title: Dissemination of ST131 and ST393 community-onset, ciprofloxacin-resistant Escherichia coli clones causing urinary tract infections in Korea.
abstract: OBJECTIVE
  Ciprofloxacin-resistant Escherichia coli is growing concern in clinical settings. In this study, we investigated the distribution of virulence determinants and phylogenetic groups among community-onset, ciprofloxacin-resistant E. coli isolates causing urinary tract infections (UTIs) in Korea. In addition, the evidence of clonal spread in the community was also examined.
  
  
  METHODS
  From November 2006 to August 2007, 543 community-onset E. coli isolates causing UTIs were collected as part of a multicenter surveillance study. In vitro susceptibility testing was performed using broth microdilution method. Distribution of virulence determinants and phylogenetic groupings were examined. In addition, multilocus sequence typing (MLST) analysis was performed.
  
  
  RESULTS
  In vitro antimicrobial susceptibility testing revealed that 154 isolates (28.4%) were ciprofloxacin-resistant. Of these, 129 ciprofloxacin-resistant E. coli isolates were further characterized. As a result of phylogenetic subgrouping, we found that phylogenetic subgroup D was the most predominant (46 isolates, 35.7%), followed by B2 (44 isolates, 34.1%), A (21 isolates, 16.3%), and B1 (18 isolates, 14.0%). MLST analysis showed 48 sequence types (STs). The most prevalent ST was ST131 (32 isolates, 24.8%), followed by ST393 (23 isolates, 17.8%). While all ST131 isolates belonged to phylogenetic subgroup B2, which is known to be a highly virulent, all ST393 isolates belonged to subgroup D. ST131 and ST393 showed different profiles of virulence factors; papA, papG allele III, and traT genes were significantly more prevalent in ST131 than in ST393 (p values, <0.001).
  
  
  CONCLUSIONS
  Based on genotyping, it is suggested that epidemic and virulent ciprofloxacin-resistant E. coli clones such as ST131 and ST393 have disseminated in Korea. However, the diversity of CTX-M genes in ST131 isolates may indicate that ESBL genes have been acquired independently or several ESBL-producing, ciprofloxacin-resistant E. coli clones may have disseminated in the Korean community.
authors.affiliation: Asian-Pacific Research Foundation for Infectious Diseases (ARFID), Seoul, South Korea.
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Lee
authors.forename: Hyeon Jin
authors.initials: HJ
authors.lastname: Choi
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Minsuk
authors.initials: M
authors.lastname: Song
authors.forename: Yoosuk
authors.initials: Y
authors.lastname: Song
authors.forename: Shin-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Hyun-Ha
authors.initials: HH
authors.lastname: Chang
authors.forename: Sook-In
authors.initials: SI
authors.lastname: Jung
authors.forename: Yeon-Sook
authors.initials: YS
authors.lastname: Kim
authors.forename: Hyun Kyun
authors.initials: HK
authors.lastname: Ki
authors.forename: Jun Seong
authors.initials: JS
authors.lastname: Son
authors.forename: Ki Tae
authors.initials: KT
authors.lastname: Kwon
authors.forename: Sang Taek
authors.initials: ST
authors.lastname: Heo
authors.forename: Joon-Sup
authors.initials: JS
authors.lastname: Yeom
authors.forename: Sang Yop
authors.initials: SY
authors.lastname: Shin
authors.forename: Doo Ryeon
authors.initials: DR
authors.lastname: Chung
authors.forename: Kyong Ran
authors.initials: KR
authors.lastname: Peck
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Song
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Ko
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002939:Ciprofloxacin / Q000494:pharmacology*; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010802:Phylogeny; D056910:Republic of Korea / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D037521:Virulence Factors; D002939:Ciprofloxacin