Organic solvent tolerance and antibiotic resistance increased by overexpression of marA in Escherichia coli.
AUTOR(ES)
Asako, H
RESUMO
We previously reported that overexpression of the soxS or robA gene causes in several Escherichia coli strains the acquisition of higher organic solvent tolerance and also increased resistance to a number of antibiotics (H. Nakajima, K. Kobayashi, M. Kobayashi, H. Asako, and R. Aono, Appl. Environ. Microbiol. 61:2302-2307, 1995). Most E. coli strains cannot grow in the presence of cyclohexane. We isolated the marRAB genes from a Kohara lambda phage clone and cyclohexane-tolerant mutant strain OST3408. We found a substitution of serine for arginine at position 73 in the coding region of marR of OST3408 and designated the gene marR08. Our genetic analysis revealed that marR08 is responsible for the cyclohexane-tolerant phenotype. We observed that the marA gene on high-copy-number plasmids increased the organic solvent tolerance of E. coli strains. Furthermore, exposure of E. coli cells to salicylate, which activates the mar regulon genes, also raised organic solvent tolerance. Overexpression of the marA, soxS, or robA gene increased resistance to numerous antibiotics but not to hydrophilic aminoglycosides.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=168437Documentos Relacionados
- Overexpression of the MarA positive regulator is sufficient to confer multiple antibiotic resistance in Escherichia coli.
- Autoactivation of the marRAB multiple antibiotic resistance operon by the MarA transcriptional activator in Escherichia coli.
- Overexpression of the robA gene increases organic solvent tolerance and multiple antibiotic and heavy metal ion resistance in Escherichia coli.
- Role of the acrAB locus in organic solvent tolerance mediated by expression of marA, soxS, or robA in Escherichia coli.
- marA, a regulated locus which controls expression of chromosomal multiple antibiotic resistance in Escherichia coli.