Redefining the role of the β-lactamase locus in methicillin-resistant Staphylococcus aureus: β-lactamase regulators disrupt the MecI-mediated strong repression on mecA and optimize the phenotypic expression of resistance in strains with constitutive mecA expression.

Abstract excerpt

In response to β-lactam chemotherapy, Staphylococcus aureus has acquired two resistance determinants: blaZ, coding for β-lactamase, which confers resistance to penicillins only, and mecA, coding for an extra cell wall cross-linking enzyme with reduced affinity for virtually all other β-lactams. The transcriptional control of both resistance determinants is regulated by homologous repressors (BlaI and MecI,...

Topics

• Bacterial Proteins
• Gene Expression Regulation, Bacterial
• Methicillin-Resistant Staphylococcus aureus
• Microbial Sensitivity Tests
• Penicillin-Binding Proteins
• Polymorphism, Single Nucleotide
• Promoter Regions, Genetic
• Proteolysis
• Repressor Proteins
• Staphylococcal Infections
• beta-Lactam Resistance