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.

抗生素在医学以及兽医实践中的广泛使用导致抗生素耐药性的发展，这引起了全球日益关注。所谓的“超级细菌”或具有多重耐药性的细菌使当今的抗生素无效。因此，寻找替代品是一个小时的需求，而抗菌肽（AMPs）可能是一个很好的方法。AMP相对较短（12至100个氨基酸），是从多种生物中分离的两亲性肽。通过固相肽合成法合成了四种肽。Magainin（Pep-1）和Mastoparan（Pep-2）以及Pep-3和Pep-4（Magainin和Mastoparan的新型杂种）。这些肽在大肠杆菌上的MIC发现（ATCC-25922）菌株分别为12μM，24μM，11μM和40μM。针对这些肽在各自的1xMIC和2xMIC下筛选了100种临床大肠杆菌分离物。不同肽段在2xMIC抑制的分离株百分比为Pep-1（74％）；Pep-2（91％）; Pep-3（86％）；Pep-4（75％）。ATCC-25922上肽段的MBC与1xMIC相同，而对于大多数抗性菌株，其MBC均为2xMIC。甚至在4xMIC时，牛RBC的溶血百分比<2％，狗RBC的<5％，这可以忽略不计。由于低MIC和耐药性发展的机会可以忽略不计，AMPs可以作为抗微生物耐药性的良好治疗选择。