Mesocestoides Species Research Articles

Distribution and prevalence of Taenia hydatigena, Taenia multiceps, and Mesocestoides spp. in Mongolian sheepdogs.

Gastrointestinal parasite infections in livestock and companion animals in Mongolia have not been investigated sufficiently. This study aimed to determine the prevalence of cyclophyllid cestodes (Taeniidae and Mesocestoididae) in Mongolian sheepdogs using copro-DNA analysis. Sheepdog fecal samples (n=1242) were collected from five ecological zones (mountain taiga, forest-steppe, steppe, desert-steppe, and desert) and four geographical regions (Western, Khangai, Central, and Eastern) within 20 of the country's 21 provinces. Among the 1242 samples, 201 (16.2%) tested positive for mitochondrial cytochrome c oxidase subunit 1 (cox1) and ribosomal 12S rRNA encoding genes of cyclophyllid cestodes. Prevalence in the mountain taiga, forest-steppe, steppe, desert-steppe, and desert zones was 29.2%, 15.4%, 15.1%, 20.1%, and 9.1%, respectively. Prevalence in the Western, Khangai, Central, and Eastern regions was 19.9%, 18.6%, 12.1%, and 12.8%, respectively. Taenia hydatigena, Taenia multiceps, and two Mesocestoides species (Mesocestoides sp.1 and Mesocestoides sp.2) were identified. T. hydatigena was found in the samples from all 20 provinces (all five zones and four regions), while T. multiceps was detected in the samples from 19 provinces (all five zones and four regions). Mesocestoides sp.1 infection was detected in the samples from all zones (except desert) and regions; it was detected in 14 provinces. Mesocestoides sp.2 infection was detected in the samples from all zones (except mountain taiga) and regions and found in seven provinces. Cyclophyllidea infection in sheepdogs is highly prevalent across Mongolia, representing a zoonotic risk. Implementation of a surveillance program for sheepdogs and their owners, and the wild animals in all ecological zones should be considered. In addition, control measures, including public awareness campaigns, especially for sheepdog owners, and periodic deworming of sheepdogs are warranted.

Morphological and molecular analyses of Taenia and Mesocestoides species from red foxes (Vulpes vulpes) in northwestern China.

In this study, 263 tapeworms were collected from eight road-killed red foxes in Xinjiang Uygur Autonomous Region (XUAR, northwestern China). The tapeworms were analyzed based on morphological characters and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequences. Eighty-three Taenia and 180 Mesocestoides tapeworms were identified according to the presence or absence of rostellum, and the number, the length and the shape of the large rostellar hooks. The morphological and molecular analyses revealed that i) 180 Mesocestoides tapeworms, here named as Mesocestoides sp. (Vulpes vulpes), showed 99.21% (378/381 bp) identity to Mesocestoides sp. reported from red fox in Mongolia; and ii) 83 Taenia tapeworms belonged to three species. The first Taenia species [n = 16, named as Taenia sp. (Vulpes vulpes)], based on the length of large rostellar hooks (337–342 μm) and its cox1 sequence, was identified as a potentially novel species, which is phylogenetically close to Taenia laticollis. The second species [n = 54, named as Taenia sp. (Vulpes vulpes & Rhombomys opimus)], was morphologically similar to Taenia endothoracicus according to the number (n = 52), the length (319–332 μm) and the shape of the large rostellar hooks. This species, infecting three red foxes, shared 100% cox1 sequence identity with Taenia sp. (Rhombomys opimus) genotype C found previously in great gerbils (Rhombomys opimus) in the same region. The third species (n = 13, named as Taenia polyacantha-like), had shorter large rostellar hooks (178–180 μm) and showed 96.27% (361/375 bp) sequence identity to Taenia polyacantha reported from red fox in Italy. The “great gerbil-red fox” life cycle of Taenia sp. (Vulpes vulpes & Rhombomys opimus), belonging to the mitochondrial lineage of T. endothoracicus, is confirmed. The T. polyacantha-like species was firstly found in red fox in China. Taenia sp. (Vulpes vulpes) is a potentially novel species, which is close to T. laticollis based on its phylogenetic properties.

Molecular identification of Taenia hydatigena and Mesocestoides species based on copro-DNA analysis of wild carnivores in Mongolia.

Cyclophyllidean tapeworms obligatorily parasitize numerous mammalian species, including herbivores, domestic animals and humans, of which, the genera Taenia and Mesocestoides are well characterized. However, little is known about these parasitic infections in wild animals. This study aims to investigate the prevalence and distribution of Taenia sp. and Mesocestoides sp. in wild carnivores in Mongolia by identifying tapeworm species based on mtDNA analysis. The field survey was carried out in 2012–2013 in 19 provinces located in different ecological regions. A total of 405 fecal samples from wild carnivores were collected. Specific DNA markers in fecal samples was detected via copro-DNA analysis and tapeworm species were identified by DNA sequencing. From 27.7% (112/405) of samples, cox1 and 12S rRNA genes of tapeworms were amplified. Further, Taenia hydatigena (50.0%, 56/112) and two Mesocestoides species, including Mesocestoides sp.-1 (36.6%, 41/112) and Mesocestoides sp.-2 (13.4%, 15/112) were identified by DNA sequencing. The prevalence of T. hydatigena was 19.9% (27/136), 13.8% (23/167), 4.8% (3/62), and 7.5% (3/40) in wolves, red foxes, corsac foxes, and snow leopards, respectively. The prevalence of Mesocestoides sp.-1 was 14.7% (20/136), 9% (15/167), 9.7% (6/62) in wolves, red foxes, and corsac foxes, while the prevalence of Mesocestoides sp.-2 was 4.4% (6/136), 1.8% (3/167), 3.2% (2/62), and 10.0% (4/40) in wolves, red foxes, corsac foxes, and snow leopards, respectively. T. hydatigena was found throughout all ecological regions, while Mesocestoides sp.-1 was in the mountain taiga, forest-steppe, steppe, desert-steppe, and desert, and Mesocestoides sp.-2 in the alpine, forest-steppe, steppe, and desert-steppe ecoregions. This study revealed the prevalence and distribution of cyclophyllidean tapeworms in wild carnivores in Mongolia; while also confirming that wolves, red foxes, corsac foxes, and snow leopards serve as definitive hosts for unidentified Mesocestoides species.

Species delimitation based on mtDNA genes suggests the occurrence of new species of Mesocestoides in the Mediterranean region

BackgroundThis study is the first contribution to the molecular taxonomy of Mesocestoides spp. from domestic and wild carnivores in the Mediterranean area. A total of 13 adult worms and 13 larval stages of Mesocestoides spp. were collected from domestic and wild carnivore hosts in Italy and Tunisia. Samples collected in the Slovak Republic were used as comparative samples from outside the Mediterranean. The genes cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) of the mitochondrial genome were used as molecular markers to investigate the presence of cryptic Mesocestoides species in the area analysed.ResultsResults were consistent in showing three well-supported clusters of Mesocestoides spp. in southern Italy and Tunisia, which were strongly divergent from Mesocestoides litteratus, M. corti and M. lineatus. High levels of genetic variation and no evidence of geographical structuring was found between the clusters.ConclusionsConsidering the low dispersal capability of the intermediate hosts of Mesocestoides spp., the lack of geographical structuring among the Mediterranean regions could be due to a high potential for dispersion of the definitive hosts. This study provides a foundation for future formal descriptions of new species of the genus Mesocestoides in the Mediterranean area.

Molecular identification of Mesocestoides sp. metacestodes in a captive gold-handed tamarin (Saguinus midas)

Mesocestoides spp. are tapeworms harbored in the intestine of many domestic and wild carnivores, birds of prey and, rarely, of humans. The life cycle is assumed to involve three hosts and the metacestode juvenile stage (tetrathyridium) may reproduce asexually, provoking severe systemic infections. In the present study, a case of a peritoneal infection by Mesocestoides sp. occurred in a captive gold-handed tamarin (Saguinus midas) is described. Phylogenetic positions based on CO1 and 12S loci were analysed to describe in details this unusual finding of Mesocestoides in a callitrichid monkey. The phylogenetic analyses has not clearly resolve relationships between the metacestode forms from the tamarin and any of the described Mesocestoides species available so far, including those described from non-human primates, thus supporting the hypothesis of a new taxon within the genus.

Occurrence of Mesocestoides canislagopodis (Rudolphi, 1810) (Krabbe, 1865) in mammals and birds in Iceland and its molecular discrimination within the Mesocestoides species complex.

The life cycle of Mesocestoides tapeworms (Cestoda: Cyclophyllidea: Mesocestoididae) requires three hosts. The first intermediate host is unknown but believed to be an arthropod. The second intermediate host is a vertebrate. The primary definitive host is a carnivore mammal, or a bird of prey, that eats the tetrathyridium-infected second intermediate host. One representative of the genus, Mesocestoides canislagopodis, has been reported from Iceland. It is common in the arctic fox (Vulpes lagopus) and has also been detected in domestic dogs (Canis familiaris) and cats (Felis domestica). Recently, scolices of a non-maturing Mesocestoides sp. have also been detected in gyrfalcon (Falco rusticolus) intestines, and tetrathyridia in the body cavity of rock ptarmigan (Lagopus muta). We examined the taxonomic relationship of Mesocestoides from arctic fox, gyrfalcon, and rock ptarmigan using molecular methods, both at the generic level (D1 domain LSU ribosomal DNA) and at the specific level (cytochrome c oxidase subunit I (COI) and 12S mitochondrial DNA). All stages belonged to Mesocestoides canislagopodis. Phylogenetic analysis of the combined 12S-COI at the specific level confirmed that M. canislagopodis forms a distinct clade, well separated from three other recognized representatives of the genus, M. litteratus, M. lineatus, and M. corti/vogae. This is the first molecular description of this species. The rock ptarmigan is a new second intermediate host record, and the gyrfalcon a new primary definitive host record. However, the adult stage seemed not to be able to mature in the gyrfalcon, and successful development is probably restricted to mammalian hosts.

Tetrathyridiosis and Tubulopapillary Carcinoma Occurring Simultaneously in the Mammary Gland of a Cat

This report describes a case of tubulopapillary carcinoma and concomitant tetrathyridiosis in a 5-year-old female cross-breed cat. A mass was located at right inguinal mammary gland and measured 5.5 × 5 × 3 cm in size with multilobulated to solid appearance. The cut surface of the mass had a centrally located large cyst (approximately 3 cm in diameter) surrounded by other smaller cysts. Histologically, the mass was diagnosed as tubulopapillary mammary carcinoma, intensely positive for AE1/AE3 cytokeratins. The cyst found at post-mortem examination was tetrathyridia of Mesocestoides species surrounded by inflammatory cells and a loose fibrous capsule. To the authors' best knowledge, this is the first description of a tubulopapillary carcinoma and tetrathyridiosis found simultaneously in the mammary gland of a cat.

Canine peritoneal larval cestodosis in a dog

Mesocestoides spp. are parasites in intestines of birds and mammals, including humans (7, 9). Taxonomic classification of the cestodes belonging to the Mesocestoididae family is unclear according to recent morphological and genetical studies (12, 13, 17). This family may not take be part of the order Cyclophyllidea. In respect to biological (life cycle with three hosts), morpho-anatomical (the median location of the genital pore and vitellarium consisting of two compact masses) and sperm characters (rotation of flagellum, the number of axonemes and twisting of cortical microtubules), Mesocestoididae spp. differ from the other members of Cyclophyllidea (9, 13). Also, molecular analysis reveals that Mesocestoididae spp. are basal to the Tetrabothriidea (12). The three species of Mesocestoides taken into consideration are as follows: Mesocestoides vogae (syn. M. corti), Mesocestoides line atus and Mesocestoides leptothylacus (syn. M. litteratus) (10). M. vogae is found in the intestine of dogs (8) and bobcats (18) and M. lineatus in the small intestine of wild carnivores, dogs and cats. Final hosts of M. leptothylacus are foxes, cats and dogs (7). The complete life cycle of Mesocestoides spp. is still obscure (7). The infective larval stage (tetrathyridium) of Mesocestoides spp. is found in the abdominal cavity and on lungs and livers of intermediate hosts such as amphibians, reptiles, birds and small mammals (7, 10). The life cycle is completed in definitive carni vorous hosts by eating intermediate hosts. Adult cestodes develop in the intestine of definitive hosts following a prepatent period of approximately 2–3 weeks (7, 10). Infections with adult Mesocestoides spp. are reported with a quite different incidence in various carnivorous animals such as dogs (6, 19, 21), red foxes (6, 11), wolves (1) and jackals (6). Occasionally, synchronous presence of both the adult Mesocestoides spp. and its infective larval stages in the same definitive host occurs (19) and in these cases the more severe clinic and pathologic outcomes are reported (7, 19). Metacestode stages of Mesocestoides spp. in the abdominal cavity of dogs results in canine peritoneal larval cestodosis (20). Anorexia, peritonitis, ascites, leukocytosis, tissue damage, granuloma formation and encapsulation are observed in animals infected with metacestode stages (7). The infection of the definitive host is simply detected by observation of proglottids with a typical paruterine organ excreted with the faeces (7, 10). In contrast, the detection of peritoneal larval cestodosis in dogs is more complex. The possible methods used for diagnosis of peritoneal larval cestodosis are necropsy (19), ultrasonography (20), histological and cytological examination (3). These methods together with molecular tools are subsequently used for identification of peritoneal larval cestodosis (2, 4, 22). Data on Mesocestoides species responsible for peritoneal larval cestodosis in dogs are limited (2, 22). The aim of this study is to demonstrate a clinical case of peritoneal larval cestodosis in a dog combined with the determination of the parasitic larvae by mole cular diagnosis.

Identification of taeniid eggs in the faeces from carnivores based on multiplex PCR using targets in mitochondrial DNA

A multiplex polymerase chain reaction (PCR) was evaluated for the identification of morphologically indistinguishable eggs of the taeniid tapeworms from carnivores using primers targeting mitochondrial genes. The primers for Echinococcus multilocularis (amplicon size 395 bp) were species-specific as assessed by in silico analysis and in the PCR using well-defined control samples. The design of primers that specifically amplify DNA from E. granulosus or Taenia spp. was not possible. The primers designed for E. granulosus also amplified DNA (117 bp) from E. vogeli, and those designed for Taenia spp. amplified products (267 bp) from species of Mesocestoides, Dipylidium and Diphyllobothrium. Nevertheless, as our diagnostic approach includes the concentration of taeniid eggs by sequential sieving and flotation, followed by their morphological detection, this non-specificity has limited practical importance. Sequence analysis of the corresponding amplicon can identify most of the described E. granulosus genotypes. Taenia spp. can be identified by direct sequencing of the 267 bp amplicon, or, for most species, by restriction fragment length polymorphism (RFLP) analysis. The multiplex PCR was readily able to detect 1 egg (estimated to contain 7000 targets, as determined by quantitative PCR). Having been validated using a panel of well-defined samples from carnivores with known infection status, this approach proved to be useful for the identification of taeniid eggs from both individual animals and for epidemiological studies.

FIRST LARVAL RECORD OF MESOCESTOIDES IN CARNIVORA OF TENERIFE (CANARY ISLANDS)

Larvae of Mesocestoides sp. were recovered in Tenerife (Canary Islands) in 2004 from the peritoneal cavities of 2 domestic dogs and a domestic cat. Morphological and molecular identification were carried out. Mesocestoides litteratus from Vulpes vulpes was sequenced for the first time using the ITS-2 region (18S rDNA), and was included in the phylogenetic analysis to compare the sequence variability among these and other Mesocestoides spp. belonging to different carnivores. Phylogenetic studies were carried out based on maximum parsimony and neighbor-joining analysis. The results showed the relationships between these and other previously published Mesocestoides species. Moreover, it is demonstrated that Mesocestoides sp. from Tenerife comprises a previously unreported sequence. This is the first larval record of Mesocestoides sp. in domestic animals from Tenerife, Canary Islands, Spain.

Mesocestoides litteratus (Batsch, 1786) (Cestoda: Cyclophyllidea: Mesocestoididae) from the red fox: Morphological and 18S rDNA characterization of European isolates

Abstract Mesocestoides litteratus (Batsch, 1786) (Cestoda: Cyclophyllidea: Mesocestoidae) is a common parasite of the red fox (Vulpes vulpes) and other carnivores across Europe. There has been considerable debate as to the validity of M. litteratus and other closely related, often sympatric species of Mesocestoides. We examine isolates of M. litteratus from red foxes in the Czech Republic, Slovakia and Spain both morphometrically and by characterization of 18S rDNA. Morphometric ranges of all isolates confirmed their identity as M. litteratus and were usually within the range published formerly. The sequences of 18S rDNA of one or two isolates from each country were analysed. The sequences were the same and distinct from all published Mesocestoides 18S sequences with the exception of tetrathyridia from a lizard in the Czech Republic, which was identical to those of M. litteratus.

The common vole, Microtus arvalis Pall. as intermediate host of Mesocestoides (Cestoda) in Germany.

Tetrathyridia of Mesocestoides leptothylacus Loos-Frank, 1980 were found in 1.4% of 513 common voles (Microtus arvalis) in a district of Southwest Germany where foxes (Vulpes vulpes) are frequently infected with this tapeworm. The tetrathyridia measured 1 to 1.5 mm in length and 0.5 to 1 mm in width. When injected intraperitoneally into white mice, jirds, or common voles, the tetrathyridia did not multiply. Cats fed with the larvae shed proglottids from the 21st day onwards. In one experimentally infected silver-fox proglottids were passed from day 12 onwards. One human subject infected twice with tetrathyridia of M. leptothylacus, did not develop patent infections. One common vole from another district contained tetrathyridia of a Mesocestoides species, which is rarely found in indigenous foxes and which is characterized by a broad-oval cirrus pouch with a much convoluted cirrus.

Asexual Multiplication of Mesocestoides Tetrathyridia in Laboratory Animals

Tetrathyridia from the liver and body cavity of the lizard Sceloporus occidentalis biseriatus (Hallowell, 1854), when injected intraperitoneally or fed by stomach tube to white mice, multiplied asexually in the body cavity and liver. Multiplication was by longitudinal binary or multiple fission beginning at the scolex, or by lateral budding posterior to the scolex. Tetrathyridia fed to mice penetrated the small intestine into the body cavity and the liver. No worms were found passing through the bile duct. Tetrathyridia retained their infectivity and reproductive capacity in white mice after having been maintained axenically in vitro for 4.5 months. Multiplication rates in mice were studied by injection of single organisms and examination of mice at weekly or biweekly intervals. Adult Mesocestoides, obtained by feeding mouse livers with tetrathyridia to domestic cats, were identified as Mesocestoides corti Hoeppli, 1925. The presence of tetrathyridia in the body cavity and liver of various reptiles and mammals has been noted by many workers. In California reptiles tetrathyridia have been found by Voge (1953), and by Telford (1964); a histologic description of tetrathyridia was published by Voge and Bemtzen (1963). Unfortunately, the complete life history is not known for any New World species of Mesocestoides. It has been established repeatedly that tetrathyridia, when fed to carnivores, will either develop into the intestinal strobilate phase of Mesocestoides or reach the coelom and remain there as tetrathyridia. Our observation that tetrathyridia from fence lizards survive, as well as multiply asexually, in laboratory mice prompted the studies reported here. The manner and rate of asexual reproduction of tetrathyridia and their infectivity to and maintenance in some laboratory animals was studied. Also reported are preliminary observations on their maintenance in vitro. Specific identification of these tetrathyridia as Mesocestoides corti Hoeppli, 1925 was established as described below. MATERIALS AND METHODS

A New Species of Mesocestoides, M. kirbyi, from Canis latrans

A New Species of Mesocestoides, M. kirbyi, from Canis latrans

Mesocestoides manteri n. sp. from a Lynx, with Notes on Other North American Species of Mesocestoides

There is considerable difference of opinion with respect to speciation in the genus Mesocestoides. Most writers, including Cameron (1925), Mueller (1928, 1930) and Joyeux and Baer (1932) recognize a considerable number of species parasitic in mammals, whereas Witenberg (1934) merges them all in the species litteratus, of which he recognizes three of doubtful status. I have not had an opportunity to examine specimens of Mesocestoides from other parts of the world, so am not in a position to pass judgment on Witenberg's conclusions with respect to the forms which he studied from Palestine and Europe, but I have collected and examined specimens from various North American mammals which in my opinion undoubtedly represent three distinct species. Specimens obtained from an opossum are readily recognizable as Mueller's species, latus, originally reported from a skunk in Minnesota, and later from a kitten in Minnesota and an opossum in Illinois. Specimens from a raccoon from Lufkin, Texas, and some fragments from a dog and from a raccoon from Nebraska, reported by Coatney (1936) and kindly sent to me for study by Dr. H. W. Manter, correspond closely with Mueller's variabilis var. maior, reported from a skunk in California. Some specimens from a lynx in Nebraska, also kindly supplied for study by Dr. Manter, undoubtedly constitute a new species, for which the name Mesocestoides manteri is proposed.