title: Assessment of the role of gamma-toxin in experimental endophthalmitis using a hlg-deficient mutant of Staphylococcus aureus.
abstract: Purified gamma-toxin is known to have a proinflammatory effect in the rabbit vitreous humor. To assess the biological role of the gamma-toxin, when expressed in vivo by Staphylococcus aureus strain Newman, the vitreous humor of rabbit eye was used as an infection model. A gamma-toxin-deficient mutant of strain Newman was constructed by allelic replacement. S. aureus Newman wild-type, its hlg-deficient derivative strain (N65) and the strain N65 complemented with the wild-type hlg+ gene were injected into the vitreous humor of rabbit eye. All three strains produced a strong proinflammatory effect in the eye conjunctiva, posterior and anterior chambers, suggesting a role for another unidentified proinflammatory component of strain Newman distinct from the gamma-toxin. These components are not the leucocidin of Panton-Valentine, beta-toxin or alpha-toxin which are not produced by this strain. Only the hlg-deficient mutant lacked the ability to cause inflammation in the eyelid, whereas the two Hlg-producing strains gave strong inflammation. These data suggest that in vivo, strain Newman produces as yet unidentified proinflammatory molecules and that the in vivo-produced HlgA, HlgB and HlgC molecules expressed by the gamma-toxin locus, contribute in part to the inflammatory process observed in vivo in the rabbit eye.
authors.affiliation: Institut de Bactériologie de la Faculté de Médecine, Université Louis Pasteur, 3, rue Koeberlé, Strasbourg, F-67000, France.
authors.forename: G
authors.initials: G
authors.lastname: Supersac
authors.forename: Y
authors.initials: Y
authors.lastname: Piémont
authors.forename: M
authors.initials: M
authors.lastname: Kubina
authors.forename: G
authors.initials: G
authors.lastname: Prévost
authors.forename: T J
authors.initials: TJ
authors.lastname: Foster
mesh_terms: D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000235:genetics*; D015169:Colony Count, Microbial; D009877:Endophthalmitis / Q000382:microbiology*; D005123:Eye / Q000473:pathology; D006460:Hemolysin Proteins; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011817:Rabbits; D013211:Staphylococcus aureus / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D014169:Transformation, Bacterial; D014822:Vitreous Body / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D006460:Hemolysin Proteins; C037956:gamma-hemolysin, Staphylococcus aureus