Antimicrobial Usage and Resistance in Companion Animals: A Cross-Sectional Study in Three European Countries

Abstract

Companion animals have been described as potential reservoirs of antimicrobial resistance (AMR), however data remain scarce. Therefore, the objectives were to describe antimicrobial usage (AMU) in dogs and cats in three European countries (Belgium, Italy, and The Netherlands) and to investigate phenotypic AMR. A questionnaire and one fecal sample per animal (n = 303) were collected over one year and AMU was quantified using treatment incidence (TI). Phenotypic resistance profiles of 282 Escherichia coli isolates were determined. Nineteen percent of the animals received at least one antimicrobial treatment six months preceding sampling. On average, cats and dogs were treated with a standard daily dose of antimicrobials for 1.8 and 3.3 days over one year, respectively. The most frequently used antimicrobial was amoxicillin-clavulanate (27%). Broad-spectrum antimicrobials and critically important antimicrobials for human medicine represented 83% and 71% of the total number of treatments, respectively. Resistance of E. coli to at least one antimicrobial agent was found in 27% of the isolates. The most common resistance was to ampicillin (18%). Thirteen percent was identified as multidrug resistant isolates. No association between AMU and AMR was found in the investigated samples. The issue to address, regarding AMU in companion animal, lies within the quality of use, not the quantity. Especially from a One-Health perspective, companion animals might be a source of transmission of resistance genes and/or resistant bacteria to humans.

Keywords: antimicrobial resistance; antimicrobial use; colistin resistance; companion animals; critically important antimicrobials; one health.

Figure 1

Percentage of antimicrobial treatments per active compound. Every piece of the pie chart is colored in the corresponding assigned color code based on the classification of the World Health Organization (WHO). Green color = important antimicrobial; yellow color = highly important antimicrobial; orange color = critically important antimicrobial of high priority; red color = critically important antimicrobial of highest priority; Results at species and country level are shown in Table S2.

Figure 2

Antimicrobial resistance proportions (%) among Escherichia coli isolates from feces of dogs and cats in three European countries against a set of 14 antimicrobials. (a) Shown for all samples with a successful E. coli isolations from cats (n = 137) and dogs (n = 148); (b) E. coli from Belgian cats (n = 44) and dogs (n = 44); (c) E. coli from Italian cats (n = 50) and dogs (n = 50); (d) E. coli from Dutch cats (n = 43) and dogs (n = 51). AMP = ampicillin; FOT = cefotaxime; TAZ = ceftazidime; MERO = Meropenem; CIP = ciprofloxacin; NAL = nalidixic acid; AZI = azithromycin; CHL = chloramphenicol; COL = colistin; GEN = gentamicin; SMX = sulfamethoxazole; TMP = trimethoprim; TET = tetracycline; TGC = tigecycline. (Table S4).