Comparison of host response mechanisms evoked by extended spectrum beta lactamase (ESBL)--and non-ESBL-producing uropathogenic E. coli.
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 2h, but the opposite was observed after 5 and 6h. 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.


CONCLUSIONS
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.
Faculty of Medicine and Health, Örebro University, Örebro, Sweden. isak.demirel@oru.se
Isak
I
Demirel
Annica
A
Kinnunen
Anna
A
Onnberg
Bo
B
Söderquist
Katarina
K
Persson
D002478:Cells, Cultured; D004927:Escherichia coli Infections / Q000276:immunology* / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D009504:Neutrophils / Q000276:immunology / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000276:immunology; D014552:Urinary Tract Infections / Q000276:immunology* / Q000382:microbiology*; D056689:Uropathogenic Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000276:immunology / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
D017382:Reactive Oxygen Species; D001618:beta-Lactamases