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Hymenolepis
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Hymenolepis diminuta (rat tapeworm) is morphologically similar to (also possessing unilateral genital pores and three testes per proglottid), but much larger (up to 90 cm long and 44 mm wide) than H. nana in size, with its adult worms mainly occurring in rats and mice and occasionally in humans, and cysticercoids in arthropods (e.g., beetles, fleas, earwigs, cockroaches, and caterpillars) (Table 63.1) [1]. However, H. diminuta scolex does not have hooked rostellum, and its oncospheres lack hair-like filaments embedded in the inner membrane and are two times the size of H. nana oncospheres (Figure 63.1b) [2].
Taenia
Published in Dongyou Liu, Laboratory Models for Foodborne Infections, 2017
Taenia adult worms (Taenia is derived from Greek ταίvɩα, tainia meaning ribbon, bandage, or stripe) are flat, ribbon-like in appearance, and white or yellowish-white in color. and consist of a knob-like head called scolex, a short neck, and a ribbon-like body (also known as strobila). The scolex (holdfast organ) often possesses suckers (acetabula), rostellum, and spiny hooks. It is noteworthy that the scolex of T. solium is spheroidal, with a rostellum (of 1 mm in diameter), which is armed with two rows of 22–32 hooks; that of T. saginata is cuboidal (of 2 mm in width) without rostellum or hooks; and that of T. asiatica is spheroidal, with a cuspidal rostellum (of 0.8 mm in width), which has no hooks (Table 49.1). The strobila (up to 22 m long depending on the species) is composed of a chain of segments called proglottids, each of which contains a set of male and female reproductive organs (thus hermaphroditic). The reproductive organs are made up of tubular unbranched uterus (filled with eggs), ovary, genital pore, testes, and vitelline gland, with testes and ovary opening into a common genital pore located on the side. Being an acoelomate animal, the adult worm has no body cavity or digestive system, and relies entirely on its penetrable tegument to absorb nutrients. As body growth starts from the neck region, immature proglottids are found near the neck, mature proglottids in the middle, and gravid (oldest) proglottids at the posterior end. On average, T. solium adult worm has about 1000 proglottids, each producing 50,000 eggs; T. saginata adult worm has about 1000–2000 proglottids, each producing 100,000 eggs; T. asiatica adult worm has 700–900 proglottids, each producing 80,000 eggs [5].
Chemical composition and broad-spectrum anthelmintic activity of a cultivar of toothache plant, Acmella oleracea, from Mizoram, India
Published in Pharmaceutical Biology, 2020
Pawi Bawitlung Lalthanpuii, Kholhring Lalchhandama
Albendazole and flubendazole were experimentally shown to cause damage on the rostellum, development of swellings or blebs on the tegument, erosion of the microtriches, and increased vesiculation on the cestode, Echinococcus granulosus (Elissondo et al. 2006). Albendazole alone also caused severe shrinkage, obliteration of microtriches and disintegration of the tegument in Raillietina echinobothrida (Lalchhandama 2010). A combination therapy of albendazole-praziquantel against Mesocestoides corti caused important structural damages including deformity of the suckers, erosion of the tegument and disintegration of the microtriches (Markoski et al. 2006).