Open AccessPenicillin-Binding Proteins and Cell Wall Composition in β-Lactam-Sensitive and -Resistant Strains of Staphylococcus sciuri
Author(s) -
Yanjiao Zhou,
Aude Antignac,
ShunFan Wu,
Alexander Tomasz
Publication year - 2008
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01549-07
Subject(s) - penicillin binding proteins , nafcillin , biology , sccmec , peptidoglycan , staphylococcus aureus , microbiology and biotechnology , penicillin , gene , bacteria , biochemistry , genetics , methicillin resistant staphylococcus aureus , antibiotics
A close homologue of the acquiredStaphylococcus aureus mecA gene is present as a native gene inStaphylococcus sciuri . We determined the patterns of penicillin-binding proteins (PBPs) and the peptidoglycan compositions of severalS. sciuri strains to explore the functions of thismecA homologue, namedpbpD , in its nativeS. sciuri environment. The protein product ofpbpD was identified as PBP4 with a molecular mass of 84 kDa, one of the six PBPs present in representatives of each of three subspecies ofS. sciuri examined. PBP4 had a low affinity for nafcillin, reacted with a monoclonal antibody raised againstS. aureus PBP2A, and was greatly overproduced in oxacillin-resistant clinical isolateS. sciuri SS37 and to a lesser extent in resistant laboratory mutant K1M200. An additional PBP inducible by oxacillin and corresponding toS. aureus PBP2A was identified in another oxacillin-resistant clinical isolate,S. sciuri K3, which harbors anS. aureus copy ofmecA . Oxacillin resistance depended on the overtranscribedS. sciuri pbpD gene in strains SS37 and K1M200, while the resistance of strain K3 depended on theS. aureus copy ofmecA . Our data provide evidence that bothS. aureus mecA andS. sciuri pbpD can function as resistance determinants in either anS. aureus or anS. sciuri background and that the protein products of these genes,S. aureus PBP2A andS. sciuri PBP4, can participate in the biosynthesis of peptidoglycan, the muropeptide composition of which depends on the bacterium “hosting” the resistance gene.