Ciprofloxacin resistance, virulence determinants and phylogenetic background of uropathogenic Escherichia coli isolates from general practice patients in Slovenia

Abstract number: P643

Ambro[zcaron]iè Avgu[scaron]tin J., Palandacic A., Trkov M., Grabnar M.

Objectives: Urinary tract infections are mainly caused by uropathogenic strains of Escherichia coli. Knowledge on virulence traits and phylogenetic background of extraintestinal (ExPEC) E. coli has increased tremendously over the last years. Results of several studies revealed, that human ExPEC strains mostly belong to phylogenetic group B2 followed by group D, and that quinolone-resistant ExPEC strains have less virulence factors (VFs) than quinolone susceptible strains. The aim of our study was to gain insight into the genetic difference between ciprofloxacin susceptible and resistant strains recovered from urinary tract infections of a random population of patients subjected to empirical antimicrobial treatment in general pratices in the Ljubljana region.

Methods:E. coli isolates recovered from patients with symptoms of urinary tract infections were collected and identified at the Institute of Public Health of the Republic of Slovenia. A random sample of 44 ciprofloxacin resistant and 53 ciprofloxacin susceptible isolates, as determined by the disk diffusion method according to the CLSI standards, were included in the study. All isolates were placed into phylogenetic group A, B1, B2 or D as described by Clermont et al.. The isolates were screened by PCR for 23 virulence genes, including adhesins, serum resistance genes, toxins, invasins, and genes involved in iron aquisition.

Results: Alltogether, 16.5%, 5.1%, 45.4% and 33% of the isolates were placed into phylogenetic group A, B1, B2 and D, respectively. Among the ciprofloxacin susceptible isolates the most prevalent group was B2 (56.6%), followed by group D (30.3%), whereas the resistant isolates were almost equally distributed within groups D, B2 and A (36.2%, 32% and 27.3%). Virulence genes were found in both resistance groups. However, there was an obvious difference in the distribution of kpsMTII, usp and iroN genes, being detected in 71.7%, 30%, 67.9%, and in 43.1%, 13.6% 38.6% of the ciprofloxacin susceptible and resistant isolates, respectively. The prevalence of virulence genes varied significantly between isolates from different phylogentic groups and also within each group if the isolates were divided into subgroups according to the ciprofloxacin resistance profile.

Conclusions: Since non-B2 ciprofloxacin resistant E. coli isolates with less VFs, are frequently isolated from general practice patients, they have to be considered as important uropathogens.

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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