Microbiology

Intracellular Demographics

See allHide authors and affiliations

Science  03 Nov 2006:
Vol. 314, Issue 5800, pp. 727
DOI: 10.1126/science.314.5800.727c

Mathematical models are commonly used to help predict the course of epidemics through a population of organisms. In contrast, Brown et al. have absorbed recent findings on intracellular events in salmonellosis to develop a within-organism model. Salmonella enterica grows within host phagocytes to varying cell density regardless of cell “permissiveness.” Interestingly, the model hints that apoptosis of host cells has little effect on controlling the spread of infection; rather, the driving force is necrotic bursts that release bacteria to spread into new foci of infection. Comparing attenuated (i.e., vaccine) and virulent strains of salmonellae in the model reveals that an attenuated strain replicates less well than a virulent strain and uses the same number of host cells to do so; hence, the resulting pathology may be rather similar. The model is clearly useful for predicting the effect of combination drug therapy, and it hints that drugs that kill extracellular pathogens might select for “refuge resistance”; that is, the suppression of cell lysis mechanisms. — CA

PLoS Biol. 4, e349 (2006).

Navigate This Article