Characterization of Extended-Spectrum β-Lactamases Produced byEscherichia coliIsolated from Hospitalized and Nonhospitalized Patients: Emergence of CTX-M-15-Producing Strains Causing Urinary Tract Infections

Abstract

Extended-spectrum b-lactamase (ESBL)-producing Escherichia coli isolates were obtained from hospitalized and nonhospitalized patients in Belgium between August 2006 and November 2007. The antimicrobial susceptibility of these isolates was determined and their ESBL genes were characterized. Clonal relationships between the CTX-Mproducing E. coli isolates causing urinary tract infections were also studied. A total of 90 hospital-and 45 community-acquired cephalosporin-resistant E. coli isolates were obtained. Tetracycline, enrofloxacine, gentamicin, and trimethoprim-sulfamethaxozole resistance rates were significantly different between the community-onset and hospital-acquired isolates. A high diversity of different ESBLs was observed among the hospital-acquired E. coli isolates, whereas CTX-M-15 was dominating among the community-acquired E. coli isolates (n ¼ 28). Thirteen different pulsed-field gel electrophoresis profiles were observed in the community-acquired CTX-M-15-producing E. coli, indicating that multiple clones have acquired the bla CTX-M-15 gene. All community-acquired CTX-M-15-producing E. coli isolates of phylogroups B2 and D were assigned to the sequence type ST131. The hospital-acquired CTX-M-15-producing E. coli isolates of phylogroups B2, B1, A, and D corresponded to ST131, ST617, ST48, and ST405, respectively. In conclusion, CTX-M-type ESBLs have emerged as the predominant class of ESBLs produced by E. coli isolates in the hospital and community in Belgium. Of particular concern is the predominant presence of the CTX-M-15 enzyme in ST131 community-acquired E. coli.

Sequence Type 48 Escherichia coli Carrying the bla CTX-M-1 IncI1/ST3 Plasmid in Drinking Water in France

“…The bla CTX-M-1 gene was carried by a 100-kb IncI1/ST3 plasmid, as detected with S1 nuclease treatment of DNA followed by pulsed-field gel electrophoresis (PFGE), Southern blot hybridizations with adequate digoxigenin (DIG)-labeled probes (Roche Applied Science, Mannheim, Germany), PCRbased replicon typing (Diatheva, Fano, Italy), and plasmid multilocus sequence typing (MLST) (5). The restriction fragment length polymorphism (RFLP) profile of the IncI1/ST3 plasmid after digestion with PstI or EcoRI was comparable but nonidentical to those of previously published bla CTX-M-1 IncI/ , an ST that has been observed previously in both humans and animals (7,8).…”

Antibiotic Susceptibilities and Genetic Characteristics of Extended-Spectrum Beta-Lactamase-Producing <i>Escherichia coli</i> Isolates from Stools of Pediatric Diarrhea Patients in Surabaya, Indonesia

“…The CTX-M-15-type ESBL-producing E. coli ST131 clone has spread across many regions of the world (28)(29)(30)(31). Our data showed that the CTX-M-15-type comprised 84 of the strains, including some strains with a combination CTX-M-15 and TEM-1 or SHV-7.…”

“…ESBL-producing strain ST617 has also spread worldwide (28,29,39,40) and can be found, for instance, in Belgium, Sweden, Nigeria, and France. Our MLST data showed that, although 24 of the ESBL-producing strains were non-typable, ST617 was commonly found in our ESBL isolates, as in the aforementioned studies; ST617 strains had higher resistance to most of the antibiotics tested in this study, except IPM, AMK, and FOM.…”

Virulence potential and adherence properties of Escherichia coli that produce CTX-M and NDM β-lactamases

“…ST131 is prevalent in most parts of the world, and is often associated with fluoroquinolone resistance and the production of CTX-M-15. ST405 with various types of CTX-M b-lactamases also has a worldwide distribution but is not as prevalent as ST131 (Coque et al, 2008;Jones et al, 2008;Mihaila et al, 2010;Smet et al, 2010). These reports suggest that the intercontinental dissemination of ST131, and to a lesser extent ST405, has in part contributed to the worldwide emergence of CTX-M-producing E. coli.…”