title: Increase in the rate of azithromycin-resistant Streptococcus pneumoniae isolates carrying the erm(B) and mef(A) genes in Taiwan, 2006-2010.
abstract: BACKGROUND
  This study investigated the molecular characteristics of azithromycin-resistant Streptococcus pneumoniae in Taiwan.
  
  
  METHODS
  A total of 486 non-duplicate isolates of azithromycin-resistant S. pneumoniae recovered from various clinical sources of patients treated at 22 different hospitals in Taiwan from 2006 to 2010. The presence of erm(B) and mef(A) genes using duplex PCR, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis of these isolates were studied.
  
  
  RESULTS
  Of the isolates tested, 59% carried the erm(B) gene, 22% carried the mef(A) gene, and 19% carried both genes. The prevalence of isolates carrying the erm(B) and mef(A) genes increased from 10% (11/110) in 2006 to 25% (15/60) in 2010 (p-value = 0.0136). The majority of isolates carrying both erm(B) and mef(A) genes belonged to serotypes 19 F (64%) followed by 19 F A (24%). Of these isolates, 33% were sequence type 320 (ST320), 32% were ST236, and 12% were ST271.
  
  
  CONCLUSIONS
  The increase in incidence of mef(A)/erm(B)-positive azithromycin-resistant S. pneumoniae isolates during the study period was primarily due to serotypes 19 F and 19A and ST236 and ST320.
authors.affiliation: Eijkman Institute for Molecular Biology, Jakarta, Indonesia. dodi.safari@gmail.com.
authors.forename: Dodi
authors.initials: D
authors.lastname: Safari
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. lckuo@ntu.edu.tw.
authors.forename: Lu-Cheng
authors.initials: LC
authors.lastname: Kuo
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan. yutsunghuang@gmail.com.
authors.forename: Yu-Tsung
authors.initials: YT
authors.lastname: Huang
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan. liaochunhsing@gmail.com.
authors.forename: Chun-Hsing
authors.initials: CH
authors.lastname: Liao
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. whsheng@ntu.edu.tw.
authors.forename: Wang-Huei
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. hsporen@ntu.edu.tw.|Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. hsporen@ntu.edu.tw.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017963:Azithromycin / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008780:Methyltransferases / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D016133:Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C117866:MefA protein, Streptococcus; D008565:Membrane Proteins; D017963:Azithromycin; D008780:Methyltransferases; C035181:rRNA (adenosine-O-2'-)methyltransferase