Long-term bacterial infections pose several fundamental biological questions: How metabolically active are bacteria during a persistent infection? Are they dividing, or in a state of quiescence? And how do these bacteria evade the immune system for so long?
Acute infections by pathogenic bacteria cause a dramatic activation of the innate and adaptive immune responses. If the pathogen survives initial contact with the host’s innate immune system (and the host is not killed), the infection is usually cleared by the host’s adaptive immune system. However, some bacterial pathogens maintain infections for the lifetime of their mammalian hosts, even in the presence of a robust immune response.
Most of what we’ve learned about persistent infections comes from the study of several well-known illnesses. For example, Helicobacter pylori, the cause of most stomach ulcers, inhabits the stomach lining, where its persistence can be lifelong; Mycobacterium tuberculosis is able to establish long-term infections that ...
