Macracanthorhynchus

Macracanthorhynchus
Adult Macracanthorhynchus hirudinaceus
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Acanthocephala
Class: Archiacanthocephala
Order: Oligacanthorhynchida
Family: Oligacanthorhynchidae
Genus: Macracanthorhynchus
Trevassos, 1917
Species
  • M. catulinus Kostylev, 1927
  • M. erinacei Dollfus, 1953
  • M. hirudinaceus (Pallas, 1781)
  • M. ingens (Linstow, 1879)

Macracanthorhynchus, also known as the giant thorny-headed worm of swine, is a member of the Oligacanthorhynchidae which contains four species.

Taxonomy

Phylogenetic analysis has been conducted on at least one of the four species in the genus, M. ingens, and confirms that this species belongs to the family Oligacanthorhynchidae. The type species is M. hirudinaceus.

Archiacanthocephala
Archiacanthocephala
Phylogenetic reconstruction for select species in the class Archiacanthocephala based on a 28S rRNA gene comparison from Gomes et al. (2019) and a 18S rDNA gene comparison from Amin et al. (2020). Amin et al. (2022) used the 18S rDNA gene and ITS1-5.8-ITS2 region of ribosomal RNA comparisons to add P. canicola phylogenetically to the family Oligacanthorhynchidae.

Description

Macracanthorhynchus consists of a proboscis covered in hooks and a long trunk.

Species

There are four species in the genus Macracanthorhynchus.

The encysted larvae of M. catulinus beetle Adesmia gebleri from the Kara Kum region are 6.32 mm long and have a proboscis 0.57 mm long with 12 longitudinal rows of three hooks each. The size of the hooks varies from 0.25 mm to 0.11 mm. Small vertebrates, such as the badger and weasel may be reservoir hosts. Pre-acanthellae and acanthellae of M. catulinus were found infesting Tentyria tessulataAzerbeijan, and acanthellae were found in the paratenic hosts, Sheltopusik (Ophisaurus apodus), Coluber jugularis, Agama caucasica, Eumeces schneideri, Eremias pleskei, Lacerta strigata and the Marsh frog (Pelophylax ridibundus).

M. hirudinaceus is a parasite which lives in the intestines of pigs and other suids, and very occasionally in humans or dogs. It causes enteritis, gastritis or peritonitis. Its life cycle includes beetles of the genus Melolontha as intermediate hosts.[citation needed] This species has many synonyms which include: Echinorhynchus gigas (Block, 1782), Macracanthorhynchus gigas (Block, 1782), Echinorhynchus hirundinacea (Palas, 1781), Gigantorhynchus hirundinaceus (Pallas, 1781), Gigantorhynchus gigas (Block, 1782), Hormorhynchus gigas (Block, 1782), Taenia haeruca (Pallas, 1776), and Taenia hirundinaceus (Pallas, 1781) The complete mitochondrial genome of M. hirudinaceus has been sequenced. The eggs have 4 membranes are 98 um long and have an elongation ratio of 1.85.

The eggs have three membranes, are 94 um long and have an elongation ratio of 1.66. It parasitizes the raccoon (Procyon lotor) in the United States.

Hosts and pathology

Diagram of the life cycle of Acanthocephala showing the egg on the bottom, an arrow pointing to the left to the intermediate host (an insect), then an arrow to the top showing the juvenile form, then an arrow to the right showing a human and other animals with the adult form of the parasite, then an arrow pointing back to the egg.
Life cycle of Acanthocephala

The life cycle of acanthocephala (thorny-headed worms) in general unfolds in three distinct stages. It begins when an egg develops into an infective form known as an acanthor. This acanthor is released with the feces of its definitive host, typically a vertebrate, and must be ingested by an intermediate host, an arthropod such as an insect, to continue its development. Although the specific intermediate hosts for all species of the genus Macracanthorhynchus are unidentified, it is generally accepted that insects serve as the primary intermediaries as they make up the diet of the host.

Inside the intermediate host, the acanthor molts its outer layer, becoming an acanthella (the immature larval stage). At this stage it burrows into the host's intestinal wall and continues to grow. The life cycle culminates in the formation of a cystacanth, a larval stage able to infect the definitive host while retaining juvenile features (differing from the adult only in size and stage of sexual development), which awaits ingestion by the definitive host to mature fully. Once inside the definitive host, these larvae attach themselves to the intestinal wall using the hooks on their proboscis, mature into sexually reproductive adults, and complete the cycle by releasing new acanthors into the host's feces.

A survey of the medical literature published in 2021 found most documented cases of human acanthocephaliasis are caused by Macracanthorhynchus hirudinaceus, Macracanthorhynchus ingens.

Notes

  1. ↑ A binomial authority in parentheses indicates that the species was originally described in a genus other than the present genus.
  2. ↑ A 2001 survey of the literature found many cases of human infection by several Macracanthorhynchus species.

References

  1. 1 2 Amin, Omar M.; Chaudhary, Anshu; Heckmann, Richard A.; Swenson, Julie; Singh, Hridaya S. (2022-03-01). "Redescription and Molecular Characterization of Pachysentis canicola Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) from the Maned Wolf, Chrysocyon brachyurus (Illiger, 1815) in Texas". Acta Parasitologica. 67 (1): 275–287. doi:10.1007/s11686-021-00458-5. PMID 34345996. S2CID 236914933. Archived from the original on 22 July 2023. Retrieved 28 December 2022.
  2. 1 2 Amin, Omar M. (September 19, 2013). "Classification of the Acanthocephala". Folia Parasitologica. 60 (4): 273–305. doi:10.14411/fp.2013.031. PMID 24261131.
  3. ↑ Gomes, Ana Paula N.; Amin, Omar M.; Olifiers, Natalie; Bianchi, Rita de Cassia; Souza, Joyce G. R.; Barbosa, Helene S.; Maldonado, Arnaldo (2019). "A New Species of Pachysentis Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) in the Brown-Nosed Coati Nasua nasua (Carnivora: Procyonidae) from Brazil, with Notes on the Genus and a Key to Species". Acta Parasitologica. 64 (3): 587–595. doi:10.2478/s11686-019-00080-6. PMC 6814649. PMID 31286360.
  4. 1 2 Amin, O.M.; Sharifdini, M.; Heckmann, R.A.; Zarean, M. (2020). "New perspectives on Nephridiacanthus major (Acanthocephala: Oligacanthorhynchidae) collected from hedgehogs in Iran". Journal of Helminthology. 94: e133. doi:10.1017/S0022149X20000073. PMID 32114988. S2CID 211725160.
  5. ↑ "Macracanthorhynchus Travassos, 1917". Integrated Taxonomic Information System (ITIS). November 3, 2023. Retrieved November 3, 2023.
  6. ↑ https://www.cabidigitallibrary.org/doi/full/10.5555/19540801936
  7. ↑ https://www.cabidigitallibrary.org/doi/full/10.5555/19820896112
  8. ↑ "Acanthocephala". Archived from the original on 2010-08-04. Retrieved 2019-12-24.
  9. ↑ Zoonosis y Enfermedades Transmisibles Comunes al Hombre y a los Animales: Parasitosis, Pan American Health Org. 3 edition (31 Dec 2003) ISBN 978-92-75-31993-2
  10. ↑ ITIS - Macracanthorhynchus hirudinaceus
  11. ↑ "Macracanthorhynchus hirudinaceus (ID 15792) - Genome - NCBI".
  12. 1 2 Pfenning, A. C. (2017). Egg morphology, dispersal, and transmission in acanthocephalan parasites: integrating phylogenetic and ecological approaches.Url=https://via.library.depaul.edu/cgi/viewcontent.cgi?article=1273&context=csh_etd
  13. ↑ CDC's Division of Parasitic Diseases and Malaria (April 11, 2019). "Acanthocephaliasis". Centers for Disease Control and Prevention. Archived from the original on 8 June 2023. Retrieved July 17, 2023.
  14. 1 2 3 4 Mathison, B. A.; et al. (2021). "Human acanthocephaliasis: a thorn in the side of parasite diagnostics". Journal of Clinical Microbiology. 59 (11) e02691-20. American Society for Microbiology (United States). doi:10.1128/JCM.02691-20. PMC 8525584. PMID 34076470.
  15. 1 2 Schmidt, Gerald D.; Nickol, Brent B. (1985). "Development and life cycles". Biology of the Acanthocephala (PDF). Cambridge: Cambridge University Press. pp. 273–305. ISBN 978-0521246743. Archived (PDF) from the original on 22 July 2023. Retrieved 16 July 2023.