Gene sequencing for identification of Paragonimus eggs from a human case.

OBJECTIVE To identify the etiologic agent from a paragonimiasis patient using molecular techniques. METHODS The complete nuclear ribosomal DNA second internal transcribed spacer (ITS2) gene sequence of eggs in sputum from a paragonimiasis patient was obtained by directly auto-sequencing its PCR product. ITS2 genes from eggs of Paragonimus westermani and Pagumogonimus skrjabini (both from animal hosts) were also sequenced for comparison. In addition, morphological comparisons were made with the eggs of the two species. RESULTS The ITS2 gene from the human case was 100% identical with the sequence from the eggs of P. westermani from an experimentally infected dog but only 92% identical with the sequence from the eggs of P. skrjabini. Morphologically, the eggs from the human case more resembled those from P. westermani infected dog. CONCLUSION The patient was diagnosed to be suffered from paragonimiasis westermani by gene sequence analysis.