Use of fluorescein isothiocyanate to monitor Lactobacillus salivarius DSPV 003P during intestinal transit in broilers.

BLAJMAN J.E.; ASTESANA D.M.; ZIMMEMMAN J.; BERISVIL A.; OLIVERO C.; SEQUEIRA, G.J.; ZBRUN, M. V.; FRIZZO, L.S.

San Miguel de Tucumán

Simposio; IV Simposio Internacional de Bacterias lácticas (SIBAL); 2013

Centro de Referencia de Lactobacilos

There is little knowledge about the interaction between probiotic bacteria and the gastrointestinal tract in broilers. A good method to understand the mechanisms by which probiotics mediate their effects is to mark probiotic bacteria and trace them. The objective of this study was to label and monitor lactic acid bacteria during intestinal transit in broilers. Six broilers and a bacterial strain of avian origin and in vitro probiotic properties (Lactobacillus salivarius DSPV 003P) were used. Lactobacillus salivarius DSPV 003P was multiplied in MRS broth for 24 h at 37°C. The fresh culture was centrifuged at 3500 rpm for 10 min and washed twice with phosphate-buffered saline (PBS) solution (pH 7.2). Bacteria cells were resuspended in PBS solution with fluorescein isothiocyanate (FITC; Sigma) and incubated for 2 h at 37ºC in the dark. Labelled bacteria were washed six times with PBS solution to remove unincorporated FITC. The pellet was finally resuspended in PBS and administered orally (1 ml) to each broiler on a 7 Log colony forming-units/ml dose. Thirty min, 1 h and 2 h after probiotic administration, two broilers were killed by cervical dislocation. Histological slices of crop, duodenum, cecum and bursa of Fabricius were obtained following the Sainte-Marie (1962) technique for paraffin inclusion. Tissues were observed using a fluorescence light microscope. Fluorescent bacteria were detected in all samples from the crop and the gut. No bacteria were found in the bursa of Fabricius. The number of bacterial aggregates observed was higher 30 min and 1 h after probiotic administration than the number observed 2 h after probiotic administration. In conclusion, use of FITC is a potential method to monitor the distribution and movement of lactobacilli in the gastrointestinal tract of broilers.