Isolamento de bacteriófagos para o controle de Salmonella spp. em cama de aviário

Abstract

Intensive farming systems, especially poultry, are constantly affected by the emergence of bacterial outbreaks. In addition, the reckless use of antibiotics potentiates the creation and dispersion of resistant strains. An alternative to control undesirable bacteria, including those resistant to antimicrobials, is the application of viruses specialized in infecting them, the bacteriophages. These viruses are naturally very abundant and efficient in infecting their hosts, being found in the same environments as the bacteria. The objective of this work was the isolation of bacteriophages aiming their application in the control of the growth of strains of Salmonella spp. from an aviary sample. A strain of Salmonella was isolated from a sample of poultry litter in the region, which was used for the phage enrichment step and in the isolation of a specific bacteriophage. Confirmation of the presence of phages was performed using double-layer agar assays, followed by the selection of lysis plates for purification. In order to assess the infective capacity of the phages, the host spectrum test and the efficiency of plating (EOP) were performed. Finally, inhibition tests were carried out in liquid culture of the host, where the isolated phage showed an inhibition efficiency at an MOI 1 (multiplicity of infection). The methods used for the isolation of the phage were efficient, where a specific phage with inhibitory potential was isolated capable of controlling Salmonella infection. Thus, the phage proved to be an alternative in the control of Salmonella in poultry litter, aiming to reduce contamination in chickens in the animal husbandry system.