Bioprospecting of probiotics with antimicrobial activities against Salmonella Heidelberg and that produce B-complex vitamins as potential supplements in poultry nutrition

The demand for animal protein for human consumption has been risen exponentially. Modern animal production practices are associated with the regular use of antibiotics, potentially increasing the emerging multi-resistant bacteria, which may have a negative impact on public health. In poultry production, substances capable of maximizing the animals’ performance and displaying an antimicrobial activity against pathogens are very well desirable features. Probiotic can be an efcient solution for such a task. In the present work, lactic acid bacteria (LAB) were isolated from chicken cecum and screened for their antagonistic efect towards many pathogens. Their capacity of producing the B-complex vitamins folate and ribofavin were also evaluated. From 314 isolates, three (C43, C175 and C195) produced Bacteriocin-Like Inhibitory Substances (BLIS) against Staphylococcus aureus (inhibition zones of 18.9, 21.5, 19.5mm, respectively) and also inhibited the growth of Salmonella Heidelberg. The isolate C43 was identifed as Enterococcus faecium, while C173 and C195 were both identifed as Lactococcus lactis subsp. lactis. Moreover, the isolates L. lactis subsp. lactis strains C173 and C195 demonstrated high potential to be used as probiotic in poultry feed, in addition to their advantage of producing folate (58.0 and 595.5ng/ mL, respectively) and ribofavin (223.3 and 175.0ng/mL, respectively).Fil: da Silva Sabo, Sabrina. Universidade de Sao Paulo; BrasilFil: Mendes, Maria Anita. Universidade de Sao Paulo; BrasilFil: da Silva Araújo, Elias. Universidade de Sao Paulo; BrasilFil: Bicudo de Almeida Muradian, Ligia. Universidade de Sao Paulo; BrasilFil: Makiyama, Edson Naoto. Universidade de Sao Paulo; BrasilFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Borelli, Primavera. Universidade de Sao Paulo; BrasilFil: Fock, Ricardo Ambrósio. Universidade de Sao Paulo; BrasilFil: Knöbl, Terezinha. Universidade de Sao Paulo; BrasilFil: Pinheiro de Souza Oliveira, Ricardo. Universidade de Sao Paulo; Brasi

Bacteriocinogenic probiotic bacteria isolated from an aquatic environment inhibit the growth of food and fish pathogens

The conditions of aquatic environments have a great influence on the microbiota of several animals, many of which are a potential source of microorganisms of biotechnological interest. In this study, bacterial strains isolated from aquatic environments were bioprospected to determine their probiotic profile and antimicrobial effect against fish and food pathogens. Two isolates, identified via 16S rRNA sequencing as Lactococcus lactis (L1 and L2) and one as Enterococcus faecium 135 (EF), produced a bacteriocin-like antimicrobial substance (BLIS), active against Listeria monocytogenes, Salmonella Choleraesuis and Salmonella Typhimurium. Antimicrobial activity of BLIS was reduced when exposed to high temperatures and proteolytic enzymes (trypsin, pepsin, papain and pancreatin). All strains were sensitive to 7 types of antibiotics (vancomycin, clindamycin, streptomycin, gentamicin, chloramphenicol, rifampicin and ampicillin), exhibited a high rate of adherence to Caco-2 cells and expressed no hemolysin and gelatinase virulence factors. EF showed some resistance at pH 2.5 and 3.0, and L2/EF showed higher resistance to the action of bile salts. Finally, the presence of bacteriocin genes encoding for proteins, including Nisin (L1 and L2), Enterocin A, B, P, and Mundticin KS (EF) was detected. The molecular and physiological evidence suggests that the bacterial isolates in this study could be used as natural antimicrobial agents and may be considered safe for probiotic application