Identification and characterization of potential probiotic lactic acid bacteria isolated from pig feces at various production stages.

Lactic acid bacteria (LAB) were isolated, identified, and characterized from pig feces at various growth stages and feed rations in order to be used as probiotic feed additives. Lactic acid bacteria numbers ranged from 7.10 ± 1.50 to 9.40 log CFUs/g for growing and lactating pigs, respectively. Isolates (n = 230) were identified by (GTG)5-polymerase chain reaction and partial sequence analysis of 16S rRNA. Major LAB populations were Limosilactobacillus reuteri (49.2%), Pediococcus pentosaceus (20%), Lactobacillus amylovorus (11.4%), and L. johnsonii (8.7%). In-vitro assays were performed, including surface characterization and tolerance to acid and bile salts. Several lactobacilli exhibited hydrophobic and aggregative characteristics and were able to withstand gastrointestinal tract conditions. In addition, lactobacilli showed starch- and phytate-degrading ability, as well as antagonistic activity against Gram-negative pathogens and the production of bacteriocin-like inhibitory substances. When resistance or susceptibility to antibiotics was evaluated, high phenotypic resistance to ampicillin, gentamicin, kanamycin, streptomycin, and tetracycline and susceptibility towards clindamycin and chloramphenicol was observed in the assayed LAB. Genotypic characterization showed that 5 out of 15 resistance genes were identified in lactobacilli; their presence did not correlate with phenotypic traits. Genes erm(B), strA, strB, and aadE conferring resistance to erythromycin and streptomycin were reported among all lactobacilli, whereas tet(M) gene was harbored by L. reuteri and L. amylovorus strains. Based on these results, 6 probiotic LAB strains (L. reuteri F207R/G9R/B66R, L. amylovorus G636T/S244T, and L. johnsonii S92R) can be selected to explore their potential as direct feed additives to promote swine health and replace antibiotics.

Des bactéries lactiques (LAB) ont été isolées, identifiées et caractérisées à partir de matières fécales de porc à différents stades de croissance et de rations alimentaires afin d'être utilisées comme additifs alimentaires probiotiques. Le nombre de bactéries lactiques variait de 7,10 ± 1,50 à 9,40 log UFC/g pour les porcs en croissance et en lactation, respectivement. Les isolats (n = 230) ont été identifiés par réaction d'amplification en chaîne par la (GTG)5-polymérase et analyse partielle de la séquence de l'ARNr 16S. Les principales populations de LAB étaient Limosilactobacillus reuteri (49,2 %), Pediococcus pentosaceus (20 %), Lactobacillus amylovorus (11,4 %) et L. johnsonii (8,7 %). Des tests in vitro ont été effectués, y compris la caractérisation de surface et la tolérance aux acides et aux sels biliaires. Plusieurs lactobacilles présentaient des caractéristiques hydrophobes et agrégatives et étaient capables de résister aux conditions du tractus gastro-intestinal. De plus, les lactobacilles ont montré une capacité de dégradation de l'amidon et des phytates, ainsi qu'une activité antagoniste contre les agents pathogènes à Gram négatif et la production de substances inhibitrices de type bactériocine. Lorsque la résistance ou la sensibilité aux antibiotiques a été évaluée, une résistance phénotypique élevée à l'ampicilline, à la gentamicine, à la kanamycine, à la streptomycine et à la tétracycline et une sensibilité à la clindamycine et au chloramphénicol ont été observées dans les LAB testés. La caractérisation génotypique a montré que cinq gènes de résistance sur 15 ont été identifiés dans les lactobacilles; leur présence n'était pas corrélée aux traits phénotypiques. Les gènes erm(B), strA, strB et aadE conférant une résistance à l'érythromycine et à la streptomycine ont été signalés parmi tous les lactobacilles, tandis que le gène tet(M) était hébergé par les souches L. reuteri et L. amylovorus. Sur la base de ces résultats, six souches probiotiques LAB (L. reuteri F207R/G9R/B66R, L. amylovorus G636T/S244T et L. johnsonii S92R) peuvent être sélectionnées pour explorer leur potentiel en tant qu'additifs alimentaires directs pour promouvoir la santé des porcs et remplacer les antibiotiques.(Traduit par Docteur Serge Messier).

Effect of probiotic lactobacilli supplementation on growth parameters, blood profile, productive performance, and fecal microbiology in feedlot cattle.

Lactic acid bacteria (LAB) selected on the basis of probiotic characteristics were administered to beef feedlot catlle and the effect on body condition/growth and nutritional-metabolic status as well as on E. coli O157:H7 fecal shedding, were investigated. A feeding trials involving 126 steers were used to evaluate the effects of Lactobacillus acidophilus CRL2074, Limosilactobacillus fermentum CRL2085 and Limosilactobacillus mucosae CRL2069 and their combinations (5 different probiotic groups and control) when 107-108 CFU/animal of each probiotic group were in-feed supplemented. Cattle were fed a high energy corn-based diet (16 to 88%) and samples from each animal were taken at 0, 40, 104 and 163 days. In general, animals body condition and sensorium state showed optimal muscle-skeletal development and behavioral adaption to confinement; no nasal/eye discharges and diarrheic feces were observed. The nutritional performance of the steers revealed a steady increase of biometric parameters and weight. Animals supplied with L. mucosae CRL2069 for 104 days reached the maximum mean live weight (343.2 kg), whereas the greatest weight daily gain (1.27 ± 0.16 Kg/day) was obtained when CRL2069 and its combination with L. fermentum CRL2085 (1.26 ± 0.11 kg/day) were administered during the complete fattening cycle. With several exceptions, bovine cattle blood and serum parameters showed values within referential ranges. As a preharvest strategy to reduce Escherichia coli O157:H7 in cattle feces, CRL2085 administered during 40 days decreased pathogen shedding with a reduction of 43% during the feeding period. L. fermentum CRL2085 and L. mucosae CRL2069 show promise for feedlot cattle feeding supplementation to improve metabolic-nutritional status, overall productive performance and to reduce E. coli O157:H7 shedding, thus decreasing contamination chances of meat food products.