Point mutation in the group B streptococcal pbp2x gene conferring decreased susceptibility to beta-lactam antibiotics

Antimicrob Agents Chemother. 2008 Aug;52(8):2915-8. doi: 10.1128/AAC.00461-08. Epub 2008 Jun 9.


Beta-lactam antibiotics (BLAs) are the first-line agents used against group B streptococci (GBS) infection. A clonal set of four independent, invasive GBS isolates with elevated MICs to BLAs were identified that shared a pbp2x mutation (Q557E) corresponding to a resistance-conferring pneumococcal mutation. BLA sensitivity was restored through allelic replacement or complementation with the wild-type pbp2x.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology
  • Drug Resistance, Bacterial / genetics
  • Microbial Sensitivity Tests
  • Models, Genetic
  • Molecular Sequence Data
  • Penicillin-Binding Proteins / genetics*
  • Point Mutation*
  • Sequence Homology, Amino Acid
  • Streptococcus agalactiae / drug effects*
  • Streptococcus agalactiae / genetics
  • Streptococcus agalactiae / metabolism
  • beta-Lactams / pharmacology*


  • Anti-Bacterial Agents
  • Penicillin-Binding Proteins
  • beta-Lactams
  • PBP 2x protein, Streptococcus