Prevalence of fluoroquinolone-resistant Escherichia coli O25:H4-ST131 (CTX-M-15-nonproducing) strains isolated in Japan.
ABSTRACT Fluoroquinolone-resistant and extended-spectrum β-lactamase (ESBL)-carrying multidrug-resistant Escherichia coli have become severely problematic. In particular, a lineage of multilocus sequence-type ST131 which belongs to O25:H4 and carries ESBL CTX-M-15 has spread worldwide.
Fluoroquinolone-resistant E. coli strains were isolated from various clinical specimens in a commercial clinical laboratory in 2008 and 2009 in Hokkaido Prefecture, Japan.
Among 478 clinical isolates, 112 strains (23.4%) showed levofloxacin (LVX) resistance. About 80% of the fluoroquinolone-resistant strains (88 strains) showed common features, namely O25:H4-ST131, phylogenetic group B and the same mutation pattern in quinolone resistance-determining regions. Pulsed field gel electrophoresis patterns suggested numerous lineages of O25:H4-ST131. The fluoroquinolone-resistant strains, including strains of O25:H4-ST131 and other types, more frequently shared CTX-type ESBL genes than did fluoroquinolone-susceptible strains. The ESBL genes fell into the CTX-M-9 and CTX-M-2 groups. CTX-M-15 (CTX-M-1 group) was not found among any of the strains isolated in this study. Sitafloxacin showed markedly potent activity against E. coli isolates compared with LVX, ciprofloxacin and ulifloxacin.
The most prevalent fluoroquinolone-resistant strains of E. coli isolated in Hokkaido Prefecture, Japan, are O25:H4-ST131. However, similar to other areas of Japan, the ST131 clones represent distinct lineages from the general worldwide dispersal of multidrug-resistant clones which carry CTX-M-15.
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ABSTRACT: Resistance to broad-spectrum cephalosporins (BSCs) in Enterobacteriaceae in companion animals has become a great concern for public health. To estimate the dissemination of BSC-resistant bacteria between dog and human, we examined the BSC-resistance determinants of and genetic similarities between 69 BSC-resistant Escherichia coli isolates derived from canine rectal swabs (n = 28) and human clinical samples (n = 41). Some E. coli isolates possessed blaTEM-1b (14 canine and 16 human isolates), blaCTx-M-2 (6 human isolates), blaCTx-M-14 (3 canine and 14 human isolates), blaCTx-M-27 (1 canine and 15 human isolates), and blaCMY-2 (11 canine and 3 human isolates). The possession of CTX-M-type β-lactamases was significantly more frequent in human isolates, whereas CMY-2 was more common in canine isolates. Bacterial typing methods (phylogenetic typing, O-antigen serotyping, and pulsed-field gel electrophoresis) showed little clonal relationship between canine isolates and human isolates. Plasmid analysis and Southern blotting indicated that the plasmids encoding CMY-2 were similar among canine and human isolates. Based on the differences in the major β-lactamase and the divergence of bacterial types between canine and human isolates, it seems that clonal dissemination of BSC-resistant E. coli between canines and humans is limited. The similarity of the CMY-2-encoding plasmid suggests that plasmid-mediated β-lactamase gene transmission plays a role in interspecies diffusion of BSC-resistant E. coli between dog and human.Journal of Infection and Chemotherapy 04/2014; 20(4):243-9. · 1.38 Impact Factor
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ABSTRACT: Background To compare the epidemiological and clinical features and outcome in clonal group O25b/ST131 and non-clonal group O25b/ST131 in adult patients with non-extended-spectrum B-lactamase (ESBL)-producing Escherichia coli (E. coli) bacteraemia.Methods We collected 371 consecutive isolates with community-onset non-ESBL producing E. coli bloodstream infection in 2010 in a 1200-bed hospital in Taiwan. Twenty adult patients with clonal group O25b/ST131 and 40 patients with non-clonal group O25b/ST131 were compared.ResultClonal group O25b/ST131 accounted for 5.9% of total isolates. The underlying disease and healthcare-associated risk factors were similar in the case and control groups. Patients with the clonal group O25b/ST131 were less likely to have intra-abdominal infection (0% vs. 22.5%; p¿<¿0.05) than patients from the control group. The Day 30 mortality rate was similar in the case and control groups (15% vs. 12.5%).Conclusions Clonal group O25b/ST131 was found in both multidrug-resistant and susceptible E. coli strains, causing community-onset bloodstream infection. Although O25b/ST131 does not lead to a higher mortality than other isolates, choosing an appropriate antimicrobials in the empirical therapy of community-onset E. coli bacteraemia has become more challenging.BMC Infectious Diseases 11/2014; 14(1):579. · 2.56 Impact Factor
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ABSTRACT: (See the commentary by Rogers and Doi, on pages 370-372 .) Objective. To determine prevalence, predictors, and outcomes of infection due to Escherichia coli sequence type ST131. Design. Retrospective cohort. Setting. All healthcare settings in Olmsted County, Minnesota (eg, community hospital, tertiary care center, long-term care facilities, and ambulatory clinics). Patients. Ambulatory and hospitalized children and adults with extraintestinal E. coli isolates. Methods. We analyzed 299 consecutive, nonduplicate extraintestinal E. coli isolates submitted to Olmsted County laboratories in February and March 2011. ST131 was identified using single-nucleotide polymorphism polymerase chain reaction and further evaluated through pulsed-field gel electrophoresis. Associated clinical data were abstracted through medical record review. Results. Most isolates were from urine specimens (90%), outpatients (68%), and community-associated infections (61%). ST131 accounted for 27% of isolates overall and for a larger proportion of those isolates resistant to fluoroquinolones (81%), trimethoprim-sulfamethoxazole (42%), gentamicin (79%), and ceftriaxone (50%). The prevalence of ST131 increased with age (accounting for 5% of isolates from those 11-20 years of age, 26% of isolates from those 51-60 years of age, and 50% of isolates from those 91-100 years of age). ST131 accounted for a greater proportion of healthcare-associated isolates (49%) than community-associated isolates (15%) and for fully 76% of E. coli isolates from long-term care facility (LTCF) residents. Multivariable predictors of ST131 carriage included older age, LTCF residence, previous urinary tract infection, high-complexity infection, and previous use of fluoroquinolones, macrolides, and extended-spectrum cephalosporins. With multivariable adjustment, ST131-associated infection outcomes included receipt of more than 1 antibiotic (odds ratio [OR], 2.54 [95% confidence interval (CI), 1.25-5.17]) and persistent or recurrent symptoms (OR, 2.53 [95% CI, 1.08-5.96]). Two globally predominant ST131 pulsotypes accounted for 45% of ST131 isolates. Conclusions. ST131 is a dominant, antimicrobial-resistant clonal group associated with healthcare settings, elderly hosts, and persistent or recurrent symptoms.Infection Control and Hospital Epidemiology 04/2013; 34(4):361-9. · 4.02 Impact Factor