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