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At least 19 recordsLinked to original sources

PubMed2004

Pharmacological characterisation of neuropeptide F (NPF)-induced effects on the motility of Mesocestoides corti (syn. Mesocestoides vogae) larvae.

Neuropeptide F is the most abundant neuropeptide in parasitic flatworms and is analogous to vertebrate neuropeptide Y. This paper examines the effects of neuropeptide F on tetrathyridia of the cestode Mesocestoides vogae and provides preliminary data on the signalling mechanisms employed. Neuropeptide F (>/=10 microM) had profound excitatory effects on larval motility in vitro. The effects were insensitive to high concentrations (1 mM) of the anaesthetic procaine hydrochloride suggesting extraneuronal sites of action. Neuropeptide F activity was not significantly blocked by a FMRFamide-related peptide analog (GNFFRdFamide) that was found to inhibit GNFFRFamide-induced excitation indicating the occurrence of distinct neuropeptide F and FMRFamide-related peptide receptors. Larval treatment with guanosine 5'-O-(2-thiodiphosphate) trilithium salt prior to the addition of neuropeptide F completely abolished the excitatory effects indicating the involvement of G-proteins and a G-protein coupled receptor in neuropeptide F activity. Addition of guanosine 5'-O-(2-thiodiphosphate) following neuropeptide F had limited inhibitory effects consistent with the activation of a signalling cascade by the neuropeptide. With respect to Ca(2+) involvement in neuropeptide F-induced excitation of M. vogae larvae, the L-type Ca(2+)-channel blockers verapamil and nifedipine both abolished neuropeptide F activity as did high Mg(+) concentrations and drugs which blocked sarcoplasmic reticulum Ca(2+)-activated Ca(2+)-channels (ryanodine) and sarcoplasmic reticulum Ca(2+) pumps (cyclopiazonic acid). Therefore, both extracellular and intracellular Ca(2+) is important for neuropeptide F excitation in M. vogae. With respect to second messengers, the protein kinase C inhibitor chelerythrine chloride and the adenylate cyclase inhibitor MDL-2330A both abolished neuropeptide F-induced excitation. The involvement of a signalling pathway that involves protein kinase C was further supported by the fact that phorbol-12-myristate-13-acetate, known to directly activate protein kinase C, had direct excitatory effects on larval motility. Although neuropeptide F is structurally analogous to neuropeptide Y, its mode-of-action in flatworms appears quite distinct from the common signalling mechanism seen in vertebrates.

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PubMed1980

[Mesocestoides leptothylacus n. sp. and the problem of nomenclature in the genus Mesocestoides Vaillant, 1863 (Cestoda, Mesocestoididae) (author's transl)].

M. leptothylacus n. sp., a common parasite of the Red Fox (Vulpes vulpes) in Southwest Germany, is characterized by a slender elongated cirrus pouch containing a cirrus with only one loose convolution and by approximately 90 testes surrounding the other genital organs completely, quite a number of them lying outside the lateral excretory canals.--The decision for a new name arised from the following considerations: 1. Goeze (1782) described Taenia lineata with characteristics of the genus only. 2. There is no type material left by Goeze. 3. None of the later authors could know which species was meant by T. lineata. 4. None of the later descriptions was exact enough to adjoin it to the old name today. 5. All descriptions under the name of M. lineatus have to be revised. Certkova & Kosupko (1795) in order to preserve the well known name assigned to it a completely new species but did not select a neotype nor did they choose a species from the terra typica; thus the name of that species has to be altered. 7. Goeze in the same book in which he described M. lineatus gave a very superficial account of a cestode presumed to be a variation of a Taenia cateniformis which probably was a Mesocestoides, too. The specimens apparently were not gravid so that the author neither recognized the relationship to his T. lineata nor could he be sure about a possible identity of the two. 8. Thus, the name assigned to this second description, M. literatus (Batsch, 1786) is a nomen dubium.

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PubMed2005

Ants as first intermediate hosts of Mesocestoides on San Miguel Island, USA.

This study tested the hypotheses that ants (Formicidae) function as a first intermediate host of Mesocestoides (Cestoda: Mesocestoididae) and that deer mice (Peromyscus maniculatus) develop metacestode infections after ingesting cysticercoid or procercoid-infected ants. Field studies were conducted at an island fox (Urocyon littoralis littoralis) breeding facility located on San Miguel Island, California Channel Islands National Park, USA, where > 40% of captive foxes were infected with adult Mesocestoides. Eight percent (8%) of deer mice at the fox pen site were infected with Mesocestoides metacestodes while none were infected at a distant site where foxes were absent (campground), thereby indicating the potential localized presence of a first intermediate host. To test whether ants from San Miguel Island contained Mesocestoides DNA, a polymerase chain reaction (PCR)-based diagnostic assay was developed using nested primers that could detect a single hexacanth larva within pooled samples of ten ants. Ants (Lasius niger and Tapinoma sessile) collected near the fox breeding facility were tested using the nested-PCR assay. Seven of 223 pooled samples of L. niger (3.1%) and 2 of 84 pooled samples of T. sessile (2.4%) tested positive for Mesocestoides DNA, while none of the ants were positive at the campground site. Positive samples were sequenced and found to match DNA sequences from Mesocestoides obtained from island fox and deer mice. Finally, to determine whether ants function as a first intermediate host for Mesocestoides, colony-raised deer mice (n = 47) were fed L. niger (n = 3860) or T. sessile (n = 339) collected from the San Miguel Island fox breeding facility. No mouse became infected with Mesocestoides metacestodes after ingesting ants. While both L. niger and T. sessile from SMI were positive for Mesocestoides DNA, they were not infective to deer mice in the laboratory.

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PubMed2004

Life-history studies on two molecular strains of mesocestoides (Cestoda: Mesocestoididae): identification of sylvatic hosts and infectivity of immature life stages.

Life-cycle studies were conducted on 2 molecular strains of Mesocestoides tapeworms that represent different evolutionary lineages (clades A and B). Wild carnivores, reptiles, and rodents were examined for tapeworm infections at 2 enzootic sites: (1) San Miguel Island (SMI), a small island off the coast of southern California and (2) Hopland Research and Extension Center (HREC), a field station in northern California. Results indicate that deer mice (Peromyscus maniculatus) and coyotes (Canis latrans) may play an important role in the life cycles of Mesocestoides (clades A and B) in California. Over half the coyotes at HREC and at least a third of the population of island fox (Urocyon littoralis) at SMI were found to harbor clade A adult Mesocestoides spp. One of every 4 Mesocestoides-infected coyotes had tapeworms representing both clades A and B. Experimental inoculations revealed that proglottids (clades A and B) were not directly infectious to rodents, reptiles, or dogs. On the other hand, mice, lizards, and hamsters fed tetrathyridia of Mesocestoides spp. (clades A or B) developed peritoneal tetrathyridial infections. A dog that was fed tetrathyridia (clade B) developed an adult tapeworm infection. Acephalic metacestodes given orally to western fence lizards, laboratory mice, or domestic dogs did not result in metacestode or adult tapeworm infections. Whereas most clade A acephalic metacestodes from dogs were asexually proliferative, clade A tetrathyridia isolated from wild deer mice did not show evidence of asexual replication. Our study supports the hypothesis that a second, as of yet unidentified, intermediate host is necessary to complete the life cycles of Mesocestoides spp., and that acephalic metacestodes represent an aberrant form, incapable of further development.

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PubMed2003

Cytologic diagnosis of peritoneal cestodiasis in dogs caused by Mesocestoides sp.

BACKGROUND: Canine peritoneal larval cestodiasis caused by tapeworm larvae of the genus Mesocestoides is an uncommon and possibly fatal disease that can result in ascites and peritonitis. Although abdominal fluid analysis is recommended for dogs with ascites, the cytologic features of Mesocestoides infection have not been described fully. OBJECTIVE: Our goal was to describe the cytologic features of Mesocestoides larvae and of associated ascitic fluid that was collected from the peritoneal cavity of 4 infected dogs. METHODS: Abdominal fluid was obtained from 4 dogs with Mesocestoides sp infection. Gross, chemical, and microscopic evaluations of the fluid were performed using standard techniques. RESULTS: Cytologic findings in 1 dog included intact acephalic metacestodes (larvae without 4 suckers, not tetrathyridia) in various stages of asexual development, whereas fluid from the other 3 dogs contained primarily calcareous corpuscles, remnant tissue specific to cestodes. Abdominal fluid typically was an exudate, with suppuration, hemorrhage, and evidence of necrosis. Total protein concentrations ranged from 2.4 to 5.3 g/dL. CONCLUSIONS: Abdominal fluid cytology was useful in the diagnosis of Mesocestoides larval infections in the peritoneal cavity of dogs with ascites. Observation of characteristic calcareous corpuscles or intact metacestodes can provide a definitive diagnosis of canine peritoneal larval cestodiasis in dogs.

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PubMed2000

Molecular systematics of Mesocestoides sPP (cestoda: mesocestoididae) from domestic dogs (Canis familiaris) and coyotes (Canis latrans).

The genus Mesocestoides Vaillant, 1863 includes tapeworms of uncertain phylogenetic affinities and with poorly defined life histories. We previously documented 11 cases of peritoneal cestodiasis in dogs (Canis familiaris L.) in western North America caused by metacestodes of Mesocestoides spp. In the current study, DNA sequences were obtained from metacestodes collected from these dogs (n = 10), as well as proglottids from dogs (n = 3) and coyotes (Canis latrans Say, 1823 [n = 2]), and tetrathyridia representing laboratory isolates of M. corti (n = 3), and these data were analyzed phylogenetically. Two nuclear genetic markers, 18S ribosomal DNA and the second internal-transcribed spacer (ITS 2), were sequenced. Phylogenetic analysis of the 18S rDNA data recovered a monophyletic group composed of all samples of Mesocestoides spp., distinct from closely related outgroup taxa (Amurotaenia Akhmerov, 1941 and Tetrabothrius Rudolphi, 1819). Initial analysis of the ITS 2 data resolved 3 clades within Mesocestoides. Two proglottids from dogs formed a basal clade, a second clade was represented by tetrathyridial isolates, and a third clade included all other samples. Interpretation of these data from an apomorphy-based perspective identified 6 evolutionary lineages. We also assessed whether metacestodes from dogs (n = 4) are capable of asexual proliferation in laboratory mice. One tetrathyridial and 2 acephalic isolates from dogs proliferated asexually. Further investigation is warranted to determine which of the lineages represent distinct species and to determine the life history strategies of Mesocestoides spp.

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PubMed2005

Systematics of Mesocestoides (Cestoda: Mesocestoididae): evaluation of molecular and morphological variation among isolates.

A hypothesis-based framework was used to test if 3 genetic strains of Mesocestoides (clades A, B, and C) are distinct evolutionary lineages, thereby supporting their delimitation as species. For comparative purposes, 3 established cestode species, Taenia pisiformis, Taenia serialis, and Taenia crassiceps were assessed using the same methods. Sequence data from mitochondrial rDNA (12S) and the second internal transcribed spacer of nuclear rDNA (ITS-2) revealed derived (autapomorphic) characters for lineages representing clade A (n = 6 autapomorphies), clade B (n = 4), and clade C (n = 9) as well as T. pisiformis (n = 15) and T. serialis (n = 12). Furthermore, multivariate analysis of morphological data revealed significant differences among the 3 genetic strains of Mesocestoides and between T. pisiformis and T. serialis. The level of phenotypic variation within evolutionary lineages of Mesocestoides and Taenia spp. tapeworms was similar. Results from this study support recognizing Mesocestoides clades A, B, and C as separate species, and provide evidence that clade B and Mesocestoides vogae are conspecific.

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PubMed2003

Short report: a new case report of human Mesocestoides infection in the United States.

The twenty-seventh documented case of human Mesocestoides infection, which corresponds to the seventh documented case in the United States, is reported. The case had its origin in Alexandria, Louisiana in the summer of 1998. The patient was a 19-month-old boy. The strobila consisted of 35 proglottids that included mature as well as gravid segments containing a ventral genital pore and a parauterine organ. After a detailed microscopic examination, the tapeworm was identified as belonging to the genus Mesocestoides. Mesocestoides variabilis is the probable species responsible for the infection, since the six cases previously reported in the United States were identified as this species. After the treatment with a single dose of praziquantel (10 mg/kg), the tapeworm segments were no longer detectable in the child's feces. A food-borne origin of this infection derived from culinary customs of the Acadian and Creole communities in Louisiana is proposed.

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PubMed1991

Helminth parasites of unisexual and bisexual whiptail lizards (Teiidae) in North America. V. Mesocestoides sp. tetrathyridia (Cestoidea: Cyclophyllidea) from four species of Cnemidophorus.

Two hundred and one whiptail lizards, Cnemidophorus spp., from Texas and Colorado (USA), were examined for Mesocestoides sp. tetrathyridia. Eleven (5%) were infected, including three of 58 (5%) C. dixoni, six of 70 (9%) C. gularis septemvittatus, one of 35 (3%) C. marmoratus, and one of 34 (3%) C. tesselatus; four C. inornatus heptagrammus were not infected. In addition, 41 non-cnemidophorine lizards from the same study area were not infected. Free tetrathyridia were found in the body cavity of lizards and encapsulated tetrathyridia were observed in the heart, liver, stomach, mesenteries, ovaries, intestines, and lungs. None of the Mesocestoides sp. exhibited any evidence of asexual proliferation such as multiple scoleces or buds. This note, the fifth in a series of reports on helminths of Cnemidophorus spp., represents the first time Mesocestoides sp. has been reported from these four taxa, and Colorado is a new geographic locality record for this parasite.

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PubMed1998

Diagnostic procedures and treatment of eleven dogs with peritoneal infections caused by Mesocestoides spp.

An 8-year-old spayed Schnauzer with a distended abdomen was examined because of straining to urinate and suspected urinary tract infection. Abdominal radiography revealed a ground-glass appearance, and ultrasonography revealed numerous cystic structures in the peritoneal cavity. Examination of an aspirate of abdominal fluid revealed tissues consistent with metacestodes. Tissues were definitively identified as Mesocestoides spp on the basis of polymerase chain reaction amplification of restriction fragment length polymorphisms. The dog required several courses of treatment with fenbendazole to eliminate the infection. This was 1 of 11 dogs infected with Mesocestoides metacestodes. Treatment involving the use of praziquantel and albendazole were ineffective, but fenbendazole successfully cleared Mesocestoides infections in 5 of 6 dogs.

Albendazole↗

PubMed2004

First record of metacestodes of Mesocestoides sp. in the common starling (Sturnus vulgaris) in Europe, with an 18S rDNA characterisation of the isolate.

Metacestodes of Mesocestoides sp. were recorded from Sturnus vulgaris (Passeriformes: Stumidae) in the Czech Republic in April 2002. They were found in a cutaneous cyst and in the thoracic region of the body cavity of the bird. This is the first record of metacestodes of Mesocestoides sp. in this host species in Europe as well as the first finding of the formation of a cutaneous cyst provoked by this parasite. Additional specimens from Apodemus agrarius (Mammalia: Rodentia) from Bulgaria and Lacerta agilis (Reptilia: Squamata) from the Czech Republic were compared with that from S. vulgaris. Sequence data from the V4 variable region (18S rDNA) were used to compare genetic variability among these and previously characterized isolates of Mesocestoides spp. A number of distinct clades were recognized, with metacestodes from L. agilis showing the highest degree of relative divergence.

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PubMed1983

[Therapeutic effect of paromomycin sulfate on the 13th case of Mesocestoides lineatus infection found in Japan].

Mesocestoides tapeworm is a common cestode in carnivorous mammals, but human infection with the tapeworm of this genus have been infrequent. We have recently observed the 13th case of human infection with Mesocestoides lineatus in Japan. A 35-year-old man living in Gifu prefecture was admitted to our University Hospital with chief complaints of general fatigue and discharge of cestode segments in his stool. The patient gave a history of drinking blood and eating the raw liver of a snake Agkistrodon halys for medicinal purposes as same as the previous cases of all reported in Japan. The segments were identified as those of M. lineatus. He was treated orally 3 g of paromomycin sulfate. Stool examination after treatment with paromomycin sulfate revealed no evidence of parasitism. The present case may be the 2nd to have been successfully treated with paramomycin sulfate and the 21st case of Mesocestoides tapeworm infection in man described in the literature.

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PubMed2003

First occurrence of Mesocestoides sp. in a bird, the red-legged partridge, Alectoris rufa, in Spain.

Larvae of Mesocestoides sp. were found in the celomic cavity of one red-legged partridge (Alectoris rufa) from Azuara (Aragón, north-eastern Spain). This is the first report of this larval cestode occurring in birds from Spain. None of the other 36 partridges from this area nor 150 partridges from other Spanish localities were affected. The red-legged partridge does not seem to be an important link in the Mesocestoides sp. life-cycle.

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PubMed2005

Praziquantel and albendazole damaging action on in vitro developing Mesocestoides corti (Platyhelminthes: Cestoda).

Parasitic flatworms present several steps of body architecture rearrangement during their fast transition from one developmental stage to another, which are, at least in part, responsible for their evasion from host immune response. Besides, different developmental stages present different degrees of susceptibility to drug action, and the identification of more susceptible stages is of importance for the definition of therapeutical approaches. Mesocestoides corti (syn. Mesocestoides vogae) is considered a good model to study cestode biology because it can be easily manipulated both in vivo and in vitro and due to its relatively close relationship to cestodes of medical relevance, such as those from genera Echinococcus or Taenia. We have analyzed the damaging action of two broad spectrum anthelmintic drugs (praziquantel and albendazole) throughout the in vitro strobilization process of M. corti in order to identify developmental stages or body structures more susceptible to these drugs. Tetrathyridia (larval stage) and segmented-induced worms were cultivated and treated with praziquantel and albendazole. Whole mounted samples, taken from different developmental stages, were fixed and stained with fluorophore-labeled WGA lectin and phalloidin for the analysis of tegument and muscles, respectively. Confocal laser scanning microscopy was used to identify anatomical changes and lesions caused by each anthelmintic drug in a 3D view. We demonstrated that both praziquantel and albendazole cause extensive tissue damage, especially on tegument, and that adult forms were the most susceptible to drug exposure.

Albendazole↗

PubMed2000

Effect of praziquantel on the strobilar development of Mesocestoides corti in vitro.

The effect of praziquantel (PZQ) on the strobilar development of the cyclophyllidean cestode Mesocestoides corti was explored. Mesocestoides corti larvae were cultivated under conditions reported to favour their differentiation to the adult stage. Parasites were exposed to 0.1 microg ml(-1) PZQ for 16 h and subsequently transferred to drug-free medium. The ocurrence of segmentation--an early event of the larval somatic differentiation to the adult worm-- was considered as quantitative data. This phenomenon was evidenced earlier in worms transiently exposed to PZQ with respect to control cultures. Moreover, the rate of segmentation of drug-treated worms at the end of the experiment almost doubled that of control worms. To date, no similar effect on any cestode developmental process has been reported for an anthelmintic drug. In the light of the existing knowledge and understanding of PZQ mechanisms of action, the proposed experimental approach could contribute to the elucidation of pathways and mechanisms involved in cestode strobilar development.

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PubMed1989

Action of cyclosporin A on the tapeworms Hymenolepis microstoma, H. diminuta and Mesocestoides corti in vivo.

The in vivo activity of two cyclosporins, cyclosporin A (CsA) and a non-immunosuppressive derivative of dihydrocylosporin A (DHCsA-d) against three tapeworms, Hymenolepis microstoma, H. diminuta and Mesocestoides corti, has been assessed. CsA reversibly reduced the dry weight of H. microstoma in the mouse, briefly delayed oviposition and had a statistically significant effect on worm numbers recovered. Oral and subcutaneous treatments of both CsA and DHCsA-d were effective in reducing worm weight; juvenile worms were most susceptible but worms of all ages responded to drug by a dramatic reduction in weight from which they recovered. Multiple courses of CsA were no more active than single courses of treatment but dose response suggested that a threshold level of drug was necessary to evoke activity. By contrast, H. diminuta in the rat was completely unaffected by CsA but no explanation for the differences in drug response by these two closely related helminths is forthcoming. Mesocestoides corti responded reversibly to CsA in the mouse by a reduction in asexual proliferation of both liver and peritoneal cavity tetrathyridia. The data presented argue in favour of a range of anti-parasitic activities by cyclosporins but the details of the various putative modes of action remain to be defined.

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PubMed2004

Clinical, cytological and molecular evidence of Mesocestoides sp. infection in a dog from Italy.

A 12-year-old, 13 kg, mixed-breed male dog was referred for anorexia and depression. The dog showed discomfort on abdominal palpation. Abdominal ultrasound examination revealed multiple, small, round anechoic cystic structures. Cystic fluid obtained with fine needle aspiration contained several 2-4 mm white motile flecks. Microscopic examination of the fluid revealed numerous irregularly shaped organisms measuring several hundred microns to 3 mm, the morphology of which was suggestive of intact and fragmented acephalic metacestodes of the genus Mesocestoides sp. Molecular analysis confirmed that the peritoneal infection was caused by Mesocestoides sp.

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PubMed1988

Mesocestoides sp. tetrathyridia (Cestoidea: Cyclophyllidea) in the iguanid lizards, Cophosaurus texanus texanus and Sceloporus olivaceous, from Texas.

New host records are reported for Mesocestoides sp. tetrathyridia in two species of iguanid lizards (Cophosaurus texanus and Sceloporus olivaceous) from Texas. Tetrathyridia were found free within the body cavity or encapsulated in the liver of the hosts. Prevalence of infection was generally low, with intensities ranging from 90 to over 200 tetrathyridia per host. In addition, a summary of North American lizard species reported as hosts of Mesocestoides sp. tetrathyridia is presented.

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