LAUSR

Salmonella prevalence was assessed in 816 pigs from fifteen herds which were slaughtered in ten slaughterhouses from June 2001 to December 2002. No Salmonellae were isolated in pigs from eight herds in four slaughterhouses. Salmonella prevalence in pigs originating from the other seven herds ranged from 2.0% to 12.0%. The most frequent site of Salmonella isolation was caecum (2.45%). This finding is statistically significant (P < 0.01) as compared to those obtained with mesenteric lymph nodes (0.73%) and carcass swabs (0.12%). Salmonellae were not found in samples from the environments (n = 197). A total of 27 Salmonella isolates were classified into serotypes S. infantis (n = 8), S. typhimurium (n = 5), S. agona (n = 4), S. kaapstad (n = 4), S. derby (n = 3), S. bredeney (n = 2), and S. london (n = 1). All five S. typhimurium DT 104 were resistant to the phenotype ACSSuT. Resistance genes bla P S E - 1 , floR, aadA2, sull, and tetG were identified in all pentaresistant strains. One strain of S. derby was resistant to gentamicin, streptomycin and sulphonamides. The other Salmonella isolates were sensitive to all antibiotics tested.