Open Access Research article

Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)- and non-ESBL-producing uropathogenic E. coli

Isak Demirel1*, Annica Kinnunen1, Anna Önnberg12, Bo Söderquist12 and Katarina Persson1

Author Affiliations

1 Faculty of Medicine and Health, Örebro University, Örebro, Sweden

2 Department of Laboratory Medicine, Clinical Microbiology, Örebro University Hospital, Örebro, Sweden

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BMC Microbiology 2013, 13:181  doi:10.1186/1471-2180-13-181

Published: 2 August 2013

Abstract

Background

Infections caused by extended spectrum beta-lactamases (ESBL)-producing bacteria have been emerging worldwide and the majority of ESBL-producing E. coli strains are isolated from patients with urinary tracts infections. The purpose of this study was to compare the host-response mechanisms in human polymorphonucleated leukocytes (PMN) and renal epithelial cells when stimulated by ESBL- or non-ESBL-producing uropathogenic E. coli (UPEC) isolates. The host-pathogen interaction of these ESBL-producing strains in the urinary tract is not well studied.

Results

The ability of ESBL strains to evoke ROS-production from PMN cells was significantly higher than that of the non-ESBL strains. The growth of ESBL strains was slightly suppressed in the presence of PMN compared to non-ESBL strains after 30 min and 2 h, but the opposite was observed after 5 and 6 h. The number of migrating PMN was significantly higher in response to ESBL strains compared to non-ESBL strains. Stimulation of A498 cells with ESBL strains elicited lower production of IL-6 and IL-8 compared to non-ESBL strains.

Conclusion

Significant differences in host-response mechanisms were identified when host cells were stimulated by ESBL- or non-ESBL producing strains. The obtained results on the early interactions of ESBL-producing strains with the host immune system may provide valuable information for management of these infections.

Keywords:
Extended spectrum beta-lactamases; Urinary tract infections; Renal epithelial cells; Polymorphonucleated leukocytes; Uropathogenic E. coli