Virulence of protein A-deficient and alpha-toxin-deficient mutants of Staphylococcus aureus isolated by allele replacement.
Infect Immun
; 55(12): 3103-10, 1987 Dec.
Article
en En
| MEDLINE
| ID: mdl-3679545
ABSTRACT
The gene coding for protein A (spa) of Staphylococcus aureus 8325-4 has been inactivated by substituting part of the spa coding sequence for a DNA fragment specifying resistance to ethidium bromide. The in vitro-constructed spaEtBrr substitution mutation was introduced into the S. aureus chromosome by recombinational allele replacement. Southern blot hybridization showed that the in vitro-constructed mutation was present in the chromosomal spa locus. We have previously reported the inactivation of the alpha-toxin gene (hly) by allele replacement with an in vitro-constructed hlyEmr (erythromycin resistance) mutation (M. O'Reilly, J.C.S. de Azavedo, S. Kennedy, and T.J. Foster, Microb. Pathogen. 1125-138, 1986). A double Spa- Hly- mutant was constructed by transduction. The virulence of Spa- and Hly- mutants was tested by experimental infection of mice. When subcutaneous injections were given, Hly- mutants formed a flat, darkened lesion, whereas Hly+ strains caused a raised, cream lesion. Alpha-toxin was shown to be a major factor in forming subcutaneous lesions and in causing the death of mice injected intraperitoneally. Spa- mutants were slightly less virulent than their Spa+ counterparts, which suggests that protein A is also a virulence factor of S. aureus.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Infecciones Estafilocócicas
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Proteína Estafilocócica A
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Staphylococcus aureus
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Toxinas Bacterianas
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Proteínas Hemolisinas
Límite:
Animals
Idioma:
En
Revista:
Infect Immun
Año:
1987
Tipo del documento:
Article
País de afiliación:
Irlanda