Development and preliminary evaluation of molecular tools to investigate environmental contamination with Taenia saginata and Taenia solium

Background: Taenia saginata and Taenia solium are foodborne zoonotic tapeworms that affect cattle and pigs, respectively. Human health is impacted by being a final host for both parasites. Humans can also act as intermediate hosts for T. solium , resulting in neurocysticercosis. Eggs from adult parasites are released into the environment via human faeces and are ingested by the intermediate hosts. Wastewater and open defecation are sources of parasitic egg distribution into the environment. This research addressed the critical need for sensitive and specific molecular methods to investigate environmental contamination with T. saginata and T. solium in challenging and complex environmental settings. Methods: Two polymerase chain reaction (PCR) assays were developed, one explicitly targeting T. saginata and the other designed to detect both T. saginata and T. solium simultaneously. Primers were designed to target the mitochondrial cox1 gene. The preliminary sensitivity of the PCRs was evaluated using DNA extracted from taeniid eggs. The sensitivity of two newly developed PCRs was compared with three previously used PCRs, using ten batches of eggs from differently aged T. saginata proglottids ranging from 2 to 89 weeks of age. From each batch, one, two, and five eggs were collected in triplicate using a Micro Pick and Place System. Two and five eggs from one batch of T. solium eggs were also tested. For specificity, PCRs were tested against genetically similar parasites, including Echinococcus spp. and Hymenolepis spp. Results: The analysis yielded a sensitivity of 92% for the T. saginata -specific PCR and 87% for the Taenia PCR. Echinococcus multilocularis , E. granulosus , E. canadensis, H. diminuta, and H. nana extracted DNA did not result in any amplification with either of the new methods. Conclusion: The study validated the potential of two new PCRs to investigate environmental contamination.