PRESENCE OF SALMONELLA TYPHIMURIUM IN OVINE MESENTERIC LYMPH NODES AT SLAUGHTER

R Michaelsen F.M. Cardoso R.N Schneider F.A. de Mello R.M.G. Esteves M.S. Vilanova V. Schmidt About the authors

ABSTRACT

The ovine flock in Brazil is estimated at over 16 million head. Despite that meat consumption of this species is still small when compared to other countries, general meat consumption, including mutton, has been associated to food borne diseases, especially salmonellosis. In the present study, the occurrence of salmonella in mesenteric lymph nodes and intestinal content of 175 ovines during slaughter was investigated. A pool of 5 feces samples or 5 lymph node samples of 25 grams was pre-enriched in 250 mL of buffered peptone water at 37° C for 18-24h. Following this, 0.1 mL of pre-enriched broth was transferred to 9.9 mL of Rappaport-Vassiliadis enrichment broth and 1.0 mL of pre-enriched broth was transferred to 10 mL of Muller-Kaufmann tetrationate broth, incubated at 42° C for 24h. Then, a 10 μL of the enrichment broth was spread on the surface of a BPLS and an XLT4 plate, both incubated at 37º C for 24-48h. Suspected Salmonella colonies were picked from the agar and tested with biochemical and serological methods. Biochemical testing was carried out for the identification of Salmonella, using the TSI (triple sugar iron agar), LIA (lysine iron agar) and urea agar tests. Serotyping was done at the Laboratory of Enterobactérias of the Instituto Osvaldo Cruz. Salmonella Tiphymurium was isolated from a pool of mesenteric lymph nodes from 5 animals. That Salmonella was observed in healthy carrier ovines points out the necessity of monitoring this microorganism in this species as well, especially when animals are destined to slaughter, so to assure safe food production.

KEY WORDS
Sheep; Salmonella ; carcass; mesenteric lymph nodes; intestinal tract

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E-mail: arquivos@biologico.sp.gov.br