Results of species-specific PCR for (A) H. hepaticus and (B) H. typhlonius in mixed cultures. Lanes: 1, 1-kb plus ladder; 2, Hamster B (NCBI accession no. AF072333); 3, H. bilisT; 4, H. mastomyrinusT; 5, MIT-1001; 6, H. rodentiumT; 7, novel MIT 01-6451; 8, ladder; 9, H. hepaticusT; 10, H. typhloniusT; 11, H. typhlonius (U.S. institution 16); 12 to 17, mixed cultures from European institution 12 and U.S. institutions 9 to 11 and 13 to 15, respectively; 18, ladder. PCR of these DNA samples with primers specific for H. bilis and H. rodentium gave negative results.