Sealworm Nematode Pseudoterranova decipiens (Krabbe, 1878) Gibson, 1983 (Nematoda: Rhabditida: Anisakidae)

Contents: Introduction – Synonymy – Distribution – Description – Life Cycle and Biology – Hosts – Medical Importance – Economic Importance – Management – Selected References. Also published on the Featured Creatures website at http://entnemdept.ufl.edu/Creatures/NEMATODE/Pseudoterranova_decipiens_sealworm_nematode.htm

Pathological findings in bycaught harbour porpoises (Phocoena phocoena) from the coast of Northern Norway

Due to little prior knowledge, the present study aims to investigate the health status of bycaught harbour porpoises from the northernmost Arctic Norwegian coastline. Gross, histopathological and parasitological investigations were conducted on 61 harbour porpoises (Phocoena phocoena phocoena) accidentally captured in fishing gear from February to April 2017 along the coast of Northern Norway. Most animals displayed a good nutritional status, none were emaciated. Pulmonary nematodiasis (Pseudalius inflexus, Halocercus invaginatus and Torynurus convolutus) was found in 77% and associated with severe bronchopneumonia in 33% of the animals. The majority (92%) had parasites in the stomach and intestine (Anisakis simplex sensu stricto (s. s.), Pholeter gastrophilus, Diphyllobothrium stemmacephalum, Hysterothylacium aduncum and Pseudoterranova decipiens s. s.). The prevalence of gastric nematodiasis was 69%. In the 1st stomach compartment A. simplex s. s. was found in 30% of the animals, causing severe chronic ulcerative gastritis in 23%. Campula oblonga infected the liver and pancreas of 90% and 10% of the animals, respectively, causing severe cholangitis/pericholangitis/hepatitis in 67% and moderate pancreatitis in 10% of the animals. Mesenteric and pulmonary lymphadenitis was detected in 82% and 7% of the animals, respectively. In conclusion, the major pathological findings in the investigated Arctic porpoises were parasitoses in multiple organs with associated severe lesions, particularly in the lung, liver and stomach. The animals were generally well nourished and most showed freshly ingested prey in their stomachs. The present study indicates that the harbour porpoises were able to tolerate the detected parasitic burden and associated lesions without significant health problems.

Parasites of Three Closely Related Antarctic Fish Species (Teleostei: Nototheniinae) from Elephant Island

Background Studies of parasite communities and patterns in the Antarctic are an important knowledge base with the potential to track shifts in ecological relations and study the effects of climate change on host–parasite systems. Endemic Nototheniinae is the dominant fish group found in Antarctic marine habitats. Through their intermediate position within the food web, Nototheniinae link lower to higher trophic levels and thereby also form an important component of parasite life cycles. The study was set out to gain insight into the parasite fauna of Nototheniops larseni, N. nudifrons and Lepidonotothen squamifrons (Nototheniinae) from Elephant Island (Antarctica). Methods Sampling was conducted at three locations around Elephant Island during the ANT-XXVIII/4 expedition of the research vessel Polarstern. The parasite fauna of three Nototheniine species was analysed, and findings were compared to previous parasitological and ecological research collated from a literature review. Results All host species shared the parasites Neolebouria antarctica (Digenea), Corynosoma bullosum (Acanthocephala) and Pseudoterranova decipiens E (Nematoda). Other parasite taxa were exclusive to one host species in this study. Nototheniops nudifrons was infected by Ascarophis nototheniae (Nematoda), occasional infections of N. larseni with Echinorhynchus petrotschenkoi (Acanthocephala) and L. squamifrons with Elytrophalloides oatesi (Digenea) and larval tetraphyllidean Cestoda were detected. Conclusion All examined fish species’ parasites were predominantly euryxenous regarding their fish hosts. The infection of Lepidonotothen squamifrons with Lepidapedon garrardi (Digenea) and Nototheniops larseni with Echinorhynchus petrotschenkoi represent new host records. Despite the challenges and limited opportunities for fishing in remote areas, future studies should continue sampling on a more regular basis and include a larger number of fish species and sampling sites within different habitats.

Pseudoterranova Infestation Beneath Uterine Serosa

A 49-year-old woman complained of genital bleeding in the follow-up period for her uterine leiomyomas. Close examination disclosed uterine corpus cancer, and biopsy confirmed endometrial carcinoma, grade 1. Total hysterectomy with bilateral salpingo-oophorectomy was performed. Just beneath the uterine serosa, a 9 x 4 mm-sized, yellowish-colored necrotic granuloma containing dead nematode was incidentally observed. Eosinophilic reaction was minimal. The worm was immunoreactive with a monoclonal antibody An-1 against Anisakis simplex antigen. Nested polymerase chain reaction using DNA extracted from formalinfixed, paraffin-embedded sections revealed a gene sequence indicative of Pseudoterranova decipiens. Pseudoterranova, a larval nematode morphologically similar to A. simplex, clinically causes anisakiasis. This is the first case of uterine anisakiasis confirmed morphologically and molecularly.

Phylogeny and Pathology of Anisakids Parasitizing Stranded California Sea Lions (Zalophus californianus) in Southern California

In marine mammals, nematode-inflicted pathological lesions combined with other pathogens and factors (i.e., pollution, climate change, domoic acid poisoning events, and seasonal El Nino starvation events) negatively impact pinnipeds’ health and may cause mortality. Five California sea lions (Zalophus californianus)—a female pup, three male yearlings, and an adult female—suffered mortalities during rehabilitation at the Marine Mammal Care Center Los Angeles (San Pedro, CA). According to the necropsy reports, animals developed multisystemic parasitism as a leading cause of death, combined with malnutrition and hypoglycemia. In order to reveal host–parasite dynamics that may play a role in pinniped health and recovery, we examined the type and level of histopathological stomach lesions in California sea lions caused by anisakid nematodes. All isolated anisakids were morphologically and molecularly identified, and their phylogenetic relationships were reconstructed using the sequence of the mitochondrial COII gene. Co-parasitation of different Anisakidae spp. within the same host or lesions presented the opportunity to evaluate the existence of recombinant haplotypes and their eventual pathological pressure exerted onto host. The lesions were presented as chronic granulomatous gastritis, with moderate edema and hyperemia of the tunica submucosa and lamina propria, followed by mild, focal fibrosis of the gastric wall. Ulcerative changes with mixed leukocytic infiltrate showed to be localized, shallow, and non-perforative and with no apparent bacterial coinfection, mostly accompanied by healing granulation tissue. Isolated anisakids are grouped into three distinctively separated monophyletic clades corresponding to genera Anisakis, Contracaecum, and Pseudoterranova. Most abundant were representatives of Contracaecum ogmorhini sensu lato (55.36%), followed by Anisakis pegreffii (23.21%), Pseudoterranova azarasi (17.86%), Pseudoterranova decipiens sensu lato (1.79%), and Anisakis simplex (1.79%). Phylogenetic trees revealed no differentiation at intra-species level. Our analysis of divergence revealed Contracaecum separated from other lineages in the Jurassic period at the 176.2 Mya and Anisakis diverging from Pseudoterranova in Cenozoic period at 85.9 Mya.

Spread of seafish invasions in the northen sea of okhotsk as a factor of human infection

The results of the analysis are presented in the comparative aspect of the long-term - 1989 - 2021. - dynamics of infection of commercial fish with parasites common to humans and animals, and determination of their role in the spread of invasions among the population of the region. During this period, in marine fish – herring Clupea pallasii Valenciennes, 1847 (Clupeiformes: Clupeidae), saffron cod Eleginus gracilis, flounder Acanthopsetta nadeshnyi and smelt Osmerus mordax dentex Steindachner, 1870 – 5 types of helminthes potentially dangerous for humans have been identified, which can cause such dangerous diseases like anisacidosis, diphyllobothriasis and corynosomiasis. All fish species show high rates of invasion. Herring is infested by 97.4%, saffron cod - 55.2%, flounder - 67.5%, smelt - 58.4%. Ichthyopathological examinations isolated Anisakis simplex, Pseudoterranova decipiens, Pyramicocephalus phocarum, Diphyllobothrium sobolevi, Corynosoma strumosum. Individuals with combined invasion were registered: saffron cod Anisakis simplex, Pyramicocephalus phocarum, Corynosoma strumosum; smelt Anisakis simplex (Pseudoterranova decipiens), Diphyllobothrium sobolevi, Corynosoma strumosum. The most dangerous for humans are flounder and smelt due to the localization of helminths in the muscles.

LARVAS DE HYSTEROTHYLACIUM SP (NEMATODA: RAPHIDASCARIDIDAE) EN EL PEZ VOLADOR EXOCOETUS VOLITANS LINNAEUS, 1758 (EXOCOETIDAE, BRUUN, 1935)) LIMA, PERÚ

Anisakidosis is an infection caused mainly by Anisakis simplex (Rudolphi, 1809), Pseudoterranova decipiens (Krabbe, 1878) Gibson, 1983 and very low frequency around the world by Contracaecum osculatum (Rudolphi, 1802) Baylis, 1920 and Hysterothylacium aduncum (Rudolphi, 1802). In Peru, Deardorff & Overstreet, 1982 en has been identified in Coryphaena hippurus Linnaeus, 1758, but there is no record of the morphometric characteristics of third instar larval stages in smaller teleost fishes. Given the importance of the flying fish Exocoetus volitans Linnaeus, 1758 in the trophic chain of C. hippurus, we believe that this fish would have a very important role in the biological cycle of Hysterothylacium sp. as a paratenic host. The objective of the present work was to identify the morphometric characteristics of the nematode larvae found in E. volitans and to determine their prevalence (P), mean intensity (IM) and mean abundance (AM). The sample consisted of 51 specimens of E. volitans, which were acquired in the fishing terminal of the district of Ventanilla, Callao. The collection and identification was done applying conventional methods and techniques. The presence of third stage larvae of Hysterothylacium sp. in gills and intestine is located mainly in the visceral surface and muscle tissue of E. volitans. Infected fish showed a prevalence of 90% (46/51), mean intensity of 58 with an intensity range of (1 - 1720) and a mean abundance of 52.11. Third stage larvae of Hysterothylacium sp. and parasitic indexes in E. volitans are identified for the first time in Peru.

Anisakis physeteris and Pseudoterranova decipiens in the Mugil curema fish caught in Tumaco, Colombia

Objetivo. Identificar nematodos de la familia Anisakidae en el pez de consumo Mugil curema. Materiales y métodos. Para este estudio, se recolectaron 16 peces Lisa (M. curema) del puerto de Tumaco, una ciudad en la costa colombiana del Pacífico. La identificación morfológica de las larvas se realizó mediante taxonomía clásica y se calculó el porcentaje de infestación de larvas. Para la identificación molecular, se realizó una PCR múltiple con cebadores para las especies Anisakis physeteris, Pseudoterranova decipiens, Anisakis simplex sensu stricto, Contracaecum osculatum, Hysterothylacium aduncum y Anisakis pegreffii. Resultados. La revisión taxonómica permitió la identificación de larvas de tipo II del género Anisakis y larvas del género Pseudoterranova. Las larvas se aislaron principalmente del intestino, donde se encontró que el 94% de los peces estaban parasitados por nematodos anisakidos. La PCR multiplex permitió la identificación de la especie A. physeteris (Larva tipo II) y P. decipiens. Conclusiones. Este estudio en el primer reporte del nematodo Anisakidae en Tumaco, Colombia. Estos resultados proporcionan una justificación convincente para un estudio adicional sobre la familia Anisakidae en Colombia, como un problema de salud pública.

Anisákidos y anisakidosis: generalidades y su actualidad en Colombia. Revisión bibliográfica

La anisakidosis es una parasitosis ocasionada por nematodos de la familia Anisakidae, causadapor el consumo de pescado parasitado con larvas infectivas (L3) de estos nematodos. EnEuropa y Asia es un problema de salud pública. Sin embargo, en Colombia y en general enlos países de América del Sur, es poco conocida. El objetivo de este trabajo es presentar unarevisión de las generalidades de los parásitos anisákidos y mostrar la situación actual de estaparasitosis en Colombia. Se realizó una búsqueda estructurada de términos MeSH y DeCS enMEDLINE, Cochrane, Embase, LILACS y Scopus; esta se complementó con otra no estructurada en SciELO y Google Scholar. Se incluye un reporte de caso y seis registros de hospederos. Se describen registros de peces de consumo humano parasitados por Anisakis sp., Anisakis physeteris y Pseudoterranova decipiens para el Océano Pacífico y, los géneros Pseudoterranova y Contracaecum en peces del Océano Atlántico y aguas continentales. Se concluye que la anisakidosis representa un riesgo latente para Colombia, es necesario instaurar legislaciones efectivas para un control eficiente sobre esta parasitosis y educar a la población sobre los cuidados necesarios para el consumo de pescado.