Abstract

The development of bacterial disease has been likened to a 'molecular arms race', in which the host tries to eliminate the bacteria, while the bacteria try to survive in the host. Although most bacteria do not cause disease, some cause serious human infection in a large proportion of encounters. Between these two extremes are bacteria that can coexist with humans in a carriage state but, under appropriate circumstances, cause disease. The streptococci exemplify this group of organisms, and by studying them we can begin to address why bacteria cause such a wide spectrum of disease.

Author affiliations

1. Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
   Email: t.mitchell@bio.gla.ac.uk