Peptides as adjuvants for ampicillin and oxacillin against methicillin-resistant Staphylococcus aureus (MRSA)

Publication date: Available online 14 August 2018Source: Microbial PathogenesisAuthor(s): Praveen Rishi, Shania Vij, Indresh Kumar Maurya, Ujjwal Jit Kaur, Sanjay Bharati, Rupinder TewariAbstractFast emerging antibiotic resistance in pathogens requires special attention for strengthening the reservoir of antimicrobial compounds. In view of this, several peptides with known antimicrobial activities have been reported to enhance the efficacy of antibiotics against multidrug resistant (MDR) pathogens. In the present study, potential of peptides having distinct mechanism of action, if any, was evaluated to improve the efficacy of conventional antibiotics against methicillin-resistant S. aureus (MRSA). After primary screening of six peptides, two peptides namely T3 and T4 showing very high minimum inhibitory concentrations (MICs) were selected to assess their role in altering the MICs of antibiotics to which the pathogen was resistant. In the presence of the peptides, the MICs of the antibiotics were found to be reduced as per the fractional inhibitory concentration indices (FICI) and time kill assay. These observations prompted us to look for their mechanism of action. The effect of peptides on the morphology of pathogen by Field emission scanning electron microscopy (FE-SEM) revealed no damage to the cells at the sub-inhibitory concentrations of the peptide which correlated well with the higher MIC of the peptide, indicating no direct impact on the pathogen. However, dielectric ...
Source: Microbial Pathogenesis - Category: Infectious Diseases Source Type: research