Evaluation of Antibacterial Activity of Magainin and Mastoparan and Its Novel Hybrid Against MDR E. coli Isolates of Neonatal Calves

• DOI: 10.1007/s10989-020-10154-z
• Publication Date: 2021-01-13T00:28:45Z
• Authors: Shailendri Gupta; Abhishek; Sameer Shrivastava; Rajkumar James Singh; Purnima Gogoi; Bablu Kumar
• Keywords: Magainin; Mastoparan; Haemolysis; Spectinomycin

The extensive use of antibiotics in medical, as well as in veterinary practices has led to the development of antibiotic resistance which is of increasing global concern. The so called “superbugs” or the multi-drug resistant bacteria have made the present day antibiotics less effective. Therefore, search of an alternative is the need of hour, and for which antimicrobial peptides (AMPs) could be a good approach. AMPs are relatively short (12 to 100 amino acids), amphipathic peptides isolated from wide range of living organism. Four peptides were synthesized by solid phase peptide synthesis method; Magainin (Pep-1) & Mastoparan (Pep-2) and Pep-3 and Pep-4 (novel hybrid of Magainin and Mastoparan). MIC of these peptides on E. coli (ATCC-25922) strain was found to be 12 μM, 24 μM, 11 μM, and 40 μM respectively. 100 clinical E. coli isolates were screened against these peptides at their respective 1 and 2xMIC. Percentage of isolates inhibited at 2xMIC for different peptides were Pep-1(74%); Pep-2(91%); Pep-3(86%); Pep-4 (75%). The MBC of the peptides on ATCC-25922 was same as 1xMIC and for majority of the resistant strains it was at 2xMIC. The percentage of haemolysis even at 4xMIC was < 2% in cattle RBC and < 5% in dog RBC which is negligible. Owing to the low MIC and negligible chances of resistance development, AMPs can be a good therapeutic candidate to fight antimicrobial resistance.