Use of a novel allele of the Escherichia coli aacC4 aminoglycoside resistance gene as a genetic marker in mycobacteria.

The aacC4 gene from Escherichia coli can be expressed in mycobacteria and confers resistance to apramycin. However, the major limitation of the aacC4 gene as a genetic tool is that the gene also confers resistance to kanamycin and gentamicin, two antibiotics commonly used for selection in mycobacterial genetics, thus reducing the utility of the aacC4 gene in the mycobacterial field. To overcome this problem we constructed, by chemical mutagenesis, a mutant allele of the E. coli aacC4 gene that still confers resistance to apramycin but has a reduced ability to confer resistance to kanamycin and gentamicin. We then constructed a variety of E. coli-mycobacteria shuttle plasmids containing this mutant allele. Copyright 2004 Federation of European Microbiological Societies