In vitro evaluation of BRL 42715, a novel beta-lactamase inhibitor

Area of Science:

• Microbiology
• Pharmacology
• Medicinal Chemistry

Background:

• Bacterial beta-lactamases are enzymes that confer resistance to beta-lactam antibiotics.
• Development of potent beta-lactamase inhibitors is crucial for combating antibiotic resistance.
• Existing inhibitors have limitations in potency and spectrum of activity.

Purpose of the Study:

• To evaluate the inhibitory activity of the novel penem BRL 42715 against a wide range of bacterial beta-lactamases.
• To assess the ability of BRL 42715 to potentiate the activity of beta-lactam antibiotics against resistant bacteria.
• To compare the efficacy of BRL 42715 with clavulanic acid.

Main Methods:

• Assessed the concentration of BRL 42715 required to inhibit 50% of beta-lactamase enzyme activity.
• Determined the minimum inhibitory concentration (MIC50) of amoxicillin in the presence of BRL 42715 and clavulanic acid.
• Tested activity against beta-lactamase-producing strains of Enterobacteriaceae, including Citrobacter and Enterobacter species.

Main Results:

• BRL 42715 demonstrated potent inhibition of diverse beta-lactamases at concentrations below 0.01 µg/ml, significantly lower than other inhibitors.
• Low concentrations of BRL 42715 (≤0.25 µg/ml) substantially enhanced amoxicillin activity against resistant strains.
• BRL 42715 was more effective than clavulanic acid in reducing amoxicillin MIC50 values against Enterobacteriaceae.

Conclusions:

• BRL 42715 is a highly potent inhibitor of a broad spectrum of bacterial beta-lactamases.
• BRL 42715 effectively potentiates the antibacterial activity of amoxicillin, offering a promising strategy against resistant infections.
• BRL 42715 shows superior performance compared to clavulanic acid in enhancing amoxicillin efficacy.