| Abstrakt: |
Bacterial urinary tract infections (UTI) represent a common reason requiring veterinary care and Escherichia coli is the most frequently isolated pathogen. Early diagnosis and prompt antimicrobial therapy are recommended when clinical signs of a UTI are present. Submission of urine samples for culture and sensitivity testing is the best practice approach to diagnosis. Two hundred-thirty strains of E. coli isolated from January 2016 to December 2017 from urine samples belonging to as many dogs suffering of UTI were tested for the antimicrobial susceptibility using the Kirby-Bauer disc diffusion method, following the procedures of the Clinical and Laboratory Standards Institute (CLSI). A standard panel of antimicrobials including amikacin (30 μg), amoxicillin + clavulanic acid (20/10 μg), ampicillin (10 μg), cefpodoxime (10 μg), cephazolin (30 μg), cloramphenicol (30 μg), enrofloxacin (5 μg), gentamicin (10 μg), kanamycin (30 μg), nitrofurantoin (300 μg), tetracyclin (30 μg), tilmicosin (15 μg) and trimethoprim+sulphametoxazole (1.25/23.75μg) was tested against E.coli isolates. The strains were classified as resistant, susceptible or intermediate to the tested antimicrobials by interpreting the zones of growth inhibition according to the CLSI. Intermediate strains were grouped with the resistant ones. The E.coli strains included in this study showed the following percentages of resistance: tilmicosin (87.2%), tetracyclin (73.6%), ampicillin (70.7%), cephazolin (57.7%), amoxicillin + clavulanic acid (43%), enrofloxacin (34.8%), trimethoprim+sulphametoxazole (29.9%), cefpodoxime (28.7%), kanamycin (23%), gentamicin (13%), cloramphenicol (10.6%), nitrofurantoin (6.3%), amikacin (2.9%). Empirical antimicrobial therapy is often instituted while awaiting for the results of culture and sensitivity testing. The sensitivity testing results obtained in this study showed that the antibiotics classified as highest priority critically important antimicrobials (3rd and 4th generation cephalosporins, quinolones, macrolides and polymyxins) by WHO (3) do not necessarily represent the best choice in terms of in vitro efficacy and some therapeutic alternatives, based on less critical antimicrobials are to be preferred. Periodic monitoring of pathogens isolated from UTI and their susceptibility patterns are helpful in guiding the first line empirical therapy and can also be effective for monitoring the eventual spread of resistant bacteria. [ABSTRACT FROM AUTHOR] |
