Gastrointestinal Helminths of Feral Raccoons (Procyon lotor) in Wakayama Prefecture, Japan

The ribosomal transcription units of five echinostomes and their taxonomic implications for the suborder Echinostomata (Trematoda: Platyhelminthes)

Five newly obtained nuclear ribosomal transcription unit (rTU) sequences from Echinostomatidae and Echinochasmidae are presented. The inter- and intrafamilial relationships of these and other families in the suborder Echinostomata are also analyzed. The sequences obtained are the complete rTU of Artyfechinostomum malayanum (9,499 bp), the near-complete rTU of Hypoderaeum conoideum (8,076 bp), and the coding regions (from 5'-terminus of 18S to 3'-terminus of 28S rRNA gene) in Echinostoma revolutum (6,856 bp), Echinostoma miyagawai (6,854 bp), and Echinochasmus japonicus (7,150 bp). Except for the longer first internal transcribed spacer (ITS1) in Echinochasmus japonicus, all genes and spacers were almost identical in length. Comprehensive maximum-likelihood phylogenies were constructed using the PhyML software package. The datasets were either the concatenated 28S + 18S rDNA sequences (5.7-5.8 kb) from 60 complete rTUs of 19 families or complete 28S sequences only (about 3.8-3.9 kb) from 70 strains or species of 22 families. The phylogenetic trees confirmed Echinostomatoidea as monophyletic. Furthermore, a detailed phylogeny constructed from alignments of 169 28S D1-D3 rDNA sequences (1.1-1.3 kb) from 98 species of 50 genera of 10 families, including 154 echinostomatoid sequences (85 species/42 genera), clearly indicated known generic relationships within Echinostomatidae and Echinochasmidae and relationships of families within Echinostomata and several other suborders. Within Echinostomatidae, Echinostoma, Artyfechinostomum, and Hypoderaeum appeared as monophyletic, while Echinochasmus (Echinochasmidae) was polyphyletic. The Echinochasmidae are a sister group to the Psilostomidae. The datasets provided here will be useful for taxonomic reappraisal as well as studies of evolutionary and population genetics in the superfamily Echinostomatoidea, the sole superfamily in the suborder Echinostomata.

Arthrostoma supriatnai sp. nov. (Nematoda: Ancylostomatidae) parasitic in Mydaus javanensis (Carnivora: Mephitidae) from Mount Ciremai, Java, Indonesia

Arthrostoma supriatnai sp. nov. was described from Mydaus javanensis obtained from Mount Ciremai, Java, Indonesia. It is characterized by having a buccal capsule with ten articulated plates including a pair of additional lateral plates. To date, the genus Arthrostoma consists of eleven species that are native to Asia. Of them, only A. miyazankiense and A. tunkanati have ten articulated plates including the lateral plates. However, the present species has a much stouter body, being readily distinguishable from these two species. Moreover, its male has much shorter spicules than A. miyazakiense, and an arrow-shaped gubernaculum, differing from A. tunkanati, in which gubernaculum is distally bifid. In the female, the present species is readily distinguished from these two species in the shape and number of vulval swellings.

Molecular Characterization of Mesocestoides litteratus (Cestoda: Cyclophyllidea: Mesocestoididae) Tetrathyridium Isolated from Two Species of Rodents from Iran

PURPOSE

Mesocestoides spp. are Cyclophyllidean tapeworms with zoonotic importance. The current study aimed to investigate the molecular characteristics of Mesocestoides larvae (tetrathyridium) isolated from the abdominal cavity of persion jird, Meriones persicus, and from the liver of grey hamster, Cricetulus migratorius, in Ardabil Province, northwest Iran.

METHODS

Genomic DNA of the isolates of Mesocestoides tetrathyridium were extracted, and mitochondrial gene of cytochrome-c oxidase subunit1 (cox1) was amplified. Sequencing of PCR products were performed and phylogenic analysis was run using MEGA 6.0 software.

RESULTS

Both isolates were identified as Mesocestoides litteratus, showing high identity with M. litteratus sequences available in GenBank. Also, they had 100% homology to each other. Intra-species variation within isolates of M. litteratus were 0-2.4%. The phylogenetic reconstruction based on the partial sequence of the cox1 gene showed that our sequences of M. litteratus were clustered with M. litteratus isolates from Slovakia, Netherlands, Germany and Italy.

CONCLUSION

This is the first molecular description of M. litteratus from M. persicus and C. migratorius. Phylogenetic analysis illustrated that M. litteratus isolates of the current study had very high identities with the isolates of this species from other countries.

Detection of Endoparasites in Non-Native Raccoons from Central Italy

The raccoon (Procyon lotor) is a carnivore native to North and Central America, gradually introduced into Asia and Europe, including Italy. It is an important carrier of multiple endoparasites, both Protozoa and Helminths, some of them being zoonotic. The aim of this study was to investigate the endoparasites of the non-native raccoon population of Central Italy. Sixty-two raccoons were collected by local competent authorities (sixty trapped and euthanized, two found dead) and subjected to necroscopic examination. Carcasses underwent a broad parasitological investigation, including coprological techniques (macroscopic examination of the gastrointestinal tract, lungs, trachea, and heart, Flotac^®, Baermann test, and immunofluorescence for Giardia duodenalis and Cryptosporidium spp.), research on respiratory/urinary capillariosis and artificial digestion for Trichinella spp. larvae, and a histopathological examination of the ileum. Ascarid parasites were further identified at the species level using a next-generation sequencing-based amplicon sequencing approach. The results showed the presence of different Protozoa and Nematodes: Baylisascaris procyonis (26/62; 41.9%), Pearsonema sp. (6/62; 9.6%), Capillariidae (6/62; 9.6%), Eimeria sp. (2/62; 3.2%), Cryptosporidium sp. (2/62; 3.2%), and Ancylostomatidae (2/62; 3.2%). B. procyonis is an emerging helminthic zoonotic agent considered a serious concern for public and animal health, given the possibility of its transmission to paratenic hosts, including humans and pets. The demonstrated role of the raccoon as a multi-parasite carrier should be an incentive to continuing the eradication/control of this alien species, and supports the need to implement related disease surveillance programs.

Surveillance for gastrointestinal, subcutaneous, and ectoparasites of invasive North American raccoons (Procyon lotor) in central Spain

The American raccoon (Procyon lotor) is an invasive meso-carnivore which has been introduced and established in many European countries. Although the presence of the raccoon in the Iberian Peninsula was confirmed around 20 years ago, there are few data on pathogens of these animals in this region. For this work, 72 American raccoons from two subpopulations in the central region of the Iberian Peninsula were examined for selected parasites. Ectoparasite species richness (both fleas and ticks) increased during the sampling season and was highest in the Henares subpopulation and on males. Similarly, ectoparasite abundance increased during the sampling season and was highest in Henares and on adult raccoons. Four species of ticks were detected including Rhipicephalus pusillus (71%), followed by R. sanguineus sensu lato (24%), Ixodes ventalloi (3%), and Dermacentor marginatus (1.4%). Four species of fleas were detected including Pulex irritans (44%), Ctenocephalides felis (3%), C. canis (1.4%), and Paraceras melis (1.4%) infestations. A subset of raccoons (n = 56) was examined for intestinal parasites; low prevalence and diversity were found including Strongyloides procyonis (4%), Dilepis sp. (5%), Plagiorchis sp. (2%), and Moniliformis moniliformis (2%). Importantly, Baylisascaris procyonis was not found. Finally, no subcutaneous nematodes (i.e., Dracunculus and Dirofilaria spp.) were found in the 56 raccoons examined. The results of this work show that the invasive North American raccoons currently are infected with few endoparasites but are commonly infested with native ectoparasites, several of which can transmit pathogens relevant for public and veterinary health. However, the geographically distinct populations of raccoons in Spain have different introduction histories, thus additional surveillance for parasites is warranted.

Parasites of Selected Freshwater Snails in the Eastern Murray Darling Basin, Australia

Aquatic snails serve an important role in the ecosystem. They also play an essential role in the life cycle of many parasites as hosts and may pose risks to animal and human health. In Australia, the role of snails in the transmission of parasites of livestock is well studied. However, despite the country’s unique biodiversity and wildlife, little is known about the role of snails in the transmission and survival of parasites in other ecosystems, including aquatic and aquaculture systems. This study aimed to determine the occurrence of parasites in freshwater snails in the eastern Murray Darling Basin. A total of 275 snails were collected from various localities, including aquaculture fishery ponds and natural creeks during the summer and autumn months in the southern hemisphere. Three different species of freshwater snails, all common to the area, were found, including Bullastra lessoni (n = 11), Isidorella hainesii (n = 157), and Haitia acuta (n = 107), of which 9.1%, 1.3%, and 4.7%, respectively, were found to be harboring various developmental stages of Trematoda. No other parasite was found in the examined snails. Parasites were identified as Choanocotyle hobbsi, Plagiorchis sp. and Petasiger sp. based on the sequences of their ITS2, 18S, and 28S ribosomal DNA region. Herein, we report a native parasite Choanocotyle hobbsi in an introduced snail, Haitia acuta, from both natural and aquaculture ponds. As there are no genetic sequences for adult specimens of Petasiger spp. and Plagiorchis spp. collected in Australia for comparison, whether the specimens collected in this study are the larval stage of one of the previously described species or are a new, undescribed species cannot yet be determined. Our results also suggest snails collected from aquaculture ponds may be infected with considerably more parasites.

Copro-Molecular Identification of Tapeworms in Introduced Invasive Carnivores in Poland

The raccoon (Procyon lotor) and the raccoon dog (Nyctereutes procyonoides) were introduced to Europe and, in the past decades, their populations have increased and adapted to synanthropic environments across Europe. In view of their possible further spread in Europe, the invasive species should be examined as potential reservoirs for helminths, including tapeworms. This study aims to investigate the prevalence and diversity of tapeworms in introduced wild carnivores in Poland by identifying cestode species based on copro-DNA analysis. A total of 214 individual fecal samples from non-native invasive carnivores, i.e., raccoons and raccoon dogs, and additionally 47 samples from native carnivores, i.e., European badgers (Meles meles), were analyzed for the presence of cestodes. PCR analysis of fecal samples targeting a fragment of mitochondrial (mt) 12S rRNA gene revealed the presence of cestode DNA in 19 of 103 (18.4%) raccoons, in 13 of 111 (11.7%) raccoon dogs and in 23 of 47 (48.9%) badgers. Sequence analysis demonstrated the presence of Mesocestoides litteratus in raccoons and raccoon dogs, while Mesocestoides lineatus was identified only in two samples derived from raccoon dogs. Moreover, in this study, Atriotaenia incisa was for the first time molecularly characterized by using fragments of mt 12S rRNA gene, and the DNA of this cestode species was detected in the fecal samples of all the examined host species.

Lost and found: Helminths infecting invasive raccoons introduced to Italy

North American raccoons (Procyon lotor) have been introduced to several European countries, where they may represent a sanitary threat as hosts of several pathogens such as the zoonotic ascarid Baylisascaris procyonis. We carried out parasitological analysis on raccoons introduced to Italy to verify whether the species had carried along B. procyonis or any other gastro-intestinal helminths that may threaten humans, livestock or native wildlife. We examined 64 raccoons culled in Northern Italy during control activities and 3 roadkills opportunistically sampled from a separate population located in central Italy. Helminths were collected from the gastro-intestinal tract through standard parasitological techniques and identified based on a combination of morphology and molecular methods. Overall, examined raccoons showed a poor parasitic fauna, with almost 30% of individuals free of any helminth infection. The most prevalent species were the nematodes Strongyloides procyonis (26.9%), Aonchotheca putorii (25.4%) and Porrocaecum sp. (19.4%). Plagiorchis sp. trematodes were also common (13.4%), whereas cestodes were scarcely represented. With the exception of S. procyonis introduced from North America, all the other identified taxa have either a Eurasian or a wide Holarctic distribution. Despite not finding any B. procyonis in the examined raccoons, passive surveillance for this parasite should be implemented, especially in Tuscany, since the limited host sample examined in the present survey does not allow to exclude its presence.

An opisthorchiid concept of the genus Liliatrema (Trematoda: Plagiorchiida: Opisthorchioidea): an unexpected systematic position

Liliatrema is a small genus of trematodes consisting of two species. Its systematic position has long been debated, partly because of the confusing reports about the structure of male terminal genitalia. Here we test the phylogenetic position of the genus Liliatrema using data on complete 18S rRNA and partial 28S rRNA gene sequences obtained for Liliatrema skrjabini. We also provide a detailed description of terminal genitalia in adult specimens of L. sobolevi and metacercariae of both Liliatrema species. The results of the 28S rDNA-based phylogenetic analysis indicate that Liliatrema falls within a well-supported clade, which also includes Apophallus and traditional opisthorchiids. This clade, in turn, is nested within a well-supported clade, containing Euryhelmis, Cryptocotyle and Scaphanocephalus. In the 18S+8S rDNA analysis, Liliatrema appears as a sister-taxon to the Cryptocotyle + Euryhelmis group. The Liliatrema + (Cryptocotyle + Euryhelmis) clade is a well-supported sister-group to the traditional opisthorchiids. The morphology of the terminal genitalia of the liliatrematids also corresponds to that of the opisthorchioids. Thus, the results of our morphological and phylogenetic analyses favour an unexpected conclusion that the genus Liliatrema belongs to the Opisthorchioidea. We propose that the genera Liliatrema, Apophallus, Euryhelmis, Cryptocotyle and Scaphanocephalus belong, respectively, within the subfamilies Liliatrematinae, Apophallinae, Euryhelminthinae and Cryptocotylinae of the family Opisthorchiidae.

The SSU rRNA secondary structures of the Plagiorchiida species (Digenea), its applications in systematics and evolutionary inferences

The small subunit ribosomal RNA (SSU rRNA) is widely used phylogenetic marker in broad groups of organisms and its secondary structure increasingly attracts the attention of researchers as supplementary tool in sequence alignment and advanced phylogenetic studies. Its comparative analysis provides a great contribution to evolutionary biology, allowing find out how the SSU rRNA secondary structure originated, developed and evolved. Herein, we provide the first data on the putative SSU rRNA secondary structures of the Plagiorchiida species. The structures were found to be quite conserved across broad range of species studied, well compatible with those of others eukaryotic SSU rRNA and possessed some peculiarities: cross-shaped structure of the ES6b, additional shortened ES6c2 helix, and elongated ES6a helix and h39 + ES9 region. The secondary structures of variable regions ES3 and ES7 appeared to be tissue-specific while ES6 and ES9 were specific at a family level allowing considering them as promising markers for digenean systematics. Their uniqueness more depends on the length than on the nucleotide diversity of primary sequences which evolutionary rates well differ. The findings have important implications for understanding rRNA evolution, developing molecular taxonomy and systematics of Plagiorchiida as well as for constructing new anthelmintic drugs.

Gastrointestinal helminths of wolves (Canis lupus Linnaeus, 1758) in Piedmont, north-western Italy

Free-ranging grey wolves (Canis lupus), which are presently recolonizing Italy, can be parasitized by a diversity of helminths, but have rarely been subject to studies of their parasites. Therefore, this study aims to determine the prevalence of gastrointestinal helminths of road-killed grey wolves from the Piedmont region of Italy. Forty-two wolves were collected and examined for the presence of helminths. We recorded 12 helminth species: nine Nematoda and three Cestoda. The nematodes were: Ancylostoma caninum (7.1%), Capillaria sp. (2.4%), Molineus sp. (2.4%), Pterygodermatites affinis (11.9%), Physaloptera sibirica (9.5%), Toxocara canis (9.5%), Toxascaris leonina (2.4%) and Uncinaria stenocephala (26.2%); the cestodes were: Dipylidium caninum (4.8%), Mesocestoides sp. (4.8%) and Taenia multiceps (76.2%). Physaloptera sibirica had the highest mean intensity and T. multiceps had the highest prevalence. Based on age and sex, no differences in the intensity or prevalence of helminth species were found among the hosts. Molineus sp. was recorded for the first time in wolves from the Palearctic region; P. affinis and P. sibirica are respectively reported for the first time in wolves from Europe and Italy.

Chabaudstrongylus ninhae (Trichostrongylidae: Cooperiinae) and Oesophagostomum muntiacum (Chabertiidae: Oesophagostominae) in feral alien Reeves's muntjacs on Izu-Oshima Island, Tokyo, Japan

The naturalization of alien Reeves's muntjacs (Muntiacus reevesi) on Izu-Oshima Island, Tokyo, Japan, has proceeded intensively over the last five decades. To clarify whether the gastrointestinal helminths of these animals were brought from their original endemic area or were newly acquired in Japan, 32 Reeves's muntjacs trapped on the island were parasitologically examined. In addition to Gongylonema pulchrum in the oesophagus (34.4% prevalence), Chabaudstrongylus ninhae (Dróżdż, 1967) (Trichostrongylidae: Cooperiinae) and Oesophagostomum muntiacum Jian, 1989 (Chabertiidae: Oesophagostominae) were prevalent in the small (28.1%) and large (46.9%) intestines, respectively. For the first time, these trichostrongylid or chabertiid worms were genetically characterized based on partial nucleotide sequences of the nuclear ribosomal RNA gene (rDNA) and mitochondrial DNA cytochrome c oxidase subunit 1 gene (cox-1), and the phylogenetic relationships with other members of their family were explored. Since these two intestinal nematode species are inherent in muntjacs, this study demonstrates a new distribution of exotic helminth species in Japan in accordance with the naturalization of alien mammalian hosts. The molecular genetic data collected here could assist the taxonomic assessment of morphological variants in different Muntiacus spp. and/or of different geographical origins. Furthermore, our data may help to define the phylogenetic relationships among such isolates.

Infection Status of Isthmiophora hortensis Metacercariae in Dark Sleepers, Odontobutis Species, from Some Water Systems of the Republic of Korea

Present study was performed to survey on infection status of Isthmiophora hortensis (formerly Echinostoma hortense) metacercariae (IhMc) in dark sleepers, Odontobutis spp., from some water systems of the Republic of Korea. A total of 237 Odontobutis spp. was collected in the water systems of 5 rivers, i.e., Mangyeong-gang (gang means river), Geum-gang, Tamjin-gang, Seomjin-gang, and Nakdong-gang. They were all examined with artificial digestion method for 5 years (2013-2017). A total of 137 (57.8%) Odontobutis spp. were infected with 14.8 IhMc in average. The prevalence was the highest in Nakdong-gang areas (62.9%) and followed by in Mangyeong-gang (57.1%), Geum-gang (56.3%), Tamjin-gang (54.8%), and Seomjin-gang (53.9%) areas. Metacercarial densities were 28.1 (Geum-gang), 13.9 (Mangyeong-gang), 13.3 (Nakdong-gang), 13.1 (Tamjin-gang), and 2.3 (Seomjin-gang) per infected fish. Especially, in case of Yugucheon (cheon means stream), a branch of Geum-gang, IhMc were detected in all fish (100%) examined and their density was about 48 per fish. By the present study, it was confirmed that the infection status of IhMc is more or less different by the surveyed areas and the dark sleepers, Odontobutis spp., are suitable fish hosts of I. hortensis.

Review of five species of cyclocoelids (Digenea: Cyclocoelidae) from aquatic birds in Mexico with notes on their interspecific variation

Based on a morphological approach, five species of cyclocoelids (Digenea: Cyclocoelidae) are revised based on material from birds in Mexico. The species studied are: Cyclocoelum cf. leidyi Harrah, 1922 from the black-necked stilt Himantopus mexicanus Müller (Recurvirostridae); Cyclocoelum mutabile (Zeder, 1800) from the northern jacana Jacana spinosa L. (Jacanidae) and the willet Tringa semipalmata Gmelin (Scolopacidae); Cyclocoelum pseudomicrostomum Harrah, 1922 from the American coot Fulica americana Gmelin (Rallidae); Selfcoelum lamothei Blend & Dronen, 2008, from the long-billed curlew Numenius americanus Bechstein (Scolopacidae); and Neohaematotrephus arayae Zamparo, Brooks, Causey & Rodriguez, 2003 from J. spinosa. New morphological data, illustrations and measurements are presented for these trematodes. Three species, insufficiently described, i.e. C. cf. leidyi, C. mutabile and C. pseudomicrostomum, are redescribed in detail. Our results indicate morphological variation in some important features used in the diagnosis of Cyclocoelum Brandes, 1892 (i.e. the presence or absence of oral sucker, the position of the genital pore relative to the pharynx, and the posterior extension of the uterus) and Selfcoelum Dronen, Gardner & Jiménez, 2006 (i.e. anterior extension of vitelline follicles). Finally, this study provides the first molecular data for the large subunit of the ribosomal RNA (28S rRNA) gene for N. arayae.

MOLECULAR AND MORPHOLOGICAL DISCRIMINATION OF DICROCOELIID LARVAE (TREMATODA: DIGENEA) FROM TERRESTRIAL MOLLUSKS IN JAPAN

Trematodes of the family Dicrocoeliidae commonly use terrestrial mollusks as the first intermediate host. Despite the abundant studies on the adult worms in birds and mammals, few reports exist on their larval stage in snail intermediate hosts. A present survey of mollusks in Japan led us to the discovery of dicrocoeliid sporocysts with cercariae in 16 out of 303 individuals, encompassing eight snail species and one slug species. A DNA barcoding based on sequencing of mitochondrial cytochrome c oxidase subunit 1 showed that the larvae consisted of five species. Phylogenetic trees of nuclear 18S and 28S ribosomal DNAs confirmed the five species to be members of the Dicrocoeliidae. These were temporarily termed dicrocoeliid spp. 1 to 5, since conclusive identification was impossible without adult worms. These unknown species were phylogenetically related to each other, except sp. 5. The phylogenetic trees demonstrated close genetic relationships between sp. 3 and the genus Lutztrema, and between sp. 5 and the genus Lyperosomum. The phylogenetic analysis also suggested that a division into the subfamilies Dicrocoeliinae and Leipertrematinae is a wrong classification due to the paraphyly of the Dicrocoeliinae. Morphological characterization of the cercariae and their DNA barcodes provide a primary platform for differentiating dicrocoeliids from various mollusks in Japan. The DNA barcodes, in particular, will enable tracing the parasite life cycles, in case of finding metacercariae and adults from presently unknown hosts.

The diversity and impact of hookworm infections in wildlife

Hookworms are blood-feeding nematodes that parasitize the alimentary system of mammals. Despite their high pathogenic potential, little is known about their diversity and impact in wildlife populations. We conducted a systematic review of the literature on hookworm infections of wildlife and analyzed 218 studies qualitative and quantitatively. At least 68 hookworm species have been described in 9 orders, 24 families, and 111 species of wild mammals. Black bears, red foxes, and bobcats harbored the highest diversity of hookworm species and Ancylostoma pluridentatum, A. tubaeforme, Uncinaria stenocephala and Necator americanus were the hookworm species with the highest host diversity index. Hookworm infections cause anemia, retarded growth, tissue damage, inflammation and significant mortality in several wildlife species. Anemia has been documented more commonly in canids, felids and otariids, and retarded growth only in otariids. Population- level mortality has been documented through controlled studies only in canines and eared seals although sporadic mortality has been noticed in felines, bears and elephants. The main driver of hookworm pathogenic effects was the hookworm biomass in a population, measured as prevalence, mean burden and hookworm size (length). Many studies recorded significant differences in prevalence and mean intensity among regions related to contrasts in local humidity, temperature, and host population density. These findings, plus the ability of hookworms to perpetuate in different host species, create a dynamic scenario where changes in climate and the domestic animal-human-wildlife interface will potentially affect the dynamics and consequences of hookworm infections in wildlife.

Multilocus phylogenetic analysis and morphological data reveal a new species composition of the genus Drepanocephalus Dietz, 1909 (Digenea: Echinostomatidae), parasites of fish-eating birds in the Americas

Members of the genus Drepanocephalus are endoparasites of fish-eating birds of the families Phalacrocoracidae and Sulidae distributed across the Americas. Currently, Drepanocephalus contains three species, i.e. D. spathans (type species), D. olivaceus and D. auritus. Two additional species, D. parvicephalus and D. mexicanus were transferred to the genus Petasiger. In the current study, available DNA sequences of D. spathans, D. auritus and Drepanocephalus sp., were aligned with newly generated sequences of D. spathans and Petasiger mexicanus. Phylogenetic analyses inferred with three nuclear (LSU, SSU and ITS1, 5.8S, ITS2) and two mitochondrial (cox1, nad1) molecular markers showed that the sequences of D. spathans and D. auritus are nested together in a single clade with very low genetic divergence, with Petasiger mexicanus as its sister species. Additionally, P. mexicanus was not a close relative of other members of the genus Petasiger, showing that P. mexicanus actually belongs to the genus Drepanocephalus, suggesting the need to re-allocate Petasiger mexicanus back into the genus Drepanocephalus, as D. mexicanus. Morphological observations of the newly sampled individuals of D. spathans showed that the position of the testes is variable and testes might be contiguous or widely separated, which is one of the main diagnostic traits for D. auritus. Our results suggest that D. auritus might be considered a synonym of D. spathans and, as a result, the latter represents a species with a wide geographic range across the Americas, parasitizing both the Neotropical and the double-crested cormorant in Argentina, Brazil, Paraguay, Venezuela, Colombia, Mexico, USA and Canada.

New Definitive Hosts and Differential Body Indices of Isthmiophora hortensis (Digenea: Echinostomatidae)

The present study was performed to record new definitive hosts of Isthmiophora hortensis, and to describe morphological characteristics derived from a variety of worm samples for clarification of its taxonomic validity. Morphological characteristics with dimensions were observed in worm samples (n=21) from naturally infected wild animals, including a raccoon dog Nyctereutes procyonoides from Gimhae-si (City), Gyeongsangnam-do, stray cats and a striped field mouse from several localities, and a wild boar Sus scrofa, from Gurye-gun (County), Jeollanam-do. In addition, adult flukes (n=45) recovered in albino rats experimentally infected with the metacercariae from a freshwater fish species were also subjected to morphological studies. The mean ratios of the body length (BL) to body width (BW) were 5.86 and 5.76 in worms from wild animals and experimental rats, respectively. Those of the ventral sucker to oral sucker were 2.92 and 3.01 in worms from 2 groups. The mean percentages of the hindbody length (HBL) to BL were 42.1 and 41.2 in 2 groups. Those of uterine fields to BL were 9.8 and 12.2 in the 2 worm groups. By the present study, the 2 species of wild animals, the raccoon dog and wild boar, have been added as new definitive hosts for I. hortensis. The morphological characteristics of adult flukes derived from a variety of host source were redescribed to support the taxonomic validity of this echinostome species.

Molecular and morphological characterization of Isthmiophora melis (Schrank, 1788) Luhe, 1909 (Digenea: Echinostomatidae) from American mink (Neovison vison) and European polecat (Mustela putorius) in Lithuania

The specimens collected from American mink (Neovison vison) and European polecat (Mustela putorius) in Lithuania were morphologically identified as Isthmiophora melis (Schrank, 1788) Lühe, 1909 and were molecularly characterized through sequencing of partial 18S rDNA, 28S rDNA, ITS1- 5.8S-ITS2 region, and ND1. Relations of I. melis to other species of the genus Isthmiophora Lühe 1909 were discussed. According to ITS1 and ND1 sequences the closest species to I. melis is Isthmiophora hortensis (Asada, 1926).

Molecular Description of Macroorchis spinulosus (Digenea: Nanophyetidae) Based on ITS1 Sequences

We performed a molecular genetic study on the sequences of 18S ribosomal RNA (ITS1 region) gene in 4-day-old adult worms of Macroorchis spinulosus recovered in mice experimentally infected with metacercariae from crayfish in Jeollanam-do Province, Korea. The metacercariae were round, 180 μm in average diameter, encysted with 2 layers of thick walls, but the stylet on the oral sucker was not clearly seen. The adult flukes were oval shape, and 760-820 μm long and 320-450 μm wide, with anterolateral location of 2 large testes. The phylogenetic tree based on ITS1 sequences of 6 M. spinulosus samples showed their distinguished position from other trematode species in GenBank. The most closely resembled group was Paragonimus spp. which also take crayfish or crabs as the second intermediate host. The present study is the first molecular characterization of M. spinulosus and provided a basis for further phylogenetic studies to compare with other trematode fauna in Korea.

Molecular phylogeny and systematics of the Echinostomatoidea Looss, 1899 (Platyhelminthes: Digenea)

The Echinostomatoidea is a large, cosmopolitan group of digeneans currently including nine families and 105 genera, the vast majority parasitic, as adults, in birds with relatively few taxa parasitising mammals, reptiles and, exceptionally, fish. Despite the complex structure, diverse content and substantial species richness of the group, almost no attempt has been made to elucidate its phylogenetic relationships at the suprageneric level based on molecules due to the lack of data. Herein, we evaluate the consistency of the present morphology-based classification system of the Echinostomatoidea with the phylogenetic relationships of its members based on partial sequences of the nuclear lsrRNA gene for a broad diversity of taxa (80 species, representing eight families and 40 genera), including representatives of five subfamilies of the Echinostomatidae, which currently exhibits the most complex taxonomic structure within the superfamily. This first comprehensive phylogeny for the Echinostomatoidea challenged the current systematic framework based on comparative morphology. A morphology-based evaluation of this new molecular framework resulted in a number of systematic and nomenclatural changes consistent with the phylogenetic estimates of the generic and suprageneric boundaries and a new phylogeny-based classification of the Echinostomatoidea. In the current systematic treatment: (i) the rank of two family level lineages, the former Himasthlinae and Echinochasminae, is elevated to full family status; (ii) Caballerotrema is distinguished at the family level; (iii) the content and diagnosis of the Echinostomatidae (sensu stricto) (s. str.) are revised to reflect its phylogeny, resulting in the abolition of the Nephrostominae and Chaunocephalinae as synonyms of the Echinostomatidae (s. str.); (iv) Artyfechinostomum, Cathaemasia, Rhopalias and Ribeiroia are re-allocated within the Echinostomatidae (s. str.), resulting in the abolition of the Cathaemasiidae, Rhopaliidae and Ribeiroiinae, which become synonyms of the Echinostomatidae (s. str.); and (v) refinements of the generic boundaries within the Echinostomatidae (s. str.), Psilostomidae and Fasciolidae are made.

Biomphalaria straminea (Mollusca: Planorbidae) as an intermediate host of Drepanocephalus spp. (Trematoda: Echinostomatidae) in Brazil: a morphological and molecular study

Species of trematodes belonging to the genus Drepanocephalus are intestinal parasites of piscivorous birds, primarily cormorants (Phalachrocorax spp.), and are widely reported in the Americas. During a 4-year malacological study conducted on an urban lake in Brazil, 27-collar-spined echinostome cercariae were found in 1665/15,459 (10.7 %) specimens of Biomphalaria straminea collected. The cercariae were identified as Drepanocephalus spp. by sequencing the 18S (SSU) rDNA, ITS1/5.8S rDNA/ITS2 (ITS), 28S (LSU) rDNA region, cytochrome oxidase subunit 1 (CO1), and nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) markers. In experimental life cycle studies, metacercariae developed in laboratory-reared guppies (Poecilia reticulata); however, attempts to infect birds and rodents were unsuccessful. Two closely related morphotypes of cercariae were characterized. One species, identified by molecular markers as a genetic variant of Drepanocephalus auritus (99.9 % similarity at SSU, ITS, LSU; 97.2 % at CO1; 95.8 % at ND1), differs slightly from an archived North American isolate of this species also sequenced as part of this study. A second species, putatively identified as Drepanocephalus sp., has smaller cercariae and demonstrates significant differences from D. auritus at the CO1 (11.0 %) and ND1 (13.6 %) markers. Aspects related to the morphological taxonomic identification of 27-collar-spined echinostome metacercariae are briefly discussed. This is the first report of the involvement of molluscs of the genus Biomphalaria in the transmission of Drepanocephalus and the first report of D. auritus in South America.

Redescription and phylogenetic relationships of Euparyphium capitaneum Dietz, 1909, the type-species of Euparyphium Dietz, 1909 (Digenea: Echinostomatidae)

Euparyphium capitaneum Dietz, 1909, the type-species of the genus Euparyphium Dietz, 1909, is described on the basis of material collected from the type-host Anhinga anhinga (L.) from Pascagoula River, which drains into the northern coast of the Gulf of Mexico. Combination of light and scanning electron microscopy observations of freshly collected and properly fixed specimens in our study has allowed us to provide novel information on the morphology and topology of the reproductive systems and other morphological features of the species. A Bayesian inference analysis based on the newly-obtained partial sequence of the nuclear 28S rRNA gene for E. capitaneum and 24 previously published sequences from the superfamily Echinostomatoidea Looss, 1899 provided evidence supporting the distinct status of the genera Euparyphium and Isthmiophora Lühe, 1909.

Case report: First confirmed case of canine peritoneal larval cestodiasis caused by Mesocestoides vogae (syn. M. corti) in Japan

Canine peritoneal larval cestodiasis (CPLC) is an unusual parasitic disease in dogs that is caused by asexual proliferation of larval Mesocestoides. A 12 year-old spayed Shetland sheepdog with abdominal distension was referred to the Animal Medical Center at Nihon University, Japan. The presence of ascites was confirmed by abdominal ultrasonography and X-ray imaging. In addition, a number of parasites were observed in the ascitic fluid collected by abdominal paracentesis. Each of the whitish colored parasites was less than 1mm in size. The parasites were morphologically identified as Mesocestoides sp. tetrathyridia. The parasites had four suckers and calcareous corpuscles, but no hooks or rostellum. Mitochondrial (mt) 12S rDNA and mt cytochrome c oxidase subunit 1 DNA amplified from the tetrathyridia were used for molecular identification to species level. DNA sequence analysis showed that the tetrathyridia shared more than 99% identity with M. vogae (syn. M. corti) for each gene. The patient was treated with a standard dose (5mg/kg) of praziquantel, which was administered subcutaneously twice at an interval of 14 days. This resulted in successful deworming. This is the first case that CPLC was diagnosed in a dog that had never been taken outside of Japan, indicating that M. vogae is distributed in this country.

Tetrathyridia of Mesocestoides lineatus in Chinese snakes and their adults recovered from experimental animals

Morphological characteristics of Mesocestoides lineatus tetrathyridia collected from Chinese snakes and their adults recovered from experimental animals were studied. The tetrathyridia were detected mainly in the mesentery of 2 snake species, Agkistrodon saxatilis (25%) and Elaphe schrenckii (20%). They were 1.73 by 1.02 mm in average size and had an invaginated scolex with 4 suckers. Adult tapeworms were recovered from 2 hamsters and 1 dog, which were orally infected with 5-10 larvae each. Adults from hamsters were about 32 cm long and those from a dog were about 58 cm long. The scolex was 0.56 mm in average width with 4 suckers of 0.17 by 0.15 mm in average size. Mature proglottids measured 0.29 by 0.91 mm (av.). Ovaries and vitellaria bilobed and located in the posterior portion of proglottids. The cirrus sac was oval-shaped and located median. Testes were follicular, distributed in both lateral fields of proglottids, and 41-52 in number per proglottid. Gravid proglottids were 1.84 by 1.39 mm (av.) with a characteristic paruterine organ. Eggs were 35 by 27 µm in average size with a hexacanth embryo. These morphological characteristics of adult worms were identical with those of M. lineatus reported previously. Therefore, it has been confirmed that the tetrathyridia detected in 2 species of Chinese snakes are the metacestodes of M. lineatus, and 2 snake species, A. saxatilis and E. schrenckii, play the role of intermediate hosts.

Clarifying Prehistoric Parasitism from a Complementary Morphological and Molecular Approach

This paper reports an approach to the identification of prehistoric parasitic infection, which integrates traditional morphological methods with molecular methods. The approach includes the strengths of each method while mitigating the limitations. Demonstrating the efficacy of this approach, we provide a case study from a 1,400 year old desiccated fecal sample from La Cueva de los Muertos Chiquitos, archaeological site, near Rio Zape, Durango, Mexico. Traditionally prepared microscope slides were processed via microscopy and tentative ascarids were identified. Information regarding the parasites' developmental stage was recorded. DNA was then extracted directly from the slide material. From this DNA extract, a small segment of the 18S ribosomal RNA gene variant that is specific to Ascaris, and its phylogenetically close relatives, was targeted for PCR amplification and sequencing. Phylogenetic analysis of the DNA sequence best matched a member of physalopterids, rather than ascarids, with a single exception of a match to Contracaecum spiculigerum. Subsequent extractions, amplifications and sequencing of the original rehydrated coprolite material confirmed these results. The C. spiculigerum sequence represented a phylogenetic anomaly and subsequent analysis determined the sequence was an error in the BLAST database, likely attributable to misidentification of juvenile specimens prior to sequencing and submission. Physaloptera are a difficult genus to identify morphologically and can carry major health burdens. They may be underreported in humans, in part, because of morphological similarities to the more common human parasites belonging to ascarids. We conclude that integrating traditional morphological methods with molecular methods can help resolve this issue, in both contemporary and prehistoric populations.

A molecular and ecological analysis of the trematodePlagiorchis elegansin the wood mouseApodemus sylvaticusfrom a periaquatic ecosystem in the UK

The prevalence of the digeneanPlagiorchissp. was investigated in a natural wood mouse population (Apodemus sylvaticus) in a periaquatic environment. Classical identification was complemented with the use of molecular differentiation to determine prevalence and verify species identity. Use of the complete ITS1-5.8S rDNA-ITS2 and partial 28S rDNA gene sequences have confirmed that the species reported at this location wasPlagiorchis elegansand notPlagiorchis murisas reported previously. This underlines the difficulties in identification of these morphologically similar parasites.Plagiorchis elegansis typically a gastrointestinal parasite of avian species but has also been reported from small mammal populations. Although the occurrence of this digenean inA. sylvaticusin the UK is rare, in the area immediately surrounding Malham Tarn, Yorkshire, it had a high prevalence (23%) and a mean worm burden of 26.6 ± 61.5. The distribution ofP. elegansfollowed a typically overdispersed pattern and both mouse age-group and sex were determined to be two main factors associated with prevalence. Male mice harboured the majority of worms, carrying 688 of 717 recovered during the study, and had a higher prevalence of 32.4% in comparison to only 8.7% in the small intestine of female mice. A higher prevalence of 43% was also observed in adult mice compared to 14% for young adults. No infection was observed in juvenile mice. These significant differences are likely to be due to differences in the foraging behaviour between the sexes and age cohorts of wood mice.

Ultrastructural characterization of male and female Physaloptera rara (Spirurida: Physalopteridae): feline stomach worms

Physaloptera rara (Spirurida: Physalopteridae) has been found in dogs, coyotes, raccoons, wolves, foxes, cats, and bobcats in North America. The parasites' developmental cycles involve insects, including beetles, cockroaches, and crickets, as intermediate hosts. The nematodes firmly attach to the wall of the stomach and duodenum, where they feed on the mucosa and suck blood. Frequent movement of these nematodes results in erosions and ulcers in the gastrointestinal tract. The present study reports the morphological features of adult P. rara using scanning electron microscopy. Adult worms were removed from the stomach of an infected domestic cat. Male and female worms measured 25-29 and 27-41 mm, respectively. The worms were stout and the cuticle was reflected over the lips to form a large cephalic collarette with fine transverse striations. The worms possessed two large, simple triangular lateral pseudolabia, each armed with one external tooth, three internal teeth, two submedian cephalic papillae, an amphid, and three porous-like circumscribed regions. The internal margins of the lips had a pair of cuticular folds. At the anterior end of both male and female worms, an excretory pore was located on the ventral side and a pair of lateral ciliated cervical papillae was seen. The vulva was anterior to the middle of the body of female worms. The tail ends of the female worms were stumpy, with two large phasmids near their extremities. The males' tails bore large lateral alae. Ventral ornamentation, in male worms, was composed of three different cuticular patterns; coblestone-like formations, longitudinal cuticular ridges, and rows of bead-like structures. The spicules were unequal and dissimilar; the right spicule had a thick end and the left spicule had a sharp tip. At the posterior end of the males, four pairs of stalked precloacal papillae, three pairs of postcloacal papillae, and two phasmids were present. Three and four sessile papillae were seen directly anterior and posterior to the cloaca, respectively. The middle papilla of the three sessile papillae, directly anterior to cloaca was different in shape and size.

Molecular detection of spotted fever group rickettsia in feral raccoons (Procyon lotor) in the western part of Japan

Rickettsial infection in feral raccoons (Procyon lotor) in the western part of Japan (Shimane, Fukuoka, Saga and Nagasaki Prefectures) was surveyed by a nested polymerase chain reaction (PCR) assay detecting the rickettsial citrate synthase (gltA) gene. Four of one hundred and ninety-four feral raccoon spleens (2.1%) were positive for Rickettsia spp. One gltA gene sequence was identical to R. helvetica, whereas the other 3 sequences were identical and had the highest similarity (98.4%) to R. amblyommii. Simultaneously, we determined a partial sequence of the rickettsial 17-kilodalton (17K) genus-common antigen gene in the later 3 raccoon samples. Their sequences were identical and had the highest similarity (98.5%) to Rickettsia sp. Hj126. Based on the sequences of gltA and 17K antigen genes, these raccoons might be infected with spotted fever group (SFG) rickettsia most closely related to R. amblyommii and/or Rickettsia sp. Hj126. Feral raccoons may be a susceptible reservoir for SFG rickettsiae in Japan.

Difference in age at first conception between early and late litters of feral raccoon (Procyon lotor) in Kanagawa prefecture

Due to the long parturition period of raccoons, we assumed that age at first conception of late born females was later than that of early born females. From March 2005 to September 2008, 201 females estimated to be younger than 24 months were separated into early- and late-born groups on the basis of their estimated birth month (to the nearest 2 months), and parous status and body mass index (BMI) were examined. Age at first conception of late-born females (over 18 months old) was estimated to be later than that of early-born females (over 12 months old). The average BMI in early-born individuals at 12 months old might have affected their ability to conceive because of body fat deposition.

Epizootic canine distemper virus infection among wild mammals

In the spring of 2007, seven raccoon dogs and a weasel were captured near the city of Tanabe in Wakayama prefecture, Japan. The causative agent of the animals' death 1-2 days after capture was identified as canine distemper virus (CDV) by virus isolation, immunostaining with an anti-CDV polyclonal antibody, and a commercially available CDV antigen-detection kit. Sequence analysis of hemagglutinin genes indicated the isolated viruses belong to genotype Asia-1 and possess the substitution from tyrosine (Y) to histidine (H) at position 549 that is associated with the spread of CDV to non-canine hosts. A serosurvey for CDV was then conducted among wild animals in the region. The animals assayed consisted of 104 raccoons, 41 wild boars, 19 raccoon dogs, five Sika deer, two badgers, one weasel, one marten, one Siberian weasel and one fox. Virus-neutralization (VN) tests showed that, except for fox and weasel, all of the species assayed had VN antibodies to CDV. Interestingly, 11 of the 41 wild boars (27%) and two of the five Sika deer assayed possessed VN antibodies to CDV. These findings indicate that CDV infection was widespread among wild mammals during this epizootic.

Normal and aberrant Mesocestoides tetrathyridia from Crocidura spp. (Soricimorpha) in Corsica and Spain

Tetrathyridia of Mesocestoides sp. were collected from the body cavities of the shrews (Insectivora), Crocidura russula, in Valencia, Spain and Crocidura suaveolens on the Mediterranean island of Corsica, France. Specimens were processed by routine microscopic and histological techniques, including examination with brightfield, phase-contrast, and differential-interference-contrast optics. Most tetrathyridia were clustered together inside host-derived fibrotic capsules, but some occurred free in the body cavity. All specimens examined from both locations had solid hindbodies, i.e., lacking a primary lacuna, thus conforming to the plerocercoid metacestode type; all possessed a single normal tetra-acetabulate scolex. All metacestodes from C. russula in Valencia were normal tetrathyridia. Those from C. suaveolens in Corsica were either normal tetrathyridia or had aberrant deep convolutions of an unusually elongated hindbody. No tetrathyridium from either location or host showed tegumental or excretory duct anomalies such as those reported by several authors from aberrant tetrathyridia and spargana in some other locations. No definitive evidence of asexual proliferation was visible in any of the tetrathyridia, but those with abnormally convoluted hindbodies from a single C. suaveolens in Corsica suggest the potential for asexuality by fission of the hindbody. These results add to our understanding of morphological and developmental variation among metacestodes in this widespread and variable genus.

Prevalence of Salmonella, Yersinia and Campylobacter spp. in feral raccoons (Procyon lotor) and masked palm civets (Paguma larvata) in Japan

To estimate the public and animal health risk that alien species pose, the prevalence of Salmonella, Yersinia, and Campylobacter spp. in feral raccoons (Procyon lotor, n = 459) and masked palm civets (Paguma larvata, n = 153), which are abundant alien species in Japan, was investigated in urban and suburban areas of Japan. Salmonella enterica was detected from 29 samples [26 raccoons, 5.7%, 95% confidence interval (CI) 7.8–3.5%; three masked palm civets, 2.0%, 95% CI 4.2–0%]. Many of the isolates belonged to serovars that are commonly isolated from human gastroenteritis patients (e.g. S. Infantis, S. Typhimurium, and S. Thompson). The antimicrobial susceptibility test showed that 26.9 % of the isolates from raccoons were resistant to at least one antimicrobial agent, whereas none of the isolates from masked palm civets were resistant. Yersinia sp. was detected from 193 samples (177 raccoons, 38.6%, 95% CI 43.0–34.1%; 16 masked palm civets, 10.5%, 95% CI 15.3–5.6%). All virulent Yersinia strains belonged to Yersinia pseudotuberculosis, which was isolated from seven (1.5%, 95% CI 2.6–0.4%) raccoons and six (3.9%, 95% CI 7.0–0.8%) masked palm civets. According to the detection of virulence factors, all the Y. pseudotuberculosis isolates belonged to the Far Eastern systemic pathogenicity type. Campylobacter spp. was detected from 17 samples (six raccoons, 1.3%, 95% CI 2.3–0.3%; 11 masked palm civets, 7.2%, 95% CI 11.3–3.1%). Among these, three isolates from raccoons were identified as C. jejuni. These results showed that these pathogens can be transmitted by human activities, other wild animals, and the environment to feral raccoons and masked palm civets, and vice versa. As these animals have omnivorous behaviour and a wide range of habitats, they can play an important role in the transmission of the enteric pathogens.

Visceral helminths of wild boars (Sus scrofa leucomystax) in Japan, with special reference to a new species of the genus Morgascaridia Inglis, (Nematoda: Schneidernematidae)

Twenty-nine Japanese wild boars (Sus scrofa leucomystax), collected during the hunting seasons of 2005 and 2006 in the western part of the mainland of Japan (Honshu), were examined for their visceral helminths. Eighteen helminth parasites were prevalent in them, including 17 Nematoda species (Metastrongylus elongatus, Metastrongylus salmi, Metastrongylus asymmetricus, Metastrongylus pudendotechus, Stephanurus dentatus, Gnathostoma doloresi, Physocephalus sexulata, Ascarops strongylina, Capillaria suis, Ascaris suum, Globocephalus samoensis, Globocephalus longimucronatus, Strongyloides ransomi, Trichuris suis, Bourgelatia diducta, Oesophagostomum dentatum, and Oesophagostomum watanabei), and one Cestoda species (Pseudanoplocephala nipponensis). Muscle digestion of the diaphragm (using an artificial gastric juice) of 24 wild boars detected a single diplostomulum of probably Pharyngostomum cordatum. In addition, four female and six male adults of Morgascaridia kugii sp. n. (Nematoda: Schneidernematidae) were recovered from the large intestine of a single wild boar. Examination of an additional 20 samples of the stomach and 27 samples of the large intestine could not find this species. To date, recorded species of the genus Morgascaridia are limited to M. sellsi collected from wild boars in Uganda and Congo several decades ago, and thence, no records of the recovery are available. Morgascaridia kugii sp. n. differed from M. sellsi by smaller body dimensions, shorter distance between the precloacal sucker and the cloaca, smaller sizes of the copulatory spicules and the gubernaculum, and smaller sizes of uterine eggs.

Serological survey of Ehrlichia and Anaplasma infection of feral raccoons (Procyon lotor) in Kanagawa Prefecture, Japan

Numbers of feral raccoon; the possible reservoir animal of Ehrlichia and Anaplasma, are increasing in Japan. Thus serological methods were utilized to examine Ehrlichia and Anaplasma infection in raccoons from Kanagawa Prefecture, Japan. By using an indirect immunofluorescence assay, among 187 feral raccoons examined, 1 (0.5%) serologically reacted with Ehrlichia canis, 3 (1.6%) with Ehrlichia chaffeensis and 1 (0.5%) with Anaplasma phagocytophilum with the titers of 1:40 or more. Although screening PCR for Ehrlichia and Anaplasma species failed to detect the presence of ehrlichial DNA in serum samples, results of the serological tests suggested that the feral raccoons might be infected with some species of Ehrlichia and Anaplasma.

Epidemiology, histopathology, and muscle distribution of Trichinella T9 in feral raccoons (Procyon lotor) and wildlife of Japan

The prevalences of Trichinella T9 in trapped raccoons (Procyon lotor) and several other potential mammalian reservoirs in Hokkaido, Wakayama, and Nagasaki Prefectures were investigated. Muscle samples were collected from 2003 to 2006 from 1,080 raccoons, 113 raccoon dogs including 2 species (Nyctereutes procyonoides albus and N. p. viverrinus), 41 wild boars (Sus scrofa leucomystax), 14 martens (Martes melampus), 10 badgers (Meles meles), 5 Siberian weasels (Martes sibirica coreana), 7 mink (Mustela vison), and 1 red fox (Vulpes vulpes japonica). The samples were digested, and the prevalence and mean intensity of infection with the Trichinella muscle larvae were determined. The prevalence and intensity of the muscle larvae were 0.9% and 93.3 larvae/g (range 0.4-201.8) in raccoons, and 1.6% and 61.6 larvae/g in raccoon dogs, respectively. The infected animals were captured in different areas in Hokkaido Prefecture. These results confirmed that raccoons, which have been introduced from North America since the 1970s, are involved in the sylvatic cycle of Trichinella in Japan. In raccoons, the muscle density of Trichinella T9 larvae was highest in the tongue, and larvae were not found in the heart muscle or diaphragm. This is the first report of Trichinella T9 infection of feral raccoons in Japan.

Nematodes from Raccoon Dogs (Nyctereutes procyonoides viverrinus) Introduced Recently on Yakushima Island, Japan

Nematodes were collected from 14 raccoon dogs (Nyctereutes procyonoides viverrinus) on Yakushima Island, Kagoshima Prefecture (Kyushu), Japan, that were the progeny of recently introduced animals to this World Natural Heritage Area, probably within the last 2 decades. Seven nematode species (Toxocara tanuki, Ancylostoma kusimaense, Arthrostoma miyazakiense, Strongyloides planiceps, Trichuris vulpis, Gongylonema sp., and Dirofilaria immitis) were collected from the raccoon dogs. Two nematode species (Molineus legerae and Strongyloides martis) were collected from 2 Japanese weasels (Mustela itatsi) indigenous to this island that were killed by traffic accidents. Considering that foxes and other carnivores, except for weasels, dogs and cats, are not distributed on this island, most of soil-borne nematodes such as roundworms, hookworms, and threadworms in raccoon dogs should have been introduced by the original population from the mainland Japan, and the infection hence maintained at a high level by new generations. Recovery of the third-stage larvae of Gongylonema sp. from the esophagus of raccoon dogs was remarkably frequent (79%), suggesting that the animals might vigorously take insect hosts. Although S. martis have never been recorded from weasels in Japan until this study, this threadworm might be prevalent in a variety of mustelids in Eurasia.