Pharyngostomum Cordatum Research Articles

A relatively high zoonotic trematode prevalence in Orientogalba ollula and the developmental characteristics of isolated trematodes by experimental infection in the animal model

BackgroundFood-borne parasitic diseases decrease food safety and threaten public health. The snail species is an intermediate host for numerous human parasitic trematodes. Orientogalba ollula has been reported as intermediate hosts of many zoonotic trematodes. Here, we investigated the prevalence of zoonotic trematodes within O. ollula in Guangxi, China, and assessed their zoonotic potential.MethodsSnails were collected from 54 sites in 9 cities throughout Guangxi. The snail and trematode larvae species were determined by combining morphological characteristics and molecular markers. The trematodes prevalence and constituent ratio were calculated and compared among different habitat environments. Phylogenetic trees of the trematode species were constructed using the neighbor-joining method with nuclear internal transcribed spacer 2 (ITS2) sequences. The developmental cycles of the isolated trematodes were examined by experimental infection in ducks. The developmental characteristics of Echinostoma revolutum was recorded by dissecting infected ducklings from 1-day post infection (dpi) to 10 dpi.ResultsThe overall prevalence of trematode larvae was 22.1% (1818/8238) in O. ollula from 11 sample sites. Morphological together with molecular identification, showed that E. revolutum, Australapatemon sp., Hypoderaeum conoideum, Pharyngostomum cordatum, and Echinostoma sp. parasitized O. ollula, with the highest infection rate of E. revolutum (13.0%). However, no Fasciola larvae were detected. The trematodes prevalence and constituent ratio varied in two sub-biotypes (P < 0.01). A neighbor-joining tree analysis of ITS2 sequences resulted in distinct monophyletic clades supported by sequences from isolated larvae with high bootstrap values. Ducklings exposed to O. ollula infected with Echinostoma sp., E. revolutum, and H. conoideum larvae were successfully infected. The animal model for Echinostoma revolutum was successfully established. E. revolutum matured from larvae to adult at 10 dpi in the intestine of the duck, and the developmental characteristics of E. revolutum were characterized by the maturation of the reproductive and digestive organs at 6–8 dpi.ConclusionsThis study revealed a high prevalence of zoonotic trematodes in O. ollula from Guangxi, China. Existing trematodes infection in animals and human clinical cases, coupled with the wide geographical distribution of O. ollula, necessitate further evaluations of the potential risk of spillover of zoonotic infection from animal to human and vice versa.Graphical

An Overview of the Helminths of Moor Frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) in the Volga Basin

This is the first review of the helminth fauna of the moor frog Rana arvalis Nilsson, 1842 from the Volga river basin (Russia). The article summarizes the authors’ and literature data on the helminthic fauna of this species. The method of complete helminthological dissection was used. Thirthy-eight helminth species were recorded from three classes: Cestoda (1), Trematoda (28), and Chromadorea (9). Nine helminth species are new to the moor frog in Russia: trematodes Gorgodera varsoviensis Sinitzin, 1905, Strigea falconis Szidat, 1928, larvae, Neodiplostomum spathoides Dubois, 1937, larvae, Tylodelphys excavata (Rudolphi, 1803), larvae, Pharyngostomum cordatum (Diesing, 1850), larvae, Astiotrema monticelli Stossich, 1904, larvae and Encyclometra colubrimurorum (Rudolphi, 1819), larvae, nematodes Strongyloides spiralis Grabda-Kazubska, 1978 and Icosiella neglecta (Diesing, 1851). The cestode Spirometra erinacei (Rudolphi, 1918), larvae were observed of this amphibian species in the Volga basin for the first time. The nematodes Rhabdias bufonis, Oswaldocruzia filiformis, Cosmocerca ornata and the trematode Haplometra cylindracea form the core of the helminth fauna of the moor frog. Information on species of helminths includes systematic position, localization, areas of detection, type and scheme of life cycle, geographical distribution, and degree of specificity to host amphibians.

Short communication: An overview of the trematodes fauna of pool frog Pelophylax lessonae (Camerano, 1882) in the Volga Basin, Russia: 2. Larval stages

Abstract. Chikhlyaev IV, Ruchin AB, Fayzulin AI. 2019. Short communication: An overview of the trematodes fauna of the pool frog Pelophylax lessonae (Camerano, 1882) in the Volga Basin, Russia: 2. Larval stages. Nusantara Bioscience 11: 106-111. This paper presents data on the trematodes fauna of the pool frog Pelophylax lessonae (Camerano, 1882) from 13 regions of the Volga Basin. It consolidates data from different authors over the past 30 years, supplemented by our own research results. There are authentically known findings of 10 trematodes species at the larval stage of development. The species Codonocephalus urniger (Rudolphi, 1819), mtc., Neodiplostomum spathoides Dubois, 1937, mtc. and Pharyngostomum cordatum (Diesing, 1850), mtc. have been observed for the first time in the given host on the territory of Russia and Volga basin. For each species of trematodes, there is the following information is included: taxonomic position, localization, area of detection, biology, definitive hosts, geographic distribution and degree of host-specificity.

埼玉県内のイヌおよびネコにおける腸管寄生虫類の保有状況

We studied the prevalence of intestinal parasites in animal companions in Saitama Prefecture, Japan, where no detailed data is currently available. Between May 1999 and December 2007, fecal samples were collected from 906 dogs and 1,079 cats in public animal shelters and examined by microscopy. Overall, prevalence of intestinal parasites in dogs was 38.6% and cats 43.1%. Trichuris vulpis was the most prevalent canine parasite species (22.3%), followed by Toxocara canis (12.5%), Ancylostoma caninum (10.4%), Isospora ohioensis (2.1%), Spirometra erinaceieuropaei (1.0%), Crypstosporidium sp. (0.9%), Giardia intestinalis (0.9%), I. canis (0.6%), Taeniidae (0.3%), Dipylidium caninum (0.2%), Echinostoma sp. (0.1%), and Pentatrichomonas hominis (0.1%). T. cati was the most prevalent feline parasite species (21.8%), followed by A. tubaeforme (13.2%), S. erinaceieuropaei (8.3%), I. felis (4.5%), Cryptosporidium sp. (2.8%), I. rivolta (2.2%), Pharyngostomum cordatum (1.6%), D. caninum (1.4%), Eimeria sp. (0.3%), Taeniidae (0.2%), Trichuris sp. (0.2%), Capillaria sp. (0.1%), Diphyllobothrium nihonkaiense (0.1%), and Metagonimus yokogawai (0.1%). Further molecular analysis to identify canine Taeniidae species and canine and feline Cryptosporidium species identified one canine taeniid positive species as Echinococcus multilocularis. Cryptosporidium species were identified as C. canis and C. felis. Parasites E. multilocularis and Cryptosporidium spp. in animal hosts were the first to be recorded in this prefecture. Compared to previous surveys conducted in the same area, the endemicity of some parasites appeared to have decreased, but some others remain. Given that most of these parasites have zoonotic potential, indicates the importance of having current data on parasite dissemination among animal companions. Government public health agencies should be responsible for educating pet owners about the control and prevention of zoonotic risk from such parasites.

A New Neodiplostomid (Digenea) From the Intestine of Chicks Infected with Metacercariae From the Grass Snake, Rhabdophis tigrina

Three species of neodiplostomula are known to inhabit the European grass snake, Rhabdophis tigrina, in the Republic of Korea: Pharyngostomum cordatum (large-sized neodiplostomula), an intestinal trematode of cats; Neodiplostomum seoulense (small-sized neodiplostomula), an intestinal trematode of humans and rodents; and Neodiplostomum leei (small-sized neodiplostomula), which migrates to the livers of rodents and is an intestinal trematode of birds. The present study describes a fourth species, Neodiplostomum (Conodiplostomum) boryongense n. sp. (Digenea: Neodiplostomidae), based on adult flukes recovered from the small intestines of chicks experimentally infected with small-sized neodiplostomula from the grass snake. The new species differs from 13 previously known species. It also differs from N. seoulense in its larger body size, severely bilobed testes, and smaller genital atrium, and from N. leei in its larger body size, smaller ventral sucker, presence of a genital cone, and vitelline follicles distributed chiefly in the forebody. The new species does not migrate to the livers of rodents nor does it develop to adulthood in the rodent intestines. However, the neodiplostomula of the new species are indistinguishable from those of the other 2 species. Results show that at least 4 species of neodiplostomula inhabit the grass snake in the Republic of Korea.

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.

Infection status with helminthes in feral cats purchased from a market in Busan, Republic of Korea

The present study was performed to investigate the infection status with helminth in a group of feral cats in Korea. More than 29 helminth species including adults or eggs were detected in visceral and fecal samples of the examined cats. Among these were a host of nematodes, including toxocarids, Ancylostoma sp. and the larva of Anisakis simplex; trematodes, including Clonorchis sinensis, Paragonimus westermani, Eurytrema pancreaticum, Pharyngostomum cordatum, Metagonimus spp., Heterophyes nocens, Pygidiopsis summa, Heterophyopsis continua, Stictodora fuscata, Stictodora lari, Acanthotrema felis, Stellantchasmus falcatus, Centrocestus armatus, Procerovum varium, Cryptocotyle sp., Echinostoma revolutum, Echinostoma hortense, Echinochasmus japonicus, Stephanoprora sp., Plagiorchis muris, Neodiplostomum sp. and diplostomulum. We also detected a variety of cestodes, including Spirometra erinacei, Taenia taeniaeformis and unidentified species of tapeworm. We also found examples of the acanthocephalan, Bolbosoma sp. In our assessment of the stools, we detected at least 12 species of helminth eggs. These findings confirmed that feral cats in Korea are infected with a variety of helminth parasite species. Furthermore, among the helminths detected, E. pancreaticum, S. fuscata, S. lari, A. felis, S. falcatus, C. armatus, P. varium, Cryptocotyle sp., E. revolutum, E. japonicus, Stephanoprora sp., P. muris, Neodiplostomum sp. and Bolbosoma sp. represent helminth fauna which have not been reported previously in feral cats in the Republic of Korea.

Neodiplostomum leei n. sp. (Digenea: Neodiplostomidae) from chicks infected with metacercariae from the grass snake Rhabdophis tigrina.

Neodiplostomula from the European grass snake Rhabdophis tigrina, in the Republic of Korea, were thought to represent 2 species: Pharyngostomum cordatum (large-sized neodiplostomula), an intestinal trematode of cats, and Neodiplostomum seoulense (small-sized neodiplostomula), an intestinal trematode of humans and rodents. The present study describes N. leei n. sp. (Digenea: Neodiplostomidae) on the basis of adult flukes recovered from the small intestines of chicks experimentally infected with small-sized neodiplostomula from the grass snake. The new species differs from N. seoulense in terms of the more extensive distribution of vitellaria, the more severe bilobation of 2 testes (each having a dumbbell shape), the absence of a genital cone, and the smaller size of the tribocytic organ and eggs. Neodiplostomula of the new species and N. seoulense are almost indistinguishable. The new species develops into an adult in chicks, whereas N. seoulense matures in mice and rats. Neodiplostomula of the new species migrate to the liver in mice and rats, without maturing. Results show that there are at least 3 species of neodiplostomid trematodes in the grass snake in the Republic of Korea, i.e.. P. cordatum, N. seoulense and N. leei n. sp.

Helminth survey of wildcats in Japan.

Two Iriomote cats (Felis iriomotensis) and 2 Tsushima leopard cats (Felis bengalensis euptilura) killed probably by traffic accidents were submitted to the helminthological examination. In Iriomote cats, 8 species of parasites (Spirometra erinacei, Toxocara cati, Molineus springsmithi, Uncinaria maya, Capillaria aerophila, C. felis-cati, larvae of an unidentifiable lung worm and one species of Acanthocephala) were found. In Tsushima leopard cats, 10 species of parasites (Pharyngostomum cordatum, Spirometra erinacei, Toxocara cati, Molineus springsmithi, Arthrostoma hunanensis, Uncinaria felidis, Capillaria felis-cati, larvae of an unidentifiable lung worm, and two species of Acanthocephala) were detected.

Intestinal parasites of cats purchased in Seoul.

Fecal samples of cats purchased in Seoul were examined for helminth ova or protozoan oocysts from December 1987 to March 1988. Out of the 41 samples, 31 (75.6%) were positive and 60 (146.3%) were cumulative positive for parasites. The followings were identified in the samples: Eggs of Toxocara cati, Clonorchis sinensis, Metagonimus sp., Pharyngostomum cordatum, Spirometra erinacei, Taenia taeniaeformis and oocysts of Isospora sp. From nine autopsied cats, larvae of Anisakis simplex, adults of C. sinensis, M. yokogawai, P. cordatum, S. erinacei and T. taeniaeformis were identified. This is the first report on the detection of Anisakis larvae from cats in Korea. The possible role of cats as a source of human infection with each parasite was discussed.

Helminths of the Tsushima Leopard Cat (Felis bengalensis euptilura)

Three Tsushima leopard cats (Felis bengalensis euptilura) in Japan were collected as road kills. Three species of trematodes (Pharyngostomum cordatum, Paragonimus sp. and Dicrocoeliidae gn. sp.), one species of cestode (Spirometra erinacei) and nine species of nematodes (Arthrostoma hunanensis, Uncinaria felidis, Uncinaria sp., Ancylostoma tubaeforme, Molineus springsmithi, Toxocara cati, Capillaria aerophila, Capillaria felis-cati, and Capillaria sp.) were found. Among these helminths, Arthrostoma hunanensis, Uncinaria spp., and Molineus springsmithi have not been reported previously in Japanese domestic cats.

ニホンザルに対する壺形吸虫の感染試験

ニホンザルに対する壺形吸虫の感染試験

Metacercariae of Pharyngostomum cordatum found from the European grass snake, Rhabdophis tigrina, and its experimental infection to cats

The metacercariae of Pharyngostomum cordatum were found naturally infected in the European grass snake, Rhabdophis tigrina, purchased from a local snake collector in Jinju, Kyongsangnam-do. They were experimentally fed to several kinds of animals such as mice, rats, hamsters, ducklings, a dog, and cats. The adult worms were recovered from the cats 5 weeks after the infection, but none from other animals. The measurements and other morphological characters of the metacercariae and adults were both compatible with those of P. cordatum described by previous authors. The present study confirmed that the snake, Rhabdophis tigrina, serves as a second intermediate (or paratenic) host of P. cordatum in Korea.

Fecundity of Pharyngostomum cordatum parasitic in domestic cats.

Pharyngostomum cordatum [PC] was investigated on the relation in number between the eggs detected by fecal examination and the flukes parasitic in the small intestine of four cats. Stoll's and the MGL methods were examined on the detecting ability of the eggs in the feces. The number of eggs per day per worm (EPDPW) was calculated at about 1, 000. Based on this egg count, the average detectable number of eggs was calculated at 19.1 on average (from 6.5 to 34.4) in cats parasitized by one fluke by MGL method with 0.5g of feces. From the results, the MGL method was confirmed to be highly reliable on diagnosing Pharyngostomum cordatum infections, even with a single worm.

愛知県における壷形吸虫メタセルカリアの分布と人工感染猫における病理組織学的所見

Five species of amphibians, Rana nigromaculata, R.catesbeiana, R.rugosa, Hyla arborea japonica, and Triturus pyrrhogaster pyrrhogaster, and reptilian species, Rhabdophis tigrinus tigrinus, were collected from Toyohashi, Aichi Prefecture, from June to September, 1979, and examined for parasites.Metacercariae were found in the mesentery and intramuscular connective tissue, and identified as Pharyngostomum cordatum by morphological examination of adult flukes obtained from cats experimentally infected with those metacercariae.In these cats, the epithelium was lost from the sites of the intestine harboring the flukes.