Demonstrating the importance of local culture and susceptibility data: antibiograms from dogs at a veterinary tertiary care center

Abstract

Abstract OBJECTIVE To create antibiograms for commonly cultured organisms in a small animal tertiary care hospital following Clinical and Laboratory Standards Institute guidelines and to compare these local resistance patterns to published first-tier antimicrobial recommendations. SAMPLE Urine (n = 429), respiratory (41), and skin (75) isolates cultured from dogs between January 1, 2019, and December 31, 2020, at the Tufts University Foster Hospital for Small Animals. PROCEDURES MIC and susceptibility interpretations were recorded for multiple sites for 2 years. Sites with greater than 30 isolates for at least 1 organism were included. Urinary, respiratory, and skin antibiograms were created using Clinical and Laboratory Standards Institute breakpoints and guidelines. RESULTS Urinary Escherichia coli had a higher susceptibility percentage for amoxicillin–clavulanate (80% [221/275]) than amoxicillin alone (64% [175/275]). Respiratory E coli were greater than 80% susceptible to only 2 antimicrobials (imipenem, amikacin). Of skin Staphylococcus pseudintermedius isolates, 40% (30/75) were methicillin-resistant and frequently also displayed resistance to non-beta lactam antimicrobials. Susceptibility to recommended first-line antimicrobials varied and was greatest for gram-negative urinary isolates and lowest for methicillin-resistant S pseudintermedius skin isolates and respiratory E coli. CLINICAL RELEVANCE Local antibiogram creation identified frequent resistance that may preclude the use of guideline-recommended first-line therapy. High levels of resistance identified in methicillin-resistant S pseudintermedius isolates supports growing concern for methicillin-resistant staphylococci in veterinary patients. This project highlights the need for population-specific resistance profiles to be used in conjunction with national guidelines.