Kinetics of β -Lactam Interactions with Penicillin-Susceptible and -Resistant Penicillin-Binding Protein 2x Proteins from Streptococcus pneumoniae: Involvement of Acylation and Deacylation in β -Lactam Resistance
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منابع مشابه
A low-affinity penicillin-binding protein 2x variant is required for heteroresistance in Streptococcus pneumoniae.
Heteroresistance to penicillin in Streptococcus pneumoniae is the ability of subpopulations to grow at a higher antibiotic concentration than expected from the MIC. This may render conventional resistance testing unreliable and lead to therapeutic failure. We investigated the role of the primary β-lactam resistance determinants, penicillin-binding protein 2b (PBP2b) and PBP2x, and the secondary...
متن کاملGenetic analysis of pbp2x in clinical Streptococcus pneumoniae isolates in Quebec, Canada.
OBJECTIVES To investigate the nature of the amino acid motifs found in penicillin-binding protein (PBP) 2x of penicillin-resistant Streptococcus pneumoniae isolates across the province of Quebec (Canada), and to obtain preliminary information regarding the prevalence of these alterations. METHODS The pbp2x genomic region encompassing codons 178-703, which includes the entire region of the tra...
متن کاملHow allosteric control of Staphylococcus aureus penicillin binding protein 2a enables methicillin resistance and physiological function.
The expression of penicillin binding protein 2a (PBP2a) is the basis for the broad clinical resistance to the β-lactam antibiotics by methicillin-resistant Staphylococcus aureus (MRSA). The high-molecular mass penicillin binding proteins of bacteria catalyze in separate domains the transglycosylase and transpeptidase activities required for the biosynthesis of the peptidoglycan polymer that com...
متن کاملIdentical penicillin-binding domains in penicillin-binding proteins of Streptococcus pneumoniae clinical isolates with different levels of beta-lactam resistance.
We have sequenced the penicillin-binding domains of the complete repertoire of penicillin-binding proteins and MurM from 22 clinical isolates of Streptococcus pneumoniae that span a wide range of beta-lactam resistance levels. Evidence of mosaicism was found in the genes encoding PBP 1a, PBP 2b, PBP 2x, MurM, and, possibly, PBP 2a. Five isolates were found to have identical PBP and MurM sequenc...
متن کاملFive independent combinations of mutations can result in low-affinity penicillin-binding protein 2x of Streptococcus pneumoniae.
Penicillin-binding protein 2x (PBP 2x) of Streptococcus pneumoniae is one of the high-molecular-weight PBPs involved in the development of intrinsic beta-lactam resistance. Point mutations in the PBP 2x genes (pbpX) have now been characterized in five independent spontaneous laboratory mutants in order to identify protein regions which are important for interaction with beta-lactam antibiotics....
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