Why Are Staph So Pathogenic (Able to Cause Diseases)?
Staphylococci have the ability to synthesize and secrete many factors that either allow the bacteria to survive in the host or cause damage to host tissues. The list below summarizes these substances and their effects on the host: • Surface proteins (for example, capsular polysaccharide, Protein A) — enhance attachment to host cells; others reduce phagocytosis (host immune cell’s ability to ingest and kill bacteria) • Membrane-altering toxins (for example, alpha, beta toxins plus leukocidin) — all damage host cells by making holes in their membranes • Exfoliatin toxins (exotoxins ETA and ETB) — cause scalded skin syndrome (exfoliation of skin after erythematous cellulitis) in infants and children • Enterotoxins (exotoxins secreted into the gastrointestinal tract termed SE-A, B, C, D, E, and G) — cause nausea and vomiting associated with food poisoning • Toxic shock syndrome toxin (TSST-1 toxin) — syndrome of rapidly onset of fever (102 F or higher), low blood pressure (hypotension
