title: Streptococcus agalactiae from pregnant women: antibiotic and heavy-metal resistance mechanisms and molecular typing.
abstract: We investigated the antibiotic and heavy-metal resistance mechanisms, virulence genes and clonal relationships of macrolide- and/or lincosamide-resistant (M+/-LR) Streptococcus agalactiae (group B Streptococcus, GBS) isolates from pregnant women in La Rioja in Northern Spain, a region with a significant immigrant population. In total 375 GBS isolates were recovered during 2011. About three-quarters of isolates were from European nationals and the remainder distributed among 23 other nationalities. Seventy-five (20%) were classified as M+/-LR strains and 28 (37%) of these were resistant to ⩾3 classes of antibiotics. Capsular serotypes III (29·3%), V (21·3%) and II (12%) were the most frequent. A wide variety of antibiotic resistance genes were detected in M+/-LR strains; notably, 5·3% harboured the lsa(C) gene associated with cross-resistance, and tet(W) was identified in a single strain. We report, for the first time, the detection of cadmium and copper resistance encoded by tcrB + cadA + cadC genes in 20 M+/-LR strains, which raises the possibility of co-selection of antibiotic and heavy-metal resistance disseminated through mobile genetic elements. The M+/-LR strains were highly diverse by DNA macrorestriction profiles (65 patterns) and 16 multilocus sequence types (STs) distributed among six clonal complexes; the most frequent were ST1, ST19, and ST12, and two strains were novel (ST586 and ST601). In conclusion, a wide diversity of genetic lineages of macrolide, lincosamide and heavy-metal- resistant GBS strains was observed in an ethnically diverse maternal population.
authors: Área de Microbiología Molecular,Centro de Investigación Biomédica de La Rioja (CIBIR),Logroño,Spain.
authors: B
authors: B
authors: Rojo-Bezares
authors: Área de Diagnóstico Biomédico,Laboratorio de Microbiología,Hospital San Pedro,Logroño,Spain.
authors: J M
authors: JM
authors: Azcona-Gutiérrez
authors: Área de Diagnóstico Biomédico,Laboratorio de Microbiología,Hospital San Pedro,Logroño,Spain.
authors: C
authors: C
authors: Martin
authors: Área de Diagnóstico Biomédico,Laboratorio de Microbiología,Hospital San Pedro,Logroño,Spain.
authors: M S
authors: MS
authors: Jareño
authors: Área de Microbiología Molecular,Centro de Investigación Biomédica de La Rioja (CIBIR),Logroño,Spain.
authors: C
authors: C
authors: Torres
authors: Área de Microbiología Molecular,Centro de Investigación Biomédica de La Rioja (CIBIR),Logroño,Spain.
authors: Y
authors: Y
authors: Sáenz
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D006801:Humans; D055231:Lincosamides / Q000494:pharmacology; D018942:Macrolides / Q000494:pharmacology; D019216:Metals, Heavy / Q000633:toxicity*; D008875:Middle Aged; D011247:Pregnancy; D013030:Spain / Q000453:epidemiology; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000187:drug effects* / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D014774:Virulence / Q000187:drug effects* / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides; D019216:Metals, Heavy; D037521:Virulence Factors
keywords: Antibiotic resistance; bacterial typing; streptococcal infections