MODIFICATION OF INTESTINAL MICROBIOTA OF YOUNG CALVES INOCULATED WITH LACTIC ACID BACTERIA AND INFECTED WITH SALMONELLA DUBLIN

SOTO, L.P., FRIZZO, L.S., ZBRUN, M.V., BERTOZZI, E., SIGNORINI, M.L., LAVARI, L., SEQUEIRA, G.J., DALLA SANTINA, R. & ROSMINI, M.R.

San Miguel de Tucumán, Tucumán

Simposio; III Simposio Internacional de Bacterias Lácticas y Segundo Encuentro Red BAL Argentina; 2009

CERELA - CONICET

The composition of the intestinal microbiota influences the health status of the host. The intensive rearing of calves impedes colonization of the indigenous intestinal microbiota and facilitates the activity of pathogenic microorganisms. The regular administration of a probiotic inoculum support the establishment of a balanced and more stable intestinal flora, which would improve the health of calves. The aim of this study was to determine the effect of the administration of a probiotic inoculum and lactose on some populations of the intestinal microbiota of young calves in a normal state and after suffering an intestinal infectious disease. We used 28 Holstein calves (Bos taurus) with a mean age of 5 days. The calves of the probiotic group (GBAL) received 150 ml daily of a probiotic inoculum grown and preserved by freezing milk. The inoculum was composed of the following microorganisms: Lactobacillus casei DSPV 318T, Lactobacillus salivarius DSPV 315T, 006T and Pediococcus acidilactici DSPV, which were resistant to rifampicine, a feature that allowed distinguish them from the rest of the lactic flora. The members of the control group (CG) received 150 ml of milk daily as a placebo. All animals were fed with milk replacer (4 l/d) and starter food without antibiotics supplied ad libitum throughout the experiment. GBAL animals received 100 g/d of lactose together with the milk replacer. The 11th day of the experiment, all animals were inoculated with 109 CFU/animal of Salmonella dublin DSPV 595T. Samples of stool from 3 calves in each group on days 1, 5, 10 and 27 were taken to determine by counting plate the following microbiological populations: lactic flora in LAMVAB, probiotic inoculum in LAMVAB with 10 µg/ml of rifampicine, coliforms in VRBL agar, enterobacterias in VRBG agar, enterococcus in Slanetz and Bartley agar and yeast in Sabouraud dextrose with chloramphenicol. The BAL of the GBAL group increased during the first days of the experiment, before inoculation with Salmonella, however, during that same period, the BAL of the GC group decreased showing ay 10th day an average of 8.2 and 4.9 log UFC/g, respectively (P<0.05). After infection with the pathogen (day 27) counts of BAL declined up to 6 log UFC/g in GBAL and 1.1 log UFC/g in CG (P <0.05). The BAL presents in GBAL were mostly those belonging to the inoculum. With regard to yeasts, the GC presented a sharp decline between day 5-10 from 6.4 to 4.4 logUFC/g while the population GBAL maintained between 6.7 to 6.4, respectively. These values remained constant after infection (day 27). Besides producing a change in the population of indigenous yeasts, the administration of the inoculum allowed accommodate large numbers of BAL in the intestine of calves after an intestinal infection that causes diarrhea and economic loss in farm.