[1] Acad Sci Czech Republ, Ctr Biol, Ceske Budejovice, Czech Republic
[2] Univ South Bohemia, Fac Agr, Ceske Budejovice, Czech Republic
[3] Hosp Tabor, Tabor, Czech Republic
[4] Wroclaw Med Univ, Dept Biol & Med Parasitol, Wroclaw, Poland
[5] N Dakota State Univ, Dept Vet & Microbiol Sci, Fargo, ND 58105 USA