Staphylococcus (1)
- 1. Staphylococcus Eva L. Dizon, M.D.,FPPS,FPIDSP
- 2. Staphylococcus Staphyle- Bunch of grapes 0.5 to 1 um Non motile Aerobic or Facultative Anaerobic Catalase positive Grow in media containing 10% NaCl at temp 18 to 40 C Present on the skin and mucuos membrane
- 3. Species S. aureus S. epidermidis S. saphrophyticus S. capitis S. haemolyticus Micrococcus sp Stomatococcus mucilaginosus Alloiococcus otitidis
- 5. Structure
- 7. Structure CAPSULE - loose fitting polysaccharide layer (slime layer) - protects bacteria by inhibiting chemotaxis and phagocytosis - facilitates adherence of bacteria to catheters and synthetic materials PEPTIDOGLYCAN - half of the cell wall - consist of layers of glycan chains with alternating subunits of N –acetylmuramic acid and N- acetylglucosamine - has endotoxin like activity
- 8. Structure TEICHOIC ACID- phosphate containing polymers bound to peptidoglycan layer or to cytplasmic membrane - mediates the attachment of staphylococcus to mucosal surfaces S. aureus Ribitol teichoic acid with N-acetylglucosamine ( Polysaccharide A) S. epidermidis glycerol teichoic acid with glucosyl residues (polysaccharide B)-
- 9. PROTEIN A- covalentlylinked to peptidoglycan - has affinity to Fc receptor of Ig - blocks opsonization and phagocytosis
- 10. Structure CYTOPLASMIC MEMBRANE- osmotic barrier for the cell and provides an anchorage for the biosynthetic and respiratory enzyme COAGULASE and other SURFACE PROTEIN -Clumping factor or Bound coagulase binds fibrinogen convert to insoluble fibrin causing staphylococcus to clump - collagen , elastin and fibronectin binding protein
- 11. Toxins A. 5 Cytolytic or membrane damage toxin Alpha Beta Gamma Delta Panton Valentine B. 2 Exfoliative toxin C. 8 Enterotoxin D. Toxic Shock Syndrome Toxin(TSST 1)
- 12. Cytotoxins Lyse neutrophils release of lysosomal enzymes damage sorrounding tissues Alpha toxin – disrupts the smooth muscle in blood vessels - toxic to erythrocytes, hepatocytes, platelets, cultivated cells - integrates to host cell membrane pores efflux of K and influx of Na,Ca osmotic swelling cell lysis - septic shock
- 13. Cytotoxin Beta Toxin - Sphingomyelinase C - specific for sphingomyelin and lysophosphatidylcholine - toxic to RBC, WBC,Macrophage and fibroblast - catalyze hydrolysis of membrane phospholipids in susceptible cells - tissue destruction and abscess formation Delta toxin- disrupts cell membrane - toxic to variety of cells
- 14. Cytotoxin Gamma toxin and Panton Valentine -both damage membrane of susceptible cells - lyze nuetrophils and macrophages - cell lysis is mediated by pore formation Cause necrotizing skin infection -PVL -potent leukotoxicity
- 15. Exfoliative toxin ETA - heat stable ETB – heat labile Serine protease Exposure splitting of desmosomes or intercellular bridges in the stratum granulosum epidermis Common in neonates – ETA and ETB binds to GM4 like glycolipids present in neonates
- 16. Enterotoxin A-E, G-I Stable to heating , resistant to hydrolysis Enterotoxin A – most commonly associated with disease Enterotoxin C and D- contaminated milk products Enterotoxin B- Pseudomembranous colitis Superantigens
- 18. TSST-1 Formerly pyrogenic exotoxin C and entertoxin F Induce cytokine release from macrophage and T lymphocytes Increase sensitivity to endotoxin Produce leakage of endothelial cells Penetrate mucosal barrier
- 19. Staphylococcal enzymes convert fibrinogen react with globulin plasma factor insoluble fibrin to form staphylothrombin Clumping Cause formation of fibrin layer around abscess protecting staphylococcus from phagocytosis Coagulase Bound Free
- 20. Staphylococcal enzymes Catalase - catalyze the conversion of toxic hydrogen peroxide to water and oxygen Hyalurodinase - hydrolyzes hyaluronic acid in acellular matrix of connective tissue spread
- 21. Staphylococcal enzymes Fibrinolysin- staphylokinase . Dissolve fibrin clot- aid in bacterial spreading Lipases hydrolyse lipid to ensure survival in sebaceous areas of the body Nuclease Penicillinase- plasmid Fatty acid modifying enzyme (FAME)- antibacterial lipid- prolonged bacterial survival
- 22. Epidemiology Transient colonizer of skin Nasal carriage – anterior nasopharynx Persistent carrier – hospital personnel Killed by high temperature and disinfectant Direct contact, fomites Handwashing
- 24. Ritters disease or SSSS Perioral erythema spread body bullous desquamation Nikolsky sign Bullous impetigo – localized form of SSSS - localized blister - culture positive
- 25. SSSS most commonly in children and neonates. Starts abruptly with perioral (around the mouth) erythema with sunburn-like rash rapidly turning bright red spreading to bullae (large vesicle appearing as a circumscribed area) in 2-3 days and desquamating (peeling) within 5 days.
- 26. Staphylococcal food poisoning Ham , salted pork, custard, potato sald, ice cream Hands, Nasal carriage I.P. – 4 hrs Vomiting, diarrhea, abd. pain
- 27. Toxic shock syndrome Growth of organism in vagina or wound release of TSST-1 Fever, macular erythematous rashes, hypotension, multiorgan involvement, desquamation of palm and sole
- 28. TSS
- 29. Cutaneous infection Impetigo Folliculitis Furuncle Carbuncle Wound infection
- 30. Folliculitis - superficial folliculitis is essentially a staphylococcal impetigo in which a small area of erythema develops around a hair follicle and subsequently becomes a dome-shaped pustule. Carbuncle - a deep-seated pyogenic infection of the skin and subcutaneous tissues.
- 31. Impetigo - a contagious superficial pyoderma, caused by S. aureus and Streptococcus pyogenes, that begins with a superficial flaccid vesicle which ruptures and forms a thick yellowish crust, most commonly occurring in the face.
- 32. Others Bacteremia Endocarditis Pneumonia Empyema Osteomyelitis Septic arthritis
- 33. Pneumonia
- 34. S.Epidermidis and CNS Endocarditis- native or artificial valves Catheter and shunt infection Prosthetic joint infection UTI
- 35. Laboratory diagnosis Microscopy Culture Grow rapidly within 24 hours Large, golden, smooth colonies Blood Agar- hemolysis Selective media- add NaCl 7.5% Mannitol – fermented by S. aureus Serology Insensitive Antibody against teichoic acid Bacteremia. Endocarditis After 2 weeks
- 36. Culture – S. aureus
- 37. S. epidermidis S. saphrophyticus
- 38. Coagulase test Showing positive (upper tube) and negative (lower tube) coagulase tests.
- 39. Mannitol Salt Agar test
- 40. Identification Biochemical testing Coagulase Heat stable nuclease Alkaline phospatase Mannitol fermentation test
- 41. Treatment and Prevention Semisynthetic penicillinase resistant penicillin Resistance ( mecgene A –codes for PBP 2’)
- 44. Thank You