Low in vitro selection frequencies of enterococcal and staphylococcal mutants resistant to the oxazolidinone AZD2563.
Mutants with oxazolidinone MICs, 2- to 16-fold higher than those of parents, were selected from two of five clinical isolates of Enterococcus faecalis during exposure to AZD2563, but only at frequencies of ca. 10(-8). Resistance was not selected in Enterococcus faecium, Staphylococcus aureus or coagulase-negative staphylococci (CoNS). Mutants of one E. faecalis isolate had a G2576-->U 23S rRNA mutation; mutants derived from the second E. faecalis isolate lacked this mutation.
Stockdale
Mark W
MW
Antibiotic Resistance Monitoring and Reference Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency-Colindale, 61 Colindale Ave, London NW9 5HT, UK.
Tysall
Luke
L
Johnson
Alan P
AP
Livermore
David M
DM
Woodford
Neil
N
D016983:Enterococcus / Q000187:drug effects* / Q000302:isolation & purification; D066298:In Vitro Techniques; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D023303:Oxazolidinones / Q000737:chemistry* / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification
D023303:Oxazolidinones