Journal: Parasitology

Abbreviation

Parasitology

Publisher

Cambridge University Press

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ISSN

0031-1820
1469-8161

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Publications 1 - 10 of 16
  • Temperature-related parasite infection dynamics: the case of proliferative kidney disease of brown trout
    Item type: Journal Article
    Strepparava, Nicole; Segner, Helmut; Ros, Albert; et al. (2018)
    Parasitology
    Climate change, in particular rising temperature, is suspected to be a major driver for the emergence of many wildlife diseases. Proliferative kidney disease of salmonids, caused by the myxozoan Tetracapsuloides bryosalmonae, was used to evaluate how temperature dependence of host–parasite interactions modulates disease emergence. Brown trout (Salmo trutta fario) kept at 12 and 15 °C, were experimentally infected with T. bryosalmonae. Parasite development in the fish host and release of spores were quantified simultaneously to unravel parasite transmission potential from the vertebrate to the invertebrate host. A change to a stable plateau in infection intensity of the kidney coincided with a threshold at which spore shedding commenced. This onset of parasite release was delayed at the low temperature in accordance with reaching this infection intensity threshold, but the amount of spores released was irrespective of temperature. The production of parasite transmission stages declined with time. In conclusion, elevated temperature modifies the parasite transmission opportunities by increasing the duration of transmission stage production, which may affect the spread and establishment of the parasite in a wider range of rivers.
  • Acanthocephalan size and sex affect the modification of intermediate host colouration
    Item type: Journal Article
    Benesh, D. P.; Seppälä, O.; Valtonen, E. T. (2009)
    Parasitology
  • Conditional persistence and tolerance characterize endoparasite-colonial host interactions
    Item type: Journal Article
    Fontes, Inês; Hartikainen, Hanna; Taylor, Nick G.H.; et al. (2017)
    Parasitology
    Colonial hosts offer unique opportunities for exploitation by endoparasites resulting from extensive clonal propagation, but these interactions are poorly understood. The freshwater bryozoan, Fredericella sultana, and the myxozoan, Tetracapsuloides bryosalmonae, present an appropriate model system for examining such interactions. F. sultana propagates mainly asexually, through colony fragmentation and dormant propagules (statoblasts). Our study examines how T. bryosalmonae exploits the multiple transmission routes offered by the propagation of F. sultana, evaluates the effects of such transmission on its bryozoan host, and tests the hypothesis that poor host condition provokes T. bryosalmonae to bail out of a resource that may soon be unsustainable, demonstrating terminal investment. We show that infections are present in substantial proportions of colony fragments and statoblasts over space and time and that moderate infection levels promote statoblast hatching and hence effective fecundity. We also found evidence for terminal investment, with host starvation inducing the development of transmission stages. Our results contribute to a growing picture that interactions of T. bryosalmonae and F. sultana are generally characterized by parasite persistence, facilitated by multiple transmission pathways and host condition-dependent developmental cycling, and host tolerance, promoted by effective fecundity effects and an inherent capacity for renewed growth and clonal replication.
  • Whole transcriptome analysis of the poultry red mite Dermanyssus gallinae (De Geer, 1778)
    Item type: Journal Article
    Schicht, Sabine; Qi, Weihong; Poveda, Lucy; et al. (2014)
    Parasitology
  • Naturally acquired immunity to Plasmodium pitheci in Bornean orangutans (Pongo pygmaeus)
    Item type: Journal Article
    Sánchez, Karmele Llano; Baird, John Kevin; Nielsen, Aileen; et al. (2024)
    Parasitology
    Naturally acquired immunity to the different types of malaria in humans occurs in areas of endemic transmission and results in asymptomatic infection of peripheral blood. The current study examined the possibility of naturally acquired immunity in Bornean orangutans, Pongo pygmaeus, exposed to endemic Plasmodium pitheci malaria. A total of 2140 peripheral blood samples were collected between January 2017 and December 2022 from a cohort of 135 orangutans housed at a natural forested Rescue and Rehabilitation Centre in West Kalimantan, Indonesia. Each individual was observed for an average of 4.3 years during the study period. Blood samples were examined by microscopy and polymerase chain reaction for the presence of plasmodial parasites. Infection rates and parasitaemia levels were measured among age groups and all 20 documented clinical malaria cases were reviewed to estimate the incidence of illness and risk ratios among age groups. A case group of all 17 individuals that had experienced clinical malaria and a control group of 34 individuals having an event of >2000 parasites mu L-1 blood but with no outward or clinical sign of illness were studied. Immature orangutans had higher-grade and more frequent parasitaemia events, but mature individuals were more likely to suffer from clinical malaria than juveniles. The case orangutans having patent clinical malaria were 256 times more likely to have had no parasitaemia event in the prior year relative to asymptomatic control orangutans. The findings are consistent with rapidly acquired immunity to P. pitheci illness among orangutans that wanes without re-exposure to the pathogen.
  • Host genotype and infection status interact to shape microbiomes in Daphnia magna
    Item type: Journal Article
    Rajarajan, Amruta; Decaestecker, Ellen; Bulteel, Lore; et al. (2024)
    Parasitology
    Host-bacterial communities (microbiomes) are influenced by a wide range of factors including host genotype and parasite exposure. However, few studies disentangle temporal and host- genotype-specific variation in microbiome response to infection across several host tissues. We experimentally exposed the freshwater crustacean Daphnia magna to its fungal parasite Metschnikowia bicuspidata and characterized changes in host-bacterial communities associated with the parasite's development within the host. We used 16S rRNA gene sequencing to assess bacterial communities of the host (a) 24 h ('initial parasite exposure') and (b) 10 days ('successful infection') after exposure to a standard dose of M. bicuspidata spores, in host guts, body tissue (excluding guts) and whole individuals. We also investigated whether bacterial community responses to parasite exposure varied by host genotype. Parasite exposure did not immediately alter host gut bacterial communities, but drove host- genotype-specific changes in the bacterial community composition of whole individuals. We validated that these changes were not driven by shifts in bacterial communities of the culturing medium, due to the addition of the parasite spore solution. Successful infection (i.e. the proliferation of M. bicuspidata spores in the host body) reduced alpha diversity and shifted abundance of dominant bacterial orders in the gut. Moreover, it induced a host-genotype-specific changes in body bacterial community composition. Overall, bacterial community responses to parasite exposure and subsequent infection are complex: they occur in a host-genotype-dependent manner, differentially at distinct timepoints after parasite exposure, and in specific host tissue.
  • A formative appraisal of female genital schistosomiasis (FGS) score card results against point-of-care gynaecological and molecular parasitological information within four counties of Liberia
    Item type: Journal Article
    Bell-Gam Woto, Ayesha E.R.; Cunningham, Lucas J.; Bettee, Anthony K.; et al. (2025)
    Parasitology
    Liberia (West Africa) has an extensive (co)burden of urogenital and intestinal schistosomiasis; each largely restricted to more inland areas. Where urogenital schistosomiasis is endemic, as both disease surveillance and case management are nascent, many women may unknowingly be living with Female Genital Schistosomiasis (FGS). Using a recently developed FGS score card, we appraised FGS score card valuations with point-of-care gynaecological and molecular parasitological evaluations as undertaken within typical primary care settings of four Liberian counties. A total of 400 women, 100 participants from each of four endemic inland counties, underwent a cursory gynaecological examination using a speculum for visible FGS lesions, undertaken by a midwife, and provided a urine sample that was examined by centrifugation with microscopy for Schistosoma ova. Urine-sediments in ethanol were later analysed with a high-resolution melt (HRM) real-time (rt) PCR assay to screen for Schistosoma genetic markers. Using a combination of clinical and parasitological information, overall prevalence of UGS and FGS was <10% and a single case of putative FGS-associated co-infection with Schistosoma mansoni was observed. Participant interviews with the FGS score cards provided an insight into at-risk lifestyle and environmental factors, e.g. women who fished regularly were more likely to present with FGS whereas those who lived > 15 km from a local river were less likely to present with FGS. In this resource-poor setting of Liberia, active surveillance for FGS with either clinical or parasitological methods remains challenging such that sole future use of the FGS score card is most pragmatic for primary care.
  • Seasonal changes in host phenotype manipulation by an acanthocephalan
    Item type: Journal Article
    Benesh, D.P.; Hasu, T.; Seppälä, O.; et al. (2009)
    Parasitology
Publications 1 - 10 of 16