A New Synthetic Peptide with In vitro Antibacterial Potential Against Escherichiacoli O157:H7 and Methicillin-Resistant Staphylococcusaureus (MRSA)

• Published in: Probiotics and antimicrobial proteins 2016, Vol.8 (3), p.134-140
• Main Authors: Prada, Y. A., Guzmán, F., Rondón, P., Escobar, P., Ortíz, C., Sierra, D. A., Torres, R., Mejía-Ospino, E.
• Format: Article
• Language: English
• Subjects: Applied Microbiology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Microbiology; Nutrition; Protein Science
• ISSN: 1867-1306; 1867-1314
• DOI: 10.1007/s12602-016-9219-9

In this work, we performed the rational design of a cationic antimicrobial peptide, GIBIMPY4, using the software DEPRAMPs developed at the GIBIM research group. GIBIMPY4 has a length of 17 amino acids, it is amphipathic, its structure is α-helix and it has a net charge of (+5). Solid-phase peptide synthesis was performed using the Fmoc strategy in acid medium. The primary structure was confirmed by MALDI-TOF mass spectrometry. The antimicrobial activity of the peptide was evaluated by broth microdilution method by measuring optical density in 96-well microplates. The minimal inhibitory concentration of GIBIMPY4 to kill 50 % of the bacterial cells (MIC 50 ) was 6.20 ± 0.02 µM for MRSA and 4.55 ± 0.02 µM for E . coli O157:H7, while also reporting a bacteriostatic effect for the later. GIBIMPY4 activity was sensitive to salt concentration in E . coli but insignificant effect in its activity against MRSA. The peptide seems to be a broad-spectrum antimicrobial agent based on the results against Gram-positive and Gram-negative bacteria and was specific for bacterial cells E . coli O157:H7 with index of specificity equal to 9.01 in vitro assays.