title: Human vaginal Lactobacillus rhamnosus harbor mutation in 23S rRNA associated with erythromycin resistance.
abstract: Little is known about the diversity and distribution of resistance determinants in human commensal bacteria. The aim of this study was to determine the molecular mechanism responsible for high-level erythromycin resistance among five human vaginal Lactobacillus rhamnosus isolates. PCR screening for the presence of ermA, ermB and ermC methylase genes revealed no determinants responsible for detected erythromycin resistance. Therefore, sequences of 23S rRNA genes from L. rhamnosus strains were studied by PCR-RFLP analysis and sequencing of 23S rRNA genes. According to the results, in all erythromycin-resistant L. rhamnosus strains, the presence of a A-->G transition mutation at position 2058 was discovered. Additionally, the isolates exhibited heterozygosity for the A2058/G2058 mutation among 23S rRNA gene copies. Presumably, the greatest number of mutated 23S rRNA operons was observed for the L. rhamnosus BGHV1' strain that also had the highest MIC for erythromycin (MIC=2048 microg mL(-1)). This study reports the presence of transition mutations in the V region of 23S rRNA genes that most probably account for high-level erythromycin resistance observed for the first time in human vaginal lactobacilli.
authors.affiliation: Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, 11010 Belgrade, Serbia. lab6@eunet.yu
authors.forename: Jelena
authors.initials: J
authors.lastname: Begovic
authors.forename: Geert
authors.initials: G
authors.lastname: Huys
authors.forename: Baltasar
authors.initials: B
authors.lastname: Mayo
authors.forename: Klaas
authors.initials: K
authors.lastname: D'Haene
authors.forename: Ana Belén
authors.initials: AB
authors.lastname: Florez
authors.forename: Jelena
authors.initials: J
authors.lastname: Lozo
authors.forename: Milan
authors.initials: M
authors.lastname: Kojic
authors.forename: Ivana
authors.initials: I
authors.lastname: Strahinic
authors.forename: Ljubisa
authors.initials: L
authors.lastname: Topisirovic
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004917:Erythromycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D052201:Lacticaseibacillus rhamnosus / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D014621:Vagina / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012338:RNA, Ribosomal, 23S; D004917:Erythromycin