Seroprevalence and antibiotic sensitivity of serotypes of Salmonella enterica in Greek pig herds

Blood samples were taken from 50 pigs in each of 59 farrow-to-finish produc tion herds and from 40 pigs in each of four of five registered multiplying herds. Samples of feed and faeces were also collected from 17 of the produc tion herds and from the four multiplying herds. The sera were tested for an tibodies to Salmonella enterica by the Danish mix-ELISA, and the organisms were isolated, serotyped and sensitivity tested by standard techniques. The average within-herd seroprevalence was 3.4 per cent and at least one pig t ested seropositive in 21 of the 59 herds. In the multiplying herds, only a single seroreactor was detected. Salmonellae were isolated from only five o f 95 feed samples, from two of the 17 herds sampled, Salmonella tennessee i n four of five samples from one herd and an untypable strain in one of five samples from another Four infected faecal samples were detected in four he rds; they harboured Salmonella typhimurium, Salmonella bredeney or Salmonel la london. No salmonellae were isolated from the samples of feed and faeces taken from the multiplying herds. The S london and S typhimurium had a law sensitivity to streptomycin, kanamycin and neomycin, and the S typhimurium also had low sensitivity to amoxycillin, ticarcillin, piperacillin, amoxyc illin + clavulanic acid, cefalotin and cefoperazone. The other isolates wer e sensitive to all the antimicrobial agents tested.