The Urinary System Infections caused by Extended-Spectrum-β-Lactamase-producing Escherichia coli and Klebsiella pneumoniae Strains

INTRODUCTION: Production of β-Lactamase enzymes is an important mechanism of resistance in Gram-negative bacteria. The aim of this study was to investigate the relationship between the Extended-Spectrum β-Lactamase (ESBL)-positive Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) strains isolated from the urine cultures and the underlying diseases and also to assess the antibiotic resistance.
METHODS: The bacteria were identified according to conventional methods including colony morphology, gram stains, oxidase test and biochemical tests (indole production, Triple Sugar Iron (TSI) agar, Simmon’s Citrate agar, Christensen’s Urea agar, and motility test medium). BD Phoenix automated system (Becton Dickinson, USA) was used for further identification of the bacteria that were identified as E. coli and K. pneumoniae and for assessing the resistance rates and ESBL production.
RESULTS: A total of 401 E. coli and 58 K. pneumoniae strains were isolated from the urinary specimens. Of these, 159 (39.6%) of E. coli and 26 (44.8%) of K. pneumoniae strains were ESBL-positive. The most active antibiotics against ESBL-positive E. coli and K. pneumoniae strains were carbapenems. Underlying diseases were detected in a total of 148 ESBL-positive strains (80%), including 127 (79.8%) of E. coli and 21 (80.8%) of K. pneumoniae strains. Common underlying diseases were benign prostate hyperplasia (BPH), urolithiasis, neurogenic bladder, urethral stricture, vesicoureteral reflux (VUR), hypospadias, ureteropelvic junction (UPJ) obstruction, vesicointestinal fistula, and cystocele (p<0.05).
DISCUSSION AND CONCLUSION: In the treatment of urinary system infections, ESBL-positive E. coli and K. pneumoniae strains should be kept in mind and the underlying diseases should be studied and treated.