Pentastomid Research Articles

Occurrence of tongue worm, Linguatula cf. serrata (Pentastomida: Linguatulidae) in wild canids and livestock in south-eastern Australia.

Pentastomids are obligate zoonotic arthropod parasites utilising canids and vulpids as their definitive hosts and several herbivorous species as their intermediate hosts. Reported only 10 times in Australia over the last 150 years as incidental findings, adult Pentastomids referred to as Linguatula serrata have been encountered in nasal cavities of domestic and wild dogs, and foxes. Nymphs have been reported in cattle and rabbits. In the present study, a number of potential definitive hosts, including red foxes (Vulpes vulpes), wild dogs (Canis lupus dingo and C.l. dingo x C. familiaris) and feral cats (Felis catus), and intermediate hosts cattle (Bos taurus), sheep (Ovis aries), feral pigs (Sus scrofa), rabbits (Oryctolagus cuniculus), goats (Capra hircus) and a European hare (Lepus europaeus), from the highlands of south-eastern Australia were examined. Of the animals examined 67.6% of wild dogs (n = 37), 14.5% of red foxes (n = 55) and 4.3% of cattle (n = 164) were found to be infected with Pentastomids, herein identified as Linguatula cf. serrata. The common occurrence of the parasite in wild dogs and less frequently in foxes suggests these wild canids have potential to act as a reservoir for infection of livestock, wildlife, domestic dogs and possibly humans. The unexpected high frequency of the parasite in wild dogs and foxes in south-eastern Australia suggests the parasite is more common than previously realised. Of the potential intermediate hosts in the region, only 4.3% of cattle were found to be infected with pentastomid nymphs which suggest the search for the host(s) acting as the main intermediate host in the region should continue. Future studies should investigate transmission patterns, health impacts on hosts and whether the parasite has zoonotic significance in Australia.

Molecular characterization and phylogeny of Linguatula serrata (Pentastomida: Linguatulidae) based on the nuclear 18S rDNA and mitochondrial cytochrome c oxidase I gene.

Linguatula serrata, a cosmopolitan parasite, is commonly known as tongue worm belonging to the subclass Pentastomida.We collected the nymphal stage of the worm from mesenteric lymph nodes of cattle and identified these as L. serrata based on morphology and morphometry. The 18S rDNA sequences showed no intraspecific variation, although cox1 sequences showed 99.7–99.9% homology. In the phylogenies inferred from both gene loci, members of the genus Linguatula (order Porocephalida) were closer to those of the order Cephalobaenida than to those of Porocephalida, reflecting a mismatch with the corresponding morphology-based taxonomy. Accordingly, analyses of additional gene loci using a larger number of taxa across the Pentastomida should be undertaken to determine an accurate phylogenetic position within the Arthropoda.

Tongue worm (Pentastomida) infection in ball pythons (Python regius) – a case report

Tongue worms (Pentastomida) are endoparasites causing pentastomiasis, an invasive disease representing a threat to exotic animals and humans. Animals acquire infection via the alimentary tract. In reptiles, the parasite is present in the lungs, resulting in symptoms from the respiratory system. Pentastomiasis may be asymptomatic, but nonspecific symptoms may occur at high parasite concentrations. Due to the harmful effects of many antiparasitic substances, tongue worm invasion in reptiles remains not fully treatable. Although pentasomiasis is rarely diagnosed in Poland, pentastomids were diagnosed in two ball pythons, who were patients of the “Poliklinika Weterynaryjna” veterinary clinic. They demonstrated problems with the respiratory system and a significant deterioration of health. Fenbendazole at a dose of 100 mg/kg b.w., repeated after 7 days was shown to be effective.

A 425-Million-Year-Old Silurian Pentastomid Parasitic on Ostracods

Pentastomids (tongue worms) are worm-like arthropods known today from ∼140 species [1]. All but four are parasitic on vertebrates. Their life cycle typically involves larval development in an intermediate host followed by maturation in the respiratory tract of a definitive terrestrial host. Fossil pentastomids are exceedingly rare and are known only from isolated juveniles [2-6]. The identity of the possible hosts of fossil pentastomids and the origin of their lifestyle have generated much debate. A new, exceptionally preserved species, described based on adults from 425-million-year-old marine rocks, is the only known fossil pentastomid associated with a host, in this case a species of ostracod crustacean. The pentastomids are preserved near eggs within the ostracod and also, uniquely for any fossil or living pentastomid, are attached externally to the host. This discovery affirms the origin of pentastomids as ectoparasitic on marine invertebrates. The terrestrialization of pentastomids may have occurred in parallel with the vertebrate invasion of land.

The first case of human infestation with Linguatula serrata in Kermanshah province

Linguatula serrata is a cosmopolitan organism belonging to the Phylum Pentastomida. Humans may act as an intermediate (Halzoun syndrome) or accidental definitive host of this parasite, manifesting the nasopharyngeal or visceral form. Linguatulosis occurs accidentally in human by ingestion of raw or undercooked visceral tissues of sheep, goat, camel, and other herbivores. This is the first report of Halzoun syndrome in Kermanshah province. In this case report, a 34-year-old man, from Salas-o-babajani district infested with this parasite was presented. Clinical signs and symptoms included pricking sensation in throat, coughing, sneezing and nasal discharge, which started 2-3 hours after eating undercooked goat liver. An organism in about 8 mm length was isolated from his pharyngeal discharge. The sample was examined in the pparasitology llaboratory of Kermanshah school of medicine. The results of analysis showed that this organism was the nymph of L. The serrata had a mouth surrounded by four hooks and a segmented body with small hooks. The patient was treated using oral anti histamines and gargling and nasal washing with saline solution. So, it is recommended that physicians consider L. Serrata infestation in patients with complaints such as pharyngitis accompanied by pharyngeal pain, coughing, sneezing and vomiting.

Prevalence of Linguatula serrata nymphs in slaughtered goats in Isfahan province

BACKGROUND: Linguatula serrata, a tongue worm, is an aberrant cosmopolitan parasite, which inhabits the canine respiratory system (final host). The discharged eggs infect many plant feeder, including ruminants and human being, that produce visceral and nasopharyngeal linguatulosis which is known as Marrara syndrome in man. OBJECTIVES: In the current study, the prevalence rate of infection with L. serrata nymphs in mesenteric and mediastinal lymph nodes (MLNs) of slaughtered goats was investigated by cutting in MLNs and observing them in Isfahan Province, Iran. METHODS: The MLNs of 620 slaughtered goats, including 197 females and 423 males, after the preparation of the lymph nodes, were examined for L. serrata nymphs by cutting them longitudinally and testing them by using a dissecting microscope for L. serrata nymphs. Then, in the suspected cases, the samples were digested by pepsin and hydrochloric acid and were examined for presence of L. serrata nymphs. Goats were categorized into four age groups, including 3.5 years. RESULTS:The results showed that 54.35% of the examined goats were infected with L. serrata. Sex had no significant effect on the prevalence rate of this parasite in goats. CONCLUSIONS: A high prevalence rate of infection in goats suggests a possible similar high rate of infection in other animals and man in the investigated area, which emphasizes undertaking strict control measures to reduce the risk of zoonotic outbreaks.

A pentastome (Armillifer moniliformis) parasitizing a common rat-snake

Pentastomes are a group of relatively poorly known parasites that are neglected both in veterinary parasitology text books and curriculum. The pentastomes are currently classified in a separate phylum, Pentastomida, because they exhibit characteristics of both the phylum Arthropoda and Annelid. This group comprises of approximately 100 species of vermiform arthropods that are all obligate parasites of the lower and less often upper respiratory tract of vertebrates. Adult pentastomes are segmented and worm like, measuring 0.5 to 20 cm in length. However they are easily distinguished from any other parasite because they bear 2 pairs of retractile hooks on either side of the mouth. They also have a distinct tongue shaped appearance; hence they are called linguatulids or tongue worms.

Levisunguis subaequalis n. g., n. sp., a tongue worm (Pentastomida: Porocephalida: Sebekidae) infecting softshell turtles, Apalone spp. (Testudines: Trionychidae) in the southeastern United States

A new tongue worm (Pentastomida) belonging to the Sebekidae Sambon, 1922 (Porocephaloidea Sambon, 1922) is described based on exemplars collected from softshell terrapins Apalone spinifera aspera (Agassiz) and Apalone ferox (Schneider) in the southeastern United States; a new genus is erected to accommodate the new species. The new species belongs in the Sebekidae because adults possess four simple hooks arranged in a trapezoid pattern on the ventral surface of the cephalothorax, a mouth opening between the anterior and posterior pairs of hooks, a terminal anus, an elongated uterus with preanal uterine pore, and a Y-shaped seminal vesicle. Nymphs possess geminate hooks, and the new species has an aquatic life-cycle in which nymphs become encapsulated in the body cavity of a freshwater fish and mature in the lungs of a terrapin. The new genus is distinct from other genera in the Sebekidae primarily by differences in hook morphology and the fact that representatives use a terrapin as a definitive host. Nymphs infecting fish and presumed to be the new species matured as postlarval juveniles conspecific with the new species when they were fed to the eastern mud turtle, Kinosternon subrubrum (Lacépède). Nymphs of the new species are anatomically similar to but larger than nymphs of Sebekia mississippiensis Overstreet, Self & Vliet, 1985 found in the mesentery of fishes captured in Florida, U.S.A. Adults of the new species differ from those of S. mississippiensis based on hook features, chloride cell pore pattern on annuli, body size, and use of a turtle rather than crocodilian definitive host. The new species is the third North American member of the Sebekidae.

Prevalence of Linguatula serrata nymphs in slaughtered sheeps in Isfahan province, southwest of Iran.

Linguatula serrata, well known as tongue worm; is an aberrant cosmopolitan parasite, which inhabits the carnivorous mammals (especially Canidae) respiratory system. The discharged eggs infect many plant feeder animals including human that produces visceral and nasopharyngeal linguatulosis which is known as Marrara syndrome in man. In current study, the prevalence rate of infection with L. serrata nymphs in mesenteric and mediastinal lymph nodes (MLNs) of slaughtered sheeps was investigated in Esfahan Province, Iran. The MLNs of 506 slaughtered sheeps, including 236 females and 270 males, were examined for L. serrata nymphs by cutting the MLNs longitudinally and then microscopic studies for L. serrata nymphs. Sheeps were categorized into four age groups, including <1year, 1-2years, 2-3years and >3years. Results showed that 11.66% of examined sheeps were infected with L. serrata. Age had significant effect on the prevalence rate of this parasite in sheeps (infection in sheeps with >3years old was more than other groups significantly) and sex had no significant effect on the prevalence rate of this parasite in sheeps. Infection rate in winter was significantly lower than infection rate in spring; but there were no significant differences between the other seasons. As high prevalence rate of infection in sheeps, suggesting possibly similar high rate of infection in other animals and man in the investigated area, which this emphasizes undertaking strict control measures to reduce risk of zoonotic outbreaks. This study was demonstrated infection rate of L. serrata in sheeps in central parts of Iran.

Linguatula serrataTongue Worm in Human Eye, Austria

Linguatula serrata, the so-called tongue worm, is a worm-like, bloodsucking parasite belonging to the Pentastomida group. Infections with L. serrata tongue worms are rare in Europe. We describe a case of ocular linguatulosis in central Europe and provide molecular data on L. serrata tongue worms.

New pentastomids from the Late Cambrian of Sweden – deeper insight of the ontogeny of fossil tongue worms

New pentastomids from the Late Cambrian of Sweden – deeper insight of the ontogeny of fossil tongue worms

What genes and chromosomes say about the origin and evolution of insects and other arthropods

At the turn of the 21st century, the use of molecular and molecular cytogenetic methods led to revolutionary advances in systematics of insects and other arthropods. Analysis of nuclear and mitochondrial genes, as well as investigation of structural rearrangements in the mitochondrial chromosome convincingly supported the Pancrustacea hypothesis, according to which insects originated directly from crustaceans, whereas myriapods are not closely related to them. The presence of the specific telomeric motif TTAGG confirmed the monophyletic origin of arthropods (Arthropoda) and the assignment of tongue worms (Pentastomida) to this type. Several different types of telomeric sequences have been found within the class of insects. Investigation of the molecular organization of these sequences may shed light on the relationships between the orders Diptera, Siphonaptera, and Mecoptera and on the origin of such enigmatic groups as the orders Strepsiptera, Zoraptera and suborder Coleorrhyncha.

An annotated catalogue of the tongue worms (Pentastomida) held in the Museum für Naturkunde Berlin

An annotated catalogue of the type and non-type material belonging to the enigmatic arthropod group Pentastomida (tongue worms) in the Museum fur Naturkunde Berlin is presented. Aspects of human infection, current ideas on their affinities and some recent developments in the study of these animals are briefly reviewed. Types of eight species have been recorded: Raillietiella affinis Bovien, 1927, Raillietiella bicaudata Heymons & Vitzthum, 1935, “Pentastomum ” javanicum Bovien, 1927, Raillietella kochi Heymons, 1926, Elenia lialisi Heymons, 1939a, Raillietiella mabuiae Heymons, 1922, Raillietella shipleyi Heymons, 1926 and Cephalobaena tetrapoda Heymons, 1922. Five of these types are currently considered valid species. According to the literature, type material from Elenia travassosi (Heymons, 1932) should be in Berlin, but could not be traced during the present review and may have to be considered lost. A further twenty-six non-type species were recorded, plus specimens assigned to two names currently regarded as nomina dubia. This yields a total of 31 currently valid species in Berlin, representing nearly 25 % of the known world fauna. Much of the Berlin material derives from the important Richard Heymons collection, but significant historical specimens collected in Brazil in the early nineteenth century by Johann Natterer was also discovered during the course of this project. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Diagnosis of Human Visceral Pentastomiasis

Visceral pentastomiasis in humans is caused by the larval stages (nymphs) of the arthropod-related tongue worms Linguatula serrata, Armillifer armillatus, A. moniliformis, A. grandis, and Porocephalus crotali. The majority of cases has been reported from Africa, Malaysia, and the Middle East, where visceral pentastomiasis may be an incidental finding in autopsies, and less often from China and Latin America. In Europe and North America, the disease is only rarely encountered in immigrants and long-term travelers, and the parasitic lesions may be confused with malignancies, leading to a delay in the correct diagnosis. Since clinical symptoms are variable and serological tests are not readily available, the diagnosis often relies on histopathological examinations. This laboratory symposium focuses on the diagnosis of this unusual parasitic disease and presents its risk factors and epidemiology.

Pentastomiasis (Armillifer armillatus infestation).

Pentastomiasis, also known as 'tongue worm' infestation or porocephalosis, is a parasitic zoonosis endemic to western and central Africa. In 1847, Pruner described the first human infection by a pentastomid in Cairo.

Linguatuliasis in Germany

Linguatuliasis in Germany

Further use of nearly complete 28S and 18S rRNA genes to classify Ecdysozoa: 37 more arthropods and a kinorhynch

This work expands on a study from 2004 by Mallatt, Garey, and Shultz [Mallatt, J.M., Garey, J.R., Shultz, J.W., 2004. Ecdysozoan phylogeny and Bayesian inference: first use of nearly complete 28S and 18S rRNA gene sequences to classify the arthropods and their kin. Mol. Phylogenet. Evol. 31, 178–191] that evaluated the phylogenetic relationships in Ecdysozoa (molting animals), especially arthropods. Here, the number of rRNA gene-sequences was effectively doubled for each major group of arthropods, and sequences from the phylum Kinorhyncha (mud dragons) were also included, bringing the number of ecdysozoan taxa to over 80. The methods emphasized maximum likelihood, Bayesian inference and statistical testing with parametric bootstrapping, but also included parsimony and minimum evolution. Prominent findings from our combined analysis of both genes are as follows. The fundamental subdivisions of Hexapoda (insects and relatives) are Insecta and Entognatha, with the latter consisting of collembolans (springtails) and a clade of proturans plus diplurans. Our rRNA-gene data provide the strongest evidence to date that the sister group of Hexapoda is Branchiopoda (fairy shrimps, tadpole shrimps, etc.), not Malacostraca. The large, Pancrustacea clade (hexapods within a paraphyletic Crustacea) divided into a few basic subclades: hexapods plus branchiopods; cirripedes (barnacles) plus malacostracans (lobsters, crabs, true shrimps, isopods, etc.); and the basally located clades of (a) ostracods (seed shrimps) and (b) branchiurans (fish lice) plus the bizarre pentastomids (tongue worms). These findings about Pancrustacea agree with a recent study by Regier, Shultz, and Kambic that used entirely different genes [Regier, J.C., Shultz, J.W., Kambic, R.E., 2005a. Pancrustacean phylogeny: hexapods are terrestrial crustaceans and maxillopods are not monophyletic. Proc. R. Soc. B 272, 395–401]. In Malacostraca, the stomatopod (mantis shrimp) was not at the base of the eumalacostracans, as is widely claimed, but grouped instead with an euphausiacean (krill). Within centipedes, Craterostigmus was the sister to all other pleurostigmophorans, contrary to the consensus view. Our trees also united myriapods (millipedes and centipedes) with chelicerates (horseshoe crabs, spiders, scorpions, and relatives) and united pycnogonids (sea spiders) with chelicerates, but with much less support than in the previous rRNA-gene study. Finally, kinorhynchs joined priapulans (penis worms) at the base of Ecdysozoa.

Case Report

Case Report

A new Late Cambrian pentastomid and a review of the relationships of this parasitic group

A new Late Cambrian pentastomid and a review of the relationships of this parasitic group

A new Late Cambrian pentastomid and a review of the relationships of this parasitic group

ABSTRACTPentastomida, tongue worms, are a taxon of about 130 species of parasites, living exclusively in the respiratory tracts of vertebrates. Three-dimensionally preserved Upper Cambrian larvae already demonstrate a high degree of adaptation to parasitism, striking morphological conservatism, and a high diversification by the Late Cambrian, thereby suggesting a likewise diversified host group. Not least due to their highly modified morphology, the systematic affinities of pentastomids remain controversial. The two major alternatives place the group as either close to branchiuran crustaceans or as stem-lineage derivatives of the Euarthropoda. To this set of Cambrian fossil representatives of the pentastomids we can add a new form from Lower Ordovician boundary beds from Sweden, most likely reworked from Upper Cambrian horizons. Based on this new species, named Aengapentastomum andresi gen. et sp. nov., and the available information about fossil and Recent pentastomids, we review the diverging ideas on the systematic position of this fully parasitic taxon.