Study of the spread of the antibiotic resistance phenomenon in a wolf population (Canis lupus, Linneaus 1758) in the Aspromonte National Park

Monitoring antibiotic resistance in wildlife is a useful method of evaluating the impact of anthropic pressure (THALLER et al., 2010). Several studies have shown that the increasing prevalence of antibiotic-resistant bacteria in humans and in veterinary medicine is accompanied by a similar co-emergence in wild species (GILLIVER et al., 1999; OSTERBLAD et al., 2001; GUENTHER et al., 2010; HO et al., 2011). This eventuality can presumably be related to environmental exposure to antimicrobial residues, resistant bacteria or resistance genes (GILLIVER et al., 1999; OSTERBLAD et al., 2001; ALLEN et al., 2011). The study aimed to identify little known epidemiological aspects by focusing on the isolation of potentially pathogenic enterobacteria in a wolf population (Canis lupus, Linneaus, 1758) living in the Aspromonte National Park (Reggio Calabria, Italy). The Park enjoys an extraordinary faunistic wealth and the local mountains are an excellent retreat for the wolves that are distributed across the protected area in three reproductive packs. Furthermore, the antimicrobial susceptibility of the isolated strains was tested in order to highlight the possible spread of the antimicrobial resistance in this animals that, surely, have never received therapeutic protocols and which may be considered environmental sentinels. Eighty faecal samples were collected from 15 different areas of the Aspromonte National Park. All samples were cultured using standard bacteriological methods. The identification of the strains was carried out using mass spectrometry MALDI-TOF. Antibiotic sensitivity test of the isolates was performed on Mueller-Hinton agar plates by Kirby Bauer’s Disk Diffusion Test (BAUER et al., 1966). The bacteriological analysis produced 101 strains belonging to 18 different species of the Enterobacteriaceae Family. The most frequently recovered bacterial species was Citrobacter spp (n. 24), Escherichia coli (n. 23) and Hafnia alvei (n. 18). Potentially pathogenic species including Salmonella spp., Serratia spp. and Yersinia enterocolitica have also been identified. The isolates displayed some high resistances. A high percentage of strains was resistant to Amoxicillin (78.3%), Amoxicillin- clavulanic acid (60.4%), Ampicillin (55.4%), Streptomycin (36.6%). Antibiotic resistance in wolf can be monitored to evaluate the impact of anthropic pressure. Wild animals can be regarded as sentinel species and considered as environmental health indicators.