Antimicrobial Resistance in Pasteurellaceae Isolates from Pyrenean Chamois (Rupicapra pyrenaica) and Domestic Sheep in an Alpine Ecosystem

SIMPLE SUMMARY: Antimicrobial resistance (AMR) is a public health concern. Increasing resistance has arisen due to the inappropriate use of antimicrobial drugs in both, human and veterinary medicine. Although AMR is mainly linked to direct and indirect human activities, little is known about the presence and impact that AMR has on wild animals, especially for those bound to habitats subjected to little human pressure. Our study analyzed the AMR profiles of different Pasteurellaceae species obtained from the infected lungs of Pyrenean chamois (Rupicapra pyrenaica) and domestic sheep found in a National Hunting Reserve from Spain. We have found evidence of the presence of AMR in both animal species. Furthermore, some isolates were resistant to cephalosporins and fluoroquinolones, which are antimicrobials of critical importance in human medicine. Further research is needed to discern pathways of AMR dissemination within natural environments and assess its persistence in wildlife in order to prevent further AMR spreading at a global scale. ABSTRACT: Antimicrobial resistance (AMR) has spread worldwide due to the inappropriate use of antimicrobial drugs in human and veterinary medicine, becoming a public health problem. However, little is known about its occurrence and maintenance in wild animals, and very few studies have been carried out in ecosystems subjected to low human pressure. In our study, nasal and lung swabs were collected from hunted Pyrenean chamois (Rupicapra pyrenaica), and nasal swabs from sympatric domestic sheep were also collected. The swabs were cultured in agar plates to obtain bacterial isolates from the Pasteurellaceae family. The presence of AMR was assessed in a total of 28 Pasteurellaceae isolates from 45 Pyrenean chamois, and 9 isolates from sympatric domestic sheep found in the National Hunting Reserve of Freser-Setcases (Northeastern Pyrenees, Spain). The isolates belonged to one of the following three species: Pasteurella multocida, Mannheimia haemolytica and Bibersteinia trehalosi. Some P. multocida and M. haemolytica isolates tested positive for AMR. The statistical analysis revealed no differences between the AMR levels from chamois and domestic sheep isolates. However, one P. multocida of chamois origin presented resistance to cephalosporins and fluoroquinolones, which are antibiotics of critical importance for human health. Further studies are required to elucidate potential routes of dissemination of AMR genes in natural environments and assess any significant persistence in wildlife to design risk mitigation actions.