Farm | Piglet genotype | Pathotype | Virotype | O serogroups |
|---|
1 | LYLL | ETEC | F4 | |
2 | LYHH | ETEC | | O149 |
3 | LYLL | ETEC | | O138 |
4 | LYLD | ETEC | LT:STb | |
5 | LYHH | STEC | Stx2e:F18 | O139 |
- The pathotypes, virotypes and O serogroups verified at the case herds 1 to 5 prior to recruitment for the trials are listed. Strains of E.coli isolated from fecal samples of piglets after post mortem examination were either forwarded by the veterinarian in charge to the Norwegian Veterinary Institute for serotype determination (agglutination in microtiterplates with boiled antigen and single O-antisera) or to the Norwegian School of Veterinary Science in Oslo for virulence pattern determination (PCR analysis). The pathotype Enterotoxigenic E. coli (ETEC) was found at Farms 1 to 4 while Shiga-toxigenic E. coli (STEC) was found at Farm 5. Virotypes at Farms 1, 4 and 5 were F4, LT:STb and Stx2e:F18, respectively. The O serogroups O149, O138 and O139 were identified at Farms 2, 3 and 5, respectively. Genetic combinations of piglets included Landrace x Yorkshire (LY) x Landrace x Landrace (LL) (LYLL) at Farm 1. At Farm 2, LY x Hampshire/Hampshire (HH) (LYHH) were used. At Farm 3, LYLL piglets were utilized. LY x Landrace/Duroc (LYLD) and LYHH were used at Farms 4 to 5, respectively
