In the European Union, salmonellosis is one of the most important zoonoses reported. Poultry meat and egg products are the most common food matrices associated with Salmonella presence. Moreover, wild and domestic animals could represent an important reservoir that could favour the direct and indirect transmission of pathogens to humans. Salmonella spp. can infect carnivorous or omnivorous wild birds that regularly ingest food and water exposed to faecal contamination. Birds kept in captivity can act as reservoirs of Salmonella spp. following ingestion of infected prey or feed. In this paper, we describe the isolation of different Salmonella serovars in several species of raptors hosted in aviaries in an Italian wildlife centre and in the raw chicken necks used as their feed but intended for human consumption. Characterisations of strains were carried out by integrating classical methods and whole genome sequencing analysis. The strains of S. bredeney isolated in poultry meat and birds belonged to the same cluster, with some of them being multidrug-resistant (MDR) and carrying the Col(pHAD28) plasmid-borne qnrB19 (fluoro)quinolone resistance gene, thus confirming the source of infection. Differently, the S. infantis found in feed and raptors were all MDR, carried a plasmid of emerging S. infantis (pESI)-like plasmid and belonged to different clusters, possibly suggesting a long-lasting infection or the presence of additional undetected sources. Due to the high risk of fuelling a reservoir of human pathogens, the control and treatment of feed for captive species are crucial.

Salmonella is a Gram-negative enteric bacterium responsible for the foodborne and waterborne disease salmonellosis, which was the second most reported foodborne gastrointestinal infection in humans in the European Union in 2023. Animals represent the principal reservoir of this pathogen, with animal-derived food products serving as the main route of transmission to humans. In a household context, having numerous animals can be a crucial factor for contracting Salmonella spp. infection. In the present study, we report a case of a familiar outbreak of Salmonella Thompson that occurred in 2024 in central Italy, involving an infant and the companion animals (a dog, a cat and ten birds) of the family’s farm. To support the epidemiological investigations, antimicrobial susceptibility testing and whole-genome sequencing (WGS) were conducted on strains from the human case and from animals. Eleven strains were isolated in total, from fecal samples collected from the child and the animals at different times. WGS confirmed the genetic relatedness between human and animal isolates, supporting the hypothesis of a shared source of infection, but genes or plasmid involved in antibiotic resistance were not found. Moreover, AST revealed that isolates were fully susceptible to major antimicrobial classes tested. Despite being an uncommon serotype, the involved Salmonella Thompson serovar 6,7: k:1,5 O:7 (C1) demonstrated a high pathogenic potential, emphasizing the need for vigilance even toward serotypes not typically associated with major public health concerns. Moreover, these findings underscore the critical need for an integrated One Health approach to effectively monitor, prevent, and control zoonotic infections.