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A VETERINARIAN PRODUCT WITH LACTIC ACID BACTERIA (LAB) TO IMPROVE THE HEALTH OF POSTPARTUM COWS AND NEWBORN CALVES. Otero1, M C; Ovejero1, C A, González Moreno, C1; Maldonado, N C1 and Nader-Macías1, M E. 1CERELA-CONICET, Chacabuco 145, San Miguel de Tucumán. Tucumán, CP: T4000ILC, Argentina - fnader@cerela.org.ar Introduction LAB are present in the reproductive tract of healthy cows (Otero et al., 2000) being the first colonizers of the intestinal tract of calves, where prevent pathogen entry. Postpartum metritis and diarrhea are two of the main causes of losses in bovine heard productivity. A probiotic product could be a sustainable treatment to prevent these infectious diseases, and decrease adverse effects mainly those caused by antibiotics in breeding systems (spread of resistance and food contamination). Probiotics are ?live microorganisms administered to the host to produce a beneficial physiological effect? (Reid et al,2003). Our main objective is the design of a veterinarian vaginal product containing beneficial LAB (vaginal and intestinal strains) to restore the reproductive tract microbiome and to colonize the newborn calf mucosa. Therefore, the selected LAB should be able to maintain the viability in the formula and grow in the host conditions. Objectives The aim of this study was to evaluate the compatibility of the intestinal and vaginal LAB and theis behavior with natural substances for the design of a veterinary formula. Materials and methods Bovine LAB: from calves gut; Lb.amylovorius CRL1697, Lb.johnsonii CRL1693, Lb.mucosae CRL1696, Lb.salivarius CRL1702, Lb. murinus CRL1695, Enterococcus faecium CRL1703. From reproductive tract: Lb.gasseri CRL1412, Lb.gasseri CRL1421, Lb.gasseri CRL1460 and Lb.delbrueckii subsp delbrueckii CRL1461 were selected by their ability to inhibit bovine pathogens and by colonization properties (Nader-Macías et al.,2008). Compatibility assay (Diffusion method in agar plates): different concentrations of LAB strains were inoculated into agar plates and free cells supernatants of all of them seeded in holes. Their compatibility was evaluated by the absence of inhibition halo around the well after 24h incubation at 37ºC. LAB Sensitivity to natural active substances: i) Minimal Inhibitory Concentration (MIC) of Vitamin A and Arnica montana extract on LAB was performed by modified agar plate dilution method (CLSI). ii) Growth Kinetic: three natural substances at different concentrations: Ascorbic acid (30, 20, 10 mg/mL), Inulin (15, 10, 5 mg/mL) and Matricaria chamomilla extract (10, 5 mg/mL) on the LAB growth was evaluated by a complete factorial experimental design. The growth was followed at 37°C, by OD540nm measures during 14h. Results All the LAB assayed were compatible, except Lb. amylovorius CRL 1697 that was slightly inhibited by the vaginal and intestinal LAB. The lower MICs values were obtained for Lb. johnsonii CRL 1693 and Lb. amylovorius CRL 1697; the other LAB have grown under the concentrations range assayed. The maximal growth rate was significantly (p<0,005, Fisher test) affected by the natural substances added to the culture medium, with a different effect for each strain. The length of the lag phase was characteristic of each LAB, but retarded by ascorbic acid. Conclusions The results will be applied for the design of a veterinary product containing bovine beneficial LAB and natural substances, to restore the native microbiome and host tissues of the postpartum reproductive tract and also to promote the colonization of LAB in the intestinal calves microbiome. References -C. Otero, L. Saavedra, C. Silva de Ruiz, O. Wilde, A.R. Holgado, M.E. Nader-Macías. 2000. Letters in Appl.Microbiol.,31:251. -Reid G, Sanders ME, Gaskins HR, Gibson GR, Mercenier A, Rastall R, Roberfroid M, Rowland I, Cherbut C, Klaenhammer TR.2003.JClin Gastroenterol37:105-118. -Nader-Macías ME, Otero MC, Espeche MC, Maldonado NC.2008. J. Ind. Microb.& Biotech:438.

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