See Overheads
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TSS
Foodborne Intoxication
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MICROBIAL |
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PATHOGEN |
ADHESIN |
RECEPTOR |
Staphylococcus aureus |
Lipoteichoic acid |
Unknown |
Staphylococcus spp. |
Slime layer |
Unknown |
Group A Streptococcus |
LTA-M protein complex Fibronectin |
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Streptococcus pneumoniae |
Protein |
N-acetylhexosamine-gal |
Escherichia coli |
Type 1 fimbriae |
D-Mannose |
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CFA 1 fimbriae |
GM ganglioside |
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P fimbriae |
P blood grp glycolipid |
Other Enterobacteriaceae |
Type 1 fimbriae |
D-Mannose |
Neisseria gonorrhoeae |
Fimbriae |
GD1 ganglioside |
Treponema pallidum |
P1, P2, P3 |
Fibronectin |
Chlamydia spp. |
Cell surface lectin |
N-acetylglucosamine |
Mycoplasma pneumoniae |
Protein P1 |
Sialic acid |
Vibrio cholerae |
Type 4 pili |
Fucose and mannose |
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Cell-Associated Virulence Factors
•Capsule or slime layer (glycocalyx)
•Peptidoglycan (PG)
•Teichoic acid is covalently linked to PG and is species specific:
S. aureus ribitol teichoic acid
(polysaccharide A)
S. epidermidis glycerol teichoic acid
(polysaccharide B)
•Protein A is covalently linked to PG
•Clumping factor (bound coagulase)
Virulence Factors
Extracellular Enzymes
• Coagulases (bound or free)
Antigenic
• Hyaluronidase
“spreading factor” of S. aureus
• Nuclease
Cleaves DNA and RNA in S. aureus
• Protease
Staphylokinase (fibrinolysin)
•Lipases
•Esterases
Virulence Factors: Exotoxins
•Cytolytic (cytotoxins; cytolysins)
Alpha toxin - hemolysin
•Reacts with RBCs
Beta toxin
•Sphingomyelinase
Gamma toxin
•Hemolytic activity
Delta toxin
•Cytopathic for:
–RBCs
–Macrophages
–Lymphocytes
–Neutrophils
–Platelets
•Enterotoxic activity
Leukocidin
Virulence Factors: Exotoxins
•Enterotoxin
•Exfoliative toxin (epidermolytic toxin)
•Pyrogenic exotoxins
Pathogenesis
•Pass skin – first line of defense
Benign infection
•Phagocytosis
•Antibody
•Inflammatory response
Chronic infections
• Delayed hypersensitivity
Clinical Manifestations/Disease
•SKIN
folliculitis
boils (furuncles)
carbuncles
impetigo (bullous & pustular)
scalded skin syndrome
•Neonates and children under 4 years
Clinical Manifestations/Disease
•Other infections
Primary staphylococcal pneumonia
Food poisoning vs. foodborne disease
Toxic shock syndrome