Avian Schistosome Biodiversity
The subclass Digenea, with more than 2,500 genera, and 18,000 species worldwide exemplifies one of the most spectacular radiations among metazoan parasites. Adult digenetic trematodes are obligate parasites in most vertebrates. Digeneans have a unique dependence on mollusks as first intermediate hosts in which they reproduce asexually thus immensely increasing the number of infective larvae, one of the most distinctive attributes enabling their success. Representatives of several phyla serve as second intermediate hosts. As a result, these parasites inhabit a number of phyla and have colonized nearly every organ in their hosts. One of the most distinctive, biologically intriguing and medically significant families of digeneans is the Schistosomatidae.
Schistosomes are significant pathogens of birds and mammals. They are primarily associated with freshwater habitats and are found in temperate and tropical regions of the world. Schistosomes are biologically fascinating due to such features as dioecy, sexual dimorphism and a two-host life cycle: bird or mammal and snail. Some species cause schistosomiasis, a chronic debilitating disease in humans and domestic animals. Because of their profound medical and veterinary importance, the systematics and diversity of the four genera and 25 species of mammalian schistosomes are relatively well known. In contrast, study of the six genera and 60 species of avian schistosomes has suffered due to lack of expertise and challenges applying traditional methods of study. Lack of a sound systematic framework has, until recently, greatly impeded our understanding of cercarial dermatitis (swimmer’s itch) caused by these organisms.
Our work since 2004, greatly aided by NSF funding, to discover the biodiversity of schistosomes and their hosts has led to several interesting observations:
1. A majority of the species diversity of schistosomes uses bird definitive hosts.
2. Diversification by host switching into new snail hosts may be one of the major mechanisms, then secondarily schistosome species diversity is correlated with defnitive host ecological diversity and fidelity (in the case of migratory birds).
3. We have found more diversity in the cercarial stages from snails than adults from birds or mammals.
4. The genus Trichobilharzia is the most speciose of the schistosome genera. These parasites occur almost exclusively a few clades of ducks and one species has been found in geese. Thus far they use two families of snails as intermediate hosts, Physidae and Lymnaeidae.
5. Along with our collaborators, to date, we have found 20 distinct lineages of avian schistosomes from North and South America, Kenya, South Africa, Nepal, China, New Zealand, and Iran.
6. These diversity studies alone contributed to a better understanding of the epidemiology of cercarial dermatitis, or swimmer's itch and resulted in a nice review paper as well as the foundational background for development of probes to more quickly assess species and dermatitis risk in waters.
7. Currently there is an effort to use the large amounts of data and diversity to look more specifically at a few species of avian schistosomes using phylogeographic and population genetic approaches to ask how host traits influence parasite evolution and population dynamics.
|July 2017 - Sara Brant, Erika Gendron (Ebbs) and Sam Loker travel to Edmonton Alberta, Canada for the American Society of Parasitologist national meeting and each gave oral presentations.
April 2017 - Sara Brant travel to Lake Texoma to the meeting of the Southwestern Society of Parasitology.
October 2016 - Sara Brant travels to North Dakota to work on NSF project with Vasyl Tkach.
September 2016 - Vasyl Tkach travels to New Mexico to work on NSF project with Sara Brant and Sam Loker.
July 2016 - Sara Brant, Emily Sarvis, and Sam Loker travel to Edmonton Alberta, Canada for the American Society of Parasitologist national meeting and each gave presentations.
April 2016 - Sara Brant and Emily Sarvis (NSF REU) travel to Lake Texoma to the meeting of the Southwestern Society of Parasitology. Emily gave an oral presentation.
January 2016 - Erika Gendron (Ebbs) and Emily Sarvis (NSF REU) travel to North Carolina to collect schistosomes from ducks.
November 2015 - Erika Gendron (Ebbs) goes to Florida to collect schistosomes from snails and ducks.
June 2015 - Sara Brant, Sam Loker and Erika Gendron (Ebbs) travel to Omaha, Nebraska for the American Society of Parasitologist national meeting and all gave presentations.
April 2015 - Sara Brant, Erika Gendron (Ebbs) and Emily Sarvis (NSF REU) travel to Lake Texoma to the meeting of the Southwestern Society of Parasitology. Erika gave an oral presentation.
July 2014 - Sara Brant, Sam Loker and Erika Gendron (Ebbs) travel to New Orleans, Louisiana for the American Society of Parasitologist national meeting and all gave presentations.
July 2014 - Sam Loker and Sara Brant travel to Rocky Mountain Biological Station to collect snails from high elevation ponds for schistosomes with collaborator, Dr. John Mischler
June 2014 - Sara Brant is invited to University of Reims, France, to work with one of the other leading schistosome researchers, Dr. Damien Jouet, as well as his colleague, Dr. Hubert Ferte. The focus was the genus Trichobilharzia.
May 2014 - Sara Brant and Erika Gendron travel to northern Argentina to collect birds and snails, working with Kevin McCracken and his student Matt Smith.
April 2014 - Sara Brant, Erika Gendron and Keith Keller travel to Lake Texoma to the meeting of the Southwestern Society of Parasitology. Erika gave an oral presentation and Keith presented a poster.
June 2013 - Sara Brant, Sam Loker and Erika Gendron travel to Quebec City, Quebec Canada for the American Society of Parasitologist national meeting and all gave presentations. Sam gives the Presidential Address.
June 2013 - a new genus of schistosome is described, Anserobilharzia! Brant, Jouet, Ferte, & Loker 2013 Zootaxa
April 2013 - Sara Brant, Erika Gendron and Keith Keller travel to Lake Texoma to the meeting of the Southwestern Society of Parasitology. Erika gave an oral presentation.
April 2013 - Erika Gendron present some of her results on population history of Trichobilharzia querquedulae at the Biology Department Research Day
April 2013 - Sam Loker is invited to attend are present in Cambridge, England for The Evolution of Parasite Genomes and Origins of Parasitosm Symposium, on the work we have been doing.
March 2013 - Erika and Keith travel to northwestern New Mexico to collect ducks for schistosomes. Sam is invited to present at the Japanese Society of Parasitologists, Tokyo, Japan. Sam attends the Southeastern Society of Parasitologists in Bowling Green, Kentucky.
February 2013: NSF funds REU Supplement for the REVSYS grant. Keith Keller joins the lab as a new REU student.
January 2013 - Erika Gendron travels to central Florida to search for avian schistosomes in ducks and snails.
November 2012 - Visit from Dr. Sean Locke. Sam presents at the American Society of Tropical Medicine and Hygeine conference.
October 2012 - Meet with our database programmer for Arctos to improve the interface to include parasites. This database will include parasite AND host information as well as active links to the host if it is in a collection, GenBank accession numbers, publications, images and any other link appropriate for that sample. Go to http://arctos.database.museum/home.cfm and search under MSB Parasites to see what schistosomes have been deposited so far, about 61 records.
July 2012 - Sara Brant, Sam Loker and Erika Gendron travel to Richmond VA for the American Society of Parasitologist national meeting and all gave presentations.
June 2012 - Sara Brant travels to China to work with Dr. Yi Zhang from the Chinese CDC on finding and identifying avian schistosomes from type localities or localities from which cases of swimmer's itch have been reported. Erika Gendron collects snails for avian schistosomes in Montana and California.
April 2012 - Sara Brant, Erika Gendron and D'Eldra Malone travel to Lake Texoma for the meeting of the Southwestern Society of Parasitology and all gave presentations.
March 2012 - Erika Gendron present research proposal work on avian schistosome diversity at the Biology Department Research Day.
February 2012: NSF funds REU Supplement for the REVSYS grant
January 2012 - Sara Brant and Erika Gendron go to Free State, South Africa to collect avian schistosomes. Sam Loker goes to Kenya to include collection of avian schistosomes
October 2011 - Erika Gendron goes to UND to work with Vasyl Tkach
August 2011 - UNM welcomes grad student Erika Gendron who will be working on various aspects of this project.
August 2011 - Vasyl Tkach collects birds and snails in Ukraine
July 2011 - REU student D'Eldra Malone who will be working on various aspects of this project.
5-13 June 2011 - Sara Brant and Vasyl Tkach collected snails and ducks in Alaska. Collected several taxa of schistosomes for which we needed whole worms. Rob Wilson (and his dog Gabby) from USGS in Anchorage helped with collecting the birds.
1-4 June 2011 - Attended the American Soceity of Parasitologist meeting in Anchorage, Alaska.
14 February 2011: NSF funds REU Supplement for the REVSYS grant
1 August 2010: NSF funds COLLABORATIVE RESEARCH-REVSYS: Phylogenetic and revisionary systematics of a diverse clade of avian schistosomes (Platyhelminthes: Schistosomatidae). Click here to learn more.
© copyright 2017 Sara V. Brant, University of New Mexico