Evolution of a Dominant Natural Isolate of Escherichia coli in the Human Gut over the Course of a Year Suggests a Neutral Evolution with Reduced Effective Population Size

• DOI: 10.1128/aem.02377-17
• Publication Date: 2018-01-08T12:10:28Z
• Authors: Mohamed Ghalayini; Adrien Launay; Antoine Bridier-N...; Olivier Clermont; Erick Denamur; Mathilde Lescat; Olivier Tenaillon
• Keywords: Experimental Evolution; Effective population size; Molecular evolution; clone (Java method)

In vitro and in vivo evolution experiments on Escherichia coli revealed several principles of bacterial adaptation. However, few data are available the literature describing behavior E. its natural environment. We attempted here to study human gut a commensal dominant clone, ED1a belonging B2 phylogroup, through longitudinal genomic study. sequenced 24 isolates sampled at three different time points within healthy individual over almost year. computed mutation rate 6.90 × 10-7 mutations per base year chromosome for gut. observed very limited diversity could not detect any evidence selection, contrast what is experimental similar length time. therefore suggest that ED1a, being well adapted gut, evolves mostly neutrally with low effective population size (Ne ≈500 1,700).IMPORTANCE this study, we follow fate clone about compute annual supports diversity, retrieve clear signature selection. These observations support neutral compatible deviates drastically made previously evolution.