Open AccessPenicillin-binding proteins in a Staphylococcus aureus strain resistant to specific beta-lactam antibiotics
Author(s) -
Nafsika H. Georgopapadakou,
Sarah M. Smith,
Daniel P. Bonner
Publication year - 1982
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.22.1.172
Subject(s) - penicillin binding proteins , staphylococcus aureus , cephalosporin , antibiotics , penicillin , microbiology and biotechnology , strain (injury) , cephem , chemistry , biology , bacteria , biochemistry , genetics , carboxylic acid , anatomy
The penicillin-binding proteins (PBPs) of a clinical isolate of Staphylococcus aureus specifically resistant to oral cephalosporins were compared with those of a susceptible strain. In the resistant strain, PBP3 (75,000 molecular weight) was missing or had substantially (greater than 100-fold) reduced affinity for penicillin; PBP2 (80,000 molecular weight) was increased in amount and contained a satellite band, PBP2'; PBPs 1 and 4 were unchanged. Oral cephalosporins bound poorly to PBP2 in both susceptible and resistant strains, but only in the latter did binding correlate with antibiotic activity. The results are consistent with the suggestion that PBP2 is essential in S. aureus. PBP2 might in addition compensate for PBP3 when the latter is missing. In the susceptible strain the lack of correlation between binding to PBP2 and beta-lactam antibiotic activity is due to the very high affinity of the also essential PBP3 for beta-lactam antibiotics.