Classification and identify of infected Gnathostoma sp. from Monopterus albus and loaches

To identify the third stage larvae of Gnathostoma in Monopterus albus and loaches，19 batches of M. albus imported from the port of Baiyun Airport in Guangzhou，12 batches of M. albus and loaches from Guangzhou， Chongqing，Sichuan Neijiang，Hubei Jingzhou，Fujian Zhangzhou and Jilin Changchun were inspected. After digestion of the viscera and muscles，the filtrate was precipitated and the larvaes were picked out under the stereo microscope. Morphological identification was carried out to determine that the isolated larvaes were the third larvae of Gnathostoma. The infection rate in M. albus from Indonesia was 91.7%，but no Gnathostoma was found in M. albus from Philippines. At the same time，18 Gnathostoma from loaches and 1 Gnathostoma from M. albus were isolated from Zhangzhou city，but no Gnathostoma was found in other cities at home. Genomic DNA of Gnathostoma was extracted to amplify internal transcribed spacer region 2（ITS-2） by PCR，the product of which was analyzed by electrophoresis and sequencing. The sequences were aligned with corresponding sequences in GenBank， and phylogenetic tree was constructed. Morphological dentification and sequence alignment analysis results showed that the larvae from Indonesia was G. spinigerumn and G. hispidum，the larvae from Zhangzhou city was G. nipponicum and G. spinigerumn.