Wednesday/Mercredi, May/Mai 8
8:30-10:30
PIE symposium
A slice of PIE in the Maritimes
Location/Lieu: Shediac A
Chair/Animé par: Laura Ferguson (Acadia University)
8:30-9:10
Lloyd V.K.
Department of Biology, Mount Allison University, Sackville, NB, Canada
The trouble with tick tourism – ticks and tick-borne pathogens in the Canadian Maritimes
Ticks are ectoparasites that transmit a greater variety of zoonotic pathogens than any other arthropod vector. Under the influence of climate change and other factors, the species composition of ticks in Canada has been changing. Expansion of generalist tick species, Ixodes scapularis, the black legged tick, and Dermacentor variabilis, the wood or American dog tick, being the most notable. We have documented both increasing tick presence, and pathogen presence in the Canadian Maritime Provinces. This pattern of tick range expansion is likely to include further invasive tick species such as Amblyomma americanum, the lone star tick. In addition to importing pathogens, invasive tick species have the potential to hybridize with local tick species, which may enhance pathogen transfer and population establishment. Another factor potentially driving pathogen prevalence is increased survival and questing of infected ticks. Investigation of epigenetic drivers of altered gene expression in Borrelia-infected ticks has revealed no DNA methylation changes but changes in the expression of a euchromatic histone methyl transferase. These findings offer a pathway to better understand the impact of pathogens on tick gene regulation and physiology, and ultimately a means to better understand the risk posed by ticks and the zoonotic pathogens that they vector.
9:10-9:50
Riley, J.L.
Mount Allison University, Sackville, NB, Canada
Disease Monitoring in Canadian Amphibians and Reptiles
One major threat to biodiversity is disease, and amphibians are one taxonomic group that has been severely impacted. Since discovery of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), in 1998, it has driven extinction of 90 species and declines of ~500 others. Today novel pathogens continue to impact amphibians, as well as reptiles, and both groups are of conservation concern with 41% and 38% of species, respectively, at risk of extinction. In 2013, a new chytrid fungus, Batrachochytrium salamandrivorans (Bsal), was described after it resulted in a devastating decline of Fire Salamanders in the Netherlands. Its presence has yet to be documented in North America but is likely due to the pet trade with Europe. So, a surveillance program for Bsal called the Student Network of Amphibian Pathogen Surveillance (SNAPS) was established. In Canada, SNAPS is coordinated by the Canadian Wildlife Health Cooperative and, to date, Bsal has not been detected. I will summarise our surveillance efforts since 2022. In reptiles, the fungus that causes ophidiomycosis or snake fungal disease (SFD), Ophidiomyces ophiodiicola, was described in 2009 and has been reported across most of the USA and Great Lakes region of Ontario and Québec. In 2022, my lab investigated whether O. ophiodiicola is present in New Brunswick and Nova Scotia. I will present and interpret our findings and discuss on-going plans for a national monitoring program. Further research on amphibian and reptile disease will advance their conservation and ensure continuation of the services they provide for ecosystem and human health.
9:50-10:30
Shutler D.
Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada
On parasites in food webs
Parasites are important participants in food webs, and despite repeated pleas for considering them, there has been limited attention to quantifying their contribution. Those studies that have been published tend to have a restricted taxonomic focus, and there has been virtually no consideration of the participation of viruses or bacteria. Moreover, research has been restricted largely to quantifying biomass as a proxy of energy use within food webs, but parasites also divert energy by selecting hosts to maintain and upregulate immune function and by requiring hosts to invest in tissue repair. An often overlooked effect of parasites is energy investment in sexually selected ornaments that honestly reflect a bearer’s health. Finally, parasites may provoke extended phenotypes, as for example in gigantism in snails. Understandably, research in this area is hampered by the complexity of these processes and of the difficulty in quantifying entire parasite communities. As additional caveats, there can be considerable spatiotemporal variability in both host and parasite communities. Nonetheless, against this backdrop, progress will be limited until dedicated investments are made.
Chair/Animé par: Laura Ferguson (Acadia University)
8:30-9:10
Lloyd V.K.
Department of Biology, Mount Allison University, Sackville, NB, Canada
The trouble with tick tourism – ticks and tick-borne pathogens in the Canadian Maritimes
Ticks are ectoparasites that transmit a greater variety of zoonotic pathogens than any other arthropod vector. Under the influence of climate change and other factors, the species composition of ticks in Canada has been changing. Expansion of generalist tick species, Ixodes scapularis, the black legged tick, and Dermacentor variabilis, the wood or American dog tick, being the most notable. We have documented both increasing tick presence, and pathogen presence in the Canadian Maritime Provinces. This pattern of tick range expansion is likely to include further invasive tick species such as Amblyomma americanum, the lone star tick. In addition to importing pathogens, invasive tick species have the potential to hybridize with local tick species, which may enhance pathogen transfer and population establishment. Another factor potentially driving pathogen prevalence is increased survival and questing of infected ticks. Investigation of epigenetic drivers of altered gene expression in Borrelia-infected ticks has revealed no DNA methylation changes but changes in the expression of a euchromatic histone methyl transferase. These findings offer a pathway to better understand the impact of pathogens on tick gene regulation and physiology, and ultimately a means to better understand the risk posed by ticks and the zoonotic pathogens that they vector.
9:10-9:50
Riley, J.L.
Mount Allison University, Sackville, NB, Canada
Disease Monitoring in Canadian Amphibians and Reptiles
One major threat to biodiversity is disease, and amphibians are one taxonomic group that has been severely impacted. Since discovery of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), in 1998, it has driven extinction of 90 species and declines of ~500 others. Today novel pathogens continue to impact amphibians, as well as reptiles, and both groups are of conservation concern with 41% and 38% of species, respectively, at risk of extinction. In 2013, a new chytrid fungus, Batrachochytrium salamandrivorans (Bsal), was described after it resulted in a devastating decline of Fire Salamanders in the Netherlands. Its presence has yet to be documented in North America but is likely due to the pet trade with Europe. So, a surveillance program for Bsal called the Student Network of Amphibian Pathogen Surveillance (SNAPS) was established. In Canada, SNAPS is coordinated by the Canadian Wildlife Health Cooperative and, to date, Bsal has not been detected. I will summarise our surveillance efforts since 2022. In reptiles, the fungus that causes ophidiomycosis or snake fungal disease (SFD), Ophidiomyces ophiodiicola, was described in 2009 and has been reported across most of the USA and Great Lakes region of Ontario and Québec. In 2022, my lab investigated whether O. ophiodiicola is present in New Brunswick and Nova Scotia. I will present and interpret our findings and discuss on-going plans for a national monitoring program. Further research on amphibian and reptile disease will advance their conservation and ensure continuation of the services they provide for ecosystem and human health.
9:50-10:30
Shutler D.
Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada
On parasites in food webs
Parasites are important participants in food webs, and despite repeated pleas for considering them, there has been limited attention to quantifying their contribution. Those studies that have been published tend to have a restricted taxonomic focus, and there has been virtually no consideration of the participation of viruses or bacteria. Moreover, research has been restricted largely to quantifying biomass as a proxy of energy use within food webs, but parasites also divert energy by selecting hosts to maintain and upregulate immune function and by requiring hosts to invest in tissue repair. An often overlooked effect of parasites is energy investment in sexually selected ornaments that honestly reflect a bearer’s health. Finally, parasites may provoke extended phenotypes, as for example in gigantism in snails. Understandably, research in this area is hampered by the complexity of these processes and of the difficulty in quantifying entire parasite communities. As additional caveats, there can be considerable spatiotemporal variability in both host and parasite communities. Nonetheless, against this backdrop, progress will be limited until dedicated investments are made.