Collaborative Research: The Causes and Consequences of Pathogen Resistance on Fitness and Community Structure

University Of Houston, Houston TX

Investigators

Abstract

Organisms have developed numerous mechanisms for resisting predators and pathogens. These mechanisms are generally thought to incur a "cost" to the organism, such that predator resistant organisms are inferior competitors (relative to sensitive organisms) in the absence of predators. However, the causes and consequences of this tradeoff have proven difficult to examine in most experimental systems. Escherichia coli and its viral predators (bacteriophage) are ideal model organisms with which to study this tradeoff, because they are easy to propagate, they grow rapidly and because there is an abundance of background literature on their biology. Experiments will be performed that directly examine the genetic and physiological causes of the tradeoff between competitive ability and bacteriophage resistance in E.coli, and the effects of this tradeoff on populations and communities over short (ecological) and long (evolutionary) time scales under specific environmental conditions. The premise that there is a tradeoff between resistance and competitive ability forms the basis for numerous hypotheses on the origin of biodiversity and the interaction of predators or pathogens and their prey. Understanding this tradeoff will have widespread value in both pure and applied sciences, including increasing the accuracy of predictions of climate change effects on biodiversity, the impact of foreign species introduction, and the evolution of virulence in human pathogens.