Pen feces samples were taken in ten finishing farms in Rio Grande do Sul (Brazil) and submitted to Salmonella isolation protocol. Two farms negative and one positive in the preliminary screening were chosen, and feces from 25 randomly selected pigs in each of them were individually collected. The same animals were later sampled (rectal swab, intestinal content and mesenteric lymph nodes) at the slaughterhouse. After the introduction of new animals into farm N1 and P1, other 25 pigs on each farm were examined as described above. In the preliminary screening, Salmonella was isolated from pen feces samples of 3 of the 10 investigated farms. Two of these herds showed a high level contamination. Eight Salmonella serotypes (Agona, Bredeney, Lexington, London, Mbandaka, Panama, Schwartzengrund, Salmonella sp) were found, with serotypes Agona and Bredeney being the most frequent. When individual animals were sampled, Salmonella was isolated in all selected farms. Salmonella was isolated in 6.4% of feces collected on the farm, 5.3% of intestinal contents and 5.6% of lymph nodes. Antibiogram testing of the isolated strains showed 97.8% resistance to sulphonamides, 82.6% to streptomycin, 36.9% to tetracyclin and 15.2% to sulfazotrim.
Salmonella; swine; lymph nodes; feces; serotypes; antibiogram
