Biology subjects

Dheilly, N. M.

Publications and source records attributed to Dheilly, N. M..

5 recordsLinked to original sources

bioRxiv2025

Fluke-borne viruses are a risk factor for diseases caused by carcinogenic trematodes

Three trematode parasites, Schistosoma haematobium, Opisthorchis viverrini, and Clonorchis sinensis are recognized group 1 carcinogens for their roles in squamous cell carcinoma of the urinary bladder and bile duct cancer (cholangiocarcinoma). We aimed to assess the presence of fluke viruses and their association with malignancy in fluke infections. We showed that all three carcinogenic trematodes harbored related viruses. Focusing on O. viverrini, we observed virus persistence at discrete life stages and viral tropism for the fluke tegument, and we provided molecular and serological evidence of parasitized hosts exposure to viral RNA and proteins. Serological analyses confirmed seroconversion of residents in endemic sites and revealed that antibody titers and avidity against fluke-borne viruses increase in individuals with hepatobiliary diseases. Random forest models discriminated efficiently between liver-fluke-infected participants without disease and those with periductal fibrosis or cholangiocarcinoma. Thus, we show that fluke-borne viruses are risk factors and diagnostic targets for fluke-associated cancer.

microbiology↗

bioRxiv2021

A world of viruses nested within parasites: Unraveling viral diversity within parasitic flatworms (Platyhelminthes)

Because parasites have an inextricable relationship with their host, they have the potential to serve as viral reservoirs or facilitate virus host-shifts. Yet, little is known about viruses infecting parasitic hosts except for blood-feeding arthropods that are well-known vectors of zoonotic viruses. Herein we uncover viruses of flatworms (Phylum Platyhelminthes, group Neodermata) that specialize in parasitizing vertebrates and their ancestral free-living relatives. We discovered 115 novel viral sequences, including 1 in Macrostomorpha, 5 in Polycladida, 44 in Tricladida, 1 in Monogenea, 15 in Cestoda and 49 in Trematoda, through data mining. The majority of newly identified viruses constitute novel families or genera. Phylogenetic analyses show that the virome of flatworms changed dramatically during the transition of Neodermatans to a parasitic lifestyle. Most Neodermatan viruses seem to co-diversify with their host, with the exception of rhabdoviruses which may switch host more often, based on phylogenetic relationships. Neodermatan rhabodviruses also have an ancestral position to vertebrate-associated viruses, including Lyssaviruses, suggesting that vertebrate rhabdoviruses emerged from a flatworm rhabdovirus in a parasitized host. This study reveals an extensive diversity of viruses in Platyhelminthes and highlights the need to evaluate the role of viral infection in flatworm-associated diseases.

microbiology↗

bioRxiv2019

Characterization of vertically and cross-species transmitted viruses in the cestode parasite Schistocephalus solidus

Parasitic flatworms (Neodermata) represent a public health and economic burden due to associated debilitating diseases and limited therapeutic treatments available. Despite their importance, there is scarce information regarding flatworm-associated microbes. We report the discovery of six RNA viruses in the cestode Schistocephalus solidus. None were closely related to classified viruses and they represent new taxa. Mining transcriptomic data revealed the broad distribution of these viruses in Alaskan and European S. solidus populations. We demonstrate through in vitro culture of S. solidus that five of these viruses are vertically transmitted. With experimental infections and field-sampling, we show that one of the viruses is transmitted to parasitized hosts. The impact of these viruses in parasite fitness and pathogenicity, and in host-parasite co-evolutionary dynamics remains to be determined. The detection of six novel viruses in this first characterization of viruses in Neodermatans likely represents a fraction of virus diversity in parasitic flatworms.

microbiology↗

bioRxiv2018

Genome characterization, prevalence and transmission mode of a novel picornavirus associated with the Threespine Stickleback (Gasterosteus aculeatus)

The complete genome sequence of an RNA virus was assembled from RNA sequencing of virus particles purified from threespine stickleback intestine samples. This new virus is most closely related to the Eel Picornavirus and can be assigned to the genus Potamipivirus in the family Picornoviridae. Its unique genetic properties are sufficient to establish a new species, dubbed the Threespine Stickleback Picornavirus (TSPV). Due to their broad geographic distribution throughout the northern hemisphere and parallel adaptation to freshwater, threespine sticklebacks have become a model in evolutionary ecology. Further analysis using diagnostic PCRs revealed that TSPV is highly prevalent in both anadromous and freshwater populations of threespine sticklebacks and is transmitted vertically to offspring obtained from in vitro fertilization in laboratory settings. It is thus necessary to test the impact of TSPV on the biology of threespine sticklebacks as this widespread virus could interfere with the behavioral, physiological, or immunological studies that employ threespine sticklebacks as model system.\n\nAbstract ImportanceThe threespine stickleback species complex is an important model system in ecological and evolutionary studies because of the large number of isolated divergent populations that are experimentally tractable. For similar reasons, its co-evolution with the cestode parasite Schistocephalus solidus, its interaction with gut microbes, and the evolution of its immune system are of growing interest. Herein we describe the discovery of a RNA virus that infects both freshwater and anadromous populations of sticklebacks. We also show that the virus is transmitted vertically from parent to offspring in laboratory settings, suggesting that most experiments using sticklebacks from these lakes, and potentially others, were conducted in presence of the virus. This discovery can serve as a reminder that the presence of viruses in wild-caught animals for laboratory purpose is possible, even when animals appear healthy. Regarding threespine sticklebacks, the impact of TSPV on the fish biology should be investigated further to ensure that it does not interfere with experimental results.

microbiology↗

bioRxiv2018

Not so sterile after all: The endomicrobiome of plerocercoids of the cestode parasite Schistocephalus solidus and changes to the microbiome of its Threespine Stickleback host

Despite the growing recognition of the role of bacteria in animal biology, the microbiome of parasites remains largely unexplored. In particular, the presence of bacteria in tapeworms has never been investigated and parasites that exit the intestine would be considered sterile. We characterized for the first time the microbiome of a tapeworm. Schistocephalus solidus plerocercoids, collected from the body cavity of its stickleback host, were found to harbor a complex microbiome. The most abundant and the most prevalent bacteria was Polynucleobacter sp.. In addition, S. solidus infection was associated significant changes in the stickleback host gut microbiome with an increase in microbial load and changes in diversity and composition. Finally, the same bacteria were often found in S. solidus and the stomach and intestine of the corresponding hosts, a result that highlights the importance of characterizing the microbiome of host tissues and parasites from the same individuals to assess the potential for horizontal transmission of microbes. This study clearly emphasizes the need for further characterization of the microbiome of a broad range of parasites and for studies to determine the ecological, evolutionary and functional role that microbes play in host-parasite interactions.

microbiology↗