Clinical and laboratory profiles of urinary tract infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in a tertiary care center in central Saudi Arabia.

OBJECTIVE: To study the clinical and laboratory characteristics of urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli).

METHODS: A retrospective clinical and laboratory study was performed at the Bacteriology Unit, Department of Pathology/Microbiology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from June 2009 to June 2011. A total of 339 adults and pediatric patients with UTI was included in the study. Two groups of patients (ESBL E. coli UTI and non-ESBL E. coli UTI) were studied. Symptoms and signs of illness, comorbidities, outcomes, and urine analysis results were analyzed.

RESULTS: There was 339 episodes of culture-verified UTI, 113 (33.3%) cases were caused by ESBL E. coli, and 226 (66.7%) cases were caused by non-ESBL E. coli. Non-ESBL E. coli UTI was more commonly found in children, and ESBL E. coli was more predominant in female patients. Identified risk factors for acquisition of ESBL E. coli UTI included patients who had underlying renal disease and renal transplant (p=0.017), children with vesicoureteric reflux (p=0.044), surgical intervention, recurrent UTI (p<0.004), and in inpatients. Non-ESBL E. coli patients are more likely to present with UTI. The ESBL E. coli uropathogen are resistant to antibiotics, including the third generation cephalosporin, gentamicin, and ciprofloxacin, whereas the non-ESBL E. coli were more resistant to antibiotics Ampicillin and cotrimoxazole.

CONCLUSION: Identifying the risk factors and the antimicrobial resistance patterns associated with ESBL producing E. coli UTI is necessary for the development of an appropriate empirical antibiotic treatment.