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Beta-Lactamase Repressor BlaI Modulates Staphylococcus aureus Cathelicidin Antimicrobial Peptide Resistance and Virulence.
Document Type
article
Source
PloS one. 10(8)
Subject
Animals
Humans
Mice
Staphylococcus aureus
Staphylococcal Infections
Penicillanic Acid
beta-Lactamases
Antimicrobial Cationic Peptides
DNA Transposable Elements
Penicillin Resistance
Gene Expression Regulation
Bacterial
Gene Expression Regulation
Bacterial
General Science & Technology
Language
Abstract
BlaI is a repressor of BlaZ, the beta-lactamase responsible for penicillin resistance in Staphylococcus aureus. Through screening a transposon library in S. aureus Newman for susceptibility to cathelicidin antimicrobial peptide, we discovered BlaI as a novel cathelicidin resistance factor. Additionally, through integrational mutagenesis in S. aureus Newman and MRSA Sanger 252 strains, we confirmed the role of BlaI in resistance to human and murine cathelidicin and showed that it contributes to virulence in human whole blood and murine infection models. We further demonstrated that BlaI could be a target for innate immune-based antimicrobial therapies; by removing BlaI through subinhibitory concentrations of 6-aminopenicillanic acid, we were able to sensitize S. aureus to LL-37 killing.