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Multidrug-resistance bacteria are a serious problem for health specialists and all the people in the world. The main reasons for this problem are the misuse of antibiotics and the limited number of antibiotics as compared to the different human diseases. Important antibiotic-resistant bacteria include Methicillin-resistant Staphylococcus aureus (MRSA) and Extended-Spectrum β-Lactamases E. coli (ESBL E. coli), These two types of bacteria can cause life-threatening diseases and poses a big problem in choosing suitable antibiotics for infections caused by them. Antimicrobial peptides (AMPs) are considered promising antimicrobial agents that meet the required criteria for novel antimicrobial drugs. This study aims to design novel and safe AMP to be used as antimicrobial agents. In this study, an unique modified AMPs called WW-158 was designed to have a hydrophilic and hydrophobic balance using arginine to represent the cationic part and tryptophan to show the hydrophobic part. It showed good activity against MRSA with a MIC value of 35 μM. These effective concentrations were associated with negligible toxicity toward human red blood cells. Furthermore, our results showed that most of the combined groups of peptides with eight conventional antibiotics displayed synergistic modes of action or additive effects.

Bacterial resistance is a difficult limitation in the treatment of infections. The potential antibacterial activity of WOW peptide conjugation with silver nanoparticles against selected pathogens is investigated in this study. The peptide WOW was created by combining two tryptophan subunits and one ornithine amino acid, and its purity was determined using reverse phase high performance liquid chromatography. Mass spectrometry and electrospray ionization mass spectrometry were used to confirm the WOW peptide. Silver nanoparticles conjugated with WOW were created by adding WOW to a solution of silver nitrate in the presence of the reducing agent sodium borohydride. The yellow-brown color indicated the presence of WOW-AgNPs, which was confirmed by ultraviolet/visible spectrophotometry. The minimum inhibitory and bactericidal concentrations of WOW nanoparticles were determined using the micro dilution method against Staphylococcus aureus, Escherichia coli, Methicillin resistant Staphylococcus aureus (MRSA), and ESBL Escherichia coli. The Erythrocyte Hemolytic Assay was used to assess the toxicity of nanoparticles conjugated with WOW. WOW alone was effective (MICs between 120 and 215 µgml-1) against both standard and resistant strains of bacteria. WOW –AgNPs, on the other hand, were more effective, with MICs ranging from 30 to 100 µgml-1 depending on the bacteria used. WOW -–after 30 minutes of incubation, silver nanoparticles at a concentration of 100 µgml-1 caused only 3% hemolysis in human erythrocytes.in conclusion, WOW –silver nanoparticles were found to have good antibacterial activity against pathogenic strains of gram positive and gram negative bacteria. Furthermore, the conjugate demonstrated low hemolytic activity and cytotoxicity. As a result, WOW conjugation with AgNPs is a promising treatment candidate for bacterial infection with low toxicity.