Morpho-functional characteristics of the scolex of Wardium chaunense (Cestoda: Aploparaksidae) penetrated into host intestine

Evagination of metacestodes of the WFU strain of Taenia crassiceps and evaluation of the impact of immune suppression of hamsters during tapeworm development

Taeniosis-cysticercosis caused by Taenia crassiceps (Zeder, 1800) is a useful experimental model for biomedical research, in substitution of Taenia solium Linnaeus, 1758, studied during decades to develop effective vaccination, novel anti-helminthic drugs and diagnostic tools. Cysticercosis in mouse (Mus musculus Linnaeus) is achieved by the larval subculturing of the Wake Forest University (WFU) strain of T. crassiceps. Golden hamster, Mesocricetus auratus (Waterhouse), has been shown to be the most suitable host for adult forms of parasite in experimental taeniosis. Metacestodes of T. crassiceps WFU multiply by budding without restrictions once inoculated into the mouse, while the number of tapeworms developed from these larvae in hamsters remains highly variable. Three objectives have been proposed to improve the infection of T. crassiceps WFU in hamsters: (1) to re-evaluate the need of immune suppression; (2) to investigate the advantage of infecting hamsters with metacestodes with in vitro protruded scolices; and (3) to compare a number of tapeworms developed from metacestodes subcultured in hamsters against those proliferated in mice. Our results demonstrated that when the evagination of murine metacestodes was high, the number of T. crassiceps WFU adults obtained from hamsters was also high. Immunosuppressive treatment remains relevant for this experimental rodent model. The hamster-to-hamster cysticercosis-taeniosis by T. crassiceps overcame the mouse-to-hamster model in the yield of adult specimens. In vitro scolex evagination and metacestode asexual proliferation in hamsters place this rodent model by T. crassiceps WFU as the most affordable experimental models with taeniids.

Design and Validation of a Biosensor Implantation Capsule Robot

We have proposed a long-term, noninvasive, nonrestrictive method of delivering and implanting a biosensor within the body via a swallowable implantation capsule robot (ICR). The design and preliminary validation of the ICR’s primary subsystem—the sensor deployment system—is discussed and evidence is provided for major design choices. The purpose of the sensor deployment system is to adhere a small biosensor to the mucosa of the intestine long-term, and the modality was inspired by tapeworms and other organisms that employ a strategy of mechanical adhesion to soft tissue via the combined use of hooks or needles and suckers. Testing was performed to refine the design of the suction and needle attachment as well as the sensor ejection features of the ICR. An experiment was conducted in which needle sharpness, needle length, and vacuum volume were varied, and no statistically significant difference was observed. Finally, preliminary testing, coupled with prior work within a live porcine model, provided evidence that this is a promising approach for implanting a biosensor within the small intestine.

Biology and Systematics of Echinococcus

The biology of Echinococcus, the causative agent of echinococcosis (hydatid disease) is reviewed with emphasis on the developmental biology of the adult and metacestode stages of the parasite. Major advances include determining the origin, structure and functional activities of the laminated layer and its relationship with the germinal layer; and the isolation, in vitro establishment and characterization of the multipotential germinal cells. Future challenges are to identify the mechanisms that provide Echinococcus with its unique developmental plasticity and the nature of activities at the parasite-host interface, particularly in the definitive host. The revised taxonomy of Echinococcus is presented and the solid nomenclature it provides will be essential in understanding the epidemiology of echinococcosis.