title: CTX-M-27- and CTX-M-14-producing, ciprofloxacin-resistant Escherichia coli of the H30 subclonal group within ST131 drive a Japanese regional ESBL epidemic.
abstract: OBJECTIVE
  The global increase in ESBL-producing Escherichia coli is associated with the ST131 clonal group, especially its CTX-M-15-producing H30Rx subset. To understand the rapid spread of ESBL-producing E. coli in Japan, we investigated the molecular epidemiology and ESBL-associated genetic environments of Japanese ST131 isolates.
  
  
  METHODS
  Between 2001 and 2012, 1079 ESBL-producing E. coli isolates were collected at 10 Japanese acute-care hospitals. ESBL types, ST131 status, fimH allele, H30Rx-defining sequences and ESBL-associated genetic environments were defined using PCR and sequencing. Subclonal groups were defined based on fimH allele and H30Rx status.
  
  
  RESULTS
  Overall, 461 (43%) of the 1079 ESBL-producing E. coli isolates represented ST131. According to fimH-based subclonal typing, the ST131 isolates included 398 fimH allele 30 (H30) isolates, 49 H41 isolates, 10 H22 isolates and 4 other fimH-type isolates. The 398 H30 isolates included 396 ciprofloxacin-resistant H30R isolates, of which 64 (16%) represented the H30Rx subset. Between 2001 and 2007, the CTX-M-14-producing H30R subgroup predominated, accounting for 46% of ST131 isolates, whereas the CTX-M-27-producing H30R and CTX-M-15-producing H30Rx subgroups were rarely detected. In contrast, from 2008 onward the latter two subgroups rose to dominance, accounting for 45% and 24% of ST131 isolates, respectively, versus only 15% for the (formerly dominant) CTX-M-14-producing H30R subgroup. The emergent CTX-M-27-H30R subgroup frequently had an IS26-ΔISEcp1-blaCTX-M-27-ΔIS903D-IS26-like structure, whereas the older CTX-M-14-H30R subgroup frequently had an ISEcp1-blaCTX-M-14-IS903D-like structure.
  
  
  CONCLUSIONS
  This Japanese regional ESBL-producing E. coli epidemic is closely associated with newly identified CTX-M-27- and CTX-M-14-producing ST131 H30R subclonal groups and with mobile elements IS26, ISEcp1 and IS903D.
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan yazblood@kuhp.kyoto-u.ac.jp.
authors: Yasufumi
authors: Y
authors: Matsumura
authors: Veterans Affairs Medical Center and University of Minnesota, Minneapolis, MN, USA.
authors: James R
authors: JR
authors: Johnson
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Masaki
authors: M
authors: Yamamoto
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Miki
authors: M
authors: Nagao
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Michio
authors: M
authors: Tanaka
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Shunji
authors: S
authors: Takakura
authors: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Satoshi
authors: S
authors: Ichiyama
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial; D058872:Epidemics; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000378:metabolism; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007564:Japan / Q000453:epidemiology; D017720:Molecular Epidemiology; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D065288:Serogroup; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D002939:Ciprofloxacin; C477098:CTX-M-27, E coli; C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases
keywords: CTX-M; E. coli; ESBLs; MLST; clonal genotypes