This series ofreviews focuses on recent developments in understandingbacterialpathogenesisthathavebeengained by studying the genetic control of the susceptibility to particular diseases. The topics of the reviews include a description ofbacterial genes that effect virulence and a studyofthe genetic susceptibilityofhumans to group A streptococci and to leprosy. The most versatile model system for studies of disease susceptibility is the inbred mouse. Although seven of the chapters deal with the geneticsoftheresistanceofmice to infection, allofthem point out general principles and, wherever...