Plasmid Loss in Plasmid-carrying Strains of Escherichia coli Treated with Phenoxazines and an Approach to Study Their DNA Binding Properties

Chandramouli, K. H. and D'Souza, Cletus and Thimmaiah, K. N. (2008) Plasmid Loss in Plasmid-carrying Strains of Escherichia coli Treated with Phenoxazines and an Approach to Study Their DNA Binding Properties. Nucleosides, Nucleotides and Nucleic Acids, 27 (1). pp. 70-83. ISSN 1532-2335

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Abstract

The effect of subinhibitory concentrations of 2-trifluoromethyl-N10-substituted phenoxazines on plasmid-coded antibiotic resistance in Escherichia coli was investigated. Phenoxazine treatment resulted in the loss of resistance markers to an extent of 8-63% in all the strains tested, and the disappearance of plasmid DNA in phenoxazine sensitive colonies was evidenced by agarose gel electrophoresis. The resistant strains were sensitized in the presence of phenoxazines with a concomitant reduction in the MIC (minimum inhibitory concentration) values. The UV, fluorescence spectral, and ethidium bromide displacement agarose gel assay methods revealed that phenoxazines are intercalated with plasmid DNA. Progressive addition of DNA led to a significant reduction in the peak intensity of the absorption maximum of phenoxazine derivative. Further, destabilization of ethidium bromide-DNA complex as seen from fluorescence microscopy in the presence of phenoxazines was observed. The potency of phenoxazines to sensitize the resistant organisms follows the order butyl > propyl > acetyl derivatives.

Item Type:	Article
Additional Information:	PMID: 18188772
Subjects:	C Chemical Science > Biochemistry
Divisions:	Department of > Biochemistry
Depositing User:	Manjula P Library Assistant
Date Deposited:	27 Aug 2019 06:09
Last Modified:	27 Aug 2019 06:09
URI:	http://eprints.uni-mysore.ac.in/id/eprint/7108

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