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The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
| ArticleTitle |
Multidrug-Resistant Phenotype and Prevalence of CTX-M-27 in Extended-Spectrum β-Lactamase-Producing Uropathogenic Escherichia coli |
| Language |
J |
| AuthorList |
Tatsuya Hattori1), Kunihiko Nakane1,2), Kumiko Kawamura1,3) |
| Affiliation |
1) Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine
2) City of Okazaki Reseach Center, Hygiene Testing Group
3) Department of Medical Technology, Nagoya University School of Health Science |
| Publication |
J.J.C.M.: 21 (1), 25-34, 2011 |
| Received |
July 30, 2010 |
| Accepted |
January 14, 2011 |
| Abstract |
The susceptibilities against 312 uropathogenic Escherichia coli strains isolated from clinical specimens were investigated, and 15 were extended-spectrum b-lactamase (ESBL)-producing isolates. Among the 15 ESBL-producing isolates, 13 were resistant to levofloxacin (LVFX) and 6 were resistant to both LVFX and trimethoprim/sulfamethoxazole (TMP/SMX), suggesting that ESBL-producing isolates tend to become multidrug-resistant (MDR) phenotypes. The genotypes of ESBL were determined by PCR and sequencing. Four isolates were CTX-M-14 producers and 8 isolates harbored blaCTX-M-27, which harbor the Asp240Gly substitution, have greater catalytic efficiencies against ceftazidime than parental enzymes. None of these isolates harbored plasmid-mediated quinolone resistance genes, but 6 were serotype O25: H4 among 13 ESBL-producing and LVFX-resistant isolates, suggesting fluoroquinolone-resistant phenotypes are associated with serotype O25. The CTX-M encoding plasmid was successfully transferred to recipient E. coli CSH-2 at a frequency of 3.4×10-5 cells per recipient by conjugation in vitro, suggesting the easy dissemination of blaCTX-M-harboring plasmids. Moreover, the transconjugants obtained showed both ESBL-producing and TMP/SMX-resistant phenotypes. Among uropathogenic E. coli, the serotype O25: H4 isolates harboring CTX-M-27 blaCTX-M have become prevalent strains, so due care should be taken in monitoring the epidemiology of ESBL-producing isolates. |
| Keywords |
extended-spectrum β-lactamase, uropathogenic Escherichia coli, CTX-M-27 |
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