Molecular epidemiology of Escherichia coli producing CTX-M β-lactamases: the worldwide emergence of clone ST131 O25:H4 (original) (raw)
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Journal of Antimicrobial Chemotherapy, 2004
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. Methods: PCR was used to detect alleles encoding CTX-M enzymes and to assign these to their bla CTX-M phylogenetic groups. Selected alleles were sequenced. Producers were compared by analysis of banding patterns generated by pulsed-field gel electrophoresis of Xba I-digested genomic DNA. MICs were determined by an agar dilution method or by Etest. Results: Of 291 CTX-M-producing E. coli isolates studied from 42 UK centres, 70 (24%) were reportedly from community patients, many of whom had only limited recent hospital contact. Community isolates were referred by 12 centres. Two hundred and seventy-nine (95.9%) producers contained genes encoding group 1 CTX-M enzymes and 12 contained bla CTX-M-9-like alleles. An epidemic CTX-M-15-producing strain was identified, with 110 community and inpatient isolates referred from six centres. Representatives of four other major strains also produced CTX-M-15, as did several sporadic isolates examined. Most producers were multi-resistant to fluoroquinolones, trimethoprim, tetracycline and aminoglycosides as well as to non-carbapenem b-lactams. Conclusions: CTX-M-producing E. coli are a rapidly developing problem in the UK, with CTX-M-15 particularly common. The diversity of producers and geographical scatter of referring laboratories indicates wide dissemination of bla CTX-M genes. Because of the public health implications, including for the treatment of community-acquired urinary tract infections, the spread of these strains-and CTX-M-15 b-lactamase in particular-merits close monitoring.
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.
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...
Diagnostic Microbiology and Infectious Disease, 2010
One hundred ninety-three single-patient isolates of Escherichia coli harboring extended-spectrum β-lactamases (ESBL) were identified among 11 407 E. coli urine isolates recovered from single-patient outpatient urine cultures from 2003 to 2008. The percentage of ESBLproducing E. coli among community-onset E. coli urine isolates increased from 0.21% in 2003 to 2.99% in 2008. One hundred seven of the ESBL producers were positive for the presence of bla CTX-M genes. The percentage of CTX-M-producing E. coli rose from 0.07% in 2003 to 1.66% in 2008. The annual percentage of ESBL E. coli producing CTX-Ms changed from 35% in 2003 to 64% in 2008. Genes belonging to 3 bla CTX-M groups: bla CTX-M-1 group, bla CTX-M-2 group, and bla CTX-M-9 group, were detected. In addition, resistance to commonly used antimicrobial agents for community-acquired urinary tract infections was found common among CTX-M-producing E. coli isolates. Ertapenem and nitrofurantoin showed good in vitro activity against CTX-M producers.
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.
Antimicrobial Agents and Chemotherapy, 2013
A case-case-control study was conducted to identify independent risk factors for recovery of Escherichia coli strains producing CTX-M-type extended-spectrum β-lactamases (CTX-M E. coli ) within a large Southeastern Michigan medical center. Unique cases with isolation of ESBL-producing E. coli from February 2010 through July 2011 were analyzed by PCR for bla CTX-M , bla TEM , and bla SHV genes. Patients with CTX-M E. coli were compared to patients with E. coli strains not producing CTX-M-type ESBLs (non-CTX-M E. coli ) and uninfected controls. Of 575 patients with ESBL-producing E. coli , 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-M E. coli (282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-M E. coli patients and to uninfected controls. Independent risk factors for CTX-M E. coli isolation compared to non-CTX-M E. coli included male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillin...
Antimicrobial Agents and Chemotherapy, 2013
ABSTRACTA case-case-control study was conducted to identify independent risk factors for recovery ofEscherichia colistrains producing CTX-M-type extended-spectrum β-lactamases (CTX-ME. coli) within a large Southeastern Michigan medical center. Unique cases with isolation of ESBL-producingE. colifrom February 2010 through July 2011 were analyzed by PCR forblaCTX-M,blaTEM, andblaSHVgenes. Patients with CTX-ME. coliwere compared to patients withE. colistrains not producing CTX-M-type ESBLs (non-CTX-ME. coli) and uninfected controls. Of 575 patients with ESBL-producingE. coli, 491 (85.4%) isolates contained a CTX-M ESBL gene. A total of 319 (84.6%) patients with CTX-ME. coli(282 [74.8%] CTX-M-15 type) were compared to 58 (15.4%) non-CTX-ME. colipatients and to uninfected controls. Independent risk factors for CTX-ME. coliisolation compared to non-CTX-ME. coliincluded male gender, impaired consciousness, H2 blocker use, immunosuppression, and exposure to penicillins and/or trimethoprim-s...
Please use Adobe Acrobat Reader to read this book chapter for free. Just open this same document with Adobe Reader. If you do not have it, you can download it here. You can freely access the chapter at the Web Viewer here. Clinical Management of Complicated Urinary Tract Infection 20 has been called CTX-M in reference to the potent hydrolytic activity of these enzymes against cefotaxime(6). There are over 40 of these enzymes reported. CTX-M producing ESBL pathogens usually have cefotaxime in the resistant range (MIC>64). More recently, and of greater concern is the occurrence of carbapenemases which show activity against oxyimino-cephalosporins and cephamycins but also against carbapenems (7). There are two major groups in this class called metallo-b-lactamases (Verona integron encoded metallo b lactamases) (VIM) and carbapenemases. Structural studies of ESBL indicate that active site expansion and remodeling are responsible for the extended hydrolytic activity (8).These enzymes are globally present and appear to cause clinically significant disease such as urinary tract infections, abscesses and bacteremia. With the advent of the ESBL pathogens, there has been a significant increase in the morbidity and mortality related to these infections. If the number of carbapenemaseproducing organisms continues to increase, the treatment options will be seriously compromised. In addition, ESBL producing pathogens are not only resistant to penicillin and cephalosporins but also to trimethoprim-sulphamethoxazole and fluroquinolones which can compromise the treatment of both nosocomial and community acquired infections caused by Enterobacteriaceae and other species (9). One of the major clinical problems has been the recognition of both nosocomial and community acquired urinary tract infections resulting from ESBL pathogens. The treatment options for these infections are limited, especially in the out patient setting. This chapter will review the epidemiology, risk factors, clinical features and therapeutics options for ESBL-induced infections of the urinary tract. 2. Recent epidemiological data ESBL producing organisms have been implicated in nosocomial infections. Over the last decade, there has been a steady increase of these infections in the community. In fact, a recent study from Spain suggest there was been an increase in ESBL E.coli producers from 0.3% to 4.8% between 1995 and 2002. (10) Interestingly, during this same period there was a drop in the rate of ESBL producing K.pneumoniae following the control of nosocomial transmission of this pathogen. These K. pneumoniaie were mostly clonally related and produced SHV and TEM. In contrast, the ESBL E.coli strains were not clonally related and the predominant strain was a CTX-M. In addition, half of these strains were isolated from outpatients (10,11). France was one of the first countries to report an outbreak of ESBL infections in 1986. In this study, 30% of Enterobacter aerogenes isolates in 2000 were ESBL producers (12). Since that time, virtually every country in Europe has reported ESBL producers with considerable geographical variability in the occurrence of ESBL's. Examples of this include a prevalence rate of ESBLs K. pneumoniaie in Sweden of 3% to 34% in Portugal (13). In one study done in France, it was noted that intestinal carriage prevalence of ESBL-E.coli was 8.0%, mainly the CTX-M type. At the same time, it was noted that there was an increase in antibiotic usage, especially the beta-lactams. This variability probably occurred because of the repeated introduction of new strains and plasmids and from inter-individual dissemination (14) In Central and South America ESBL, rates in Klebsiella varied from 30 to 60% in countries such as Brazil, Columbia and Venezuela (15). The ESBL strains included SHV-2, 5, CTX-M and even non-TEM and non-SHV with no geographical predilection. (16, 17) www.intechopen.com Please use Adobe Acrobat Reader to read this book chapter for free. Just open this same document with Adobe Reader. If you do not have it, you can download it here. You can freely access the chapter at the Web Viewer here.
Antimicrobial Agents and Chemotherapy, 2012
Escherichia coli sequence type 131 (O25b:H4), associated with the CTX-M-15 extended-spectrum beta-lactamases (ESBLs) and linked predominantly to the community-onset antimicrobial-resistant infections, has globally emerged as a public health concern. However, scant attention is given to the understanding of the molecular epidemiology of these strains in high-burden countries such as India. Of the 100 clinical E. coli isolates obtained by us from a setting where urinary tract infections are endemic, 16 ST131 E. coli isolates were identified by multilocus sequence typing (MLST). Further, genotyping and phenotyping methods were employed to characterize their virulence and drug resistance patterns. All the 16 ST131 isolates harbored the CTX-M-15 gene, and half of them also carried TEM-1; 11 of these were positive for bla OXA groups 1 and 12 for aac(6=)-Ib-cr. At least 12 isolates were refractory to four non-beta-lactam antibiotics: ciprofloxacin, gentamicin, sulfamethoxazole-trimethoprim, and tetracycline. Nine isolates carried the class 1 integron.
BMC Infectious Diseases, 2012
Background: The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been increased not only in the hospital but also in the community worldwide. This study was aimed to characterize ESBL-producing E. coli isolates and to investigate the molecular epidemiology of community isolates in comparison with hospital isolates at a single center in Korea. Methods: A total of 142 ESBL-producing E. coli isolates were collected at Daejeon St Mary's Hospital in Korea from January 2008 to September 2009. The ESBLs were characterized by PCR sequencing using specific primers. The genetic relatedness was determined by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).