Low host-specific Enterocytozoon bieneusi genotype BEB6 is common in Swedish lambs.

Enterocytozoon bieneusi was found in 49/72 (68%) fecal samples from Swedish lambs while 37 samples from 24 adult sheep were negative. Molecular characterization of the internal transcribed spacer (ITS) revealed three genotypes: BEB6, OEB1, and OEB2, the latter two of which were novel and all three of which belonged to a group of genotypes (Group 2) of probably limited zoonotic importance. Our observations suggest that E. bieneusi is common in young Swedish sheep and add support to emerging evidence that the common BEB6 genotype, originally thought to be adapted to cattle, is capable of infecting a variety of hosts, suggesting low host specificity.