[1] Kasetsart Univ, Fac Grad Sch, Interdisciplinary Grad Program Genet Engn, Bangkok, Thailand
[2] Kasetsart Univ, Dept Parasitol, Fac Vet Med, Bangkok 10900, Thailand
[3] Kasetsart Univ, Dept Publ Hlth & Diagnost Serv, Fac Vet Med, Bangkok 10900, Thailand
[4] Kasetsart Univ, Dept Microbiol & Immunol, Fac Vet Med, Bangkok 10900, Thailand
[5] Univ Bristol, Sch Vet Sci, Bristol BS40 5DU, Avon, England
[6] Univ Missouri, Dept Vet Pathobiol, Columbia, MO USA