Investigating the Antibacterial Effects of 3 Novel Peptides Isolated from the Venom of Iranian Odontobuthus doriae and Buthotus saulcyi Scorpions on Escherichia coli (UTI89) and Enterococcus faecalis Causing Urinary Tract Infection

Urinary tract infection (UTI) is one of the most common bacterial infections and can lead to severe diseases such as bacteremia and kidney scarring. Escherichia coli ( E. coli ) is the most common cause of UTI. Additionally, Enterococci are also acquired pathogens in urinary tract infection. Due to the increasing prevalence of antimicrobial resistance in patients with UTI, the research for new antimicrobial candidates is necessary. Unlike conventional antibiotics, resistance to antimicrobial peptides is highly unlikely. Scorpion venom is a valuable source for these antimicrobial peptides. The results of HPLC, Mass Spectrometry, Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis (SDS PAGE) and Bradford test identified three synthetic novel; peptide 2, peptide 3 and peptide 4 (P2, P3 and P4) and Pantinin3 synthetic peptide “passed quality control” and was well synthesized. Although all four studied peptides had an inhibitory effect on both bacterial strains, it was observed that peptide (P3) had the most potent inhibitory effect on both Gram-positive and Gram-negative bacterial strains. Its IC50 value for Enterococcus faecalis and E. coli UT189 bacteria is 160 and 80 µg/ml respectively. According to the results of this study, Peptide 3 could be a suitable candidate for the development of new antimicrobial drugs of natural origin to which microorganisms cannot become resistant.