Leukocidal toxins of staphylococci

Leukocidal toxins (synergohymenotropic toxin) are cytotoxins produced by st aphylococci (S. aureus and S. intermedius) and consist of two separate comp onents. The toxic effect depends on the synergistic action of two proteins. One of them belongs to class F (e. g. LukF-PV, LukF-R, LukF-I, LukM, HlgB) and the other, to class S (e.g. LukS-PV, LukS-R, LukS-I, HlgA, HlgC). Best known are the toxins produced by S. aureus: gamma-haemolysins, HlgA/HlgB a nd HlgC/HlgB and leukocidin Panton-Valentine, LukS-PV/LukF-PV (Luk-PV, PVL) . Very few data are available concerning the relationship between the produ ction of these toxins and the pathology of staphylococcal infections, becau se little is known about local and general effects of these leukocidal prod ucts in vivo. Frequent isolations of staphylococcal strains producing leuko cidal toxins from necrotic skin lesions and furuncles suggest a role of the se toxins in the virulence of staphylococci, at least in cutaneous infectio ns. Recent data on mechanisms of cytotoxic effects of staphylococcal leukoc idal toxins in vitro as well as effects of leukocidal toxins in vitro are d iscussed. Cell membranes appear to be a primary target for triggering the l ysis of phagocytic cells caused by staphylococcal leukocidal toxins.