METHOD OF SELECTION OF ALLELIC EXCHANGE MUTANTS

摘要

A process for replacing a nucleotide sequence in the genome of a mycobacterium strain comprises the steps of: a) providing a vector containing SacB gene coding for levane saccharase enzyme and a nucleotide sequence of interest; b) transfecting the mycobacterium strain with the vector; c) selecting clones of the resulting transfected mycobacteria for replacement of the nucleotide sequence of interest by propagating the transfected clones in a culture medium supplemented with sucrose; and d) isolating the recombinant strain. The process is useful for positive selection of allelic exchange mutants, such as in Mycobacterium tuberculosis complex.