Significance of Molecular Diagnosis using Histopathological Specimens in Cestode Zoonoses

Abstract

Cestode zoonosis cases confirmed by PCR-based mitochondrial DNA analysis were investigated. The cestodiosis included taeniasis, cysticercosis, alveolar echinococcosis, cystic echinococcosis, sparganosis mansoni, diphyllobothriasis and diplogonoporiasis. DNA samples were extracted from the ethanol-fixed, formalin-fixed, paraffin-embedded sections, HE-stained, and the PAS- or acetocarmine-stained samples submitted for histopathology. For PCR-based analysis, cytochrome c oxidase subunit 1 and⁄or cytochrome b genes were amplified by multiplex PCR or conventional PCR coupled with DNA sequencing. Although DNA molecules were degraded in most formalin-fixed samples, smaller gene fragments were successfully amplified and the species causing cestodiosis could be identified by DNA sequence analysis of the amplicons. This review describes cestode zoonosis cases in which mitochondrial DNA analysis was useful not only for routine and retrospective diagnosis, but also for genetic polymorphism analysis and molecular identification of the species associated with pathogenicity. The significance of molecular diagnosis using histopathological specimens for cestode zoonoses is also discussed.