Title : Antimicrobial activity of peptides derived from lycosa erythrognatha spider venom against quinolone-resistant uropathogenic escherichia coli (UPECs)
Abstract:
Uropathogenic Escherichia coli (UPECs) is the leading pathogen involved in urinary tract infection. Although quinolones are widely used in these cases, the resistance of UPECs to this class has been growing significantly, challenging the effectiveness of antibacterial therapy. Thus, the development of novel antimicrobials agents for the treatment of quinolone-resistant UPECs infections is imperative. Herein, arthropod toxin stand out as a promising source of new bioactive compounds against superbugs such as quinolone-resistant UPECs, especially antimicrobial peptides (AMPs).
Objectives: To study the antibacterial effect of synthetic peptides derived from a natural compound present in the venom of the spider Lycosa erythrognatha against clinical isolates of quinolone-resistant UPECs.
Methodology: Ten clinical isolates of UPECs were included. The bacteria were identified by biochemical-physiological assay. Antimicrobial resistance profile and the extended spectrum beta-lactamase (ESBL) production was determined. Next, the antibacterial effect of the peptides was studied by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In silico study was performed to determine the mode of action of the peptide against the E. coli adhesins PapG and FimH via ClusPro webserver.
Results: Five compounds were tested, but LyeTx I mnΔK (16 amino acid residues; 1871.32 Da) showed the best activity. The MIC and MBC of this compound was of 2 µM and 8 µM, respectively, to all included isolates. All the isolates were resistant to nalidixic acid, ofloxacin, norfloxacin ciprofloxacin and levofloxacin. In addition, five isolates were ESBL-positive. Peptide showed binding with both of the adhesins, PapG and FimH, that help E. coli in binding to kidney and bladder cells, respectively.
Conclusion: The LyeTx I mnΔK peptide is a potential prototype to development of new antimicrobial agents against quinolone-resistant uropathogenic Escherichia coli.
