Detection and assessment of antibiotic-resistant strains of Salmonella Typhimurium in raptors referred to the Environmental Protection Organization of Kerman, Iran

Wildlife can serve as a long-term asymptomatic reservoir for zoonotic bacteria, such as Salmonella spp. wild birds are carriers of different serovars of Salmonella enterica, which can play a significant role in the epidemiology of Salmonella disease in humans and livestock. In this study, we detect and evaluate the antibiotic resistance of Salmonella strains, particularly Salmonella Typhimurium, from 33 raptors that carry this pathogen. For this purpose, 66 swab samples were collected: 33 choanal swabs and 33 cloacal swabs. So that, 9 Salmonella spp. isolates and 4 Salmonella Typhimurium isolates were obtained through culture, biochemical tests, and PCR. Continuing the study, the antibiotic resistance of Salmonella-positive samples was measured against seven antibiotics. Among the nine Salmonella detects the highest antibiotic resistance was observed against neomycin, fosfomycin, colistin, and enrofloxacin. In contrast, trimethoprim-sulfadiazine, lincomycin-spectinomycin, and chloramphenicol showed the lowest resistance, with similar percentages. The isolation of Salmonella species, specifically Typhimurium, from raptors in Kerman province, coupled with the observed antibiotic resistance in these strains, has reduced available treatment options. Furthermore, the role of birds of prey in transmitting resistant and pathogenic bacteria to humans and domestic animals, due to their migratory patterns, underscores the importance of adopting a One Health approach. The monitoring, treating, and studying of this disease in infected captive raptors are critical components in controlling Salmonella within the animal-human-ecosystem cycle.