Evaluation of pet animals involved in assisted interventions (AAI) as potential carriers of bacteria resistant to antimicrobials: Preliminary data

      Purpose: The attention paid to pets involved in Animal-Assisted Interventions (AAI) for their therapeutic benefits to humans is increasing worldwide. Their close contact with vulnerable categories prompts the consideration of the transmission of zoonotic pathogens between animals and patients. This study is aimed to verify the health conditions of pets used for AAI and to evaluate the potential spread of pathogens to humans, especially those causing severe hospital and community acquired-infections (HAI) such as extended-spectrum cephalosporin and carbapenem resistant Enterobacteriaceae, other Gram-negative multidrug-resistant bacteria (such as Pseudomonas aeruginosa, Acinetobacter baumannii, erythromycin and ciprofloxacin resistant Campylobacter spp., e.g.), methicillin-resistant Staphylococcus spp., vancomycin-resistant Enterococcus spp. and toxigenic Clostridium difficile.
      Methods & Materials: Clinical examination of 65 animals (42 dogs, 22 donkeys and 1 horse, owned by 19 different therapists/handlers) involved in AAI was assessed. Faecal, perineal and oral/nasal samples were processed following classical microbiological procedures. The phenotypic antimicrobial-resistance profiles were determined by selective/chromogenic media supplemented with specific drugs or by the disk diffusion method according to the CLSI guidelines.
      Results: The 65 animals tested were all in good health and none carried multidrug-resistant Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella spp. nor Salmonella spp. Of the 42 dog sampled, 3 (7%) were positive to thermophilic Campylobacter spp., 1 (2%) to extended-spectrum cephalosporin-resistant E. coli, 6 (14%) to vancomycin-resistant Enterococcus spp., 3 (7%) to methicillin-resistant Staphylococcus spp., 1 (2%) to multidrug-resistant Stenotrophomonas maltophilia and 1 (2%) to C. difficile, respectively. Lastly, 1 (5%) donkey was positive to methicillin-resistant Staphylococcus spp..
      Conclusion: These preliminary data highlight the good health conditions of the animals tested. Only few pets carried potentially zoonotic antimicrobial-resistant human pathogens. These data confirm that HAI are mainly associated with the spread of pathogens through person-to-person transmission and medical devices contaminations. However, our findings suggest that the presence of potential pathogens with resistant traits is not irrelevant and should be evaluated especially in animals in close-contact with immunocompromised/diseased persons. The lack of guidelines and of a systematic surveillance on pets involved in AAIs as possible asymptomatic carriers of antimicrobial-resistant pathogens, poses the need to investigate their role in the transmission of these zoonoses to humans.