Article
Version 1
Preserved in Portico This version is not peer-reviewed
Comparison of Ultrastructure, ECM, and Drug Susceptibility in M. avium Biofilms
Version 1
: Received: 18 September 2023 / Approved: 18 September 2023 / Online: 19 September 2023 (15:34:32 CEST)
How to cite: McManus, W. R.; Schorey, J. S. Comparison of Ultrastructure, ECM, and Drug Susceptibility in M. avium Biofilms. Preprints 2023, 2023091215. https://doi.org/10.20944/preprints202309.1215.v1 McManus, W. R.; Schorey, J. S. Comparison of Ultrastructure, ECM, and Drug Susceptibility in M. avium Biofilms. Preprints 2023, 2023091215. https://doi.org/10.20944/preprints202309.1215.v1
Abstract
Pulmonary infections with Mycobacterium avium occur in susceptible individuals following exposure to the bacterium in the environment, where it often persists in biofilms. Many methods have been used to generate biofilms of M. avium, and it is unknown whether different approaches generate similar structures and cell phenotypes. To make a parallel comparison of in vitro biofilm ultrastructure, extracellular matrix (ECM) composition, and drug susceptibility of biofilm resident bacteria, we used two published methods to generate M. avium biofilms: four week incubation in M63 medium or 24 hour exposure to dithiothreitol (DTT). Scanning electron microscopy revealed differences in biofilm ultrastructure between the two methods, including variation in appearance of ECM materials and morphology of resident cells, while light microscopy and staining with calcofluor white indicated that both biofilms contained polysaccharides characteristic of cellulose. Measuring susceptibility of biofilms to degradation by enzymes suggested differences in structurally important ECM molecules, with DTT biofilms having important protein and, to a lesser extent, cellulose components, and M63 biofilms having moderate protein, cellulose, and DNA components. Both biofilms conferred resistance to the bactericidal effects of amikacin and clarithromycin, with resident cells being killed at >10-fold lower rates than planktonic cells at almost all concentrations. Though these comparisons indicate differences in biofilm responses by M. avium under differing conditions, they also suggest common features of biofilm formation including cellulose production and antimicrobial resistance.
Keywords
Mycobacterium avium; biofilm; resistance; extracellular matrix
Subject
Biology and Life Sciences, Immunology and Microbiology
Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Comments (0)
We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.
Leave a public commentSend a private comment to the author(s)
* All users must log in before leaving a comment