title: Transition mutations in 23S rRNA account for acquired resistance to macrolides in Ureaplasma urealyticum.
abstract: OBJECTIVE
  To study the mechanisms of acquired resistance of Ureaplasma urealyticum (Uu) to Macrolide antibiotics.
  
  
  METHODS
  Eighteen strains of Uu clinical isolates with different phenotypes of resistance to Macrolide antibiotics were screened for mutations in 23S rRNA in comparison with the reference strain ATCC 27618 and AF272627-1 in GenBank, which is susceptible to Macrolide antibiotics.
  
  
  RESULTS
  Compared to the sequence of reference strains ATCC 27618 and AF272627-1, three transitions were found in 23S rRNA of Uu clinical isolates with acquired resistance to Macrolide antibiotics. The C2243N (T or C) transition was found in the 23S rRNA sequence of five strains with the phenotype of acquired resistance to Roxithromycin (ROM) and Azithromycin (AZM). The two changes of A2149C and A2181T were found in the 23S rRNA sequence of nine strains with the phenotype of resistance to ROM and midrange resistance to AZM, and they were also found in that of four strains with the phenotype of sensitivity to macrolides (Josamycin, Clarithromycin, ROM, and AZM). No mutation was found in the ATCC 27618.
  
  
  CONCLUSIONS
  The mechanisms of Uu resistance to ROM and AZM may be associated with the C2243N (T or C) mutation in 23S rRNA. Further studies are necessary to confirm this hypothesis.
authors: Department of Clinical laboratory, Liao Ning North Hospital, Shenyang, Liaoning, China.
authors: Meng
authors: M
authors: Dongya
authors: Xue
authors: X
authors: Wencheng
authors: Ma
authors: M
authors: Xiaobo
authors: Wang
authors: W
authors: Lu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D012338:RNA, Ribosomal, 23S / Q000235:genetics*; D016990:Ureaplasma urealyticum / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D012338:RNA, Ribosomal, 23S