Influence of High Intensity Focused Ultrasound on the Microstructure and c-di-GMP Signaling of Pseudomonas aeruginosa Biofilms

Bharatula, LD; Marsili, E; Rice, SA; Kwan, JJ

Influence of High Intensity Focused Ultrasound on the Microstructure and c-di-GMP Signaling of Pseudomonas aeruginosa Biofilms

Bharatula, LD Marsili, E Rice, SA Kwan, JJ

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Publisher:: Frontiers Media SA
Publication Type:: Journal Article
Citation:: Frontiers in Microbiology, 2020, 11
Issue Date:: 2020-01-01

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Field	Value	Language
dc.contributor.author	Bharatula, LD
dc.contributor.author	Marsili, E
dc.contributor.author	Rice, SA
dc.contributor.author	Kwan, JJ
dc.date.accessioned	2021-01-12T01:42:48Z
dc.date.available	2021-01-12T01:42:48Z
dc.date.issued	2020-01-01
dc.identifier.citation	Frontiers in Microbiology, 2020, 11
dc.identifier.issn	1664-302X
dc.identifier.issn	1664-302X
dc.identifier.uri	http://hdl.handle.net/10453/145318
dc.description.abstract	<jats:p>Bacterial biofilms are typically more tolerant to antimicrobials compared to bacteria in the planktonic phase and therefore require alternative treatment approaches. Mechanical biofilm disruption from ultrasound may be such an alternative by circumventing rapid biofilm adaptation to antimicrobial agents. Although ultrasound facilitates biofilm dispersal and may enhance the effectiveness of antimicrobial agents, the resulting biological response of bacteria within the biofilms remains poorly understood. To address this question, we investigated the microstructural effects of <jats:italic>Pseudomonas aeruginosa</jats:italic> biofilms exposed to high intensity focused ultrasound (HIFU) at different acoustic pressures and the subsequent biological response. Confocal microscopy images indicated a clear microstructural response at peak negative pressures equal to or greater than 3.5 MPa. In this pressure amplitude range, HIFU partially reduced the biomass of cells and eroded exopolysaccharides from the biofilm. These pressures also elicited a biological response; we observed an increase in a biomarker for biofilm development (cyclic-di-GMP) proportional to ultrasound induced biofilm removal. Cyclic-di-GMP overproducing mutant strains were also more resilient to disruption from HIFU at these pressures. The biological response was further evidenced by an increase in the relative abundance of cyclic-di-GMP overproducing variants present in the biofilm after exposure to HIFU. Our results, therefore, suggest that both physical and biological effects of ultrasound on bacterial biofilms must be considered in future studies.</jats:p>
dc.language	en
dc.publisher	Frontiers Media SA
dc.relation.ispartof	Frontiers in Microbiology
dc.relation.isbasedon	10.3389/fmicb.2020.599407
dc.rights	info:eu-repo/semantics/openAccess
dc.subject	0502 Environmental Science and Management, 0503 Soil Sciences, 0605 Microbiology
dc.title	Influence of High Intensity Focused Ultrasound on the Microstructure and c-di-GMP Signaling of Pseudomonas aeruginosa Biofilms
dc.type	Journal Article
utslib.citation.volume	11
utslib.for	0502 Environmental Science and Management
utslib.for	0503 Soil Sciences
utslib.for	0605 Microbiology
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Strength - ithree - Institute of Infection, Immunity and Innovation
pubs.organisational-group	/University of Technology Sydney
utslib.copyright.status	open_access	*
pubs.consider-herdc	false
dc.date.updated	2021-01-12T01:42:41Z
pubs.publication-status	Published online
pubs.volume	11

Abstract:

Bacterial biofilms are typically more tolerant to antimicrobials compared to bacteria in the planktonic phase and therefore require alternative treatment approaches. Mechanical biofilm disruption from ultrasound may be such an alternative by circumventing rapid biofilm adaptation to antimicrobial agents. Although ultrasound facilitates biofilm dispersal and may enhance the effectiveness of antimicrobial agents, the resulting biological response of bacteria within the biofilms remains poorly understood. To address this question, we investigated the microstructural effects of Pseudomonas aeruginosa biofilms exposed to high intensity focused ultrasound (HIFU) at different acoustic pressures and the subsequent biological response. Confocal microscopy images indicated a clear microstructural response at peak negative pressures equal to or greater than 3.5 MPa. In this pressure amplitude range, HIFU partially reduced the biomass of cells and eroded exopolysaccharides from the biofilm. These pressures also elicited a biological response; we observed an increase in a biomarker for biofilm development (cyclic-di-GMP) proportional to ultrasound induced biofilm removal. Cyclic-di-GMP overproducing mutant strains were also more resilient to disruption from HIFU at these pressures. The biological response was further evidenced by an increase in the relative abundance of cyclic-di-GMP overproducing variants present in the biofilm after exposure to HIFU. Our results, therefore, suggest that both physical and biological effects of ultrasound on bacterial biofilms must be considered in future studies.

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http://hdl.handle.net/10453/145318