In-vitro activity and beta-lactamase stability of methicillin, isoxazolyl penicillins and cephalothin against coagulase-negative staphylococci.
Forty-nine clinical strains of coagulase-negative staphylococci were investigated for susceptibility to methicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin and cephalothin. The highest level of resistance was found to methicillin and the lowest to cephalothin. The resistance-level of the isoxazolyl penicillins showed a high degree of uniformity. However more strains were resistant to cloxacillin and oxacillin than to dicloxacillin and flucloxacillin. Only a weak correlation was found between beta-lactamase production, and resistance to the six antibiotics. Methicillin was the most stable. The inactivation of cephalothin differed from that of the other antibiotics.
Jarløv
J O
JO
Department of Clinical Microbiology, Hvidovre University Hospital, Copenhagen, Denmark.
Rosdahl
V T
VT
Mortensen
I
I
Bentzon
M W
MW
D002512:Cephalothin / Q000494:pharmacology*; D003030:Coagulase / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D008712:Methicillin / Q000494:pharmacology*; D010406:Penicillins / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology; D001618:beta-Lactamases / Q000378:metabolism*
D003030:Coagulase; D010406:Penicillins; D001618:beta-Lactamases; D008712:Methicillin; D002512:Cephalothin