Penicillin-binding proteins and ampicillin resistance in Haemophilus influenzae

J Antimicrob Chemother. 1990 Apr;25(4):525-34. doi: 10.1093/jac/25.4.525.

Abstract

Ampicillin-resistant, non-beta-lactamase-producing isolates of Haemophilus influenzae contain a variety of penicillin-binding protein (PBP) patterns that differ from the single pattern of eight PBPs characteristic of susceptible strains. During genetic transformation of resistance, only some of the anomalies in PBP pattern were transformed, specifically those relating to the penicillin-binding capacities of PBPs 4 (Mr of 62,000) and 5 (Mr of 59,000) and, in some transformations, PBP 3 (Mr of 71,000). Comparison of the binding of penicillin by PBPs 4 and 5 of three resistant transformants (derived with DNA from different donors) revealed a decrease in the rate of PBP acylation and no appreciable change in the rate of deacylation as compared to the susceptible recipient. Thus, rapid turnover of these PBPs does not play a role. Retransformation studies confirm that altered PBPs 3, 4, and 5 are associated with resistance and suggest that these PBPs are major targets for the beta-lactam antibiotics in H. influenzae.

Publication types

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

MeSH terms

  • Acylation
  • Ampicillin Resistance / genetics*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Crosses, Genetic
  • DNA, Bacterial / genetics
  • Haemophilus influenzae / drug effects*
  • Haemophilus influenzae / genetics
  • Hexosyltransferases*
  • Microbial Sensitivity Tests
  • Muramoylpentapeptide Carboxypeptidase / genetics
  • Muramoylpentapeptide Carboxypeptidase / metabolism*
  • Penicillin-Binding Proteins
  • Penicillins / metabolism*
  • Peptidyl Transferases*
  • Transformation, Genetic / physiology

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • DNA, Bacterial
  • Penicillin-Binding Proteins
  • Penicillins
  • Peptidyl Transferases
  • Hexosyltransferases
  • Muramoylpentapeptide Carboxypeptidase