Molecular Characterization of Wenyonella philiplevinei from Ducks in Hunan Province, China

Wenyonella philiplevinei is one of the important pathogens of duck coccidiasis. In the present study, a portion of the 18S rDNA was amplified from W. philiplevinei by Polymerase chain reaction (PCR), cloned and then sequenced. The sequences of 18S rDNA of all samples were 422 bp in size. A + T content of the 18S rDNA sequences was 58-59%. Sequence comparison revealed that the similarity in 18S rDNA sequences between Hunan isolates and W. philiplevinei available (Guangdong isolate) was more than 98%. Intra-specific sequence variations within each of the Hunan isolates were 0-1.7%. However, the inter-specific sequence differences between W. philiplevinei and coccidian available in GenBank were more than 7%. Phylogenetic analysis using neighbour joining (NJ), maximum likelihood (ML) and maximum parsimony (MP) methods indicated that the genus Wenyonella was more closely related to Eimeria + Cyclospora than to Isospora. These novel data provide useful genetic marker for the differentiation of W. philiplevinei or other closely related coccidians.