Further Characterization of Staphylococcal Gamma-Hemolysin

Abstract

It was confirmed that staphylococcal gamma-hemolysin is composed of two separate proteins (gamma-lysin components I and II) which act synergistically. The molecular weights of the two components, determined by gel filtration, are 29,000 and 26,000, respectively, and their isoelectric points, determined by isoelectric focusing, are at pH 9.8 and 9.9. Both components are susceptible to the action of Pronase and subtilisin. A wide range of lipids, some in minute amounts, are capable of inhibiting the hemolytic activity of gamma-lysin.

Panton-Valentine leucocidin and gamma-hemolysin from Staphylococcus aureus ATCC 49775 are encoded by distinct genetic loci and have different biological activities

“…This toxin, having a cytolytic effect on only human and rabbit PMNs (8,9), has been described recently as a marker of virulence, since PVL-producing strains were strongly associated (5,6,22) with necrotizing primary cutaneous infections, especially furuncles, and vice versa. A second toxin, gamma-hemolysin, was later identified as a bicomponent toxin (2,10,21,33) having lytic activity on erythrocytes from a wide range of animal species. Its leukotoxic capacity (16) was not generally considered.…”

“…Staphylococcus aureus is one of the most frequently isolated pathogens in hospital routine. It produces numerous virulence factors, including the bicomponent toxins gamma-hemolysin (2,10,21,28,33) and Panton-Valentine leucocidin (PVL) (8,9,20,(37)(38)(39). These toxins consist of two separately secreted and nonassociated proteins (class S and class F components) acting synergistically on human and rabbit polymorphonuclear cells, monocytes, and macrophages.…”

“…Furthermore, three other S. aureus bicomponent toxins which are leukotoxic, hemolytic, and structurally related have been reported. These toxins are (i) gamma-hemolysin (2,10,21,33), which is encoded by the hlg locus of strain Smith 5R (4), (ii) bovine leucocidin (or leucocidin R) (29), which is encoded by the lukR locus (31) of strain P83, and (iii) a leucocidin produced by a methicillin-resistant S. aureus (MRSA) strain which is encoded by the luk locus (12,23,24). These three loci all consist of two consecutive transcription units in the same orientation, the first encoding a single open reading frame (ORF) and the second encoding two ORFs.…”

The hemolysins of Staphylococcus aureus.

“…It now seems clear that Elek could not have detected gamma hemolysin on blood agar plates since its activity is apparently inhibited by agar. Reports by Jackson (90), Guyonnet et al (77), Guyonnet and Plommet (76), Mollby and Wadstrom (146), Taylor and Bernheimer (186), and Fackrell and Wiseman (56) have demonstrated its existence as a hemolysin distinct from alpha, beta, and delta hemolysins.…”

Clinical and Microbiological Profile of Chronic Osteomyelitis Cases with Reference to Virulence Markers in Staphylococcus aureus

“…Previous reports say that antibodies to γ-haemolysin have been assessed as a method of diagnosis of bone and joint infection, but it is unclear what significance should be attached to this in terms of pathogenesis. 35 Majority of the MSSA (100%) showed resistance to amoxicillin, followed by cephalexin and ciprofloxacin (76.9% each); whereas in case of MRSA resistance was seen with amoxicillin (100%), followed by cephalexin, netilmicin, and ciprofloxacin being 68.4% each. Of the MRSA, 26.3% and 5.3% strains were resistant to vancomycin and linezolid respectively, by disc diffusion method.…”