All are true regarding staphylococcal toxin except ?: (A) Beta haemolysin shows hot cold phenomenon, (B) Mainly endotoxin, (C) Enterotoxin causes food poisoning, (D) Exfoliative toxin causes Reiter's syndrome
Answer is B. Ans. is 'b' i.e., Mainly endotoxin Impoant facts about virulence factors . Clumping factor is bound coagulase which is responsible for the slide coagulase test. . Coagulase (free coagulase) - Acts along with a coagulase reacting factor (CRF) in plasma. - Eight type of coagulase have been identified, most human strains form coagulase A. - Most constant association of virulence is production of enzyme coagulase and to lesser extent with mannitol fermentation. . Heat stable nuclease (DNAase) is a characteristic feature of staph aureus. . Staphylococcus produces five cytolytic toxins, consisting of four hemolysins (alpha, beta, gamma and delta) and a leucocidin. . a - hemolysin is the most impoant hemolysin. . Beta - hemolysin is a sphingomyelinase. It exhibits a hot-cold phenomenon, the hemolysis being initiated at 37degC, but becoming evident only after chilling. . Leucocidin is also called the Panton-valentine toxin. . Staphylococcal leucocidin and gamma lysin have been grouped as synergohymenotropic toxins. . Toxic shock syndrome toxin (TSST) and enterotoxins are superantigens which are potent activators of T lymphocytes and lead to an excessive and dysregulated immune response with release of cytokines IL-1, IL-2, TNF-a and IFN - y. . Enterotoxin is responsible for food poisoning. . Exfoliative (epidermolytic toxin) - Responsible for staphylococcal scalded skin syndrome (S.S.S.S.). - Severe form of SSSS is known as Ritter disease in newborn and toxic epidermal necrolysis in older patients. Milder forms are pemphigus neonatorum and bullous impetigo. . Staphylococcus does not produce endotoxin. Endotoxin is produced by gram (-) ye organisms, the only gram (+) ye organism secreting endotoxin is listeria.