Analysis of PBP5 of early U.S. isolates of Enterococcus faecium: sequence variation alone does not explain increasing ampicillin resistance over time. Academic Article uri icon


  • Recent studies have shown that ampicillin resistance has increased steadily over the past 3 decades within U.S. Enterococcus faecium isolates. Analysis of the predicted PBP5 protein of 41 isolates showed a consensus PBP5 pattern for the 9 isolates with MICs of <4 g/ml that is distinctly different from the PBP5 consensus of the 32 isolates with MICs of >4 g/ml with 5% difference between these; however, there were no consistent amino acid changes that correlated with specific increases in the MICs of ampicillin within the latter group. Analysis of three other genes encoding cell wall/surface proteins also showed that there are two distinct evolutionary groups for each gene, but with occasional mixing of genes, consistent with a species that evolves by recombination.

published proceedings

  • Antimicrob Agents Chemother

altmetric score

  • 0.5

author list (cited authors)

  • Galloway-Pea, J. R., Rice, L. B., & Murray, B. E.

citation count

  • 61

complete list of authors

  • Galloway-Peña, Jessica R||Rice, Louis B||Murray, Barbara E

publication date

  • July 2011