Prevalence of transferable blaCTX-M-15 from hospital- and community-acquired Klebsiella pneumoniae isolates in Scotland.

OBJECTIVES This study was performed to investigate the prevalence and genetic characteristics of transferable bla(CTX-M-15) from hospital- and community-acquired Klebsiella pneumoniae isolates in Scotland. METHODS A total of 219 clinical isolates of K. pneumoniae collected in 2006 and 2007 at the Royal Infirmary of Edinburgh, Scotland, were tested for antimicrobial susceptibility by the agar double dilution method. PCR and sequencing were used to detect bla(CTX-M), bla(TEM), bla(SHV) and qnr genes. Clonality of the isolates was assessed by PFGE. RESULTS Sixteen (7.3%) isolates were found to be producers of CTX-M-15 extended-spectrum β-lactamases (ESBLs), of which two isolates (12.5%) were reported to be from patients with community-acquired infections. The ISEcp1 was detected by sequencing 48 nucleotides upstream of bla(CTX-M-15) in all isolates but one. A total of one to two plasmids, ranging in size from ~40 to 210 kb, were observed per strain. By a PCR-based replicon typing method, plasmids carrying bla(CTX-M-15) were assigned to IncFII or IncN types. Sequencing and PCR analysis revealed the presence of complex class 1 integrons in all isolates but one. Two isolates positive for class 1 integrons were positive for class 2 integrons as well. Five different clones of CTX-M-15-producing isolates were identified by PFGE. CONCLUSIONS This work reports the emergence of hospital- and community-acquired CTX-M-type enzymes in the Edinburgh area of Scotland.