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The Korean Journal of Parasitology Dec 2021Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular...
Total 513 heterophyid flukes were collected from a carcass of wild Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. With morphological and molecular characteristics, the flukes were identified to Cryptocotyle lata. The adult C. lata were minute, transparent, pentagonal, 522 µm long by 425 µm wide. Ceca extended into post-testicular region. Ventrogenital sac elliptical, 79 µm by 87 µm with genital pore and ventral sucker. Two testes semielliptical and slightly lobed, located in the posterior region, right testis 173 µm by 155 µm, left testis 130 µm by 134 µm. In a phylogenetic tree, the fluke specimen of this study was grouped with C. lata divergent from Cryptocotyle lingua. We report here N. procyonoides koreensis first as a natural definitive host of C. lata.
Topics: Animals; Heterophyidae; Male; Phylogeny; Raccoon Dogs; Republic of Korea; Trematoda
PubMed: 34974672
DOI: 10.3347/kjp.2021.59.6.645 -
Annals of Parasitology 2022Centrocestus formosanus is a zoonotic small invasive heterophyid fluke with worldwide distribution. Its three-host life cycle requires a thiarid snail as first...
Further contribution to the life history of Centrocestus formosanus (Nishigori, 1924) Price, 1932 (Trematoda: Heterophyidae) with special reference to a new first intermediate host from the South Western Ghats, India.
Centrocestus formosanus is a zoonotic small invasive heterophyid fluke with worldwide distribution. Its three-host life cycle requires a thiarid snail as first intermediate host, fishes as second intermediate hosts and piscivorous birds and mammals as definitive hosts for completion. As far as is known, the only first intermediate host being utilized, globally, by this parasite is the snail, Melanoides tuberculata. In the present study, life cycle stages of C. formosanus were recovered naturally and successfully tested in the laboratory. Study also adds a new host to its life cycle, the snail Bithynia (Digoniostoma) pulchella, as the first intermediate host with natural infection. Parasitological descriptors (prevalence, mean intensity and mean abundance) of infection were measured for each host. Being an invasive parasite, addition of a new host to C. formosanus life cycle has notable ecological and evolutionary significance.
PubMed: 37702283
DOI: 10.17420/ap6804.482 -
Acta Parasitologica Mar 2022Metagonimiasis, commonly seen in East Asian countries, is a parasitic disorder caused by definitive hosts' ingestion of undercooked freshwater fishes. Recently, genetic...
PURPOSE
Metagonimiasis, commonly seen in East Asian countries, is a parasitic disorder caused by definitive hosts' ingestion of undercooked freshwater fishes. Recently, genetic analysis has proved 28S rRNA and cytochrome c oxidase subunit I (COI) mtDNA gene to be a successful marker differentiating species of the genus Metagonimus. In the present study, using specimens from the newly discovered Joseon Dynasty human remains of Goryeong, we obtained updated genetic data on genus Metagonimus, which was also prevalent during the Joseon period.
METHODS
The ancient DNA (aDNA) was retrieved from the coprolite sample of the seventeenth century, half-mummified individual discovered at Goryeong Country, South Korea. Cloning and sequencing were performed on PCR-amplified amplicons for M. yokogawai 28S rRNA and COI mtDNA gene. The consensus sequences were used for species identification and phylogenetic analysis using NCBI/BLAST and MEGA X software.
RESULTS
Based on the COI mtDNA gene region, the Goryeong sequence was confirmed as belonging to M. yokogawai, as it was shown to form a separate cluster with other M. yokogawai taxa that are distinct also from M. takahashii and M. miyatai.
CONCLUSION
In a series of our genetic analyses on genus Metagonimus using samples retrieved from Joseon-period cases, aDNA sequences of genus Metagonimus revealed in South Korea thus far are those of M. yokogawai, but not of M. miyatai or M. takahashii yet.
Topics: Animals; Body Remains; DNA, Ancient; Heterophyidae; Humans; Phylogeny; Republic of Korea; Trematode Infections
PubMed: 34731404
DOI: 10.1007/s11686-021-00487-0 -
Revista Brasileira de Parasitologia... 2021Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids...
Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids predatory birds and mammals are its definitive hosts. The occurrence of cysts holding A. longa metacercariae is described in mugilids with a prevalence of up to 100%. The wide geographical distribution of A. longa and its intermediate hosts coupled with the rise in the consumption of raw or poorly cooked fish may elevate the risk of human infection. Therefore, in this study, we aimed to verify the distribution pattern of cysts holding A. longa in mugilids. The tissue and organ samples of these fish were processed in a domestic blender and examined under a stereoscopic microscope to identify the cysts holding the digenetic metacercariae. Of the 24 (100%) fish samples that were analyzed, 12 of Mugil curema and 12 of Mugil liza possessed cysts holding A. longa metacercariae. Digenetic cysts were identified to be present in the gills, heart, stomach, liver, intestines, mesentery, and muscular tissues collected from M. curema and M. liza. Conclusively, in M. curema, the cysts holding A. longa metacercariae were found to be distributed randomly throughout the fish body in almost every tissue and organ that was examined.
Topics: Animals; Cysts; Fish Diseases; Heterophyidae; Metacercariae; Smegmamorpha; Trematoda; Trematode Infections
PubMed: 34495044
DOI: 10.1590/S1984-29612021071 -
Parasitology Research Oct 2021Trematode larvae (metacercariae) causing black spot disease occur frequently in gills, fins, skin and the superficial muscle layers of marine fish. Species within the...
Morphological and molecular identification of Cryptocotyle lingua metacercariae isolated from Atlantic cod (Gadus morhua) from Danish seas and whiting (Merlangius merlangus) from the English Channel.
Trematode larvae (metacercariae) causing black spot disease occur frequently in gills, fins, skin and the superficial muscle layers of marine fish. Species within the genus Cryptocotyle Lühe, 1899 are frequently associated with this disease. Descriptions of the metacercarial stage are relatively limited and none has hitherto been reported from fish from the English Channel. The present study reports the morphological and molecular identifications of encysted black spot-inducing parasites from whiting (Merlangius merlangus) and Atlantic cod (Gadus morhua) caught respectively from the north coast of France (English Channel) and from Danish sea waters. Metacercariae were characterised morphologically based on microscopic observations and molecularly using Sanger sequencing of fragments of the mitochondrial cox1 gene and rDNA ITS region. Morphological data were compared with available data in the literature. Phylogenetic trees including reference sequences were built to confirm morphological and molecular identifications. This survey constitutes the first description of C. lingua metacercariae in the English Channel ecosystems.
Topics: Animals; Denmark; Ecosystem; Gadus morhua; Metacercariae; Phylogeny
PubMed: 34448921
DOI: 10.1007/s00436-021-07278-6 -
Anais Da Academia Brasileira de Ciencias 2021Centrocestus formosanus is a digenean parasite first described from Asia, which parasitizes Melanoides tuberculata (Gastropoda: Thiaridae) at the first intermediate...
Centrocestus formosanus is a digenean parasite first described from Asia, which parasitizes Melanoides tuberculata (Gastropoda: Thiaridae) at the first intermediate stage, and different fish species as second intermediate host. C. formosanus was previously recorded in Brazilian states, but never before in the southern region of this country. Recording and identification of digenean species through morphological identification is a taxonomic challenge. In light of this, we use an integrative taxonomic approach to report the occurrence of cercariae and metacercariae of C. formosanus in molluscs and fish, respectively, in an urban park located in southern Brazil. Specimens of M. tuberculata and the fishes Poecilia reticulata and Xiphophorus sp. (Poeciliidae) were collected for screening for parasites and molecular analyses using partial fragments of the 28S rDNA gene. The identification of C. formosanus obtained from molluscs and fish specimens permitted us to partially solve the life cycle of this parasite for the first time in the studied environment, demonstrating the necessity of monitoring and controlling molluscs populations. Nevertheless, our results will support future studies aiming to elucidate the life-cycle of C. formosanus in this region, since all sampled hosts' species are invasive in this environment.
Topics: Animals; Brazil; Fish Diseases; Heterophyidae; Trematoda; Trematode Infections
PubMed: 34406283
DOI: 10.1590/0001-3765202120191017 -
Journal of Fish Diseases Nov 2021Some trematode metacercariae, including marine digeneans belonging to the genus Cryptocotyle, induce black spots in target tissues due to the attraction of fish host...
Some trematode metacercariae, including marine digeneans belonging to the genus Cryptocotyle, induce black spots in target tissues due to the attraction of fish host melanophores. To promote precise quantification of infection, the counting of black spots has to be confirmed by reliable quantification of metacercariae after tissue digestion. This process ensures the isolation of undamaged parasites for morphological and molecular identification. The aim of this work was to optimize the pepsin digestion protocol and to assess the duration of viability of Cryptocotyle metacercariae in fish post-mortem (pm). Four digestion protocols were compared by measuring the viability rate of metacercariae. The present study shows that the orbital digestion method was the least destructive for metacercariae and allowed better quantification of Cryptocotyle infection. Moreover, morphological identification seemed reliable up to 8 days pm for Cryptocotyle infection.
Topics: Animals; Fish Diseases; Gadiformes; Heterophyidae; Metacercariae; Trematode Infections
PubMed: 34289140
DOI: 10.1111/jfd.13495 -
The Korean Journal of Parasitology Jun 2021In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes...
In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807-1,103 µm long and 1,270-1,550 µm wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33-35×15-16 µm in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.
Topics: Animals; Female; Heterophyidae; Male; Raccoon Dogs; Republic of Korea; Trematoda
PubMed: 34218603
DOI: 10.3347/kjp.2021.59.3.303 -
Journal of Microbiological Methods Aug 2021The superfamily Opisthorchioidea encompasses the families Cryptogonimidae, Opisthorchiidae and Heterophyidae. These parasites depend on the aquatic environment and... (Review)
Review
The superfamily Opisthorchioidea encompasses the families Cryptogonimidae, Opisthorchiidae and Heterophyidae. These parasites depend on the aquatic environment and include marine and freshwater species. Some species, such as Clonorchis sinensis and Opisthorchis viverrini, have a high impact on public health with millions of infected people worldwide and have thus been the object of many studies and tool developments. However, for many species, tools for identification and detection are scarce. Although morphological descriptions have been used and are still important, they are often not efficient on the immature stages of these parasites. Thus, during the past few decades, molecular approaches for parasite identification have become commonplace. These approaches are efficient, quick and reliable. Nonetheless, for some parasites of the superfamily Opisthorchioidea, reference genomic data are limited. This study reviews available genetic data and molecular tools for the identification and/or the detection of this superfamily. Molecular data on this superfamily are mostly based on mitochondrial and ribosomal gene sequence analyses, especially on the cytochrome c oxidase subunit 1 gene and internal transcribed spacer regions respectively.
Topics: Animals; DNA Primers; DNA, Helminth; DNA, Mitochondrial; DNA, Ribosomal; DNA, Ribosomal Spacer; Electron Transport Complex IV; Genes, Helminth; Heterophyidae; Molecular Diagnostic Techniques; Nucleic Acid Amplification Techniques; Opisthorchidae; Parasitology; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Trematoda
PubMed: 34082051
DOI: 10.1016/j.mimet.2021.106258 -
Diseases of Aquatic Organisms May 2021In this study, Scaphanocephalus parasite (Platyhelminthes: Heterophyidae) metacercariae were found in Siganus argenteus (forktail rabbitfish or streamlined spinefoot) in...
In this study, Scaphanocephalus parasite (Platyhelminthes: Heterophyidae) metacercariae were found in Siganus argenteus (forktail rabbitfish or streamlined spinefoot) in the Arabian Gulf of Jubail province, Saudi Arabia. The findings may constitute new host and locality records for this parasite. Based on the number of black spots containing parasite cysts per fish, our study indicated that Siganus argenteus had high infection intensities of encysted metacercariae belonging to the genus Scaphanocephalus. Of the 3500 S. argenteus specimens examined, 800 (22.9%) showed multiple black cysts over the entire body surface, including the membranous parts of fins, while none were seen on the internal organs. The prevalence of infection was highest in summer (June-August) (8.8%). The excysted metacercariae differed morphologically from previously identified Scaphanocephalus spp. Molecular analysis of rDNA showed 100% identity with an unnamed Scaphanocephalus sp. reported in Caribbean fish. Therefore, our findings may indicate a new species of this previously rarely recorded fish parasite. The histopathological examination revealed that the encysted parasites were restricted to the dermal layer of the skin and surrounded by melanophores and a fibrous connective tissue capsule, with focal myositis and Zenker's necrosis in the underlying muscle tissue. The characteristically 'winged' parasite was clearly observed within the cysts. The high prevalence of Scaphanocephalus infection in siganid fish we detected requires further epidemiological study.
Topics: Animals; Caribbean Region; Fish Diseases; Heterophyidae; Metacercariae; West Indies
PubMed: 34042069
DOI: 10.3354/dao03586