Antibacterial Activity of a Lytic Enzyme Encoded by Pseudomonas aeruginosa Double Stranded RNA Bacteriophage phiYY

Abstract

Multidrug-resistant Pseudomonas aeruginosa is one of the most life-threatening pathogens for global health. In this regard, phage encoded lytic proteins, including endolysins and virion-associated peptidoglycan hydrolases (VAPGH), have been proposed as promising antimicrobial agents to treat P. aeruginosa. Most dsDNA phages use VAPGH to degrade peptidoglycan (PG) during infection, and endolysin to lyse the host cells at the end of lytic cycle. By contrast, dsRNA phage encodes only one lytic protein, which is located in the viral membrane to digest the PG during penetration, and also serves as an endolysin to release the phage. Currently, there are only seven sequenced dsRNA phages, and phiYY is the only one that infects human pathogen P. aeruginosa. In this study, dsRNA phage phiYY encoded lysin, named Ply17, was cloned and purified. Ply17 contains a PG-binding domain and a lysozyme-like-family domain. Ply17 exhibited a broad antibacterial activity against the outer membrane permeabilizer treated Gram-negative bacteria. The best lytic activity was achieved at 37°C, pH 7.5, in the presence of 0.5 mM EDTA. Moreover, it could effectively lyse Gram-positive bacteria directly, including Staphylococcus aureus. Therefore, dsRNA phage encoded Ply17 might be a promising new agent for treating multidrug-resistant pathogens.

Liposomal Delivery of Newly Identified Prophage Lysins in a Pseudomonas aeruginosa Model

“…In this study, we found that, in conjugation with 5 mM EDTA, 100 µg/mL Pa7 and Pa119 reduced about seven times the OD in 60 min when incubated with P. aeruginosa cells. This result is in line with the application of lysins isolated from Pseudomonas phages, LysPA26 [ 49 ], EL188 [ 50 ], Ppl65 [ 51 ], and Ply17 [ 52 ], which presented activity against P. aeruginosa in the presence of EDTA. Only the lysin Ppl65 may derive from a phage with lysogenic capacity, since the Pseudomonas phage PPpW-3 (NC_023006.1) that codes for this lysin harbours an integrase gene.…”

Phage vB_PaeS-PAJD-1 Rescues Murine Mastitis Infected With Multidrug-Resistant Pseudomonas aeruginosa

“…Therefore, the PlyPAJD-1 (lysin of PAJD-1) was expressed and purified. However, PlyPAJD-1 could not penetrate the outer membrane directly to kill bacteria, but it showed synergetic bactericidal efficacy when combined with EDTA, which disrupts the outer membrane by removing stabilizing cations and facilitating bacterial lysis by PlyPAJD-1 (Yang et al, 2018). At present, many studies have proposed different methods to transform lysin to effectively kill Gram-negative strains, including combining lysins with outer membrane permeabilizers (Oliveira et al, 2016), protein engineering (Wang et al, 2017;Yan et al, 2017) and formulating with nanocarriers (Ciepluch et al, 2019), which is the focus of our future research.…”

Characterization, genome analysis and in vitro activity of a novel phage vB_EcoA_RDN8.1 active against multi-drug resistant and extensively drug-resistant biofilm-forming uropathogenic Escherichia coli isolates, India

“…The growth experiment was carried out at 37°C using a multimode reader (Tecan Group Limited, Switzerland) with an orbital shaking for 5 s. The optical density of the cultures was automatically measured at 600 nm with an interval of 2 h. up to 20 h. The experiment was performed in triplicates. The antibacterial activity of phage vB_EcoA_RDN8.1 was also determined by colony forming units (CFU) reduction analysis, as previously described (Yang et al, 2018). We used 10 8 CFU ml −1 in trypticase soy broth initially for both control and treatment groups.…”