Digenetic Trematode Parasites in Two Fresh Water Fishes Ophiocephalus Punctatus and Xenentodon Cancila From North West Himalayas

The study was conducted during September 2018-August 2019 to study the digenetic trematode infection in fresh water fishes of some of the water bodies viz. Gho-manhasan, Chakrali and Chadwal of Jammu region of J&K union territory A total of 220 fishes comprising Ophiocephalus punctatus and Xenentodon cancila belonging to families Channidae and Belonidae respectively were examined. A total of 4 digenetic trematode parasites belonging to 4 different families i.e., Euclinostomum heterostomum (Clinostomidae Luhe, 1901); Phyllodistomum tripathi (Gorgoderidae Looss, 1901); Genarchopsis piscicola (Hemiuridae, Luhe, 1901), and Bucephalopsis karvei (Bucephalidae Poche, 1907) were detected. The overall prevalence of digenetic trematode infection was 65.90% and the mean intensity was 3.58. Among these Genarchopsis piscicola showed the highest prevalence (40.38%) with mean intensity 2.95 in the host fish Xenentodon cancila, while in other species the prevalence ranged between 26.23% and 34.62%. Present study authenticates the presence of several species of digenetic trematode parasites in the fishes inhabiting freshwater of J&K union territory.

Genomic Insights into the Biology of Digenetic Fluke, Explanatum explanatum Infecting Domestic Water Buffalo, Bubalus bubalis from India: New Targets for Drug Designing

Explanatum explanatum is a digenetic trematode mostly found parasitizing bile duct and the gall bladder of domestic buffaloes in India .The parasite fabricates productivity loss and occasionally turns out as severe clinical disease leading to granulomatous nodules in the bile duct mucosa, glandular hyperplasia and thickening of the blood vessels. Ribosomes are macromolecular machinery for cell protein synthesis in all organisms. The present study deals with the identification of different DNA motif in 5.8S rDNA to block the activity of ribosome translocation, thereby hindering the process of protein synthesis within the parasite and thus serving as a novel tool for controlling its growth. Moreover, this segment of gene remains evolutionary conserved thus, enhancing the rate of success in designing potent drug molecules for these identified motifs in the genome of E. explanatum. This is first report of the identification of position of DNA motifs in 5.8S rDNA of E. explanatum from India and an attempt to provide new insights for further designing of new potent drugs for its efficient treatment as the parasite has developed tolerance power for already available drugs and the significant loss caused by it to the livestock and economy. Our study will form the foundation for future in-depth analysis of the parasite biology and development, immune evasion strategies, virulence and long-term survival within the definitive host. Our findings aim to provide a better understanding of the parasite genome, the search for new drug design research and thus, can prove as a vital tool for improving animal health that would ultimately succor to meet the ever increasing demand for food.

Proteomic insights into the biology of Clinostomum piscidium from a fish, Colisa fasciatus in India using computational tools

Clinostomum is a fish-borne pathogen,digenetic trematode with worldwide distribution. Despite its zoonootic significance, the molecules involved in the host-parasite interaction remains unknown. The present study deals with the proteome profile of the rDNA of Clinostomum piscidium using in silico workflow.The physicochemical properties, mass spectrometry ,atomic composition,estimated half-life in different hosts ,Grand average of hydropathy (GRAVY),extinction coefficient and instability index of the rDNA was studied.We identified hypothetical proteins(polar in nature) that showed similarities with proteins of Trichellina pseudospiralis and Melampsora laricipopulina.The functionality of these proteins revealed their role in intracellular signalling as a substrate for O - linked N - acetylglucosaminetransferases and death transcription factor(DIDO-1). This is the first report of our findings that aims to provide a better understanding of the mechanism by which this digenetic trematode adapts to extreme environments. It is expected that this study will lead to new insights into drug designing strategies and disease control.

STOMACHICOLA LYCENGRAULIDIS N. SP. (DIGENEA, HEMIURIDAE), PARASITE OF THE ATLANTIC SABRETOOTH ANCHOVY LYCENGRAULIS GROSSIDENS (CLUPEIFORMES, ENGRAULIDAE)

This paper describes and illustrates a new species of digenetic trematode, parasitic in the stomach of the sabretooth anchovy Lycengraulis grossidens (Agassiz, 1829) from the Bahía Blanca estuary and the Paraná River, Argentina, designated as Stomachicola lycengraulidis n.sp. The new taxon differs from S. bayagbonai and S. singhi congeneric species from the Gulf of Guinea and Indian Ocean respectively, mainly in the body size, the structure of the reproductive system, the development of the ecsoma and the sinus sac. It differs from the first one mainly in the presence of two frontal protuberances at the level of the preoral lobe, which are absent in the specimens studied here. Also in general terms, S. bayagbonai is comprised of slightly larger individuals, with larger pharynx, testicles and ovary. And it differs from S. singhi by their smaller duct and hermaphroditic sac and for having a well developed seminal receptacle, which is absent in the Bay of Bengal specimens. When comparing the relative size of the ecsoma, we found significant differences among both of the populations of digeneans examined, the worms collected in the Paraná River was more developed than those from the Bahia Blanca estuary. The host, L. grossidens, migrates to the Paraná river in winter and spring and then, from December to March it makes a trophic migration towards the sea and is found all along the Atlantic coast of Buenos Aires province. For this reason, it is here hypothesized that the relative development of the tail, is affected by environmental conditions, such as pH and osmolarity of the stomach, salinity and/or water temperature.

Diagnosis of Centrocestus formosanus Infection in Zebrafish (Danio rerio) in Italy: A Window to a New Globalization-Derived Invasive Microorganism

Centrocestus formosanus is a digenetic trematode with a complex life cycle, involving invertebrate and vertebrate hosts, humans included. In particular, it causes gill lesions and mortality in freshwater fish species, and gastrointestinal symptoms in infected humans. Here, we describe the occurrence of C. formosanus infection in zebrafish imported in Italy and propose a newly designed species-specific primer pair to ameliorate the diagnostic investigations for C. formosanus. Gill arches of 30 zebrafish were examined for the presence of encysted metacercariae under a stereomicroscope and processed through molecular analyses targeting the ribosomal internal transcribed sequence 2 (ITS2). Although C. formosanus distribution was originally restricted to Asia, it has been subsequently reported in new countries, revealing itself as an invasive species and raising important concerns for biodiversity, economy, scientific research, as well as animal and public health. Given the crucial role played by the ornamental fish industry in spreading this parasite, there is an urgent need for control measures to prevent the introduction and establishment of C. formosanus in non-endemic areas, including Europe. We also suggest developing new strategies in microbiology and epidemiology to better explore this new globalization-derived invasive species.

Infections of Digenetic Trematode Metacercariae in Wrestling Halfbeak, Dermogenys pusilla from Bangkok Metropolitan Region in Thailand

This study aimed to investigate metacercarial infections in the wrestling halfbeak, <i>Dermogenys pusilla</i>, collected from Bangkok metropolitan region of Thailand. A total of 4,501 fish from 78 study sites were commonly examined with muscle compression and digestion methods (only head part of fish) during September 2017 to July 2018. The overall prevalence of metacercarial infection was 86.1% (3,876/4,501 individuals), and the mean intensity was 48.9 metacercariae per fish infected. Four species, i.e., <i>Posthodiplostomum</i> sp., <i>Stellantchasmus falcatus</i>, Cyathocotylidae fam. sp., and <i>Centrocestus formosanus</i>, of digenetic trematode metacercariae (DTM) were detected. The prevalences were 65.8%, 52.0%, 2.1%, and 1.2%, respectively and their mean intensities were 23.1, 51.6, 1.4, and 3.2 per fish infected, respectively. The seasonal prevalences were 81.0% in winter, 87.8% in summer and 87.4% in rainy, and the mean intensities were 38.9, 46.6, and 55.2 metacercariae per fish infected, respectively. Conclusively, it was confirmed that the wrestling halfbeak play the role of second intermediate hosts of 4 species of digenetic trematodes including <i>S. falcatus</i> and <i>Posthodiplostomum</i> sp. in Bangkok metropolitan region. And then the metacercariae of <i>C. formosanus</i> and Cyathocotylidae fam. sp. are to be first found in the wrestling halfbeak by this study.

Infection Status with Digenetic Trematode Metacercariae in Fishes from Coastal Lakes in Gangwon-do, Republic of Korea

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., <i>Metagonimus</i> spp., <i>Pygidiopsis</i> <i>summa</i>, <i>Centrocestus</i> <i>armatus</i>, <i>Metorchis</i> <i>orientalis</i>, <i>M</i>. <i>taiwanensis</i>, <i>Clinostomum</i> <i>complanatum</i>, <i>Echinostoma</i> spp., <i>Stictodora</i> spp., <i>Diplostomum</i> sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. <i>Metagonimus</i> spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, <i>Tribolodon</i> <i>hakonensis</i>, from 5 lakes, and their density was 14.6 per fish infected. <i>P</i>. <i>summa</i> metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. <i>C</i>. <i>armatus</i> metacercariae were detected in 7 (14.6%) <i>T</i>. <i>hakonensis</i> and 3 (15.0%) <i>Tridentiger</i> <i>brevispinis</i> from Hyang-ho, and 5 (19.2%) <i>Acanthogobius</i> <i>flavimanus</i> from Gyeongpo-ho. <i>Stictodora</i> spp. metacercariae were found in 4 fish species, i.e., <i>Tridentiger</i> <i>obscurus</i>, <i>Tridentiger</i> <i>trigonocephalus</i>, <i>Chelon</i> <i>haematocheilus</i>, and <i>Acanthogobius</i> <i>lactipes</i>, from Gyeongpo-ho. Total 15 <i>C</i>. <i>complanatum</i> metacercariae were detected in 2 (9.1%) crucian carp, <i>Carassius</i> <i>auratus</i>, from Songji-ho. <i>M</i>. <i>taiwanensis</i> metacercariae were found in <i>T</i>. <i>hakonensis</i> from Hyang-ho and Gyeongpo-ho and in <i>Pseudorasbora</i> <i>parva</i> from Gyeongpo-ho. Total 11 <i>M</i>. <i>orientalis</i> metacercariae were detected in 3 (6.3%) <i>T</i>. <i>hakonensis</i> from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.