Despite being the first line of defense against infection, little is known about how host-pathogen interactions determine avoidance. Caenorhabditis elegans can become infected by chemoattractant-producing bacteria through ingestion. The worms can learn to associate these chemoattractants with harm through aversive learning. As a result, the worms will avoid the pathogen. Evolutionary constraints have likely shaped the attraction, intoxication and learning dynamics between bacteria and C. elegans, but these have not been explored. Using bacteria engineered to express an acylhomoserine lactone chemoattractant and a nematicidal protein, we explored how manipulating the amount of attractant produced by the bacteria affects learning and intoxication in mixed stage populations of C. elegans. We found that increasing the production rate of the chemoattractant increased the feeding rate in C. elegans, but decreased the time required for C. elegans to learn to avoid the chemoattractant. Learning generally coincided with a decreased feeding rate. We also observed that the percentage of intoxicated worms was maximized at intermediate production rates of the attractant. We propose that interactions between attractant driven feeding rate and aversive learning are likely responsible for this trend. Our results increase our understanding of behavioral avoidance in C. elegans and have implications in understanding host-pathogen dynamics that shape avoidance.

尽管是抵御感染的第一道防线，但对于宿主-病原体相互作用如何决定避免的知之甚少。秀丽隐杆线虫可通过摄入而被产生化学引诱剂的细菌感染。蠕虫可以通过厌恶性学习来学习将这些趋化剂与伤害联系起来。结果，蠕虫将避免病原体。进化的限制可能已经塑造了细菌和秀丽隐杆线虫之间的吸引力，陶醉和学习动力，但尚未对此进行探索。使用工程改造的细菌表达酰基高丝氨酸内酯化学引诱剂和杀线虫蛋白，我们探索了操纵细菌产生的引诱剂的量如何影响混合阶段种群的学习和中毒。秀丽隐杆线虫。我们发现增加化学引诱剂的生产率可以提高秀丽隐杆线虫的进食速度，但是减少了秀丽隐杆线虫学会避免化学引诱剂所需的时间。学习通常与降低的进食率相吻合。我们还观察到，在诱剂的中间生产速率下，陶醉蠕虫的百分比最大。我们认为，引诱剂驱动的进食速度与厌恶性学习之间的相互作用可能是这一趋势的原因。我们的结果增加了我们对秀丽隐杆线虫行为规避的理解，并有助于理解形成规避行为的宿主-病原体动力学。