| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1274-1 | ||||
Resumo:Intensive farming systems, especially poultry, are constantly affected by the advent of bacterial outbreaks. These microorganisms’ persistent presence in livestock are a commercial, environment and public health threat. In addition, the reckless use of antibiotics promoted the emergence and dispersion of resistant strains. An alternative to control undesirable bacteria, including antimicrobial resistant ones, is the application of lytic bacteriophages (phages). These viruses infect specific and efficiently bacteria and can be isolated from the same environments as their hosts. In this study, a lytic phage, that infects a Salmonella strain was isolated from poultry litter. Confirmation of the phage presence was performed using double-layer agar assays, followed by the selection of lysis plaques for purification. To assess the phage infectivity and biocontrol ability, the host range test, efficiency of plating (EOP) and one step growth curve assays were performed. Additionally, inhibition tests were carried out in liquid culture by monitoring the host growth kinetics. The isolated phage was able to produce visible lysis plaques in the bacteria plate lawn, confirming its infection capacity. One step growth curve test resulted in a phage latent time close to 50 minutes and a burst size of 3000 plaque forming units (PFU)/cell. These parameters revealed that this phage can be a good biocontrol candidate. Moreover, the virus showed satisfactory bacteria growth inhibition when compared with the control culture. As expected, higher phage initial concentrations - as multiplicity of infection close to 10 (MOI10) - had better inhibition performances. Overall, this study shows that the isolated phage can be an alternative for Salmonella spp. growth and dispersion control in poultry litter. These represents an initial step for contamination effective management and, consequently, quality gains in the whole poultry production chain. Palavras-chave: Antibiotic resistance, Livestock, Microbial control, Phages, Salmonellosis Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) | |||||