Antibiotic resistance in community-acquired urinary tract infections: prevalence and risk factors

This study aimed to identify the agents causing community-acquired urinary tract infections (CAUTIs) and their resistance patterns and to investigate risk factors for ESBL production. Patients diagnosed at the Department of Infectious Diseases in the Cukurova University School of Medicine Hospital with CAUTI between January 2006 and April 2007 were included prospectively. Patient data were recorded and the microorganisms and their sensitivity patterns were evaluated by the university's central microbiology laboratory. A total 146 patients with CAUTIs, 109 women and 37 men (mean age: 50.9+/-18.44 years), were included in the study. The most common infectious agents were Escherichia coli (76.9%), Klebsiella pneumoniae (9.2%), Proteus mirabilis (4.1%), and Enterococcus spp. (1.6%). The ciprofloxacin resistance rate for E. coli was 35% and resistance to TMP-SMZ 43%, whereas amikacin resistance was substantially low (3%). Four of 12 K. pneumoniae strains were resistant to ciprofloxacin and 2 to TMP-SMZ. Resistance to amikacin was not found in the K. pneumoniae strains. ESBL production was identified in 25 of the 112 E. coli and K. pneumoniae strains. A history of a UTI within the last 6 months (p=0.029) and a history of frequent UTI (p=0.028) were found to be significant risk factors for ESBL production by univariate analysis. The only independent risk factor was a history of urinary system infection in the past 6 months (p=0.025) according to multivariate regression analysis. These high resistance rates to antimicrobials and particularly the extremely high rate of ESBL production in CAUTI should be carefully considered.