IN-VIVO EXPRESSION OF EXOPROTEIN SYNTHESIS WITH A SAE MUTANT OF STAPHYLOCOCCUS-AUREUS

The expression of exoprotein synthesis of Staphylococcus aureus Sae mu tant RC121 and its parental strain was studied under in vivo growth co nditions, Cultures of both strains were inoculated into dialysis sacs implanted in sheep peritoneum, Results indicated that similar to in vi tro grown mutant cells, Sae mutant RC121 shows diminished synthesis of alpha- and beta-hemolysin, coagulase, DNase and protein A, However, i n vitro and in vivo grown mutant cultures showed different exoprotein profiles in SDS-PAGE; some bands from in vivo mutant cultures were dim inished or missing and others appeared as more concentrated, when comp ared with the pattern of the in vivo grown parental strain, while all the exoprotein bands from the in vitro cultures of the mutant were dim inished or missing as compared to the in vitro grown parental strain, The virulence of the Sae mutant, assayed by intraperitoneal injection in mice, was lower than that of the parental strain after both in vivo and in vitro growth conditions.