Detection of pathogenic genes pap, hlyA and cnf1 IN E. coli strains isolated from adult patients with urinary tract infection

Abstract number: P1295

Alepopoulou E., Panopoulou M., Konstantinidis T., Konstantinidou E., Compelitou S., Petinaki E., Kartali S.

Objective: Urinary tract infection (UTI) is one of the most commonly acquired bacterial infections in ambulatory and hospitalised populations. Most UTIs are caused by E. coli strains that exhibit certain virulent factors. Urovirulence factors as pap (pilus associated with pyelonephritis), hlyA (alfa haemolysin) and CNF (cytotoxic necrotising factor) play important role in the pathogenesis of E. coli causing of UTI. The present study was comparable in University hospital of Alexandroupolis in northern Greece. The aim was to determine the occurrence of virulence genes expressing pap, hlyA and cnf1 in adult patients with UTI.

Methods: A total 131 strains E. coli isolated from urines of 131 adult patients as follow: 103 subjects were women and 29 men. Fifty six strains were isolated from ambulatory and 75 from hospitalised patients. The laboratory criterion for acute E. coli UTI was the presence of positive culture on MC agar with of least 105 CFU/ml. The biochemical identification of the strains was performed by automated system VITEK2 (BioMerieux). Specific primers were used to amplify sequences of the pap, hlyA and cnf1 genes. Amplification products 336bp, 1177bp and 498 bp respectively were electophoresed in 2% agarose gel and visualised by ethidium bromide staining.

Results: Overall, of the 131 isolates strains E. coli 67(51%) carried pathogenic genes. From 67 strains 28(42%) were isolated from ambulance patients and 54 (80%) from women. The genes pap, hlyA and cnf occurred in several combinations. The combinations of pathogenic genes were as follow: 22 (33%) strains yielded pap gene, 2 (3%) hlyA, 9(13%) cnf1, 9 (13%) pap+cnf1, 8(12%) pap+hlyA, 3 (4%) cnf1+hlyA and 14 (20%) pap+cnf1+hlyA. From 22 strains pap+ and 14 strains (pap+cnf1+hlyA)+ 86% and 90% respectively were isolated from women.

Conclusion: Sixty seven (51%) E. coli isolates were found to carry at least one pathogenic gene. The most prevalent pathogenic gene was pap and combination pap+cnf1+hlyA. The frequency of pathogenic genes was higher in women, specifically in regard of strains with genes pap and pap+cnf1+hlyA.

The presence of pathogenic genes in E. coli contributes to colonisation, invasion, promote biofilm formation and persistence of strains in the urinary tract. Therefore knowledge of pathogenic genes of the microorganisms causing the UTI it would anticipate the evolution of infection in the host

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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