title: The genetic diversity of predominant Escherichia coli strains isolated from cattle fed various amounts of hay and grain(1).
abstract: When the 16S rDNA of predominant Escherichia coli strains from cattle was digested with HhaI and HaeIII, the strains could be sub-divided into four operational taxonomic units. When genomic DNA was digested with XbaI, strains could be grouped into 24 pulsed-field gel electrophoresis genotypes (>95% Dice similarity) and five clades (>20% Dice similarity). Diet (hay versus grain) and gastrointestinal compartment (rumen versus colon) did not have a large impact on diversity. However, both analyses indicated that the cows (n=2) had different E. coli populations. When all 22 colonic strains were inoculated into a maltose-limited chemostat, only a single genotype persisted. Based on these results, the genetic diversity of E. coli in the cattle is very great and this bacterium can occupy different niches.
authors.initials: GN
authors.lastname: Jarvisa
authors.initials: MG
authors.lastname: Kizoulisa
authors.initials: F
authors.lastname: Diez-Gonzaleza
authors.initials: JB
authors.lastname: Russellab