Effects of plant extracts on the growth of beneficial indigenous lactic acid bacteria (BLAB) for their potential use in preventing bovine reproductive tract infections

There is a renewed interest in products based on phytocompounds, prebiotics and probiotics in recent years, applied to different hosts to exert a wide variety of effects. The microbiome of the bovine reproductive tract can become unbalanced for many reasons, favoring the entry and proliferation of pathogenic microorganisms, currently treated with antibiotics that exert adverse effects and generate antimicrobial resistance. To deal with this situation, "phytobiotic" formulas are proposed that combine phytocompounds and probiotics. This study aims to determine the compatibility of beneficial autochthonous lactic acid bacteria (BALB) with plant extracts, prebiotics and vitamins, to incorporate them into intravaginal formulas with therapeutic activity. Nine beneficial strains isolated from different bovine ecosystems were evaluated against nine phytocompounds, two prebiotics and five vitamins. Compatibility was assayed using the diffusion technique on agar plates, and the effect of the phytocompounds on the growth of lactic acid bacteria by microplates. The growth of all the strains was affected by some plant extracts, showing a stimulating or inhibitory effect. By the qualitative method, only vitamin A affected the viability of Lactobacillus johnsonii CRL1702 at concentrations higher than 7.5 mg/ml, however, when studying the growth kinetics of the strains with the phytocompounds, the results show that the effect was different in each of one the associated strains + plant extracts, indicating a strain specific effect of plant extacts on each BALB strain. Lapacho and Malva have a stimulating effect on most of the microorganisms, while Garlic and Belladonna inhibited the growth of all of them. Plant extracts at different concentrations did not inhibit the growth of most of the pathogens responsible for endometritis. On the other hand, the highest concentrations of phenolic compounds were detected in Echinacea, Lapacho and Llantén; and the best percentages of antioxidant activity were evidenced in Garlic, Blueberry and Chamomile (<60%). The results obtained in this stage are original, since the combination of natural extracts with lactobacillus strains for veterinary application was not studied previously

Milk Microbiota: What Are We Exactly Talking About?

The development of powerful sequencing techniques has allowed, albeit with some biases, the identification and inventory of complex microbial communities that inhabit different body sites or body fluids, some of which were previously considered sterile. Notably, milk is now considered to host a complex microbial community with great diversity. Milk microbiota is now well documented in various hosts. Based on the growing literature on this microbial community, we address here the question of what milk microbiota is. We summarize and compare the microbial composition of milk in humans and in ruminants and address the existence of a putative core milk microbiota. We discuss the factors that contribute to shape the milk microbiota or affect its composition, including host and environmental factors as well as methodological factors, such as the sampling and sequencing techniques, which likely introduce distortion in milk microbiota analysis. The roles that milk microbiota are likely to play in the mother and offspring physiology and health are presented together with recent data on the hypothesis of an enteromammary pathway. At last, this fascinating field raises a series of questions, which are listed and commented here and which open new research avenues

Lactococcus lactis SpOx Spontaneous Mutants: a Family of Oxidative-Stress-Resistant Dairy Strains

Numerous industrial bacteria generate hydrogen peroxide (H(2)O(2)), which may inhibit the growth of other bacteria in mixed ecosystems. We isolated spontaneous oxidative-stress-resistant (SpOx) Lactococcus lactis mutants by using a natural selection method with milk-adapted strains on dairy culture medium containing H(2)O(2). Three SpOx mutants displayed greater H(2)O(2) resistance. One of them, SpOx3, demonstrated better behavior in different oxidative-stress situations: (i) higher long-term survival upon aeration in LM17 and milk and (ii) the ability to grow with H(2)O(2)-producing Lactobacillus delbrueckii subsp. delbrueckii strains. Furthermore, the transit kinetics of the SpOx3 mutant in the digestive tract of a human flora-associated mouse model was not affected

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.Fil: Mansilla, Flavia Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Miranda, Maria Hortencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Uezen, Jose David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Maldonado, Natalia Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: D'urso Villar, Marcela Adriana. Universidad Nacional de Tucumán; ArgentinaFil: Merino, Luis Antonio. Universidad Nacional del Nordeste; ArgentinaFil: Vignolo, Graciela Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Nader Macias, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin