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Mol Microbiol. 2008 May;68(3):786-99. doi: 10.1111/j.1365-2958.2008.06204.x. Epub 2008 Mar 25.

Borrelia burgdorferi membranes are the primary targets of reactive oxygen species.

Author information

1
National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratories, 903 S 4th Street, Hamilton, MT 59840, USA.

Abstract

Spirochetes living in an oxygen-rich environment or when challenged by host immune cells are exposed to reactive oxygen species (ROS). These species can harm/destroy cysteinyl residues, iron-sulphur clusters, DNA and polyunsaturated lipids, leading to inhibition of growth or cell death. Because Borrelia burgdorferi contains no intracellular iron, DNA is most likely not a major target for ROS via Fenton reaction. In support of this, growth of B. burgdorferi in the presence of 5 mM H(2)O(2) had no effect on the DNA mutation rate (spontaneous coumermycin A1 resistance), and cells treated with 10 mM t-butyl hydroperoxide or 10 mM H(2)O(2) show no increase in DNA damage. Unlike most bacteria, B. burgdorferi incorporates ROS-susceptible polyunsaturated fatty acids from the environment into their membranes. Analysis of lipoxidase-treated B. burgdorferi cells by Electron Microscopy showed significant irregularities indicative of membrane damage. Fatty acid analysis of cells treated with lipoxidase indicated that host-derived linoleic acid had been dramatically reduced (50-fold) in these cells, with a corresponding increase in the levels of malondialdehyde by-product (fourfold). These data suggest that B. burgdorferi membrane lipids are targets for attack by ROS encountered in the various stages of the infective cycle.

PMID:
18373524
PMCID:
PMC2327290
DOI:
10.1111/j.1365-2958.2008.06204.x
[Indexed for MEDLINE]
Free PMC Article

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