title: Regional outbreak of CTX-M-2 β-lactamase-producing Proteus mirabilis in Japan.
abstract: Proteus mirabilis is a common cause of urinary tract infection. Wild-type P. mirabilis strains are usually susceptible to penicillins and cephalosporins, but occurrences of P. mirabilis producing extended-spectrum β-lactamases (ESBLs) have been recently reported. Here, we surveyed the prevalence of cefotaxime resistance among P. mirabilis strains at seven different hospitals in Kanagawa Prefecture, Japan, and investigated their molecular epidemiology to explain the mechanism of their spread. The prevalence of cefotaxime resistance among P. mirabilis increased annually, from 10.1 % in 1998 to 23.1 % in 2003, and increased drastically in 2004, exceeding 40 %. We collected 105 consecutive and non-duplicate cefotaxime-resistant P. mirabilis isolates (MIC 16 to >256 µg ml(-1)) from these hospitals from June 2004 to May 2005 and characterized their profile. PCR and sequence analysis revealed that all resistant strains produced exclusively CTX-M-2 β-lactamase. PFGE analysis identified 47 banding patterns with 83 % or greater similarity. These results indicated that a regional outbreak of P. mirabilis producing CTX-M-2 β-lactamase has occurred in Japan and suggest that the epidemic spread occurred within and across hospitals and communities by extended clonal strains. Plasmid analysis revealed that 44.8 % of plasmids harboured by bla(CTX-M-2) isolates had common profiles, encoding ISEcp1, IS26 and Int1, and belonged to incompatibility group T. Spread of the resistant isolates in Japan resulted from dissemination of narrow-host-range plasmids of the IncT group encoding bla(CTX-M-2). These findings indicate the rapidly developing problem of treating the species to prevent dissemination of ESBL producers.
authors.affiliation: Department of Microbiology and Immunology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan.|Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nakano
authors.affiliation: School of Veterinary Medicine Azabu University, 1-17-71 Fuchinobe, Chuoh-ku, Sagamihara, Kanagawa 252-5201, Japan.
authors.forename: Akiyo
authors.initials: A
authors.lastname: Nakano
authors.affiliation: Department of Medical Laboratory Sciences, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Microbiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.|Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Matsuhisa
authors.initials: M
authors.lastname: Inoue
authors.affiliation: Department of Microbiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.|Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Okamoto
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002439:Cefotaxime / Q000494:pharmacology*; D003428:Cross Infection; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D010957:Plasmids; D011512:Proteus Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011513:Proteus mirabilis / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; C071167:beta-lactamase CTX-2; D001618:beta-Lactamases; D002439:Cefotaxime