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

2021 ◽  
Author(s):  
Nolwenn M Dheilly ◽  
Yannick Blanchard ◽  
Karyna Rosario ◽  
Pierrick Lucas
Keyword(s):  
Phylogenetic Analyses ◽  
Blood Feeding ◽  
Viral Reservoirs ◽  
Free Living ◽  
Host Shifts ◽  
Zoonotic Viruses ◽  
Need To Evaluate ◽  
Parasitic Lifestyle ◽  
Viral Sequences

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.

scholarly journals Novel Viruses Found in Antricola Ticks Collected in Bat Caves in the Western Amazonia of Brazil

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 48 ◽  
Author(s):  
Anne-Lie Blomström ◽  
Hermes R. Luz ◽  
Pontus Öhlund ◽  
Matthew Lukenge ◽  
Paulo Eduardo Brandão ◽  
...  
Keyword(s):  
Rna Viruses ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Blood Feeding ◽  
Dominant Group ◽  
Data Set ◽  
Adult Feeding ◽  
Viral Sequences ◽  
Negative Sense ◽  
Bat Guano

In this study, we describe the viral composition of adult Antricola delacruzi ticks collected in a hot bat cave in the state of Rondônia, Western Amazonia, Brazil. A. delacruzi ticks, are special, compared to many other ticks, in that they feed on both bats (larval blood feeding) and bat guano (nymphal and adult feeding) instead of feeding exclusively on vertebrate hosts (blood feeding). Considering this unique life-cycle it is potentially possible that these ticks can pick up/be infected by viruses not only present in the blood of viremic bats but also by virus shed through the bat guano. The viral metagenomic investigation of adult ticks showed that single-stranded negative-sense RNA viruses were the dominant group of viruses identified in the investigated ticks. Out of these, members of the Nairoviridae family were in clear majority constituting 88% of all viral reads in the data set. Genetic and phylogenetic analyses indicate the presence of several different orthonairoviruses in the investigated ticks with only distant relationship to previously described ones. In addition, identification of viral sequences belonging to Orthomyxoviridae, Iflaviridae, Dicistroviridae, Polycipiviridae, Reoviridae and different unclassified RNA viruses showed the presence of viruses with low sequence similarity to previously described viruses.

scholarly journals Tick Ecdysteroid Hormone, Global Microbiota/Rickettsia Signaling in the Ovary versus Carcass during Vitellogenesis in Part-Fed (Virgin) American Dog Ticks, Dermacentor variabilis

2021 ◽  
Vol 9 (6) ◽  
pp. 1242
Author(s):  
Loganathan Ponnusamy ◽  
Haley Sutton ◽  
Robert D. Mitchell ◽  
Daniel E. Sonenshine ◽  
Charles S. Apperson ◽  
...  
Keyword(s):  
Hormonal Regulation ◽  
Natural Populations ◽  
Blood Feeding ◽  
Dermacentor Variabilis ◽  
Transovarial Transmission ◽  
Rickettsia Species ◽  
Adult Females ◽  
Dog Tick ◽  
Total Bacteria

The transovarial transmission of tick-borne bacterial pathogens is an important mechanism for their maintenance in natural populations and transmission, causing disease in humans and animals. The mechanism for this transmission and the possible role of tick hormones facilitating this process have never been studied. Injections of physiological levels of the tick hormone, 20-hydroxyecdysone (20E), into part-fed (virgin) adult females of the American dog tick, Dermacentor variabilis, attached to the host caused a reduction in density of Rickettsia montanensis in the carcass and an increase in the ovaries compared to buffer-injected controls. This injection initiates yolk protein synthesis and uptake by the eggs but has no effect on blood feeding. Francisella sp. and R. montanensis were the predominant bacteria based on the proportionality in the carcass and ovary. The total bacteria load increased in the carcass and ovaries, and bacteria in the genus Pseudomonas increased in the carcass after the 20E injection. The mechanism of how the Rickettsia species respond to changes in tick hormonal regulation needs further investigation. Multiple possible mechanisms for the proliferation of R. montanensis in the ovaries are proposed.

scholarly journals NRAMP1 Polymorphism and Viral Factors in Sardinian Multiple Sclerosis Patients

2008 ◽  
Vol 35 (4) ◽  
pp. 491-494 ◽  
Author(s):  
Maria Gazouli ◽  
Leonardo Sechi ◽  
Daniela Paccagnini ◽  
Stefano Sotgiu ◽  
Giannina Arru ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Autoimmune Disease ◽  
Promoter Region ◽  
Viral Infections ◽  
Jc Virus ◽  
Allelic Variation ◽  
Sardinian Population ◽  
Multiple Sclerosis Patients ◽  
Viral Sequences

Background:Multiple sclerosis (MS) is believed to be an autoimmune disease occurring in genetically predisposed individuals after an appropriate environmental exposure such as viral infections. Recent studies suggest a significant association between MS and the functional 5’-(GT)n polymorphism in the promoter region of the NRAMP1 gene. In the present study we aimed to evaluate the contribution of the allelic variation in the NRAMP1 promoter to MS susceptibility and to study the role of viral infection in relation to specific NRAMP1 genotypes, in a Sardinian cohort.Methods:Sixty MS patients and 66 healthy individuals were genotyped, and screened for the presence of Epstein-bar virus (EBV) and JC virus (JCV) sequences.Results:Consistent with previous autoimmune disease studies, allele 3 at the functional 5’(GT)n promoter region repeat polymorphism, was significantly overrepresented among MS patients when compared to controls (p=0.02). The EBV and JCV sequences were detected in 8/60 (13.33%) and in 4/60 (6.66%) of MS patients respectively and in 5/66 (7.57%) and in 0/66 of controls.Conclusion:The allelic variation in the NRAMP1 promoter may contribute to MS susceptibility in the Sardinian population. The viral sequences were not confined to a specific NRAMP1 genotype.

scholarly journals Molecular and Biological Characterisation of Turnip mosaic virus Isolates Infecting Poppy (Papaver somniferum and P. rhoeas) in Slovakia

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 430 ◽  
Author(s):  
Miroslav Glasa ◽  
Katarína Šoltys ◽  
Lukáš Predajňa ◽  
Nina Sihelská ◽  
Slavomíra Nováková ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Turnip Mosaic Virus ◽  
Biological Assays ◽  
Genetic Complexity ◽  
The World ◽  
History Of ◽  
Virus Isolates

In recent years, the accumulated molecular data of Turnip mosaic virus (TuMV) isolates from various hosts originating from different parts of the world considerably helped to understand the genetic complexity and evolutionary history of the virus. In this work, four complete TuMV genomes (HC9, PK1, MS04, MS15) were characterised from naturally infected cultivated and wild-growing Papaver spp., hosts from which only very scarce data were available previously. Phylogenetic analyses showed the affiliation of Slovak Papaver isolates to the world-B and basal-B groups. The PK1 isolate showed a novel intra-lineage recombination pattern, further confirming the important role of recombination in the shaping of TuMV genetic diversity. Biological assays indicated that the intensity of symptoms in experimentally inoculated oilseed poppy are correlated to TuMV accumulation level in leaves. This is the first report of TuMV in poppy plants in Slovakia.

scholarly journals Nematode Hsp90: highly conserved but functionally diverse

Parasitology ◽  
2014 ◽  
Vol 141 (9) ◽  
pp. 1203-1215 ◽  
Author(s):  
VICTORIA GILLAN ◽  
EILEEN DEVANEY
Keyword(s):  
Life Cycle ◽  
Heat Shock Protein 90 ◽  
Ecological Niches ◽  
Actual Number ◽  
Host Organism ◽  
Free Living ◽  
Parasitic Species ◽  
Free Living Nematode ◽  
Functionally Diverse

SUMMARYNematodes are amongst the most successful and abundant organisms on the planet with approximately 30 000 species described, although the actual number of species is estimated to be one million or more. Despite sharing a relatively simple and invariant body plan, there is considerable diversity within the phylum. Nematodes have evolved to colonize most ecological niches, and can be free-living or can parasitize plants or animals to the detriment of the host organism. In this review we consider the role of heat shock protein 90 (Hsp90) in the nematode life cycle. We describe studies on Hsp90 in the free-living nematode Caenorhabditis elegans and comparative work on the parasitic species Brugia pahangi, and consider whether a dependence upon Hsp90 can be exploited for the control of parasitic species.

scholarly journals Evaluation of antibiotics as a methodological procedure to inhibit free-living and biofilm bacteria in marine zooplankton culture

2016 ◽  
Vol 88 (suppl 1) ◽  
pp. 733-746 ◽  
Author(s):  
Vanessa O. Agostini ◽  
Alexandre J. Macedo ◽  
Erik Muxagata
Keyword(s):  
Half Life ◽  
Culture Medium ◽  
Metabolic Inhibitors ◽  
Penicillin G ◽  
Streptomycin Sulphate ◽  
Free Living ◽  
Marine Zooplankton ◽  
Scientific Experiments ◽  
Biofilm Bacteria

There is a problem with keeping culture medium completely or partially free from bacteria. The use of prokaryotic metabolic inhibitors, such as antibiotics, is suggested as an alternative solution, although such substances should not harm non-target organisms. Thus, the aim of this study was to assess the effectiveness of antibiotic treatments in inhibiting free-living and biofilm bacteria and their half-life in artificial marine environment using the copepod Acartia tonsa as bioindicador of non-harmful antibiotic combinations. Regarding to results, the application of 0.025 g L-1 penicillin G potassium + 0.08 g L-1 streptomycin sulphate + 0.04 g L-1 neomycin sulphate showed great potential for use in marine cultures and scientific experiments without lethal effects to non-target organisms. The effect of this combination starts within the first six hours of exposure and reduces up to 93 % the bacterial density, but the half-life is short, requiring replacement. No adverse changes in water quality were observed within 168 hours of exposure. As a conclusion, we can infer that this treatment was an effective procedure for zooplankton cultures and scientific experiments with the aim of measuring the role of free-living and biofilm in the marine community.

scholarly journals Detection and Quantification of Superoxide Formed within the Periplasm of Escherichia coli

2006 ◽  
Vol 188 (17) ◽  
pp. 6326-6334 ◽  
Author(s):  
Sergei Korshunov ◽  
James A. Imlay
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Phagocytic Cells ◽  
Free Living ◽  
E Coli ◽  
Superoxide Formation ◽  
Genes Encoding ◽  
Copper Zinc ◽  
Primary Substrate

ABSTRACT Many gram-negative bacteria harbor a copper/zinc-containing superoxide dismutase (CuZnSOD) in their periplasms. In pathogenic bacteria, one role of this enzyme may be to protect periplasmic biomolecules from superoxide that is released by host phagocytic cells. However, the enzyme is also present in many nonpathogens and/or free-living bacteria, including Escherichia coli. In this study we were able to detect superoxide being released into the medium from growing cultures of E. coli. Exponential-phase cells do not normally synthesize CuZnSOD, which is specifically induced in stationary phase. However, the engineered expression of CuZnSOD in growing cells eliminated superoxide release, confirming that this superoxide was formed within the periplasm. The rate of periplasmic superoxide production was surprisingly high and approximated the estimated rate of cytoplasmic superoxide formation when both were normalized to the volume of the compartment. The rate increased in proportion to oxygen concentration, suggesting that the superoxide is generated by the adventitious oxidation of an electron carrier. Mutations that eliminated menaquinone synthesis eradicated the superoxide formation, while mutations in genes encoding respiratory complexes affected it only insofar as they are likely to affect the redox state of menaquinone. We infer that the adventitious autoxidation of dihydromenaquinone in the cytoplasmic membrane releases a steady flux of superoxide into the periplasm of E. coli. This endogenous superoxide may create oxidative stress in that compartment and be a primary substrate of CuZnSOD.

scholarly journals Potential reverse spillover of infectious bursal disease virus at the interface of commercial poultry and wild birds

Virus Genes ◽  
2020 ◽  
Vol 56 (6) ◽  
pp. 705-711
Author(s):  
Rania F. El Naggar ◽  
Mohammed A. Rohaim ◽  
Muhammad Munir
Keyword(s):  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Potential Role ◽  
Wild Birds ◽  
Infectious Bursal Disease ◽  
Free Living ◽  
Bean Goose ◽  
Bursal Disease ◽  
Commercial Poultry

AbstractRecently, multiple spillover events between domesticated poultry and wild birds have been reported for several avian viruses. This phenomenon highlights the importance of the livestock-wildlife interface in the possible emergence of novel viruses. The aim of the current study was to investigate the potential spillover and epidemiological links of infectious bursal disease virus (IBDV) between wild birds and domestic poultry. To this end, twenty-eight cloacal swabs were collected from four species of free-living Egyptian wild birds (i.e. mallard duck, bean goose, white-fronted goose and black-billed magpie). Genetic and phylogenetic analysis of three positive isolates revealed that the IBDV/USC-1/2019 strain clustered with previously reported very virulent IBDV (vvIBDV) Egyptian isolates. Interestingly, two other wild bird-origin isolates (i.e. IBDV/USC-2/2019 and IBDV/USC-3/2019) grouped with a vaccine strain that is being used in commercial poultry. In conclusion, our results revealed the molecular detection of vaccine and vvIBDV-like strains in Egyptian wild birds and highlighted the potential role of wild birds in IBDV epidemiology in disease-endemic regions.

scholarly journals Immunity to pathogenic free-living amoebae: role of cell-mediated immunity

1980 ◽  
Vol 29 (2) ◽  
pp. 408-410
Author(s):  
R T Cursons ◽  
T J Brown ◽  
E A Keys ◽  
K M Moriarty ◽  
D Till
Keyword(s):  
Immune System ◽  
Inhibition Test ◽  
Delayed Hypersensitivity ◽  
Cell Mediated Immunity ◽  
Pathogenic Species ◽  
Free Living

The role of cell-mediated immunity in defense against pathogenic free-living amoebae was examined. Both the in vitro macrophage inhibition test and the in vivo delayed hypersensitivity test showed responses to both heterologous and homologous antigens, although homologous systems were the most efficient. It is suggested that exposure to nonpathogenic species of free-living amoebae can stimulate the immune system to be effective against pathogenic species. The significance of cell-mediated immunity as a defense against invasion by pathogenic free-living amoebae is discussed.

scholarly journals Eat Tasty and Healthy: Role of Polyphenols in Functional Foods

2021 ◽  
Author(s):  
Catarina Bessa-Pereira ◽  
Ricardo Dias ◽  
Elsa Brandão ◽  
Nuno Mateus ◽  
Victor de Freitas ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Phenolic Compounds ◽  
Functional Foods ◽  
Unmet Need ◽  
Protective Effects ◽  
Immune Reactions ◽  
Public Health Burden ◽  
Organoleptic Characteristics ◽  
Need To Evaluate

Adverse reactions to food such as allergies and celiac disease are increasingly recognized as a growing public health burden. There is currently no cure for these diseases so that there is an unmet need to evaluate different nutritional approaches aiming at improving the quality of life of affected patients and their families. In this context, healthy promising nature-derived compounds, most of which contained in fruits and vegetables, have been studied as an alternative to attenuate the epidemic. Indeed, phenolic compounds have become an emerging field of interest in nutrition in the last decades. A growing build of research suggests that phenolic compounds inhibit pro-inflammatory transcription factors by interacting with proteins involved in gene expression and cell signaling, leading to protective effects against many inflammation-mediated chronic diseases. However, the use of phenolic compounds as attenuating agents of immune reactions to food has to be aligned to the organoleptic characteristics of food, since many compounds present unpleasant taste properties, namely bitter taste and astringency. In this framework, tasty but healthy phenolic compounds arise as attractive ingredients in the design and formulation of functional foods. This book chapter is focused on revisiting the organoleptic properties of phenolic compounds while evaluating the role of these compounds in health promoting actions, namely the management of immune reactions to food such as Food Allergies and Celiac Disease.

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