Peptoid Efficacy against Polymicrobial Biofilms Determined by Using Propidium Monoazide‐Modified Quantitative PCR

Abstract

Biofilms containing Candida albicans are responsible for a wide variety of clinical infections. The protective effects of the biofilm matrix, the low metabolic activity of microorganisms within a biofilm and their high mutation rate, significantly enhance the resistance of biofilms to conventional antimicrobial treatments. Peptoids are peptide‐mimics that share many features of host defence antimicrobial peptides but have increased resistance to proteases and therefore have better stability in vivo. The activity of a library of peptoids was tested against monospecies and polymicrobial bacterial/fungal biofilms. Selected peptoids showed significant bactericidal and fungicidal activity against the polymicrobial biofilms. This coupled with low cytotoxicity suggests that peptoids could offer a new option for the treatment of clinically relevant polymicrobial infections.

Antimicrobial Susceptibility Testing of Antimicrobial Peptides to Better Predict Efficacy

“…The de novo AMP ASP-1 was able to eradicate polymicrobial biofilms containing S, aureus, P. aeruginosa, A. baumannii , and K. pneumoniae when formulated into a polyurethane-based dressing (Bayramov et al, 2018 ) and the Komodo dragon-derived peptide DRGN-1 demonstrated moderate eradication activity against mixed biofilms containing P. aeruginosa and S. aureus (Chung et al, 2017 ). Luo and co-workers tested a library of peptoids for antibiofilm activity and demonstrated that 3 peptoids from the library were able to eradicate mixed species biofilms (formed for 8 h) containing C. albicans and S. aureus or C. albicans and E. coli (Luo et al, 2017 ).…”

Exploring the links between peptoid antibacterial activity and toxicity

“…Peptoids have been shown to have potency against a wide variety of Gram-positive and negative bacteria, 21 – 30 parasites 31 – 33 and fungi. 25 , 34 – 36 These studies highlight the clear potential that peptoids offer as a new class of antimicrobials but in order to progress their clinical development a more detailed study of their toxicity towards mammalian cells needs to be undertaken.…”

Natural Antimicrobials in the Dental Pulp

“…They can be synthesized de novo to generate novel antimicrobials with many of the generic features of antimicrobial peptides or synthesized to mimic specific antimicrobial peptides of interest. We previously designed and synthesized a de novo family of peptoids with alpha-helical secondary structure and potent antimicrobial activity against biofilms 65 . Whether such peptoids will be translated into therapeutic interventions remains to be determined.…”