Novel PCRs for differential diagnosis of cestodes

• There are many different targets described for PCR-based detection of cestodes.
• In this paper we compare four of these targets.
• We designed a novel primer set for the PCR on the 12SrRNA gene.
• Taenia sp. and Echinococcus sp. can be detected and typed using these 12S primers.

Cestodes or tapeworms belong to a diverse group of helminths. The adult Taenia saginata and Taenia solium tapeworm can infest the human gut and the larval stage of Echinococcus spp. and T. solium can infect tissues of the human body, causing serious disease. Molecular diagnostics can be performed on proglottids, eggs and on cyst fluids taken by biopsy. Detection of cestodes when a helminthic infection is suspected is of vital importance and species determination is required for appropriate patient care. For routine diagnostics a single test that is able to detect and type a range of cestodes is preferable. We sought to improve our diagnostic procedure that used to rely on PCR and subsequent sequencing of the Cox1 and Nad1 genes. We have compared these PCRs with novel PCRs on the 12S rRNA and Nad5 gene and established the sensitivity and specificity. A single PCR on the 12S gene proved to be very suitable for detection and specification of Taenia sp. and Echinococcus sp. Both targets harbour enough polymorphic sites to determine the various Echinococcus species. The 12S PCR was most sensitive of all tested.

Molecular diagnostics for cestode detection and typing using PCR can be done using 12S as a target. Often Cox1 is used in general to detect eukaryotic organisms but for cestodes this target has too many sequence polymorphisms. PCR using 12S as target is more sensitive and the PCR product harbors enough polymorphisms to determine the infecting species.Figure optionsDownload as PowerPoint slide