Groups of pigs were inoculated with genotypes of Trichinella belonging to: Trichinella
spiralis, Trichinella nativa, Trichinella britovi, Trichinella pseudospiralis (from
Caucasus), T. pseudospiralis (from USA), Trichinella murrelli, Trichinella sp. (from
North America), and Trichinella nelsoni. The pigs were sacrificed between 5 and 40weeks
p.i., and the number of muscle larvae per gram (l.p.g.) of tissue was determined as
an average of 18 muscles. All Trichinella genotypes were infective for pigs, but both
their infectivity and persistence varied: 5weeks p.i., T. spiralis muscle larvae were
present in high numbers (mean=427l.p.g.), while T. britovi, T. nelsoni, and T. pseudospiralis
larvae were present in moderate numbers (means=24-52l.p.g.); larvae of the remaining
genotypes were recovered only in low numbers (means=0.05-5. 00l.p.g.). The total larval
burden (live weight of pigxl.p.g.) was constant over time for T. spiralis, T. britovi,
and T. nelsoni, but declined significantly (P<0.05) for the other genotypes. Antibody
responses could be detected 3-4weeks p.i. by seven different Trichinella ES antigens,
but the antibody levels and dynamics differed significantly among the experimental
groups. In pigs inoculated with T. spiralis, T. britovi, or T. nelsoni, the antibody
level increased rapidly between weeks 3 and 5 p.i. and was stable or increased slightly
throughout the experimental period. In pigs inoculated with T. nativa, T. murrelli,
or Trichinella (T6) (from North America), a rapid increase was detected between weeks
3 and 5 p.i., but for these genotypes a reduction in the antibody levels was seen
thereafter. In the pigs inoculated with T. pseudospiralis, the antibody level increased
more gradually over a period from week 3 p. i. to weeks 15-20 p.i., and decreased
thereafter. In general, all species of Trichinella were detected by any of the seven
ES antigens, which points to the potential use of one common antigen for surveillance
and epidemiological studies on both domestic and sylvatic Trichinella in pigs. Homologous
ES antigens were slightly more sensitive in detecting antibodies to the corresponding
Trichinella species.