Molecular differentiation of 38 human taeniid cestodes from Yunnan and Guizhou Provinces.

Objective To molecularly differentiate 38 human taeniid cestodes and to ascertain the local prevalence of Taenia solium,Taenia asiatica,and Taenia saginata.Methods Taenia tapeworms were collected from patients given areca nuts and pumpkin seeds in Dali,Yunnan and Duyun,Guizhou.After preliminary morphological identification,DNA of the 38 isolates was extracted with a tissue DNA extraction kit,and mitochondrial cytochrome C oxidase subunit 1 gene(cox1)fragments of all DNA samples were amplified by PCR with primers specific for T.solium,T.asiatica,and T.saginata,respectively.Isolates which were negative in PCR with all specific primers were then amplified by general primers for the cox1 gene of Taenia spp and a sample which was positive for T.asiatica was used as a control.In all positive PCR products,a sample of each Taenia spp was then sequenced and the sequences were analyzed using BLAST on the NCBI website.Results PCR specific for T.solium was positive for 4 isolates(DL1-4)collected from Dali,and the products were about 980 bp.The other 25 isolates from Dali(DL5-29)and 5 isolates from Duyun(DY1-5)were positive in PCR specific for T.asiatica,and the products were about 260 bp.All samples were negative in PCR specific for T.saginata.The sequences of DL2 had 99%100% homology with those of T.solium cox1 in GenBank,and the sequences of DY1 had 100% homology with those of T.asiatica.Fragments of roughly 1 kb were amplified from the 4 Congjiang isolates,which were negative in specific PCR amplifications,and DL7 which was positive in PCR specific for T.asiatica.The sequences of CJ1 cox1 fragments had 99% homology with T.saginata and the sequences of DL7 had 99%-100% homology with T.asiatica.Conclusion PCR and sequencing of cox1 fragments indicated that taeniid cestodes from Dali,Yunnan were T.solium and T.asiatica,while those from Duyun and Congjiang,Guizhou were T.asiatica and T.saginata,respectively.