Naslov
Serum sensitivity of beta-lactamase-producing Escherichia coli strains isolated from urine of nonhospitalized patients

Autori
Marijan, Tatjana ; Mlinarić-Džepina, Ana ; Matica, Biserka ; Vraneš, Jasmina

Izvornik
Clinical microbiology and infection (1198-743X) 11 (2005), 2; 132-132

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

Ključne riječi
Escherichia coli; extended-spectrum beta-lactamases; serum-sensitivity

Sažetak
Objectives: Extended-spectrum β -lactamase (ESBL)-producing Escherichia coli has emerged in many hospitals worldwide, increasing dissemination and long-term carriage of this organism within community. Until recently, most infections caused by ESBL-producing E. coli had mostly been described as nosocomially acquired, or nursing home related. Some recent data suggest that infections due to ESBL-producing organisms might be an emergent problem in outpatients in different countries, and that ESBL-producing E. coli is an emergent cause of urinary tract infections in nonhospitalized patients. Better characterisation of these strains is needed. The aim of this study was to determine the prevalence of ESBL-producing E. coli among the strains isolated from urine of outpatients in Zagreb region, and to assess the sensitivity of those strains to bactericidal action of normal human serum. 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 isolates were screened for ESBL production by a double disk diffusion technique and 39 ESBL-producing strains were collected, as well as 45 randomly chosen non-ESBL-producing E. coli strains. Antibiotic susceptibility was determined using a standard disk diffusion NCCLS procedure. Bacterial susceptibility to serum killing was measured by assessing regrowth after incubation in serum according to Schiller and Hatch method. Results: The prevalence of ESBL-producing E. coli was 1.59%. Statistically significant difference in bacterial susceptibility to serum killing was observed between two groups of strains (p=0.03). Out of 45 non-ESBL-producing strains tested, 25 (55.6%) were serum-resistant, while only 12 out of 39 (30.8%) ESBL-producing strains were resistant to serum killing. Conclusion: The decreased prevalence of serum resistance among ESBL-producing isolates may be related to chronic colonization or recurrent infection of urinary tract.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

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