Prevalence of Wenyonella philiplevinei infection in Linwu ducks in Linwu county, subtropical China.

Wenyonella philiplevinei is one of the pathogens causing coccidiasis in ducks. The prevalence of W. philiplevinei infection in Linwu ducks (a Chinese local domesticated duck) was investigated in Linwu county (an area of Hunan province) of Hunan province, subtropical China from March 2014 to February 2015. Two hundred fifty-eight of 1800 (14.3 %) Linwu ducks were found to be infected with W. philiplevinei. To identify the species identity of the collected samples, a portion of the 18S rDNA was amplified from W. philiplevinei by polymerase chain reaction (PCR) and cloned and then sequenced. The sequences of 18S rDNA of all samples were 422 bp in size. The A + T content of the 18S rDNA sequences is 58-59 %. Sequence comparison revealed that the similarity in 18S rDNA sequences among Hunan isolates with that of the W. philiplevinei available (Guangdong isolate) were more than 98 %. The intra-specific sequence variations within each of the Hunan isolates were 0-1.7 %. Phylogenetic analysis using maximum likelihood (ML) method indicated that the genus Wenyonella is more closely related to Eimeria + Cyclospora than to that of the Isospora. These new data provide a genetic marker for the differentiation of W. philiplevinei or other closely related coccidian. This is the first report of W. philiplevinei prevalence in ducks in Hunan province, subtropical China.