[Expression of staphylococci resistance to oxacillin and cefalotin ].
The comportment to oxacillin (OXA) and cefalotin (CFT) of 32 strains of staphylococci - 18 Staphylococcus aureus and 14 coagulase-negative staphylococci (SCN) - was studied by three different methods, on three types of media, with or without 5 p. cent of NaCl and incubated at two temperatures (30 degree C-37 degree C). S. aureus showed always a cross-resistance to OXA and CFT. Three types were recognized : "susceptible" (S) and "high level resistant" (RO) types, whose comportment did not vary with culture conditions; "heterogenous resistant" type (RH) for which the OXA - resistance expression was better at 30 degree C and on salt medium. SCN did not always present a cross-resistance. In addition to S, RO and RH types, one strain showed a dissociated resistance to OXA and CFT, with a better expression at 30 degree C and on salt medium; one strain, which appeared to be susceptible by discs method, presented a resistant population level higher than that of the susceptible reference strain, whatever the culture conditions were.
D002512:Cephalothin / Q000494:pharmacology*; D003470:Culture Media; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology*; D010403:Penicillin Resistance; D012965:Sodium Chloride / Q000494:pharmacology; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000187:drug effects; D013696:Temperature
D003470:Culture Media; D012965:Sodium Chloride; D002512:Cephalothin; D010068:Oxacillin
Expression de la résistance des staphylocoques à l'oxacilline et à la céfalotine.