Alginate oligosaccharides enhance diffusion and activity of colistin in a mucin-rich environment

Stokniene, Joana, Varache, Mathieu ORCID: https://orcid.org/0000-0001-7166-2253, Rye, Philip D, Hill, Katja E ORCID: https://orcid.org/0000-0002-8590-0117, Thomas, David W ORCID: https://orcid.org/0000-0001-7319-5820 and Ferguson, Elaine L ORCID: https://orcid.org/0000-0002-0125-0234 2022. Alginate oligosaccharides enhance diffusion and activity of colistin in a mucin-rich environment. Scientific Reports 12 , 4986. 10.1038/s41598-022-08927-1

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Abstract

In a number of chronic respiratory diseases e.g. cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD), the production of viscous mucin reduces pulmonary function and represents an effective barrier to diffusion of inhaled therapies e.g. antibiotics. Here, a 2-compartment Transwell model was developed to study impaired diffusion of the antibiotic colistin across an artificial sputum (AS) matrix/medium and to quantify its antimicrobial activity against Pseudomonas aeruginosa NH57388A biofilms (alone and in combination with mucolytic therapy). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) revealed that the presence of AS medium significantly reduced the rate of colistin diffusion (> 85% at 48 h; p < 0.05). Addition of alginate oligosaccharide (OligoG CF-5/20) significantly improved colistin diffusion by 3.7 times through mucin-rich AS medium (at 48 h; p < 0.05). Increased diffusion of colistin with OligoG CF-5/20 was shown (using confocal laser scanning microscopy and COMSTAT image analysis) to be associated with significantly increased bacterial killing (p < 0.05). These data support the use of this model to study drug and small molecule delivery across clinically-relevant diffusion barriers. The findings indicate the significant loss of colistin and reduced effectiveness that occurs with mucin binding, and support the use of mucolytics to improve antimicrobial efficacy and lower antibiotic exposure.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Dentistry
Additional Information:	This article is licensed under a Creative Commons Attribution 4.0 International License
Publisher:	Nature Research
ISSN:	2045-2322
Funders:	MRC
Date of First Compliant Deposit:	21 March 2022
Date of Acceptance:	10 March 2022
Last Modified:	22 May 2023 21:31
URI:	https://orca.cardiff.ac.uk/id/eprint/148530

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