Genetic diversity in Enterocytozoon bieneusi from dogs and cats

24 To explore the genetic diversity, host specificity and zoonotic potential of Enterocytozoon 25 bieneusi, feces from 348 stray and pet dogs, and 96 pet cats from different locations in China 26 were examined by internal transcribed spacer (ITS) based PCR. E. bieneusi was detected in 27 15.5% of dogs including 20.5% of stray dogs and 11.7% of pet dogs, and in 11.5% of pet 28 cats. Higher infection rates were recorded in the > 2 years and 1 to 2 years age groups in 29 dogs and cats, respectively. All together, 24 genotypes, including 11 known and 13 new ones, 30 were detected in 65 infected animals. In 54 positive dogs, 18 genotypes, nine known 31 (PtEbIX, O, D, CM1, EbpA, Peru8, Type IV, EbpC and PigEBITS5) and nine new (CD1 to 32 CD9), were found. In contrast, eight genotypes, four known (D, BEB6, I and PtEbIX) and 33 four new (CC1 to CC4), were identified in 11 infected cats. The dominant genotype in dogs 34 was PtEbIX (26/54). Phylogenetic analysis revealed that eight known genotypes (D, Peru8, 35 Type IV, CM1, EbpC, PigEBITS5, O and EbpA) and seven new ones (CD1 to CD4 and CC2 36 to CC4) were the members of zoonotic group 1, whereas genotypes CD7, CD8 and CD9 37 together with PtEbIX belonged to the dog specific group, and genotypes CD6 and CC1 were 38 placed in group 2 with BEB6 and I. Conversely, genotype CD5 clustered with CM4 without 39 belonging to any previous groups. This study concludes that zoonotic genotypes are common 40 in both animals along with host specific genotypes in dogs. 41 42