Resistance Patterns, mcr-4 and OXA-48 Genes, and Virulence Factors of Escherichia coli from Apennine Chamois Living in Sympatry with Domestic Species, Italy

Antibiotic Resistance in the Apennine Wolf (Canis lupus italicus): Implications for Wildlife and Human Health

The Apennine wolf (Canis lupus italicus) is a subspecies of gray wolf that is widespread throughout Italy. Due to hunting and habitat loss, their population declined dramatically in the late 19th and early 20th centuries, but conservation efforts improved to restore the species to an estimated population of 3300 individuals. The presence of antibiotic-resistant bacteria in Apennine Wolf may pose a risk to its health and survival, as well as the health of other animals in its environment. In this study, we investigated the antibiotic resistance profiles of bacteria collected from Apennine wolves admitted to the Wildlife Research Center of Maiella National Park (Italy) in 2022. A total of 12 bacteria collected from four wolves were isolated and tested for susceptibility to antibiotics used in veterinary medicine and to critically important antibiotics for human health by means of the Vitek 2 system. All isolates were resistant to at least one antibiotic, and six bacteria were multidrug resistant to critically important antibiotics (third-generation cephalosporins, carbapenems and fluoroquinolones). The results of this pilot study have allowed for the characterization of resistant profiles in Escherichia coli, Enterococcus faecalis and other bacterial species not previously reported in Apennine wolves. Our findings provide important insights into antibiotic resistance in wildlife and its potential implications for the conservation of biodiversity and public health.

Antibiotic-Resistant Bacteria Dissemination in the Wildlife, Livestock, and Water of Maiella National Park, Italy

Antimicrobial resistance (AMR) is a global health concern that has been linked to humans, animals, and the environment. The One Health approach highlights the connection between humans, animals, and the environment and suggests that a multidisciplinary approached be used in studies investigating AMR. The present study was carried out to identify and characterize the antimicrobial resistance profiles of bacteria isolated from wildlife and livestock feces as well as from surface water samples in Maiella National Park, Italy. Ecological and georeferenced data were used to select two sampling locations, one where wildlife was caught within livestock grazing areas (sympatric group) and one where wildlife was caught outside of livestock grazing areas (non-sympatric group). Ninety-nine bacterial isolates from 132 feces samples and seven isolates from five water samples were collected between October and December 2019. The specimens were examined for species identification, antibiotic susceptibility and molecular detection of antibiotic resistance. Forty isolates were identified as Escherichia coli, forty-eight as Enterococcus spp., eight as Streptococcus spp. and ten as other gram-negative bacteria. Phenotypic antibiotic resistance to at least one antimicrobial agent, including some antibiotics that play a critical role in human medicine, was detected in 36/106 (33.9%, 95% CI: 25-43) isolates and multidrug resistance was detected in 9/106 isolates (8.49%, 95% CI: 3.9-15.5). In addition, genes associated with antibiotic resistance were identified in 61/106 (57.55%, 95% CI: 47.5-67) isolates. The samples from sympatric areas were 2.11 (95% CI: 1.2-3.5) times more likely to contain resistant bacterial isolates than the samples from non-sympatric areas. These data suggest that drug resistant bacteria may be transmitted in areas where wildlife and livestock cohabitate. This emphasizes the need for further investigations focusing on the interactions between humans, wildlife, and the environment, the results of which can aid in the early detection of emerging AMR profiles and possible transmission routes.

Microbial community and antimicrobial resistance in fecal samples from wild and domestic ruminants in Maiella National Park, Italy

This study aimed to provide new insights about antimicrobial resistance genes abundance and microbial communities of wild and domestic ruminants in wildlife-livestock interface. In total, 88 fecal samples were recovered from Apennine chamois, red deer, goat, cattle and sheep, and were collected in pools. The populations under study were selected based on ecological data useful to define sympatric and non-sympatric populations. Samples were screened for commonly used in farms under study or critically important antimicrobial resistance genes (aadA2, TetA, TetB, TetK, TetM, mcr-1). The microbial community composition was found to be different based on the species and land use of animals under study. Indeed, it was mostly characterized by phyla Firmicutes in bovine, Bacteroidota in chamois and Proteobacteria in red deer. Additionally, positive correlations between antibiotic resistance genes and microbial taxa (e.g., Tet genes correlated with Firmicutes and Patescibacteria) were described. Of the antimicrobials investigated, the abundance of mcr-1 gene suggests the importance of monitoring the wildlife in order to detect the emerging resistance genes contamination in environment. This study provides new data that highlight the importance of multidisciplinary and uncultured study in order to describe the spreading of antimicrobial resistance and related contamination in the environment.

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Multidisciplinary approach including ecological data, real time PCRs and 16S rRNA analysis

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Microbial communities composition of rare species as Apennine chamois

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Evaluation of antibiotic resistance genes abundance in feces of wild and domestic ruminants

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Detection of mcr-1 resistance gene relevant for Public Health