. Pathogenesis
 Immune evasion
Slime layer biofilm
(microcapsule)
Evades phagocytosis
Protein A on cell wall
Binds to IgG @ Fc
Blocks opsonization
 Adhesin proteins
Binds to
fibrin/fibrinogen
Binds to ECM
laminin
fibronectin
collagen

9. Enzymes
Coagulase
Catalase
Hyaluronidase
Lipase
Beta lactamase
Staphylokinase
(plasminogen activator)
Proteases
DNase
FAME (fatty acid
modifying enzyme)

10. Staphylococcus Toxins
 Cytolytic Toxins
Alpha = β hemolysis
Beta = sphingomyelinase
Delta
Gamma
Leukocidin = hemolysis
Leukotoxin = WBC destruction
 Exfoliative toxin
ETA and ETB
Protease & esterase activity
 Toxic Shock toxins
 Enterotoxins (A-E)

11. Superantigens
 Enterotoxin
 Food poisoning, V/D
TSS if B or C antigenic type
 TSST-1: desquamation; TSS

12. Virulence Factors Summary

13. Staph aureus
 Location
 Mucous membranes
 Moist areas
 Diseases
 Noninvasive
 Food poisoning
 Enterotoxin (V/D)
 Cutaneous
 Scalded skin
 Impetigo
 Folliculitis
 Boils, styes, furunculosis
 Systemic
 Soft tissue infections

14. Systemic Staph. aureus infections
 TSS
 Bacteremia
 Endocarditis
 Pneumonia
 Meningitis
 Osteomyelitis
 Septic arthritis
 UTI
 Phlebitis

15. Staphylococcal disease summary

16. S. aureus
 Dx
Isolation
DDx MRSA/VRSA
 Tx
AB based on culture
 Prevention
Wound cleansing
Hand washing

17. MRSA
 Hosptial associated
 Community assoc.

18. AMA/CDC poster

19. VRSA
vanA operon from enterococcus changes cell wall tripeptide sequence

20. Opportunistic Staph pathogens
 S. capitis
 S. epidermidis
 S. saprophyticus
 S. xylosis

21. S. epidermidis
 Location
 Normal skin flora
 opportunistic pathogen
 Skin/wound infections
 Endocarditis
 UTI
 Exposure
 Direct contact
 Newborns
 Elderly
 Fomites
 Catheters
 Shunts
 IV needles
 Prosthetics

22. S. saprophyticus
 Pathogenesis
Fimbria
Adhesion proteins
Autolysins
 Diseases
UTI/cystitis
Peritonitis
Enopthalmitis
Endocaritis
Septic arthritis

23. S. xylosus
 Commensal
 Industry
 Ferment meat
 Red color of sausage
 Ferment milk
 Orange color of cheese
 Pathogenicity
 Biofilms
 Enterotoxins
 Disease
 Nosocomial
 UTI
 Food poisoning (raw)

24. S. capitis
 Epidemiology
Skin microbiotica
Head predominantly
 Pathogenicity
Coagulase (-)
AB resistance
 Diseases
Valvular endocarditis
Neonatal septicemia
Osteomyelitis

25. S. pseudointermedius
 Animal microbiotica
 Epidemiology
Zoonotic
Enterotoxins
+/- coagulase
 Diseases
Pyoderma (animals)
Food poisoning

26. Rapid Staph test

27. Immunology
 Hyperimmune serum
Capsular proteins
Surface adhesins
 Vaccination
At risk population
ESRD
Dialysis patients
Premature infants
StaphVAX
Capsular proteins
Exotoxin A (Ps. Aeurginosa)

28. Questions?