Naslov
Clonal dissemination of ESBLs-producing Escherichia coli strains in outpatient population in Zagreb region

Autori
Marijan, Tatjana ; Vranes, Jasmina ; Bedenic, Branka ; Katic, Stjepan ; Mlinaric-Džepina, Ana ; Plecko, Vanda ; Kalenic, Smilja

Izvornik
International Journal of Infectious Diseases (1201-9712) 10 (2006), Suppl 1;

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, kongresno priopcenje, znanstveni

Ključne riječi
Escherichia coli; antibiotics; resistance; extended-spectrum beta-lactamases

Sažetak
Background: Recent data suggest that infections due to extended-spectrum beta-lactamases (ESBLs)-producing Escherichia coli strains might be an emergent problem in outpatients in different countries, and that ESBLs-producing E. coli is an emergent cause of urinary tract infections in nonhospitalized patients. The aim of this study was to characterize the ESBLs-producing E. coli strains isolated from urine of outpatients in Zagreb region. Methods: During the five-month study period (January to May 2004) a total of 2, 451 E. coli strains were isolated from urine of nonhospitalized patients with significant bacteriuria. The antimicrobial susceptibility was determined using a standard disk diffusion test. ESBLs were detected by double-disk diffusion technique and by eight fold reduction in the minimal inhibitory concentration of ceftazidime in the presence of clavulanate. A total of 39 ESBLs-producing E. coli strains (1.59%) were collected and characterised. The production of hemolysin was observed after stabbing bacteria in 5% human blood agar, and the strains were serotyped using 17 different O-antisera. The expression of adhesins was defined by hemagglutination and inhibition of hemagglutination in microtiter plates. Molecular relatedness between the strains was analyzed by pulsed-field gel electrophoresis (PFGE) after the extraction of genomic DNA and digestion with XbaI. DNA relatedness was calculated based on the Dice coefficient, and isolates were considered to be genetically related if the Dice coefficient correlation was ≥ 80%. Results: Serogroup O4, hemolysin production, expression of P- and type 1 fimbriae as well as resistance to gentamicin were all the most prevalent characteristics of the strains. Out of 39 ESBLs-producing strains tested, in 26 strains O4 serogroup was detected, and in 23 strains besides the O4 serogroup the hemolysin production and coexpression of type 1 and P-fimbriae were detected. Chromosomal DNA analysis by PFGE exhibited a great genomic similarity among those strains. The Dice coefficient of similarity for 25 strains was 83.49%. Conclusion: PFGE highlighted that highly virulent uropathogenic ESBLs-producing E. coli strains isolated from outpatients in Zagreb region had a clonal propagation. Further characterisation of these strains is needed.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

POVEZANOST RADA