Diphyllobothrium mansonoides

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Diphyllobothrium mansonoides
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Cestoda
Order: Diphyllobothriidea
Family: Diphyllobothriidae
Genus: Diphyllobothrium
Species:
D. mansonoides
Binomial name
Diphyllobothrium mansonoides
Mueller, 1935

Diphyllobothrium mansonoides (also known as Spirometra mansonoides) is a species of tapeworm (cestodes) that is endemic to North America. Infection with D. mansonoides in humans can result in sparganosis. Justus F. Mueller first reported this organism in 1935. D. mansonoides is similar to D. latum and Spirometra erinacei. When the organism was discovered, scientist did not know if D. mansonoides and S. erinacei were separate species. PCR analysis of the two worms has shown the two to be separate but closely related organisms. [1]

Contents

General Characteristics

Cestodes have a dorso-ventrally flattened shape. Cestodes are segmented worms, and their bodies are divided into three distinct regions: the scolex, the neck, and the strobila.

The scolex is the head of the cestode, and it functions as a holdfast organ that is specialized to attach to intestines using a variety of mechanisms.

Posterior to the scolex is the neck, which is an unsegmented, poorly differentiated region. The neck is where asexual reproduction of proglottid segments occurs. Proglottid segments are individual sets of reproductive organs that compose the rest of the cestode body.

The most posterior section of the cestode body consists of multiple strobila, each being made up of several proglottids. There are 3 stages that proglottids go through in their maturation. The first proglottid stage is the immature stage, characterized by functional reproductive organs. The immature stage is the most anterior proglottid, and consists of anywhere between 200 and 300 proglottids. The mature proglottid is located medially to the other proglottids, and is reproductively functional and hermaphroditic. The most posterior proglottid is the gravid stage, and it is packed with eggs. These eggs are eventually released from the gravid proglottid either through a pore in the proglottid or by disintegration of the proglottid.

Cestodes also have sensory organs in the scolex that detect tactile stimulation. The sensory organs are attached to longitudinal nerves that run along the body and are attached to organs.

Distribution

D. mansonoides is typically found in the southern US. It is especially common in Florida and along the Gulf Coast. D. mansonoides is found in freshwater. The eggs, coracidia and copepods (1st intermediate hosts) inhabit freshwater. The plerocercoids are found in the muscles of hosts. The adult stage is found in various organs (CNS, eye, muscles, etc.) of the definitive host (cat, dog, birds, and other mammals).

Digestion/Metabolism

Cestodes have no digestive tract, and instead, they absorb nutrients along their tegument, which contains microvilli and glycocalyxes. The microvilli are used to absorb nutrients. The glycocalyx is a fuzzy coat that absorbs host enzymes and inhibits host proteases.

Life cycle

[2]

Disease and Treatment

Infection with Diphyllobothrium mansonoides results in sparganosis. Sparganosis is the development of plerocercoids in tissues. There are several routes of human infection:

  • When a human mistakenly eats or drinks the procercoid-containing copepod, becoming the 2nd intermediate host.
  • When a human ingests the plerocercoid-containing 2nd intermediate host (frog or snake). The human then becomes the paratenic host.
  • When a human uses the 2nd intermediate host as a poultice on the skin, vagina, or eyes.

A biopsy of the infected area is conducted to identify the pathogen. Surgical removal of the tapeworm is usually the best method. However, drugs like praziquantel can be administered to treat the infection.

A study was conducted on free-range Florida panthers on the effectiveness of anthelmintic treatment. In the study, the intensity of infection of S. mansonoides increased 6 months after treatment instead of decreasing. [3]

Related Research Articles

<i>Diphyllobothrium</i> Genus of flatworms

Diphyllobothrium is a genus of tapeworms which can cause diphyllobothriasis in humans through consumption of raw or undercooked fish. The principal species causing diphyllobothriasis is D. latum, known as the broad or fish tapeworm, or broad fish tapeworm. D. latum is a pseudophyllid cestode that infects fish and mammals. D. latum is native to Scandinavia, western Russia, and the Baltics, though it is now also present in North America, especially the Pacific Northwest. In Far East Russia, D. klebanovskii, having Pacific salmon as its second intermediate host, was identified.

Hymenolepiasis is infestation by one of two species of tapeworm: Hymenolepis nana or H. diminuta. Alternative names are dwarf tapeworm infection and rat tapeworm infection. The disease is a type of helminthiasis which is classified as a neglected tropical disease.

<i>Taenia solium</i> Species of Cestoda

Taenia solium, the pork tapeworm, belongs to the cyclophyllid cestode family Taeniidae. It is found throughout the world and is most common in countries where pork is eaten. It is a tapeworm that uses humans as its definitive host and pigs as the intermediate or secondary hosts. It is transmitted to pigs through human feces that contain the parasite eggs and contaminate their fodder. Pigs ingest the eggs, which develop into larvae, then into oncospheres, and ultimately into infective tapeworm cysts, called cysticercus. Humans acquire the cysts through consumption of uncooked or under-cooked pork and the cysts grow into adult worms in the small intestine.

Spirometra is a genus of pseudophyllid cestodes that reproduce in canines and felines, but can also cause pathology in humans if infected. As an adult, this tapeworm lives in the small intestine of its definitive host and produces eggs that pass with the animal's feces. When the eggs reach water, the eggs hatch into coracidia which are eaten by copepods. The copepods are eaten by a second intermediate host to continue the life cycle. Humans can become infected if they accidentally eat frog legs or fish with the plerocercoid stage encysted in the muscle. In humans, an infection of Spirometra is termed sparganosis.

<i>Taenia</i> (flatworm) Genus of flatworms

Taenia is the type genus of the Taeniidae family of tapeworms. It includes some important parasites of livestock. Members of the genus are responsible for taeniasis and cysticercosis in humans, which are types of helminthiasis belonging to the group of neglected tropical diseases. More than 100 species are recorded. They are morphologically characterized by a ribbon-like body composed of a series of segments called proglottids; hence the name Taenia. The anterior end of the body is the scolex. Some members of the genus Taenia have an armed scolex ; of the two major human parasites, Taenia saginata has an unarmed scolex, while Taenia solium has an armed scolex.

<i>Dipylidium caninum</i> Species of flatworm

Dipylidium caninum, also called the flea tapeworm, double-pored tapeworm, or cucumber tapeworm is a cyclophyllid cestode that infects organisms afflicted with fleas and canine chewing lice, including dogs, cats, and sometimes human pet-owners, especially children.

<i>Hymenolepis nana</i> Species of flatworm

Dwarf tapeworm is a cosmopolitan species though most common in temperate zones, and is one of the most common cestodes infecting humans, especially children.

<i>Taenia pisiformis</i> Species of flatworm

Taenia pisiformis, commonly called the rabbit tapeworm, is an endoparasitic tapeworm which causes infection in lagomorphs, rodents, and carnivores. Adult T. pisiformis typically occur within the small intestines of the definitive hosts, the carnivores. Lagomorphs, the intermediate hosts, are infected by fecal contamination of grasses and other food sources by the definitive hosts. The larval stage is often referred to as Cysticercus pisiformis and is found on the livers and peritoneal cavities of the intermediate hosts. T. pisiformis can be found worldwide.

<span class="mw-page-title-main">Eucestoda</span> Subclass of flatworms

Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda. Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cestodaria. All tapeworms are endoparasites of vertebrates, living in the digestive tract or related ducts. Examples are the pork tapeworm with a human definitive host, and pigs as the secondary host, and Moniezia expansa, the definitive hosts of which are ruminants.

Spirometra erinaceieuropaei is a parasitic tapeworm that infects domestic animals and humans. The medical term for this infection in humans and other animals is sparganosis. Morphologically, these worms are similar to other worms in the genus Spirometra. They have a long body consisting of three sections: the scolex, the neck, and the strobilia. They have a complex life cycle that consists of three hosts, and can live in varying environments and bodily tissues. Humans can contract this parasite in three main ways. Historically, humans are considered a paratenic host; however, the first case of an adult S. erinaceieuropaei infection in humans was reported in 2017. Spirometra tapeworms exist worldwide and infection is common in animals, but S. erinaceieuropaei infections are rare in humans. Treatment for infection typically includes surgical removal and anti-worm medication.

Sparganosis is a parasitic infection caused by the plerocercoid larvae of the genus Spirometra including S. mansoni, S. ranarum, S. mansonoides and S. erinacei. It was first described by Patrick Manson in 1882, and the first human case was reported by Charles Wardell Stiles from Florida in 1908. The infection is transmitted by ingestion of contaminated water, ingestion of a second intermediate host such as a frog or snake, or contact between a second intermediate host and an open wound or mucous membrane. Humans are the accidental hosts in the life cycle, while dogs, cats, and other mammals are definitive hosts. Copepods are the first intermediate hosts, and various amphibians and reptiles are second intermediate hosts.

<i>Hymenolepis</i> (flatworm) Genus of worms

Hymenolepis is a genus of cyclophyllid tapeworms that cause hymenolepiasis. They parasitise mammals, including humans. Some notable species are:

<span class="mw-page-title-main">Cestoda</span> Class of flatworms

Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of many similar units known as proglottids—essentially packages of eggs which are regularly shed into the environment to infect other organisms. Species of the other subclass, Cestodaria, are mainly fish infecting parasites.

Bothriocephalus acheilognathi, also known as the Asian tapeworm, is a freshwater fish parasite that originated from China and Eastern Russia. It is a generalized parasite that affects a wide variety of fish hosts, particularly cyprinids, contributing to its overall success.

<i>Raillietina</i> Genus of flatworms

Raillietina is a genus of tapeworms that includes helminth parasites of vertebrates, mostly of birds. The genus was named in 1920 in honour of a French veterinarian and helminthologist, Louis-Joseph Alcide Railliet. Of the 37 species recorded under the genus, Raillietina demerariensis, R. asiatica, and R. formsana are the only species reported from humans, while the rest are found in birds. R. echinobothrida, R. tetragona, and R. cesticillus are the most important species in terms of prevalence and pathogenicity among wild and domestic birds.

Taenia asiatica, commonly known as Asian taenia or Asian tapeworm, is a parasitic tapeworm of humans and pigs. It is one of the three species of Taenia infecting humans and causes taeniasis. Discovered only in 1980s from Taiwan and other East Asian countries as an unusual species, it is so notoriously similar to Taenia saginata, the beef tapeworm, that it was for a time regarded as a slightly different strain. But anomaly arose as the tapeworm is not of cattle origin, but of pigs. Morphological details also showed significant variations, such as presence of rostellar hooks, shorter body, and fewer body segments. The scientific name designated was then Asian T. saginata. But the taxonomic consensus turns out to be that it is a unique species. It was in 1993 that two Korean parasitologists, Keeseon S. Eom and Han Jong Rim, provided the biological bases for classifying it into a separate species. The use of mitochondrial genome sequence and molecular phylogeny in the late 2000s established the taxonomic status.

<i>Raillietina tetragona</i> Species of flatworm

Raillietina tetragona is a parasitic tapeworm belonging to the class Cestoda. It is a cosmopolitan helminth of the small intestine of pigeon, chicken and guinea fowl, and is found throughout the world.

Raillietina cesticillus is a parasitic tapeworm of the family Davaineidae. Sometimes called "Broad-headed tapeworm", it infects the small intestine of chicken and occasionally other birds, such as guinea fowl and turkey, which are generally in close proximity to backyard poultry. It is a relatively harmless species among intestinal cestodes in spite of a high prevalence. In fact it probably is the most common parasitic platyhelminth in modern poultry facilities throughout the world.

Anoplocephala manubriata is a host-specific tapeworm, or cestode, that parasitizes African and Asian elephants. These parasites require intermediate and definitive hosts to complete its life cycle. A. manubriata causes gastrointestinal inflammation in elephants. When ingested in the elephant, the cestode is attached to the intestinal mucosae. The life cycle of A. manubriata have not been completely elucidated, however studies have shown through examining oribatid mites from a dung pile near an elephant site that an immature stage exists. The study concluded at least five species were contained at least one immature life stage of the cestode.

<i>Diphyllobothrium dendriticum</i> Species of Cestoda

Diphyllobothrium dendriticum is a large pseudophyllid cestode of the family Diphyllobothriidae.

References

  1. Lee SU, Huh S, Phares CK (December 1997). "Genetic comparison between Spirometra erinacei and S. mansonoides using PCR-RFLP analysis". The Korean Journal of Parasitology. 35 (4): 277–82. doi: 10.3347/kjp.1997.35.4.277 . PMID   9446910.
  2. Cestode Lecture, Spring 2009. Dr. Ravinder N.M. Sehgal. San Francisco State University, Department of Biology.
  3. Foster GW, Cunningham MW, Kinsella JM, McLaughlin G, Forrester DJ. "Gastrointestinal helminths of free-ranging Florida panthers (Puma concolor coryi) and the efficacy of the current anthelmintic treatment protocol." Journal of Wildlife Diseases. 2006 Apr;42(2):402-6