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dc.contributor.authorAstudillo, Ariel
dc.contributor.authorLeung, Sharon Shui Yee
dc.contributor.authorKutter, Elizabeth
dc.contributor.authorMorales, Sandra
dc.contributor.authorChan, Hak-Kim
dc.date.accessioned2019-05-17T02:28:07Z
dc.date.available2019-05-17T02:28:07Z
dc.date.issued2018-01-17
dc.identifier.urihttp://hdl.handle.net/2123/20426
dc.description.abstractReduced infectivity of phage due to the nebulization process has been reported previously, but no visual evidence on structural change upon nebulization has been established, or whether these structural changes can be attributed to the titer reduction. In this study, transmission electron microscopy (TEM) was employed to assess the impact of three different types of nebulizers, air-jet, vibrating-mesh and static-mesh nebulizers, on the structural stability of a Myoviridae phage, PEV44, active against Pseudomonas aeruginosa. The morphology of the phage in the nebulized samples was categorized into two groups: “whole” (the capsid and tail held together) and “broken” (the capsid separated from the tail) phages. The “whole” phage group was further divided into three sub-groups: 1) intact, 2) contracted tail and 3) empty capsid. The starting stock suspension was found to contain considerable portions of “broken” phages (35.5 ± 6.7%), “whole” phages with contracted tails (9.9 ± 5.4%) and empty capsids (19.3 ± 8.9%). The fraction of “broken” phages was significantly increased after nebulization, with the air-jet nebulizer (83%) being more pronounced than the mesh type nebulizers (50 – 60%). While the amount of intact phages (2 − 10%) and whole phages with contracted tails (0 − 3%) were significantly decreased, the proportion of phages with empty capsids (15 − 36%) were not significantly different. Phages with broken features obtained by TEM quantification were 92.9 ± 3.2%, 74.8 ± 10.4% and 71.2 ± 11.0% for the jet, vibrating-mesh and static-mesh nebulizers, respectively. These results were found to be comparable with the titer loss obtained by the conventional plaque assay results. The in vitro aerosol performance and viable phage delivery of the three nebulizers was also assessed. The Omron nebulizer achieved a significantly higher viable respirable fraction (VRF) than the SideStream and Aeroneb Go (15.1 ± 5.8%, 2.4 ± 2.0%, 4.1 ± 2.7% respectively). In conclusion, this study identified various changes in the phage structure and viability of phage from different types of nebulizers. Understanding these effects and the phage tolerance to nebulization stresses can potentially improve our choice of the delivery method for inhaled phage therapy.en_AU
dc.description.sponsorshipThis work was financially supported by the Australian Research Council (Discovery Project DP150103953). The authors acknowledge the facilities and technical assistance of the Australian Microscopy and Microanalysis Research Facility at the Australian Centre for Microscopy and Microanalysis at the University of Sydney and the Mycobiology laboratory at the Centenary Institute. Also, we would like to thanks Petr Leiman at EPFL and Alex Evilevitch at Lund University for their invaluable expert feedback on the phage structure which enhanced the understanding of the observations in this work.en_AU
dc.language.isoen_AUen_AU
dc.publisherElsevieren_AU
dc.relationARC DP150103953en_AU
dc.subjectbacteriophageen_AU
dc.subjectTEMen_AU
dc.subjectnebulizeren_AU
dc.subjectplaque assayen_AU
dc.subjectviable respirable fractionen_AU
dc.titleNebulization effects on structural stability of bacteriophage PEV 44en_AU
dc.typeArticleen_AU
dc.subject.asrcFoR::111504 - Pharmaceutical Sciencesen_AU
dc.subject.asrcFoR::110203 - Respiratory Diseasesen_AU
dc.subject.asrcFoR::110309 - Infectious Diseasesen_AU
dc.identifier.doihttps://doi.org/10.1016/j.ejpb.2018.01.010
dc.type.pubtypePre-printen_AU


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