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

Shrewsbury and Telford Hospital NHS Trust, Shrewsbury, England, United Kingdom
Journal of Antimicrobial Chemotherapy (Impact Factor: 5.31). 10/2004; 54(4):735-43. DOI: 10.1093/jac/dkh424
Source: PubMed


During 2003, the Health Protection Agency's Antibiotic Resistance Monitoring and Reference Laboratory began to receive isolates of Escherichia coli for confirmation of extended-spectrum beta-lactamase production with a phenotype implying a CTX-M-type beta-lactamase, i.e. MICs of cefotaxime > or = 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.
PCR was used to detect alleles encoding CTX-M enzymes and to assign these to their blaCTX-M phylogenetic groups. Selected alleles were sequenced. Producers were compared by analysis of banding patterns generated by pulsed-field gel electrophoresis of XbaI-digested genomic DNA. MICs were determined by an agar dilution method or by Etest.
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 blaCTX-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 beta-lactams.
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 blaCTX-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 beta-lactamase in particular--merits close monitoring.

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    • "By hydrolytic inactivation, they confer resistance to a wide spectrum of β-lactam antibiotics currently used as 1st line empirical therapy in the management of Gram negative bacterial infections. E. coli is the most frequent Gram-negative bacillus isolated from blood cultures in clinical settings and CTX-M-15 bla gene the most common coding for an ESBL worldwide (Hawkey and Jones, 2009; Livermore and Hawkey, 2005; Woodford et al., 2004). "
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    • "At, Ct,Cp,Cz, CT,An A,Ac,Cx,Cz,Cz,Ce,Pi,Tz,I,M I,M,ce,Cz,Cx,Ct,At,Tz,G,A, Cp,Tg,Fx, ,Ax,Ti, Pi Fx,Cx,Cz,At,C,G,S,T,St, CT,cp,A,Ti,Pi,I,M,Ce,CtTz, Fx,CT,Cx,Cz,Ce,An,G,Cp I,M,Ct,At,Tz,G, Cp,Tg,Fx,A,Ti, Pi,A,CT,Cx,Ce Woodford et al., 2004 Park et al 2009 Monteiro et al., 2009 Mirzae et al., 2009 Jacoby and Sutton, 1985 Moland et al., 2002 Briǹas et al., 2002 Salmonella spp "

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    • "PCR for blaTEM, blaSHV, and blaCTX-M genes were conducted using PCR primers and conditions that have been previously described [19]. The five CTX-M subgroups (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9, and CTX-M-25) were amplified using PCR primers and procedures as previously described [20]. "
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