Seleção de bactérias láticas com potencial probiótico para uso como promotor de crescimento ou como adjuvante imune em vacinas de mucosa na pecuária bovina

Abstract

The requirement for animal protein has been increasing over the past forty years, especially in developing countries, where the economy is on the rise and the increased purchasing power of the population stimulated the demand for these products. However, the safety of the main animal growth promoters used has been challenged in recent decades, making reference for the development of new approaches such as the use of microorganisms. Lactic acid bacteria are often used to promote weight gain in calves, reducing the incidence of neonatal diarrhea. Accordingly, seventy isolates belonging to the genera Lactobacillus/Weissella were obtained from the oral, vaginal and intestinal mucosaes and characterized for their functional and probiotics potentials. Were evaluated the resistance to gastric juice and bile salts, cell surface hydrophobicity, ability to antagonize pathogenic bacteria and to produce hydrogen peroxide and the antimicrobial profile. Four isolates were selected and tested in vivo in axenic mice, evaluating their ability to colonize and modulate mucosal antibody response. L. fermentum 08-V3B, W. hellenica V1V-30 and L. farciminis B4F-06 were observed, respectively, colonizing the airway, intestinal and vaginal mucosaes after ten days of monoassociação. All isolates tested induced a statistically significant production of mucosal IgA in their respective inoculum presented, therefore, great potential for use in animal production, protecting mucosal infection or as a vaccine vehicle.