Characterization of lactic acid bacteria isolated from the poultry intestinal environment with anti‑Salmonella activity in vitro

HIDALGO V. M.; BABOT J. D.; FERNÁNDEZ M. M.; PEREZ CHAIA A.; AUDISIO M. C.; APELLA M. C.

BRAZILIAN JOURNAL OF MICROBIOLOGY

SOC BRASILEIRA MICROBIOLOGIA

Año: 2022

1517-8382

The purpose of this research was the genotypic identification of lactic acid bacteria (LAB), isolated from the gastrointestinaltract (GIT) of healthy adult birds, and the study of their safety regarding antibiotic resistance, physiological and functional properties involved in the colonization of the GIT of poultry, and Salmonella exclusion, as members of a potential mixed probiotic supplement for poultry. The nucleotidic sequence from Lactobacillus crispatus P1, L. animalis L3, and Enterococcus faecium CRL 1385 (ex-J96) showed 100, 99.8, and 99.3% identity with L. crispatus DSM 20584T, Ligilactobacillus salivarius ATCC 11741T, and E. faecium ATCC 19434T, respectively. These strains showed no resistance to relevant antibiotics usually administered to animals proposed by the European Food Safety Authority. They could endure the detrimental conditions of the gastrointestinal tract (pH 2.6 and oxgall 0.1 and 0.4% w/v). In an ex vivo assay, the LAB showed high adherence to the three sections of the GIT, reaching values higher than 70%. The adhesion to mucus was strain-dependent: L. crispatus CRL 1453 evidenced the highest adhesion (> 19%) while Lig. salivarius subsp. salivarius CRL 1417 and E. faecium CRL 1385 adhered to a lower extent (> 9 and 2%, respectively). Moreover, the LAB elicited remarkable anti-Salmonella activity, taking into account that they could inhibit elevated counts of different Salmonella serovars, especially the host-specific serovars S. Gallinarum and S. Pullorum (up to 8 log CFU/mL decrease in Salmonella counts).