Parasitology Commons^™

Ecoimmunology Of Dirty Physella Acuta Snails, Kevin Arthur Mcquirk

Biology ETDs

Research on Physella acuta, an invasive freshwater snail, reveals insights into its parasitology, fitness, and molecular biology. Morphological and molecular analyses revealed two distinct mitogenomic lineages, local (B) and invasive (A) strains of native P. acuta, both having comparable trematode infection rates, suggesting that the low infection rates observed from A in invaded regions result from "enemy release" rather than immune incompatibility. Fitness assessments showed that while lineages A and B performed similarly under laboratory conditions, rewilding experiments revealed significantly higher fitness in lineage A. Transcriptomic profiling supported these differences, with A snails showing greater immune-related gene expression and …

New Insights Into T Lymphocyte-Mediated Immunity To Toxoplasma Gondii, Claire Marie Doherty

Biology ETDs

With nearly a third of the global population infected with the protozoan, Toxoplasma gondii, this parasite sits at a unique, immune-mediated interface of health and disease. In healthy individuals, Toxoplasma results in a chronic yet asymptomatic infection of the central nervous system. This quiescent infection is the result of parasite exploitation of host immune barriers, yet Toxoplasma can quickly become an opportunistic pathogen when immunity is disrupted by illness or immunosuppressive therapies. During the HIV-AIDS pandemic, it was observed that once latent Toxoplasma infections became the cause of severe, even fatal, disease in the absence of an intact T …

Unraveling The Complex Interactions Between Members Of The Schistosoma Haematobium Group And Bulinus Snails In And Around Lake Victoria In West Kenya, Caitlin Raiselle Babbitt

Biology ETDs

Schistosoma haematobium, the agent of urogenital schistosomiasis, and related schistosomes are transmitted by members of the genus Bulinus. Each of the 38 Bulinus species vary in their ability to vector schistosome species and non-schistosome trematodes resulting in a patchwork of snail-parasite compatibilities. Accurately identifying snail intermediate hosts and the disease-causing parasites they transmit is critical for snail control strategies and the management of human schistosomiasis. Towards these ends, this thesis identifies bulinid species and the parasites they transmit and implicates certain species in the transmission of S. haematobium. The thesis also includes a systematic review of methods …

Molecular Studies On The Interactions Between Biomphalaria Snails And Schistosoma Mansoni, Lijun Lu

Biology ETDs

Biomphalaria snails serve as vectors for Schistosoma mansoni, a trematode causing human schistosomiasis. Control of Schistosoma mansoni involves chemotherapy of affected people, but new control methods built on improved understanding of schistosome-snail interactions are needed. My dissertation applies molecular and bioinformatics approaches to understand such interactions. Chapter 1 shows that significant differences exist among Biomphalaria species in Africa with respect to their ability to support schistosome development. Chapters 2 and 3 reveal the transcriptional responses of Biomphalaria glabrata susceptible (SUS) or resistant (RES) to Schistosoma mansoni. Chapter 2 identifies a new family of snail immune factors, the AIG …

Physella Acuta, Comparative Immunology And Evolutionary Aspects Of Gastropod Immune Function, Jonathan H. Schultz

Biology ETDs

Gastropod immunobiology has benefitted from investigations focused on the planorbid snail Biomphalaria glabrata, intermediate host for the human parasite Schistosoma mansoni. Though such concentrated efforts have elucidated fascinating aspects of invertebrate immunity, they have not provided full knowledge regarding the evolution of immune function among other gastropod species. This dissertation presents the importance of making strategic choices regarding which organisms to select for comparative immunology. Herein, the choice was made to investigate the immunobiology of Physella acuta, a freshwater snail species of the Physidae, a sister family to Planorbidae to which B. glabrata belongs. Benefiting greatly from …

Schistosomiasis In The Wild: A Transcriptomics Perspective On Field-Derived Biomphalaria Pfeifferi And Schistosoma Mansoni, And Their Interactions, Sarah K. Buddenborg

Biology ETDs

Schistosomiasis, caused by trematodes in the genus Schistosoma, is a widespread neglected tropical disease with the species S. mansoni infecting over 100 million people. We aimed to better understand the snail host and parasite responses during intramolluscan stages of infection by performing dual RNA-Seq on field-collected snails with natural infections from western Kenya. We collected uninfected Biomphalaria pfeifferi, B. pfeifferi with a patent cercariae-producing S. mansoni infection, and B. pfeifferi exposed to field-collected S. mansoni at 1 and 3d (days post infection).

We first created a high-quality B. pfeifferi transcriptome to identify the snail response to S. mansoni infection. …