Antimicrobial effect of Tetraspanin CD9 Peptides on Pseudomonas aeruginosa

Abstract

It is critical to find an alternative therapeutic approach to combat Pseudomonas aeruginosa (P. aeruginosa) that can simultaneously reduce the occurrence of bacterial resistance. The tetraspanin CD9, a highly expressed membrane protein in melanocytes was chosen for this study because it is highly expressed in keratinocytes and has been implicated in the pathogenesis of bacterial infections in a previous study. The antimicrobial activity of CD9 peptides against the standard strain P. aeruginosa (ATCC 27853) and a clinical multidrug-resistant P. aeruginosa (MDR- P. aeruginosa) was studied using the disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CD9 peptides were determined by broth microdilution assays with concentrations ranging from 1 mg/mL to 4.88×10-4 mg/mL. The antibiofilm activity of the CD9 peptides was also determined. CD9 peptides showed an 11.75 ± 2.36 mm inhibition zone against the standard P. aeruginosa strain but none against the MDR- P. aeruginosa. Both isolates had the same MIC value, 0.25 mg/mL. The MBC for the standard strain P. aeruginosa was 0.5 mg/mL, while for the MDR- P. aeruginosa strain, it was 1 mg/mL. CD9 peptides significantly inhibited up to 70% biofilm against both P. aeruginosa isolates. CD9 peptides showed a modest inhibitory effect against the standard strain P. aeruginosa but not against MDR- P. aeruginosa. Interestingly, CD9 peptides were found to be a good anti-biofilm treatment against both P. aeruginosa isolates. This study demonstrated that CD9 peptides have the potential to be an alternative antimicrobial treatment against P. aeruginosa.