Mice with an Acquired Immunodeficiency (MAIDS) Develop a Persistent Infection after Injection with Listeria monocytogenes

Mice with a retrovirus-induced immunodeficiency were challenged with Listeria monocytogenes and resistance to this facultative intracellular bacterium was analyzed. Early innate immunity was unaltered or enhanced. Although immunodeficient mice had reduced bacterial titers after these reached their peak on Day 3, infection with L. monocytogenes generally resulted in a low-grade persistent infection and occasionally there was a delayed resolution of bacterial infection. Endogenous cytokines are important in the containment of bacteria as mice often developed a high load of bacteria or succumbed to infection in the absence of cytokine action. There was a substantial heterogeneity in disease after bacterial challenge which probably reflects the variability found in retrovirus-infected mice during the later stages of this immunodeficiency syndrome.