Parasitism in the environment
The study of biodiversity has been revolutionised by the molecular era, where high throughput molecular methods can screen environments for new diversity on unprecedented scales. Crucially, molecular methods allow easy access to that microbial diversity not visible to the naked eye. However, one trophic group that are rarely targeted using this strategy are the parasites.
Parasites are important regulators of population size, help define community structures, and a likely a major component of biological diversity. Importantly they also can represent a risk for new disease and infection in wildlife and humans, yet are largely overlooked in terms of biodiversity sampling.
We are carrying out a study of parasite diversity in the environment by surveying the diversity of microsporidia parasites using a high-throughput 454 sequencing approach. Microsporidia are a phylum of eukaryotic parasites, with species infecting just about every animal lineage. Till now, approximately 1200 species have been described, with most infections found in invertebrates and fish. However, since the spread of HIV-AIDS, microsporidia have become common infections of immunocompromised patients with the potential to cause loss of life. They are also important agricultural parasites and have recently implicated in honeybee colony collapse disorder.
Surveying UK invertebrates for microsporidian infection:
Kristina Hamilton sampling around Devon.
Kristina Hamilton (NERC postdoctoral research associate) is collecting invertebrates from six ecological sites around Devon: Bog, forest soil, rockpool, estuarine mud, oligotrophic freshwater and eutrophic freshwater and the Clyde Estuary. All collected organisms are ground in liquid nitrogen to ensure rupture of both macro-eukaryotic material and any microsporidian spores present in the sample and invertebrate hosts and DNA is extracted using a Phenol/Chloroform/Isoamyl alcohol protocol followed by an ethanol precipitation step. PCR is carried on these samples using the microsporidian specific primer V1F and universal SSU primer 530R including both negative and positive controls. Products will be separated by gel electrophoresis and amplicons within the expected size range of between 390 and 450 base pairs will be excised and gel-purified. All diverse samples will be pooled for 454-sequencing to uncover undiscovered microsporidian diversity.
Surveying UK honeybees for parasites:
Working with Devon Beekepers to collect samples of Nosema.
In association with two MSc. students from the University of Exeter, Jenny Millard and Shabbir Khorakiwala, we are looking at the diversity of microsporidia and other parasites in UK honeybees. This project has been started as a collaboration with Giles Budge at the National Bee Unit and we have received samples thanks to the Devon Beekeepers Association. Shabbir will be surveying survey honeybees for the presence of Crithidia and related parasites. Jenny will be investigating whether different strains of microsporidia parasites in the genus Nosema can be detected in Devon honeybees.
