Comparing Common Techniques for Calculating Parasite Prevalence

Raccoons (Procyon lotor) are the final host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease, known as larva migrans encephalopathy. Diagnostic tools for detecting the presence of B. procyonis within a raccoon population include necropsy, fecal flotation, and latrine analysis. Necropsies yield the highest measure of prevalence, with fecal flotation and latrine analysis often underestimating infection rates. We necropsied 225 raccoons gathered from 10 townships of Clark and Greene Counties in Ohio. We collected fecal samples from 95 raccoons negative for B. procyonis at necropsy. We suspended the feces in Sheather’s solution to float any eggs, and prepared slides from this solution. Nearly 14% of raccoons negative at necropsy for B. procyonis possessed eggs in their feces. We used a chi squared test for equality of distributions to determine the likelihood that a positive fecal analysis is related to B. procyonis prevalence or to the area in which the raccoon was trapped. These data will help us determine how well fecal analyses estimate parasite prevalence

Does Baylisascaris procyonis Phylogeny Correlate with That of the Raccoon (Procyon lotor)

Baylisacaris procyonis, commonly known as the raccoon roundworm, is a parasite that inhabits the small intestine of the North American raccoon (Procyon lotor). Although humans do not typically become the definitive host, humans can become infected through handling soil containing eggs. B. procyonis can induce serious health complications in cases of human infection, including degenerative retinal and behavioral changes, coma, and even death. High prevalence of B. procyonis in a raccoon population increases the probability of transference to human hosts. In our study, we analyzed the genetic structure of B. procyonis harvested from raccoons of southwestern Ohio, and compared this to the genetic structure of the raccoons they inhabited. It is our hypothesis that the genetic structuring of the roundworms is the same as the genetic structuring of the raccoons. We isolated DNA from the roundworms using the method outlined in the DNA Minikit (Qiagen). Our research team isolated DNA from each roundworm sample and sent it to the Plant-Microbe Genomics Facility at The Ohio State University for gene amplification and sequencing. We built phylogenetic trees using these sequences, and compared these trees to some constructed for the raccoons. The correlations drawn between the raccoon and B. procyonis phylogenetic trees will help us better understand the relationship between the two species

Baylisascaris procyonis Impacts Raccoon (Procyon lotor) Diets

Raccoons (Procyon lotor) are the definitive host for raccoon roundworms (Baylisascaris procyonis). Raccoon roundworm is responsible for a dangerous neurological disease known as larva migrans encephalopathy. Raccoons are omnivorous animals and rely on various food items. Dietary analyses help determine how a raccoon changes its diet in response to environmental features. Raccoons eat whatever food resource is most convenient and abundant. Parasite infections can potentially affect host eating habits in order to keep the host alive and active longer. In this study, we analyzed the diets of necropsied raccoons from ten townships of Clark and Greene Counties by examining their stomach contents. We categorized stomach contents by separating out plant material, vertebrate tissue, and invertebrate tissue. We measured the total stomach mass and the mass of plant material alone in order to compare and obtain a percentage of plant material in the raccoons’ diet. We conducted two chi-squared tests for equality of distributions. We tested the null hypotheses that raccoons from townships with high prevalence (\u3e60%) have the same vertebrate tissue and plant tissue prevalence as raccoons from townships with low roundworm prevalence

Baylisascaris procyonis prevalence in raccoons (Procyon lotor) and its relation to landscape features

Raccoons (Procyon lotor) are the final host for raccoon roundworm (Baylisascaris procyonis). Raccoon roundworm is the leading cause of a dangerous neurological disease known as larva migrans encephalopathy. Land fragmentation occurs when natural environments are broken up by urban or agricultural landscapes. Raccoons thrive in urban environments, while raccoons in agricultural settings forage over larger areas than raccoons in urban settings do. Land fragmentation affects concentrations of B. procyonis parasites in intermediate hosts. We calculated the prevalence of raccoon roundworm in 9 townships of Greene and Clark Counties by necropsying 226 raccoon intestines. Prevalence is defined as the number of raccoons infected with roundworm divided by the total number of raccoons sampled. We determined that the prevalence of B. procyonis from Beavercreek township is significantly lower than the other townships (χ2 = 25.19, p-value = 0.0007). Prevalence of raccoon roundworm in this region is lower than many areas in the Midwestern United States, suggesting the need for further research to determine reasons for the lower prevalence in the Ohio region

Evidence for Secretion of a Netrin-1-like Protein by Tetrahymena thermophila

Netrin-1 is a pleiotropic signaling molecule with targets in many mammalian cell types. Though first characterized as a chemotactic signal involved in neuronal guidance during development, netrin-1 has since been found to have a regulatory role in angiogenesis, and is also used as a biomarker in certain cancers. Tetrahymena thermophila are free-living protists that rely on chemotactic signals to find food, as well as to escape predators. Chemoattractants cause the cells to swim faster in the forward direction, while chemorepellents cause ciliary reversal, resulting in movement of the cell away from the noxious stimulus. We have previously found that netrin-1 is a chemorepellent in T. thermophila. More recently, we have detected netrin-1 by ELISA in both whole cell extract and secreted protein samples obtained from T. thermophila. In addition, we have immunolocalized netrin-1 staining to the cytosol of T. thermophila using an anti-netrin-1 antibody. We are currently running Western blots to determine the molecular weight of this protein and compare it to its vertebrate counterparts. Further experimentation is needed to determine the physiological role of this protein in T. thermophila