title: Increasing Incidence of High-Level Tetracycline-Resistant Neisseria gonorrhoeae due to Clonal Spread and Foreign Import.
abstract: OBJECTIVE
  The detection of high-level tetracycline-resistant strains of Neisseria gonorrhoeae (TRNG) can make important epidemiological contributions that are relevant to controlling infections from this pathogen. In this study, we aimed to determine the incidence of TRNG isolates over time and also to investigate the characteristics and genetic epidemiology of these TRNG isolates in Korea.
  
  
  METHODS
  The antimicrobial susceptibilities of 601 isolates of N. gonorrhoeae from 2004 to 2011 were tested by standard Clinical and Laboratory Standards Institute methods. To determine the molecular epidemiological relatedness, N. gonorrhoeae multi-antigen sequence typing was performed.
  
  
  RESULTS
  The incidence of TRNG increased from 2% in 2004 to 21% in 2011. The minimum inhibitory concentration distributions of ceftriaxone and susceptibility of ciprofloxacin in TRNG were different from non-TRNG and varied according to the year of isolation. Most of the TRNG isolates collected from 2004 to 2007 exhibited genetic relatedness, with sequence type (ST) 1798 being the most common. From 2008 to 2011, the STs of the isolates became more variable and introduction of genetically unrelated TRNG were noted.
  
  
  CONCLUSIONS
  The increased incidence of TRNG strains until 2007 appears to be due, at least in part, to clonal spread. However, we propose that the emergence of various STs since 2008 could be associated with foreign import.
authors: Department of Laboratory Medicine, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, Korea.
authors: Hyukmin
authors: H
authors: Lee
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Hyunsoo
authors: H
authors: Kim
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Hyo Jin
authors: HJ
authors: Kim
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Young Hee
authors: YH
authors: Suh
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Dongeun
authors: D
authors: Yong
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Seok Hoon
authors: SH
authors: Jeong
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea. leekcp@yuhs.ac.
authors: Kyungwon
authors: K
authors: Lee
authors: Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
authors: Yunsop
authors: Y
authors: Chong
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002443:Ceftriaxone / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D004269:DNA, Bacterial / Q000032:analysis; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006069:Gonorrhea / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D015994:Incidence; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D009344:Neisseria gonorrhoeae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D056910:Republic of Korea / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D013752:Tetracycline / Q000494:pharmacology; D013754:Tetracyclines / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D013754:Tetracyclines; D002939:Ciprofloxacin; D002443:Ceftriaxone; D013752:Tetracycline
keywords: NG-MAST; Neisseria gonorrhoeae; antimicrobial resistance; epidemiology; tetracycline