Low frequency of antibiotic resistance among urine isolates of Escherichia coli in the community, despite a major hospital outbreak with Klebsiella pneumoniae producing CTX-M-15 in Uppsala County

Abstract

A screening programme introduced during a major outbreak of a Klebsiella pneumoniae strain producing extended spectrum β-lactamase (ESBL), indicated a dissemination of ESBL-producing Escherichia coli in the community. A total of 360 urine samples, yielding 205 isolates, were therefore collected from primary care patients with lower urinary tract infections (UTI) in Uppsala County. The susceptibility pattern of the isolates was investigated with the disk diffusion method. The majority of the positive cultures contained E. coli (76%). Of the members of the Enterobacteriaceae family, only 2 E. coli isolates were resistant to cefpodoxime, of which one produced ESBL. The antibiotic resistance for E. coli isolates was as follows: ampicillin 29.5%, trimethoprim 18.6%, nalidixic acid 7.7%, mecillinam 1.3%, nitrofurantoin 1.3%, and cefpodoxime 1.3%. Approximately 5% of the E. coli isolates showed a combined resistance to 3 or more antibiotic drugs. Negative cultures were common, especially in men, and it was obvious that there were difficulties with the definition of both uncomplicated and lower UTI. In conclusion, a dissemination of ESBL-producing E. coli in the primary care population of Uppsala County could not be confirmed when using urine samples. The antibiotic resistance in E. coli isolates was low overall, with the exception of ampicillin and trimethoprim.

Acknowledgements

We thank Strama and all the participating general practitioners in Uppsala County for their contribution to the study.

Declaration of interest: The study was financially supported by the Department of Communicable Disease Control and Prevention. There are no conflicts of interest.