Antimicrobial Susceptibility Patterns of Bacteria Associated With Hepatobiliary Disease in Dogs and Cats (2010-2019).

Background: Description of antibiotic susceptibility of isolates from dogs and cats with hepatobiliary disease is limited.

Objectives: To describe antibiotic susceptibility patterns of bacteria associated with hepatobiliary disease in dogs and cats over a 10 year-period.

Animals: Three hundred nine dogs and cats.

Methods: Bacterial species and antibiotic susceptibility data from positive bile and liver tissue cultures were reviewed from both a Veterinary Teaching Hospital and a private laboratory. Prevalence of multidrug-resistant (MDR) bacteria was assessed, along with its association with previous antibiotic administration.

Results: A total of 343 bacterial isolates were included from 310 cultures. Monobacterial cultures were more frequent (91%, 283/310). Gram-negative bacteria were predominant (67%, 227/340), with Escherichia coli (49%, 136/340), Staphylococcus spp. (14%, 47/340), and Enterococcus spp. (10%, 34/340) being the most prevalent isolates. Resistance of gram-negative bacteria were: amoxicillin-clavulanic acid (33%, 70/214), aminopenicillins (47%, 96/205), and fluoroquinolones (16%, 67/417); for gram-positive bacteria: amoxicillin-clavulanic acid (12%, 5/41), aminopenicillins (16%, 11/67), and fluoroquinolones (17%, 35/111). Resistance was significantly higher for aminopenicillins, first-generation cephalosporins, TMPS, tetracyclines, and fluoroquinolones during 2010-2014 compared to 2015-2019. MDR isolates comprised 40% (135/430) of all isolates, 30% (41/136) of E. coli, and 68% (23/34) of Enterococcus spp. A significantly higher incidence of MDR bacteria was observed in animals with previous antibiotic treatment (81%, 17/21) compared to those without (30%, 22/75; p < 0.001).

Conclusion And Clinical Importance: Conducting culture and sensitivity testing remains crucial in dogs and cats suspected of hepatobiliary infection to ensure effective treatment.