Biology subjects

Hanington, P. C.

Publications and source records attributed to Hanington, P. C..

4 recordsLinked to original sources

bioRxiv2025

Snail-trematode dynamics in central Alberta wetlands: A longitudinal survey of infections and interactions

Previous research has shown that host diversity and heterogeneity promote parasite abundance and heterogeneity by creating additional niches for parasites to occupy. Central Alberta, Canada, sees a diverse array of native and migratory species each year. A previous snail-trematode survey conducted at six lakes in central Alberta from 2013-2015 uncovered 79 trematode species. However, analyses suggested that additional species remained to be uncovered. To build on this baseline, we conducted further snail-trematode collections from 2019 to 2022 at eight reclaimed wetland sites in various stages of reclamation, along with one established lake in Alberta. Across the nine sites, we collected 22,397 snails, of which 1,981 were infected with digenean trematodes. We also documented broader biodiversity at these sites using traditional survey techniques. Through DNA barcoding, we identified 74 trematode species infecting five snail species. Among these were 23 trematode species not previously reported in central Alberta and nine putative novel species. In addition, we observed several previously unreported snail-trematode interactions. While trematode richness did not vary significantly with the wetland reclamation stage, host identity did influence richness: Physa gyrina hosted significantly more trematode species than Planorbella trivolvis. When combined with data from the earlier survey, sample completeness analyses indicate that we captured 100% of the dominant species and 99% of the typical species, but only 63% of the overall species diversity in central Alberta. These findings underscore that trematode diversity in central Alberta remains underestimated and highlight the continued value of long-term and host-inclusive sampling efforts.

ecology↗

bioRxiv2022

Schistosoma mansoni cercarial invadolysin cleaves complement C3 and suppresses proinflammatory cytokine production

Schistosoma mansoni employs immune evasion and immunosuppression to overcome immune responses mounted by its snail and human hosts. Myriad immunomodulating factors underlie this process, some of which are proteases. Here, we demonstrate that one protease, an invadolysin we have termed SmCI-1, is released from the acetabular glands of S. mansoni cercaria and is involved in creating an immunological milieu favorable for survival of the parasite. We confirm the presence of SmCI-1 in the cercarial stage of S. mansoni and demonstrate that it is released during transformation into the schistosomula. We confirm SmCI-1 functions as a metalloprotease with the capacity to cleave collagen type IV, gelatin and fibrinogen. We also show that complement component C3b is cleaved by this protease, resulting in inhibition of the classical and alternative complement pathways. Finally, we assess the effect of SmCI-1 on cytokine release from human peripheral blood mononuclear cells, providing compelling evidence that SmCI-1 promotes an anti-inflammatory microenvironment by enhancing production of IL-10 and suppressing the production of inflammatory cytokines like IL-1B and IL-12p70 and those involved in eosinophil recruitment and activation, like eotaxin-1 and IL-5.

immunology↗

bioRxiv2021

Transient definitive host presence is sufficient to sustain avian schistosome populations

To control swimmers itch in northern Michigan inland lakes, one species of bird, the common merganser (Mergus merganser), has been relocated from several lakes since 2015. Relocation efforts are driven by a desire to reduce the prevalence of the swimmers itch-causing parasite Trichobilharzia stagnicolae. The intention of this state-sponsored control effort was to interrupt the life cycle of T. stagnicolae and reduce parasite egg contribution into the environment from summer resident mergansers such that infections of the intermediate snail host Stagnicola emarginata declined. Reduced snail infection prevalence was expected to greatly reduce abundance of the swimmers itch-causing cercarial stage of the parasite in water. With no official program in place to assess the success of this relocation effort, we sought to study the effectiveness and impact of the removal of a single definitive host from a location with high definitive host and parasite diversity. This was assessed through a comprehensive, lake-wide monitoring study measuring longitudinal changes in the abundance of three species of avian schistosome cercariae in four inland Michigan lakes. Environmental measurements were also taken at these lakes to understand how they can affect swimmers itch incidence. Results from this study demonstrate that the diversity of avian schistosomes at the study lakes would likely make targeting of a single species of swimmers itch-causing parasite meaningless from a swimmers itch control perspective. Our data also suggest that removal of the common merganser is not an effective control strategy for the T. stagnicolae parasite, likely due to parasite contributions of migratory birds in the fall and spring. This suggests that only minimal contact time between the definitive host and the lake ecosystem is required to contribute sufficient parasite numbers to maintain a thriving population of parasite species with a high host-specificity.

ecology↗

bioRxiv2020

Democratizing water monitoring: Implementation of a community-based qPCR monitoring program for recreational water hazards.

Recreational water monitoring can be challenging due to the highly variable nature of pathogens and indicator concentrations, the myriad of potential biological hazards to measure for, and numerous access points, both official and unofficial, that are used for recreation. The aim of this study was to develop, deploy, and assess the effectiveness of a quantitative polymerase chain reaction (qPCR) community-based monitoring (CBM) program for the assessment of bacterial and parasitic hazards in recreational water. This study developed methodologies for performing qPCR in the field, then engaged with water management and monitoring groups, and tested the method in a real-world implementation study to evaluate the accuracy of CBM using qPCR both quantitatively and qualitatively. This study found high reproducibility between qPCR results performed by non-expert field users and expert laboratory results, suggesting that qPCR as a methodology could be amenable to a CBM program.

scientific communication and education↗