Advances in the design of a novelty veterinarian product containing

M.C. OTERO; C.A. OVEJERO; M. E. NADER-MAC¨ªAS

SAN MIGUEL DE TUCUMÁN

Congreso; VII CONGRESO ARGENTINO DE MICROBIOLOGIA; 2011

SOCIEDAD ARGENTINA DE MICROBIOLOGÍA GENERAL

Metritis in cows increases herd healthcosts, reduces the reproductive efficiency, the conception rate (extrainseminations are required) and the feed intake, and also causes a reduction inmilk production. The probiotic lactobacilli therapy provides a validalternative to the antibiotic application for the prevention or treatment ofthese infections. Four autochthonous strains, i.e. Lactobacillus gasseriCRL1412, Lactobacillus gasseri CRL1421, Lactobacillus gasseriCRL1460 and Lactobacillus delbrueckii subsp. delbrueckii CRL1461were selected by the adhesion to bovine vaginal cells, the inhibition ofmetritis causing pathogens and by their technological properties (resistance tofreeze-drying process stress conditions and shelf-life period in two pharmaceuticalforms). In this work, the effects of natural substances with active action on theimpaired epithelium and its resident microbiota, were evaluated on the growth kineticof these microorganisms to be included in the design of a pharmaceutical product.A complete factorial experimental designwas applied to determine the effect of three natural substances at differentconcentrations: ascorbic acid (30, 20 and 10 mg/mL), inulin (15, 10 and 5 mg/mL)and Matricaria chamomilla extract (10 and 5 mg/mL) on the growth parametersof all the tested strains. Growth was evaluated in modified MRS medium at 37¡ãC.The O.D. at 540 nm was determined at 30 min intervals during 14 h, and the increasein biomass, the maximal growth rates and the length of lag and stationaryphases were calculated. The experimental procedure was repeated three times. The maximal growth rate was significantly(p¡Ü0.005) affected by the substance added to the culture medium, theeffect being different in each strain (interaction between strain x substance, p¡Ü0.005). Inulin significantly increasedthe growth rate, mainly in the CRL 1412 strain. The increase in biomass wasaffected by the type of substance, but the response depended on the concentrationand on the microorganisms (interaction strains x substance and substance x concentration,p¡Ü0.005). The maineffect was observed on the growth of CRL 1421. The time of lag phase was specificfor each microorganism and it was independent of the other factors. The lengthof the stationary phase was significantly (p¡Ü0.05) shortened with inulin, being CRL1421 and CRL 1461 faster thanother strains. The efficacy of the probiotic treatment depends on the viabilityof the microorganisms in the pharmaceutical formula during the shelf life andup the arrival to the target site in the animal. These results will allow the adequatedesign of a probiotic product by the combination of beneficial microorganisms withnatural substances to be applied in the bovine reproductive tract. This could beused in organic farmers or other safe production systems.