Antimicrobial Susceptibility Pattern of Gram Negative Bacteria Isolatedfrom Feline Urinary Tract Infections (UTIs): A Retrospective Study from2011 to 2014

The aim of the present study was to examine the antimicrobial susceptibility pattern of Gram negative bacteria (n = 93) isolated from urine samples of cats with urinary tract infections (UTIs) in Italy over a 4-year time period. The epidemiologic and clinical utility of resistance rates was discussed. An automated antimicrobial susceptibility system was used to detect antimicrobial sensitivity to a panel of antimicrobial drugs (n = 21) and to identify ESBL-E. coli and ESBL-Klebsiella spp. The presence of beta-lactamase genes among Proteus, Pseudomonas and Enterobacter isolates was detected through double-disk test. ESBL blaCTX-M, blaSHV and blaTEM were determined by PCR amplification. A susceptibility rate > 60% towards amoxycillin + beta-lactamaseinhibitors, fluoroquinolones, and trimethoprim-sulfamethoxazole was observed for E. coli, Klebsiella spp., P. mirabilis and P. aeruginosa. A high prevalence of MDR strains (63,4%) was found. Twenty-seven strains (32% E. coli and 50% Klebsiella spp.) were classified as ESBL-producers. Given that the majority of therapy for feline UTIs is empiric and that urinary tract pathogens are showing increasing antimicrobial resistance, continuously updated data concerning antimicrobial susceptibility patterns would be beneficial to guide empiric treatment.