Haplotype diversity in "source-sink" dynamics of Escherichia coli urovirulence

  • Chattopadhyay S
  • Feldgarden M
  • Weissman S
 et al. 
  • 37


    Mendeley users who have this article in their library.
  • 33


    Citations of this article.


FimH, the mannose-specific, type 1 fimbrial adhesin of Escherichia coli, acquires amino acid replacements adaptive in extraintestinal niches (the genitourinary tract) but detrimental in the main habitat (the large intestine). This microevolutionary dynamics is reminiscent of an ecological "source-sink" model of continuous species spread from a stable primary habitat (source) into transient secondary niches (sink), with eventual extinction of the sink-evolved populations. Here, we have adapted two ecological analytical tools-diversity indexes DS and alpha--to compare size and frequency distributions of fimH haplotypes between evolutionarily conserved FimH variants ("source" haplotypes) and FimH variants with adaptive mutations (putative "sink" haplotypes). Both indexes show two- to threefold increased diversity of the sink fimH haplotypes relative to the source haplotypes, a pattern that ran opposite to those seen with nonstructural fimbrial genes (fimC and fimI) and housekeeping loci (adk and fumC) but similar to that seen with another fimbrial adhesin of E. coli, papG-II, also implicated in extraintestinal infections. The increased diversity of the sink pool of adhesin genes is due to the increased richness of the haplotypes (the number of unique haplotypes), rather than their evenness (the extent of similarity in relative abundances). Taken together, this pattern supports a continuous emergence and extinction of the gene alleles adaptive to virulence sink habitats of E. coli, rather than a one-time change in the habitat conditions. Thus, ecological methods of species diversity analysis can be successfully adapted to characterize the emergence of microbial virulence in bacterial pathogens subject to source-sink dynamics.

Author-supplied keywords

  • E. coli adhesin
  • Haplotype diversity
  • Niche adaptation
  • Selection footprint

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Sujay Chattopadhyay

  • Michael Feldgarden

  • Scott J. Weissman

  • Daniel E. Dykhuizen

  • Gerald Van Belle

  • Evgeni V. Sokurenko

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free