Interactions in the Bacterial World

Résumé du livre

?Pub Inc How antibiotics influence the evolution of bacterial population interactions is the central tenet examined in this study. To test antibiotic influences I used two populations of 'Escherichia coli'; one resistant to [beta]-lactam antibiotics, and one sensitive. For both populations I vary the initial growing conditions (the frequencies of each population and the total population density), and environmental structure (homogeneous versus heterogeneous media). By using a GLM design I determined the influence of frequency and population density on the relative fitness of the sensitive bacteria in two environments. I found a significant effect of both frequency and population density dependence on the relative fitness of the sensitives within both environments but only between the environments when density was studied. These results suggest that changing the frequencies of the populations do not have an effect on population fitness levels to the same effect that population density does between different environmental structures.