Survey on the Occurrence of Zoonotic Bacterial Pathogens in the Feces of Wolves (Canis lupus italicus) Collected in a Protected Area in Central Italy

Previous investigations have explored the involvement of wolves in parasitic and viral diseases, but data on the zoonotic bacteria are limited. The aim of this study was to assess the occurrence of bacterial zoonotic agents in 16 wolf (<i>Canis lupus italicus</i>) fecal samples collected in a protected area in Central Italy. <i>Campylobacter</i> spp., <i>Salmonella</i> spp., <i>Yersinia</i> spp., <i>Listeria monocytogenes,</i> and Shiga Toxin-Producing <i>Escherichia coli</i> (STEC) were investigated by culture, while polymerase chain reaction (PCR) was employed to detect <i>Coxiella burnetii</i>, <i>Mycobacterium</i> spp., <i>Brucella</i> spp., and <i>Francisella tularensis</i>. The presence of Extended Spectrum β-Lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae was also evaluated, using selective isolation media and detection of antimicrobial resistance genes. All samples were negative for <i>Campylobacter</i> spp., <i>Salmonella</i> spp., <i>C. burnetii</i>, <i>Mycobacterium</i> spp., <i>Brucella</i> spp., <i>F. tularensis</i>, and carbapenemase-producing Enterobacteriaceae. One sample tested positive for <i>Yersinia aldovae</i> and three for <i>Yersinia enterocolitica</i> BT1A. One <i>L. monocytogenes</i> (serogroup IIa) and one STEC, carrying the <i>stx1</i> gene, were isolated. Two ESBL isolates were detected: one <i>Serratia fonticola</i>, carrying <i>bla_FONA-3/6</i> gene, and one <i>Escherichia coli</i>, carrying <i>bla_CTX-M-1</i> gene. Both ESBL isolates were resistant to different antimicrobials and therefore classified as multi-drug-resistant. Our data suggest that wolves are potential carriers of zoonotic bacteria and may contribute to the environmental contamination through their feces.