Bifidobacterium Isolated from Poultry: Stable or Transient Microbiota

GRANDE, SONIA; ARGAÑARAZ MARTÍNEZ, ELOY; EMMERT, GERMAN; BABOT, JAIME DANIEL; SAGUIR, FABIANA; PÉREZ CHAIA, ADRIANA

Córdoba

Congreso; XVII Congreso Argentino de Microbiología General; 2022

Sociedad Argentina de Microbiología General - SAMIGE

Bifidobacteria inhabit the intestinal tract, breasts, oral cavity and human vagina, as well as the gut of other animals and insects; and also, they have been found in environmental totally different as fermented food and sewage. Recently, we isolated 15 Bifidobacterium strains (6 species and 4 subspecies) from the intestinal environment of BB chicks, poultry and backyard hens. The aim of this work was to analyze the adaptive capacity of these 15 strains to the avian intestinal niche. For this purpose, the growth in intestinal simile medium (cecal water) supplemented with raffinose (CWr) and modified MRS (without acetate) in strict anaerobiosis at 41 °C was studied. The production of acids, their molar ratios; and the capacity to adhere to IEC (intestinal epithelial cells) from different regions of the intestine (jejunum, ileum) were also investigated. Most of the strains evaluated showed adaptation to the intestinal niche, evidencing good growth and active production of organic acids. Also, the ability to persist in the intestine was associated with high percentages of adhesion to IEC. Notably, B. animalis subsp. lactis LET401, showed selectivity for jejunum attachment (46 %), and grew satisfactorily in both CWr and MRS, finding molar ratios acetic/lactic acids (A/L) conserved at 3.4. B. thermacidophilum subsp. thermacidophilum LET406, significantly increased its growth in CWr with 3.5 A/L and adhered to IEC without discriminating region. B. pseudolongum subsp. pseudolongum LET 408, grew slowly, however, the acids production in CWr was relevant with 5.0 A/L. In adhesion, it presented the highest values (46 and 65% in ileum and jejunum, respectively); and the presence of structures emerging from the bacterial surface, which interact with the IEC were evidenced by SEM. On the other hand, B. pullorum LET415 adhered to IEC, remained viable in CWr and produced mainly acetic acid, probably, as a metabolic strategy to obtain more ATP, which was not observed in MRS. Through principal component analysis, B. animalis subsp. lactis LET401, B. pseudolongum subsp. pseudolongum LET 408, B. pullorum LET415, isolated from BB chicks and B. thermacidophilum subsp. thermacidophilum LET406 isolated from adult birds, stood out as a group better adapted to the ecological niche (“putative pionners”) and away from the "less adapted" B. boum LET 413 and LET 414. The study of adaptation to the intestinal niche of new strains help to elucidate the mechanisms that arbitrate interaction with the host, determine the ability to persist for long periods in the intestine and hinder colonization by intestinal pathogens. Future genomic studies of these strains will support the results reported here.