Identification and Characterization of New Bacteriophages to Control Multidrug-Resistant Pseudomonas aeruginosa Biofilm on Endotracheal Tubes

Abstract

Studies involving antimicrobial-coated endotracheal tubes are scarce, and new approaches to control multidrug-resistant Pseudomonas aeruginosa biofilm on these devices should be investigated. In this study, five new P. aeruginosa bacteriophages from domestic sewage were isolated. All of them belong to the order Caudovirales , Myoviridae family. They are pH and heat stable and produce 27 to 46 particles after a latent period of 30 min at 37°C. Their dsDNA genome (ranging from ∼62 to ∼65 kb) encodes 65 to 89 different putative proteins. They exhibit a broad lytic spectrum and infect 69.7% of the P. aeruginosa strains tested. All the bacteriophages were able to reduce the growth of P. aeruginosa strains in planktonic form. The bacteriophages were also able to reduce the biofilm viability rates and the metabolic activity of P. aeruginosa strains in a model of biofilms associated with endotracheal tubes. In addition, scanning electron microscopy micrographs showed disrupted biofilms and cell debris after treatment of bacteriophages, revealing remarkable biofilm reduction. The lytic activity on multidrug-resistant P. aeruginosa biofilm indicates that the isolated bacteriophages might be considered as good candidates for therapeutic studies and for the application of bacteriophage-encoded products.

Bacteriophage Cocktail-Mediated Inhibition of Pseudomonas aeruginosa Biofilm on Endotracheal Tube Surface

“…The analysis of the biofilm-covered areas indicated a statistically significant difference ( p < 0.05) between phage-treated and control; however, statistically significant differences were not observed among the five different phages ( Figure 1 A). Therefore, based on the broader lytic spectrum of the phages with multidrug-resistant strains; the efficiency of plating and genomic differences, reported by Oliveira et al [ 25 ]; and the anti-biofilm activity presented here ( Figure 1 B–G), the phages vB_PaeM_USP_2 and vB_PaeM_USP_18 were selected to compose a cocktail in the assays involving dynamic biofilm growth on the ET surface.…”

“…An initial screening was performed to select phages with stronger anti-biofilm activity. Biofilm-covered areas showed a significant reduction after phage treatment in 4/15 P. aeruginosa strains ( Table S1 ), in which three were classified previously as multidrug-resistant [ 25 ]. Biofilm areas of four other P. aeruginosa strains were lower, but the difference was not significant.…”

“…Aiming at treating acute infections caused by nosocomial pathogens, Aleshkin et al reported that intragastric administration of a phage cocktail in patients with mechanical ventilation promoted an important reduction in bacterial burden [ 24 ]. Furthermore, the anti-biofilm activity of recently characterized new phages was demonstrated in vitro in an ET-associated P. aeruginosa biofilm model [ 25 ]. The authors demonstrated an extensive lytic activity with multidrug-resistant P. aeruginosa biofilm, suggesting that the new phages might be considered as good candidates for therapeutic studies [ 25 ].…”

“…Furthermore, the anti-biofilm activity of recently characterized new phages was demonstrated in vitro in an ET-associated P. aeruginosa biofilm model [ 25 ]. The authors demonstrated an extensive lytic activity with multidrug-resistant P. aeruginosa biofilm, suggesting that the new phages might be considered as good candidates for therapeutic studies [ 25 ]. Although encouraging results have revealed the anti-biofilm effect of the phage therapy, the action of immobilized phages on the ET surface, to control biofilm development, is unclear.…”

Overcoming Challenges to Make Bacteriophage Therapy Standard Clinical Treatment Practice for Cystic Fibrosis

“…The vital need for a swift translation of alternative therapy into clinical use has identified bacteriophage (phage) therapy as one of the top candidates due to its successful use in humans when approved on compassionate grounds. Phage treatments are also cheaper due to shorter treatment periods, exhibit little or no toxicity, and are more effective than current antimicrobial strategies ( Alemayehu et al, 2012 ; Agarwal et al, 2018 ; Oliveira et al, 2020 ).…”