Serotypes and antimicrobial patterns of Salmonella strains isolated from three different pig production systems: farrow to finish pig herds, weaner to finish pig herds and slaughtered pigs of all origin.

Feed contamination doesn\u27t seem to play a major role in the pig infection cycle. In the farrow to finish pig herds, S. Typhimurium, predominated with 32 %. Among these S. Typhimurium strains, 15 % belonged to DT12/104 type, 55 % to DT104 type and finally, 80 % of S. Typhimurium strains were resistant to 4 out of the 6 antibiotics tested. In the slaughter isolates, S. Typhimurium dominated again (36 %) but only with 18% of DT104 type. In the weaner to finisher pig herds, S. Bredeney accounted for 89 % on farm. Nevertheless, the dominating serovar of slaughter isolates was S. Typhimurium (43%) with 17 % of DT104. Among slaughtered pig herds of all origin, S. Typhimurium accounted for 37% (19% DTI04). The high antimicrobial resistance associated to the predominating serotypes should draw attention on improper use of antibacterial in agriculture