title: Macrolide resistance phenotypes and genotypes in French clinical isolates of Streptococcus pneumoniae. Observatoire de Normandie du Pneumocoque.
abstract: The aim of this study was to analyze the mechanisms of macrolide resistance in French clinical isolates of Streptococcus pneumoniae. A total of 838 strains of pneumococci were isolated in 1997 in Normandy, a region of western France, by 19 microbiology laboratories. Fifty-three percent had displayed diminished susceptibility to penicillin G and 50% were resistant to erythromycin. From this collection, 92 penicillin-intermediate or -resistant and 18 penicillin-susceptible strains resistant to erythromycin were studied. The presence of erm genes coding for ribosomal methylases and of mefE-like genes responsible for macrolide efflux was screened by a multiplex polymerase chain reaction and confirmed by DNA/DNA hybridization. Of the 110 strains studied, 108 were cross-resistant to erythromycin, spiramycin and clindamycin, including 105 strains containing ermB-related genes and three strains that contained a combination of ermB- and mefE-related genes. Two strains apparently susceptible to clindamycin but resistant to spiramycin also contained ermB-related genes. No strain was resistant to erythromycin alone or contained only a mef-like gene. Therefore, resistance to erythromycin is mostly related to ribosomal methylation in this region of France.
authors: Service de Microbiologie, CHU C te de Nacre, Caen, France.
authors: P
authors: P
authors: Angot
authors: M
authors: M
authors: Vergnaud
authors: M
authors: M
authors: Auzou
authors: R
authors: R
authors: Leclercq
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004363:Drug Utilization; D005602:France; D005787:Gene Frequency; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D018942:Macrolides; D010641:Phenotype; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides