Open AccessMethicillin‐resistant strains of Staphylococcus aureus ; presence of identical additional penicillin‐binding protein in all strains examined
Author(s) -
Reynolds Peter E.,
Fuller Christopher
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01281.x
Subject(s) - microbiology and biotechnology , staphylococcus aureus , penicillin , penicillin binding proteins , penicillin resistance , biology , micrococcaceae , antibiotics , staphylococcus , bacteria , chemistry , antibacterial agent , genetics
The methicillin‐resistant strain of Staphylococcus aureus MR‐1 previously reported to possess a penicillin‐binding protein 3 (PBP 3) with a decreased affinity for β‐lactam antibiotics was re‐examined and, in common with other resistant strains, found to contain an additional PBP (PBP 2′). Expression of the additional protein, which has a very low affinity for β‐lactams, was not influenced by temperature or osmolarity of the medium in contrast with strains examined previously. It was the only PBP still available to bind radioactive β‐lactams and therefore still active enzymically when strain MR‐1 was grown in the presence of concentrations of β‐lactam antibiotics sufficient to kill sensitive strains of S. aureus . Penicillin‐peptides derived by partial proteolysis of PBP 2′‐penicillin complexes of MR‐1 and 3 other methicillin‐resistant strains appeared to be identical and different from the penicillin‐peptides derived from PBP 1, PBP 2 and PBP 3, each of which gave rise to a unique series of peptides containing covalently‐bound penicillin.