Ultrastructure of microtriches on the scolex of Cyathocephalus truncatus (Cestoda:  Spathe-bothriidea)

Levron, Céline; Scholz, Tomáš; Dezfuli, Bahram Sayyaf

doi:10.14411/fp.2008.039

Cited by 4 publications

(2 citation statements)

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“…6). It can be concluded that the morphology of microtriches and their distribution are highly uniform in spathebothriidean cestodes, which appears to be a typical feature of more basal tapeworms (Levron et al 2008, Chervy 2009). …”

Section: Discussionmentioning

confidence: 97%

“…Two types of filitriches have been observed on the scolex of Cyathocephalus truncatus by Levron et al (2008): small acicular filitriches up to 3 µm long and large capilliform filitriches measuring up to 10 µm in length. In Diplocotyle olrikii, Burt and Sandeman (1974) reported microtriches up to 4 µm long in plerocercoids from gammarids and adults from fish.…”

Section: Discussionmentioning

confidence: 99%

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Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda)<sup>*</sup>

Kuchta¹,

Pearson²,

Scholz³

et al. 2014

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* This paper is dedicated to Michael 'Mick' David Brunskill Burt (1938-2014 whose recent passing represents a great loss to cestodology.Abstract: Tapeworms of the order Spathebothriidea Wardle et McLeod, 1952 (Cestoda) are reviewed. Molecular data made it possible to assess, for the first time, the phylogenetic relationships of all genera and to confirm the validity of Bothrimonus Duvernoy, 1842, Diplocotyle Krabbe, 1874 and Didymobothrium Nybelin, 1922. A survey of all species considered to be valid is provided together with new data on egg and scolex morphology and surface ultrastructure (i.e. microtriches). The peculiar morphology of the members of this group, which is today represented by five effectively monotypic genera whose host associations and geographical distribution show little commonality, indicate that it is a relictual group that was once diverse and widespread. The order potentially represents the earliest branch of true tapeworms (i.e. Eucestoda) among extant forms.

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda)<sup>*</sup>

Kuchta¹,

Pearson²,

Scholz³

et al. 2014

FOLIA PARASIT

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In vitro effects of tropisetron and granisetron against Echinococcus granulosus (s.s.) protoscoleces by involvement of calcineurin and calmodulin

et al. 2021

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Background Cystic echinococcosis (CE) is a disease caused by the larval stage of Echinococcus granulosus sensu lato (s.l.). The treatment of CE mainly relies on the use of benzimidazoles, which can commonly cause adverse side effects. Therefore, more efficient treatment options are needed. Drug repurposing is a useful approach for advancing drug development. We have evaluated the in vitro protoscolicidal effects of tropisetron and granisetron in E. granulosus sensu stricto (s.s.) and assessed the expression of the calcineurin (CaN) and calmodulin (CaM) genes, both of which have been linked to cellular signaling activities and thus are potentially promising targets for the development of drugs. Methods Protoscoleces (PSC) of E. granulosus (s.s.) (genotype G1) obtained from sheep hepatic hydatid cysts were exposed to tropisetron and granisetron at concentrations of 50, 150 and 250 µM for various periods of time up to 10 days. Cyclosporine A (CsA) and albendazole sulfoxide were used for comparison. Changes in the morphology of PSC were investigated by light microscopy and scanning electron microscopy. Gene expression was assessed using real-time PCR at the mRNA level for E. granulosus calcineurin subunit A (Eg-CaN-A), calcineurin subunit B (Eg-CaN-B) and calmodulin (Eg-CaM) after a 24-h exposure at 50 and 250 µM, respectively. Results At 150 and 250 µM, tropisetron had the highest protoscolicidal effect, whereas CsA was most effective at 50 µM. Granisetron, however, was less effective than tropisetron at all three concentrations. Examination of morphological alterations revealed that the rate at which PSC were killed increased with increasing rate of PSC evagination, as observed in PSC exposed to tropisetron. Gene expression analysis revealed that tropisetron at 50 μM significantly upregulated Eg-CaN-B and Eg-CaM expression while at 250 μM it significantly downregulated both Eg-CaN-B and Eg-CaM expressions; in comparison, granisetron decreased the expression of all three genes at both concentrations. Conclusions Tropisetron exhibited a higher efficacy than granisetron against E. granulosus (s.s.) PSC, which is probably due to the different mechanisms of action of the two drugs. The concentration-dependent effect of tropisetron on calcineurin gene expression might reflect its dual functions, which should stimulate future research into its mechanism of action and evaluation of its potential therapeutical effect in the treatment of CE. Graphic Abstract

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Unified terminology for cestode microtriches: a proposal from the International Workshops on Cestode Systematics in 2002-2008

Chervy¹

2009

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The following terms were endorsed for the components of individual microtriches: The distal, electron-dense portion is the cap, the proximal more electron-lucent region is the base. These two elements are separated from one another by the baseplate. The base is composed of, among other elements, microfilaments. The cap is composed of cap tubules. The electron-lucent central portion of the base is referred to as the core. The core may be surrounded by an electron-dense tunic. The entire microthrix is bounded by a plasma membrane, the external layer of which is referred to as the glycocalyx. Two distinct sizes of microtriches are recognised: those ≤ 200 nm in basal width, termed filitriches, and those >200 nm in basal width, termed spinitriches. Filitriches are considered to occur in three lengths: papilliform (≤ 2 times as long as wide), acicular (2-6 times as long as wide), and capilliform (>6 times as long as wide). In instances in which filitriches appear to be doubled at their base, the modifier duplicated is used. Spinitriches are much more variable in form. At present a total of 25 spinithrix shapes are recognised. These consist of 13 in which the width greatly exceeds the thickness (i.e., bifid, bifurcate, cordate, gladiate, hamulate, lanceolate, lineate, lingulate, palmate, pectinate, spathulate, trifid, and trifurcate), and 12 in which width and thickness are approximately equal (i.e., chelate, clavate, columnar, coniform, costate, cyrillionate, hastate, rostrate, scolopate, stellate, trullate, and uncinate). Spiniform microtriches can bear marginal (serrate) and/or dorsoventral (gongylate) elaborations; they can also bear apical features (aristate). The latter two modifiers should be used only if the features are present. The terminology to describe the overall form of a spinithrix should be used in the following order: tip, margins, shape. Each type of microthrix variation is defined and illustrated with one or more scanning electron micrographs. An indication of the taxa in which each of the microthrix forms is found is also provided.

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Ultrastructure of microtriches on the scolex of Cyathocephalus truncatus (Cestoda: Spathe-bothriidea)

Cited by 4 publications

References 18 publications

Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda)<sup>*</sup>

Spathebothriidea: survey of species, scolex and egg morphology, and interrelationships of a non-segmented, relictual tapeworm group (Platyhelminthes: Cestoda)<sup>*</sup>

In vitro effects of tropisetron and granisetron against Echinococcus granulosus (s.s.) protoscoleces by involvement of calcineurin and calmodulin

Unified terminology for cestode microtriches: a proposal from the International Workshops on Cestode Systematics in 2002-2008

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