RESUMO
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.
Assuntos
Galinhas , Probióticos , Animais , Feminino , Bifidobacterium , DNA Ribossômico/genéticaRESUMO
The ban on the use of antibiotics as feed additives for animal growth promotion in the European Union and United States and the expectation of this trend to further expand to other countries in the short term have prompted a surge in probiotic research. Multi-species probiotics including safe and compatible strains with the ability to bind different nutritional lectins with detrimental effects on poultry nutrition could replace antibiotics as feed additives. Lactobacillus salivarius LET201, Lactobacillus reuteri LET210, Enterococcus faecium LET301, Propionibacterium acidipropionici LET103 and Bifidobacterium infantis CRL1395 have proved to be compatible as evaluated through three different approaches: the production and excretion of antimicrobial compounds, growth inhibition by competition for essential nutrients and physical contact, and a combination of both. The safety of P. acidipropionici LET103 was confirmed, since no expression of virulence factors or antibiotic resistance was detected. The innocuity of E. faecium LET301 should be further evaluated, since the presence of genes coding for certain virulence factors (gelE, efaAfm and efaAfs) was observed, albeit no expression of gelE was previously detected for this strain and there are no reports of involvement of efaAfm in animal pathogenicity. Finally, a combination of the five strains effectively protected intestinal epithelial cells of broilers from the cytotoxicity of mixtures of soybean agglutinin, wheat germ agglutinin and concanavalin A. To our knowledge, this is the first time that a combination of strains is evaluated for their protection against lectins that might be simultaneously present in poultry feeds.
Assuntos
Anti-Infecciosos/metabolismo , Bifidobacterium longum subspecies infantis/metabolismo , Enterococcus faecium/metabolismo , Lactobacillus/metabolismo , Doenças das Aves Domésticas/prevenção & controle , Probióticos/farmacologia , Propionibacterium/metabolismo , Animais , Antibiose , Bifidobacterium longum subspecies infantis/genética , Bifidobacterium longum subspecies infantis/crescimento & desenvolvimento , Bifidobacterium longum subspecies infantis/patogenicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Concanavalina A/toxicidade , Farmacorresistência Bacteriana , Enterococcus faecium/genética , Enterococcus faecium/crescimento & desenvolvimento , Enterococcus faecium/patogenicidade , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Lactobacillus/genética , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/patogenicidade , Lectinas/metabolismo , Modelos Teóricos , Lectinas de Plantas/toxicidade , Probióticos/efeitos adversos , Propionibacterium/genética , Propionibacterium/crescimento & desenvolvimento , Propionibacterium/patogenicidade , Ligação Proteica , Proteínas de Soja/toxicidade , Virulência , Fatores de Virulência/genética , Aglutininas do Germe de Trigo/toxicidadeRESUMO
Poultry fed on wheat-based diets regularly ingest wheat germ agglutinin (WGA) that has toxic effects in vitro on intestinal epithelial cells (IEC) obtained from 14-d-old broilers. Cytotoxicity and the potential role of 14 intestinal bacterial strains in the removal of bound lectins in epithelial cell cultures were investigated. Cytotoxicity was dependent on time and lectin concentration; the lethal dose (LD50) was 8.36 µg/ml for IEC exposed for 2 h to WGA. Complementary sugars to WGA were detected on the surface of one Enterococcus and 9 Lactobacillus strains isolated from poultry. These strains were evaluated as a lectin removal tool for cytotoxicity prevention. Incubation of lactic acid bacteria with WGA before IEC-lectin interaction caused a substantial reduction in the percentage of cell deaths. The protection was attributed to the amount of lectin bound to the bacterial surfaces and was strain-dependent. L. salivarius LET 201 and L. reuteri LET 210 were more efficient than the other lactic acid bacteria assayed. These results provide a basis for the development of probiotic supplements or cell-wall preparations of selected lactic acid bacteria intended to avoid harmful effects of a natural constituent of the grain in wheat-based diets.
Assuntos
Galinhas/microbiologia , Enterococcus/fisiologia , Enterócitos/efeitos dos fármacos , Lactobacillus/fisiologia , Doenças das Aves Domésticas/prevenção & controle , Aglutininas do Germe de Trigo/toxicidade , Animais , Dieta/efeitos adversos , Dieta/veterinária , Enterococcus/isolamento & purificação , Intestinos/citologia , Intestinos/microbiologia , Lactobacillus/isolamento & purificação , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/induzido quimicamente , Probióticos , Especificidade da EspécieRESUMO
Different studies in animal rearing claim the probiotic potential of species of the genus Propionibacterium. The effects of strains of Propionibacterium acidipropionici isolated from poultry intestine on microbiota activity and intestinal mucosa development were investigated in the early stage of rearing chicks and the safety of the dose used was investigated. The strains P. acidipropionici LET105 and LET107, administered as monoculture to chicks from the 1st to 14th day of life in a daily dose of 106 cfu/ml administered in the drinking water resulted harmless. The animals arrived at the expected weight for age and no differences were observed with respect to the food intake and water consumption related to control without bacteria administration. The analysis of microbiota composition revealed the presence of propionibacteria at the middle and end of the trial only in treated groups. Normal development of lactic acid bacteria and bifidobacteria, and slow colonisation by Bacteroides at the 7th day of the study was observed in the same groups. Analysis of the organic acids concentrations in the caecal content of birds revealed higher lactic acid and lower butyric acid production. Lower short chain fatty acids total concentration than expected during treatment was related to a better development of the gut mucosa. Increase in length of villus-crypt units, goblet cells counts and neutral mucins production were evidenced. Higher mucus secretion produced by dietary supplementation with propionibacteria could provide increased protection against pathogens.