Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3

Antimicrob Agents Chemother. 1988 May;32(5):706-9. doi: 10.1128/AAC.32.5.706.

Abstract

We examined clinical isolates of Neisseria meningitidis relatively resistant to penicillin G (mean MIC, 0.3 micrograms/ml; range, 0.1 to 0.7 micrograms/ml), which were isolated from blood and cerebrospinal fluid for resistance mechanisms, by using susceptible isolates (mean MIC, less than or equal to 0.06 micrograms/ml) for comparison. The resistant strains did not produce detectable beta-lactamase activity, otherwise modify penicillin G, or bind less total penicillin. Penicillin-binding protein (PBP) 3 of the six resistant isolates tested uniformly bound less penicillin G in comparison to the same PBP of four susceptible isolates. Reflecting the reduced binding affinity of PBP 3 of the two resistant strains tested, the amount of 3H-labeled penicillin G required for half-maximal binding was increased in comparison with that of PBP 3 of the two susceptible isolates. We conclude that the mechanism of resistance in these meningococci relatively resistant to penicillin G was decreased affinity of PBP 3.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins*
  • Carrier Proteins / metabolism*
  • Chromatography, Thin Layer
  • Hexosyltransferases*
  • Humans
  • Muramoylpentapeptide Carboxypeptidase / metabolism*
  • Neisseria meningitidis / drug effects*
  • Neisseria meningitidis / enzymology
  • Neisseria meningitidis / metabolism
  • Penicillin G / pharmacology*
  • Penicillin Resistance
  • Penicillin-Binding Proteins
  • Peptidyl Transferases*
  • beta-Lactamases / metabolism

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Penicillin-Binding Proteins
  • Peptidyl Transferases
  • Hexosyltransferases
  • Muramoylpentapeptide Carboxypeptidase
  • beta-Lactamases
  • Penicillin G