Variations in carotenoid content and acyl chain composition in exponential, stationary and biofilm states of Staphylococcus aureus, and their influence on membrane biophysical properties.

Autor: Perez-Lopez MI; Department of Physics, Universidad de los Andes, Bogotá, Colombia; Biological Sciences Department, Universidad de los Andes, Bogotá, Colombia., Mendez-Reina R; Department of Physics, Universidad de los Andes, Bogotá, Colombia., Trier S; Department of Physics, Universidad de los Andes, Bogotá, Colombia., Herrfurth C; Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany., Feussner I; Department of Plant Biochemistry, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Goettingen, Germany; Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany., Bernal A; Biological Sciences Department, Universidad de los Andes, Bogotá, Colombia., Forero-Shelton M; Department of Physics, Universidad de los Andes, Bogotá, Colombia., Leidy C; Department of Physics, Universidad de los Andes, Bogotá, Colombia. Electronic address: cleidy@uniandes.edu.co.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Biomembranes [Biochim Biophys Acta Biomembr] 2019 May 01; Vol. 1861 (5), pp. 978-987. Date of Electronic Publication: 2019 Feb 13.
DOI: 10.1016/j.bbamem.2019.02.001
Abstrakt: Bacteria are often found in close association with surfaces, resulting in the formation of biofilms. In Staphylococcus aureus (S. aureus), biofilms are implicated in the resilience of chronic infections, presenting a serious clinical problem world-wide. Here, S. aureus biofilms are grown under flow within clinical catheters at 37 °C. The lipid composition and biophysical properties of lipid extracts from these biofilms are compared with those from exponential growth and stationary phase cells. Biofilms show a reduction in iso and anteiso branching compensated by an increase in saturated fatty acids compared to stationary phase. A drastic reduction in carotenoid levels is also observed during biofilm formation. Thermotropic measurements of Laurdan GP and DPH polarization, show a reduction of lipid packing at 37 °C for biofilms compared to stationary phase. We studied the effects of carotenoid content on DMPG and DPPG model membranes showing trends in thermotropic behavior consistent with those observed in bacterial isolates, indicating that carotenoids participate in modulating lipid packing. Additionally, bending elastic constant (k c ) measurements using vesicle fluctuation analysis (VFA) show that the presence of carotenoids can increase membrane bending rigidity. The antimicrobial peptide Magainin H2 was less activity on liposomes composed of stationary phase compared to biofilms or exponential growth isolates. This study contributes to an understanding of how Staphylococcus aureus modulates the composition of its membrane lipids, and how those changes affect the biophysical properties of membranes, which in turn may play a role in its virulence and its resistance to different membrane-active antimicrobial agents.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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