Clinical and Laboratory Profile of Urinary Tract Infections Associated with Extended Spectrum β-Lactamase Producing Escherichia coli and Klebsiella pneumoniae

Abstract

Background: Urinary tract infection (UTI) is mainly due to invasion of the urethra, bladder or kidneys by pathogens. The emergence of extended spectrum β-lactamases (ESBL) is responsible for frequently observed empirical therapy failures.

Objectives: To study the clinical and laboratory characteristics of UTIs caused by ESBL producing Escherichia coli (E. coli) and Klebsiella pneumonia (K. pneumonia).

Methods: A cross-sectional clinical and laboratory study was performed at King Khalid Hospital, Hafr Al Batin, Saudi Arabia between March 2014 to October 2015. A total of 908 urine samples from suspected UTI patients was collected. Samples were isolated on Cysteine Electrolyte-Deficient (CLED) agar. Positive cultures were identified and tested for antimicrobial susceptibility by MicroScan(®) WalkAway-96 SI System, and then ESBL was confirmed by double disc synergy test (DDST) and phenotypic confirmatory disc diffusion test (PCDDT).

Results: A total of 680 samples (288 males and 392 females) were culture positive. 520 samples (76.5%) of E. Coli were found and 160 samples of K. pneumonia were identified (23.5%). ESBL testing showed 296 (218 E. coli and 78 K. pneumonia) samples of positive isolates. Non-ESBL isolates showed highest resistance to ampicillin followed by Mezocillin and Trimethoprim-Sulphamethoxazole-which are usually recommended as the initial treatment of UTI-while ESBL isolates showed resistance to third generation cephalosporin along with Ampicillin and Trimethoprim-Sulphamethoxazole. In this study, four significant risk factors for ESBL infection such as diabetes, recurrent UTI, previous use of antibiotics and previous hospitalization were found.

Conclusion: Identifying the risk factors and antibiotic susceptibility patterns associated with ESBL producing E. coli and K. pneumonia is a useful guide for treatment strategy and control of ESBL UTI.