Salmonella typhimurium transmission among free-living birds (Passerines) and broiler chicks

Abstract

Wild birds may be in charge of transmitting pathogens to production animals. Contact with humans can also favor the spread of pathogens and promote the birds crowding, especially in feeding places. The dynamics of Salmonella transmission this interaction is still uncertain, but it is believed that as much wild birds can be the source of the infection, as they can become infected through domestic birds. Therefore, in order to explore this dynamic, two experiments were carried out with the Typhimurium serovar (ST), using as experimental models white-rumped munia (WRM) (Lonchura striata) and broilers (Gallus gallus). Internal and external birds samples were evaluated, as well as their local environment. When the WRM were previously infected by ST the contamination of broiler chicks litter (23,3%) occurred into the first 6 hours. However, when WRM´s became infected through contact with broiler chicks (previously inoculated with ST) the contamination of non-infected broiler chicks was lower (5%), including periods in which positive birds were not detected, besides to litter, drinking water and feed from the environment of uninfected birds, remaining negative for ST throughout the experimental period. The results of experiments 1 and 2 demonstrated that the most favorable situation for the establishment of ST contamination in broiler chicks was the one in which the WRM´s were already infected, however, ST transmission was also characterized when non-contaminated WRM´s had access to previously contaminated broiler chicks, which carried ST to a group of initially negative broiler chicks. According to the research, we found that the possibility of contamination and transmission occurs between wild birds and poultry, and the dynamics on farms must be better understood.