title: Macrolide resistance phenotypes of commensal viridans group streptococci and Gemella spp. and PCR detection of resistance genes.
abstract: One hundred and sixty viridans group streptococci (VGS) and 26 Gemella spp. resistant to erythromycin were studied to detect macrolide lincosamide and streptogramin B (MLS(B)) phenotypes and to investigate resistance rates to other antibiotics. The M phenotype was most prevalent in both bacterial groups (59.6% in VGS, 69.2% in gemellae) and the iMLS(B) phenotype was found least often (9.3 and 13.9%, respectively). All isolates with M phenotype had the mef(A/E) gene, being prevalent the mef(E) subclass. cMLS(B) and iMLS(B) strains contained the erm(B) gene, alone or in combination with the mef(A/E) gene. Thirteen isolates were intermediately resistant to quinupristin/dalfopristin and 11 strains showed low susceptibility to telithromycin. Linezolid was active against all the isolates tested and tetracycline resistance was the major one in VGS (41.6%) and Gemella spp. (46.2%).
authors.affiliation: Department of Microbiology, Faculty of Medicine, Clinical University Hospital "Lozano Blesa", University of Zaragoza, c/Domingo Miral s/n, 50009 Zaragoza, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Cerdá Zolezzi
authors.forename: M C
authors.initials: MC
authors.lastname: Rubio Calvo
authors.forename: L
authors.initials: L
authors.lastname: Millán
authors.forename: P
authors.initials: P
authors.lastname: Goñi
authors.forename: M
authors.initials: M
authors.lastname: Canales
authors.forename: S
authors.initials: S
authors.lastname: Capilla
authors.forename: E
authors.initials: E
authors.lastname: Durán
authors.forename: R
authors.initials: R
authors.lastname: Gómez-Lus
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D004917:Erythromycin / Q000494:pharmacology; D005798:Genes, Bacterial; D006801:Humans; D048628:Ketolides / Q000494:pharmacology; D055231:Lincosamides; D000069349:Linezolid; D018942:Macrolides / Q000494:pharmacology*; D008565:Membrane Proteins / Q000235:genetics; D008780:Methyltransferases / Q000235:genetics; D008826:Microbial Sensitivity Tests; D023303:Oxazolidinones / Q000494:pharmacology; D040141:Staphylococcaceae / Q000187:drug effects* / Q000235:genetics*; D025381:Streptogramin B / Q000494:pharmacology; D013753:Tetracycline Resistance; D014769:Virginiamycin / Q000494:pharmacology; D034363:Viridans Streptococci / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D048628:Ketolides; D055231:Lincosamides; D018942:Macrolides; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins; D023303:Oxazolidinones; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D025381:Streptogramin B; D004917:Erythromycin; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase; D000069349:Linezolid; C106791:telithromycin