ANTIMICROBIAL AND ANTIBIOFILM ACTIVITY OF THE DESIGNED PEPTIDE P1 AGAINST PSEUDOMONAS AERUGINOSA AND MYCOBACTERIUM TUBERCULOSIS

MARTINEZ MELINA; MARTINENA CAMILA; TATEOSIAN, NANCY L.; MAFFIA, P

Workshop; I International Symposium- CIDEM; 2022

Introduction: In recent decades, antimicrobial resistance has become a substantial global public health problem. Pseudomonas aeruginosa has recently shown to be one of the most important strains of bacteria and alert pathogens among Intensive Care Unit patients. In addition tuberculosis remains a major global health problem ranking among the top ten causes of death worldwide. Antimicrobial peptides (AMPs) are promising novel antibiotics since they have shown antimicrobial activity against a wide range of bacterial species, including multiresistant bacteria.Objectives: Study and evaluate the antimicrobial and antibiofilm activity of the designed peptide P1 against P. aeruginosa M13513 clinical isolate and M. tuberculosis MtbH37RvMaterials and methods: The minimum inhibitory concentrations (MICs) and the bactericidal effect of the peptide were determined using standard CFU counting on the proper medium. The toxicity was evaluated on human red blood cells and THP1 cell line. The biofilm inhibition and biofilm disruption was analyzed by crystal violet and confocal imaging using SYTO9 and PI. Bacterial viability within the biofilm was quantified by MTT reagent. Bacterial growth was monitored by OD 600 nm, at sub MIC concentrations. Results: The peptide P1 showed antimicrobial activity against the carbapenem resistant isolate of P. aeruginosa at 32 µg/ml. It also displayed antibiofilm activity with remarkable biofilm disruption and killing activity against the bacteria inside the biofilm. We also found an anti-Mtb activity of the AMP (15 µg/ml) on the pathogenic strain MtbH37Rv. Moreover, it showed microbicidal effect at 15µg/ml in THP-1 cells infected with MtbH37Rv, displaying no cytotoxic effect on host cells.Conclusions: P1 displayed antimicrobial and antibiofilm activity in the clinical isolate of P. aeruginosa and also displayed anti mycobacterial activity on MtbH37Rv. It also displayed microbicidal effect against mycobacteria inside the macrophage cell line THP-1. This novel peptide provides a new alternative as drug candidates with potential application in P. aeruginosa and tuberculosis therapy.