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Updated: Jun 8, 2025

Production and Visualization of Bacterial Spheroplasts and Protoplasts to Characterize Antimicrobial Peptide Localization
Published on: August 11, 2018
Linear and Polyvalent Peptides with Potent Antimicrobial Activity Against Sensitive and Multidrug-Resistant E. c oli
Kelin Cuero-Amu1, Laura Daniela Bonilla-Velásquez1, Yerly Vargas-Casanova2
1Instituto de Biotecnología, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 45 No 26-85, 11321, Bogotá, Colombia.
Abstract:
Peptides containing the sequences 20RRWQWR25 and 20RRWQWRMKKLG30 derived from Bovine lactoferricin (LfcinB) were synthesized and their antibacterial effect against reference strains and sensitive and resistant clinical isolates of E. coli was evaluated. Tetra-branched multiple antigen peptide (MAP) ((RRWQWR)2-K-Ahx-C)2 exhibited significant antibacterial activity against sensitive, resistant, and multidrug-resistant clinical isolates of E. coli. Peptide 3: RRWQWR-Nal-KKLG; MIC=16 μM, 26[F]: (RRWQWRFKKLG)2-K-Ahx; MIC=15 μM, 17: (RRWQWRFK)2-K-Ahx; MIC=9 μM, and LfcinB (20-25)2: (RRWQWR)2-K-Ahx; MIC=11 μM exhibited the highest antibacterial activity against E. coli strains, with bactericidal effect and haemolytic effect at MIC less than 5 % and a therapeutic index >1. A synergistic effect of peptides 26[F] and 17 with ciprofloxacin (CIP) or ceftriaxone (CEF) was observed. Prolonged treatment of E. coli ATCC 25922 with sublethal concentrations of CIP induced resistance in this strain, whereas some peptides did not induce resistance. These peptides can be considered to be promising candidates for treating infections caused by resistant strains of E. coli.
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