Low Occurrence of ISalmonella/I spp. in Wild Animals in Bahia, Brazil—Population Assessment and Characterization in the Caatinga and Atlantic Forest Biomes

This study evaluated the possible role of wildlife in the Atlantic Forest and Caatinga biomes of Bahia, Brazil, as reservoirs of Salmonella. Very low frequencies (4/674 = 0.59%) of Salmonella infections and antibiotic resistance were observed. Thus, the findings of this study indicated that a wide variety of wildlife species do not carry Salmonella. This may be attributed to minimal human interference. Bacteria of potential public health concern were only detected in areas with high human interaction; therefore, we propose that Salmonella may be a good indicator of degradation in wildlife environments. Salmonella spp. are known to persist in the environment. Wild animals are believed to act as important reservoirs, with antimicrobial resistance frequently occurring in the environment. However, little is known about the role of the wildlife in Bahia as a reservoir for Salmonella in Brazil. This study aimed to isolate and characterize Salmonella spp. from wildlife in the Atlantic Forest and Caatinga biomes considering indicators such as the animal species, degree of anthropization, sampling area, and feeding habits. Convenience wildlife sampling and characterization were conducted, followed by microbiological and molecular identification of Salmonella isolates, serotyping, and antimicrobial susceptibility testing. A total of 674 fecal samples were collected from 12 municipalities during 2015–2021, and 4 were positive for the following Salmonella species: Salmonella enterica subspecies enterica serovar Agona (n = 1), Salmonella enterica subsp. enterica serogroup O:16 (n = 2), and Salmonella enterica subsp. enterica serovar Muenchen (n = 1). Antimicrobial susceptibility analysis revealed that one isolate was resistant to six antibiotics, including extended-spectrum penicillins and beta-lactamase inhibitors. These results indicated a low frequency of Salmonella spp. in the sampled forest fragments. The presence of Salmonella in wild animals increases the risk to public health and biodiversity and indicates that they can act as sentinels of environmental contamination or indicators of preservation.