Sporicidal and anti-biofilm activity of PIN and PIN-like peptides — ASN Events
  1. Schedule
  2. Session Five - Poster Session A including Refreshments
  3. Sporicidal and anti-biofilm activity of PIN and PIN-like peptides

Sporicidal and anti-biofilm activity of PIN and PIN-like peptides (#145)

Nadin Shagaghi 1 , Enzo Palombo 1 , Andrew Clayton 2 , Mrinal Bhave 1
  1. Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Victoria 3122, Australia
  2. Centre for Micro-Photonics, Swinburne University of Technology, PO Box 218, Victoria 3122 , Australia

The emergence of drug-resistant pathogens has necessitated research effort into new infection control and treatment strategies. The broad-spectrum activity of antimicrobial peptides (AMPs) and their low potential for development of microbial resistance make them excellent candidates for this goal. Many AMPs have been found to be tryptophan-rich and cationic. The puroindolines (PINs) are small cationic proteins present in wheat seeds. They are the primary determinants of wheat grain texture and may have roles in seed defence from pathogens. Interestingly, the PINs exhibit a unique tryptophan-rich domain (TRD) associated with antimicrobial properties. Synthetic peptides based on the TRD of PINs and the related barley hordoindolines (HINs) display antifungal and antibacterial activities. Bacterial endospores and biofilms are highly resistant cells and their persistence has significant implications for disease control in disease management, medical implants and food industries. High concentrations of chemicals or heat treatments are needed to destroy the spores or biofilms, which can be impractical. In this study, the sporicidal activity of synthetic peptides PuroA (FPVTWRWWKWWKG-NH2), Pina-M (FSVTWRWWKWWKG-NH2) and Hina (FPVTWRWWTWWKG-NH2), based on TRD of PINs and HINs, was investigated against Bacillus subtilis endospores. Additionally, the peptides were tested for inhibitory effects on the initial cell attachment and the persistence of preformed biofilms of Pseudomonas aeruginosa and Listeria innocua. The results showed that the peptides reduced the number of viable spores by approximately 4 log units, and the treated spores appeared withered and deflated under scan electron microscope. In terms of anti-biofilm activity, PuroA and Pina-M, at 2 × minimum inhibitory concentrations against planktonic cultures, prevented the initial biomass attachment by approximately 85% and 90% for P. aeruginosa and L. innocua, respectively, and also inhibited more than 90% of performed biofilm of both organisms. Hina was not active against P. aeruginosa; however, it showed a similar level of inhibitory activity against L. innocua biofilms as PuroA and Pina-M. The results demonstrate potential applications of those peptides and the PIN proteins in controlling resistant pathogens in food and health industries.