Clonal Dissemination of a CTX-M-15  -Lactamase-Producing Escherichia coli Strain in the Paris Area, Tunis, and Bangui (original) (raw)

Spread of Extended-Spectrum -Lactamase CTX-M-Producing Escherichia coli Clinical Isolates in Community and Nosocomial Environments in Portugal

Antimicrobial Agents and Chemotherapy, 2007

Of the 181 unduplicated Escherichia coli strains isolated in nine different hospitals in three Portuguese regions, 119 were extended-spectrum ␤-lactamase (ESBL)-CTX-M producers and were selected for phenotype and genotype characterization. CTX-M producer strains were prevalent among community-acquired infections (56%), urinary tract infections (76%), and patients >60 years old (76%). In MIC tests, all strains were resistant to cefotaxime, 92% were resistant to ceftazidime, 93% were resistant to quinolones, 89% were resistant to aminoglycoside, and 26% were resistant to trimethoprim-sulfamethoxazole; all strains were sensitive to carbapenems, and 92% of the strains had a multidrug resistance phenotype. Molecular methods identified 109 isolates harboring a bla CTX-M-15 gene, 1 harboring the bla CTX-M-32 gene (first identification in the country), and 9 harboring the bla CTX-M-14 gene. All isolates presented the ISEcp1 element upstream from the bla CTX-M genes; one presented the IS903 element (downstream of bla CTX-M-14 gene), and none had the IS26 element; 85% carried bla TEM-1B , and 84% also carried a bla OXA-30 . Genetic relatedness analysis based on pulsed-field gel electrophoresis defined five clusters and indicated that 76% of all isolates (from cluster IV) corresponded to a single epidemic strain. Of the 47 strains from one hospital, 41 belonged to cluster IV and were disseminated in three main wards. CTX-M-producing E. coli strains are currently a problem in Portugal, with CTX-M-15 particularly common. This study suggests that the horizontal transfer of bla CTX-M genes, mediated by plasmids and/or mobile elements, contributes to the dissemination of CTX-M enzymes to community and hospital environments. The use of extended-spectrum cephalosporins, quinolones, and aminoglycosides is compromised, leaving carbapenems as the therapeutic option for severe infections caused by ESBL producers.

Spread of Extended-Spectrum β-Lactamase CTX-M-Producing Escherichia coli Clinical Isolates in Community and Nosocomial Environments in Portugal

Antimicrobial Agents and Chemotherapy, 2007

Of the 181 unduplicated Escherichia coli strains isolated in nine different hospitals in three Portuguese regions, 119 were extended-spectrum β-lactamase (ESBL)-CTX-M producers and were selected for phenotype and genotype characterization. CTX-M producer strains were prevalent among community-acquired infections (56%), urinary tract infections (76%), and patients ≥60 years old (76%). In MIC tests, all strains were resistant to cefotaxime, 92% were resistant to ceftazidime, 93% were resistant to quinolones, 89% were resistant to aminoglycoside, and 26% were resistant to trimethoprim-sulfamethoxazole; all strains were sensitive to carbapenems, and 92% of the strains had a multidrug resistance phenotype. Molecular methods identified 109 isolates harboring a bla CTX-M-15 gene, 1 harboring the bla CTX-M-32 gene (first identification in the country), and 9 harboring the bla CTX-M-14 gene. All isolates presented the IS Ecp1 element upstream from the bla CTX-M genes; one presented the IS 90...

Dissemination of Clonally Related Escherichia Coli Strains Expressing Extended-Spectrum β-Lactamase CTX-M-15

Emerging Infectious …, 2008

We analyzed 43 CTX-M-15–producing Escherichia coli isolates and 6 plasmids encoding the blaCTX-M-15 gene from Canada, India, Kuwait, France, Switzerland, Portugal, and Spain. Most isolates belonged to phylogroups B2 (50%) and D (25%). An EC-B2 strain of clonal complex sequence type (ST) 131 was detected in all countries; other B2 isolates corresponded to ST28, ST405, ST354, and ST695 from specific areas. EC-D strains were clonally unrelated but isolates from 3 countries belonged to ST405. All CTX-M-15 plasmids corresponded to IncFII group with overrepresentation of 3 HpaI-digested plasmid DNA profiles (A, B and C; 85–120kb, similarity >70%). Plasmid A was detected in EC-B2 strains (ST131, ST354, or ST405), plasmid C was detected in B2 and D strains, and plasmid B was confined to worldwide-disseminated ST131. Most plasmids contained blaOXA-1, aac(6′)-Ib-cr, and blaTEM-1. Worldwide dissemination of CTX-M-15 seems to be determined by clonal complexes ST131 and ST405 and multidrug-resistant IncFII plasmids.

Identification and Broad Dissemination of the CTX-M-14 Lactamase in Different Escherichia coli Strains in the Northwest Area of Spain

Journal of Clinical Microbiology, 2002

During the course of a molecular epidemiology study of mechanisms of antibiotic resistance in the area served by our hospital (516,000 inhabitants), we isolated the gene encoding CTX-M-14 ␤-lactamase. Thirty clinical strains (27 Escherichia coli and 3 Klebsiella pneumoniae isolates) with a phenotype of extended-spectrum ␤-lactamase were collected from January to October 2001 and studied for the presence of the CTX-M-14 ␤lactamase gene. By isoelectric point determination, PCR, and nucleotide sequencing, we detected the presence of this gene in 17 E. coli strains belonging to 15 different genotypes (REP-PCR) causing infections in 17 different patients. Epidemiological studies based on medical records did not suggest any relationship between the patients infected with these E. coli strains and, interestingly, 7 of 30 patients harboring strains with extended-spectrum ␤-lactamases never had contact with the hospital environment before the clinical E. coli isolation. Conjugation experiments revealed that this gene was plasmid mediated in the 17 E. coli strains, and plasmid restriction fragment length polymorphisms showed 9 different patterns in the 17 E. coli strains. By PCR, the sequence of the tnpA transposase gene of the insert sequence ISEcp-1 was detected in all the plasmids harboring the CTX-M-14 gene. These results strongly suggest that plasmid dissemination between different E. coli strains in addition to a mobile element (transposon) around the ␤-lactamase gene may be involved in the spreading of the CTX-M-14 gene. This study reinforces the hypothesis that the epidemiology of the prevalence of the ␤-lactamase genes is changing and should alert the medical community to the increase in the emergence of the CTX-M ␤-lactamases worldwide.

Community and hospital spread of Escherichia coli producing CTX-M extended-spectrum -lactamases in the UK

Journal of Antimicrobial Chemotherapy, 2004

ence Laboratory began to receive isolates of Escherichia coli for confirmation of extended-spectrum b-lactamase production with a phenotype implying a CTX-M-type b-lactamase, i.e. MICs of cefotaxime > _ 8-fold higher than MICs of ceftazidime. Many were referred as being from community patients. We examined 291 CTX-M-producing isolates from the UK and investigated the genetic basis of their phenotype.

CTX-M-15-Producing Escherichia coli Clinical Isolates in Cairo (Egypt), Including Isolates of Clonal Complex ST10 and Clones ST131, ST73, and ST405 in Both Community and Hospital Settings

Microbial Drug Resistance, 2011

In Egypt, little is known about the genetic background of Escherichia coli isolates harboring extended-spectrum b-lactamase (ESBL). Five hundred twenty Enterobacteriaceae were prospectively collected (May 2007-August 2008) at the Theodor Bilharz Research Institute (Cairo). Among the collected Enterobacteriaceae, 56% (n ¼ 291) were E. coli and 32% (n ¼ 165) Klebsiella pneumoniae. A total of 16% (n ¼ 83) of all isolates were ESBL, 19% (n ¼ 55) of the E. coli and 14% (n ¼ 23) of the K. pneumoniae. The proportion of E. coli ESBL producers did not differ significantly between in and outpatients (20% vs. 17%) but was significantly different for nonE. coli ESBL producers (18.5% vs. 1.2%: p ¼ 0.0001). The majority of E. coli ESBL producers (75%) was isolated from urine. All the ESBL-producing Enterobacteriaceae available for molecular study (n ¼ 74) produced CTX-M-15. Among the CTX-M-15-producing E. coli isolates; 40% belonged to phylogenetic group A, 32% to D, and 26% to B2. ERIC-2 PCR profiles were obtained for all these E. coli isolates and multilocus sequence typing for those belonging to group B2. Genotyping analyses showed strain diversity; however, some clusters had profiles indistinguishable from that of previously published clones. Multilocus sequence typing showed that 75% of E. coli group B2 belonged to clone ST131. This indicates that a new country in Africa is adversely affected by clones of E. coliproducing CTX-M-15.