Developing Methods to Quantify Schistosoma Mansoni Miracidia Behavior and Responsiveness

Abstract

Schistosomiasis impacts over 250 million people worldwide and is caused by a family of parasitic flatworms known as schistosomes. These parasites have a complex life cycle, requiring progression through a snail intermediate host. During their first larval stage, they are called miracidia, and their main objective is to locate and infect their snail intermediate host so they can develop into a human-infective form. Currently, the mechanisms underlying these interactions are unknown. Dysregulation of these sensory abilities could be an efficient disease control measure, but a thorough understanding of miracidia behavior and responsiveness to host cues is a prerequisite for this prevention strategy. The current study sought to develop methods for quantifying Schistosoma mansoni miracidia behavior. To accomplish this, miracidia were harvested from infected tissues and input into slide-based and microfluidic-arena-based assay systems. Their behavior was recorded and then quantified with video and data analysis pipelines integrated into the InVision system. Relationships amongst responsiveness to chemical cues at both fixed and varying time points, behavioral variations amongst miracidia originating from different infected tissues, and hatch rate variability amongst those tissues were evaluated. This work lays the foundation for more efficient, high-throughput, and reproducible analyses of miracidia sensory behavior and responsiveness.