Distribution of genes encoding resistance to macrolides, lincosamides, and streptogramins among staphylococci.
The relative frequency of 10 determinants of resistance to macrolides, lincosamides, and streptogramins was investigated by PCR in a series of 294 macrolide-, lincosamide-, and/or streptogramin-resistant clinical isolates of Staphylococcus aureus and coagulase-negative staphylococci isolated in 1995 from 32 French hospitals. Resistance was mainly due to the presence of ermA or ermC genes, which were detected in 259 strains (88%), in particular those resistant to methicillin (78% of the strains). Macrolide resistance due to msrA was more prevalent in coagulase-negative staphylococci (14.6%) than in S. aureus (2.1%). Genes related to linA/linA' and conferring resistance to lincomycin were detected in one strain of S. aureus and seven strains of coagulase-negative staphylococci. Resistance to pristinamycin and quinupristin-dalfopristin was phenotypically detected in 10 strains of S. aureus and in three strains of coagulase-negative staphylococci; it was always associated with resistance to type A streptogramins encoded by vat or vatB genes and occurred in association with erm genes. The vga gene conferring decreased susceptibility to type A streptogramins was present alone in three strains of coagulase-negative staphylococci and in combination with erm genes in 10 strains of coagulase-negative staphylococci. A combination of vga-vgb-vat and ermA genes was found in a single strain of S. epidermidis.
Lina
G
G
Faculté de Médecine, Laboratoire de Bactériologie, Centre National de Référence des Toxémies à Staphylocoques, EA 1655, 69372 Lyon Cedex 08, France. geralina@univ-lyon1.fr
Quaglia
A
A
Reverdy
M E
ME
Leclercq
R
R
Vandenesch
F
F
Etienne
J
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D055231:Lincosamides; D018942:Macrolides; D013210:Staphylococcus / Q000187:drug effects / Q000235:genetics*; D014769:Virginiamycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides; D014769:Virginiamycin