Influence of Streptococcus pneumoniae Within-Strain Population Diversity on Virulence and Pathogenesis.

The short generation time of many bacterial pathogens allows the accumulation of mutations during routine culture procedures used for the preparation and propagation of bacterial stocks. Taking the major human pathogen Streptococcus pneumoniae as an example, we sought to determine the influence of standard laboratory handling of microbes on within-strain genetic diversity and explore how these changes influence virulence characteristics and experimental outcomes. A single culture of S.