The species and physiological diversity of Bifidobacterium genus in Gallus gallus domesticus are influenced by feeding model and niche adaptations.

Species diversity of the Bifidobacterium genus was scarcely explored in different rearing systems of poultry. The aim of the study was to isolate intestinal species and compare their physiological and traits for adaptation to the avian intestinal niche. Fourteen strains isolated from chickens of intensive rearing farms and free-range hens, were identified by 16S rDNA sequencing, rep-PCR fingerprinting, and carbohydrates fermentation. Strains belonged to species Bifidobacterium pseudolongum subsp. pseudolongum and subsp. globosum, B. pullorum, B. animalis subsp lactis, B. boum, B. thermacidophilum subsp. thermacidophilum and B. thermophilum. One strain of B. animalis and B. pullorum, and two of B. pseudolongum subsp. pseudolongum were obtained from chicks, while the others were from free-range adult hens. Growth (in MRSc) at the poultry physiological temperature, acids production in caecal water with raffinose (rCW), ex vivo adhesion (%) to avian intestinal epithelial cells (IEC), and auto-aggregation (%) were used for discrimination inter- and intra-specific. Significantly different acetic and lactic acids production and growth temperatures were observed in strains of the same species/subspecies. Remarkable auto-aggregation capability was observed in B. thermacidophilum subsp. thermacidophilum LET 406 (40.2 ± 1.1%), while adhesion property was highlighted in B. pseudolongum subsp. pseudolongum LET 408 (65.30 ± 4.75% in jejunum; 46.05 ± 2.80 in ileum). Scanning Electronic Microscopy of the interaction IEC-LET 408 revealed an irregular bacterial surface exhibiting vesicle-like arrangements and filaments that formed a network among bacteria cells and with the epithelial cells, as possible adaptative response to promote its persistence in the gut. These finds will be valuable for bacterial supplements design intended to intensive rearing.

Cellular ITAM-containing proteins are oncoproteins in nonhematopoietic cells.

Immunoreceptor tyrosine-based activation motifs (ITAMs) are involved in the transduction of signals necessary for activation, differentiation, and survival in hematopoietic cells. Several viruses have been shown to encode ITAM-containing transmembrane proteins. Although expression of these viral proteins has in some cases been shown to transform nonhematopoietic cells, a causal role for a functional ITAM in this process has not been elucidated. To examine the potential transforming properties of ITAM-containing proteins, a recombinant protein consisting of ITAM-containing cytoplasmic regions of the B-cell antigen receptor was expressed in immortalized murine mammary epithelial and fibroblast cells. Mammary epithelial cells expressing this construct exhibited depolarized morphology in three-dimensional cultures. This transformed phenotype was characterized by a loss of anchorage dependence and hallmarks of epithelial to mesenchymal transition. Fibroblasts expressing this ITAM construct also lost contact inhibition and anchorage dependence. The transformed phenotype seen in both cell types was abrogated upon tyrosine to phenylalanine substitutions of the ITAMs. Inhibition of Syk tyrosine kinase, which associates with the ITAM, also prevented cell transformation. Our results indicate that expression of a nonviral ITAM-containing protein is sufficient for cell transformation. Despite lacking intrinsic enzymatic activity, ITAM-containing proteins can function as potent oncoproteins by scaffolding downstream mediators.