Open AccessPositive selection of allelic exchange mutants in Mycobacterium bovis BCG
Author(s) -
Pelicic Vladimir,
Reyrat JeanMarc,
Gicquel Brigitte
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08524.x
Subject(s) - mycobacterium bovis , mutant , allele , selection (genetic algorithm) , biology , genetics , microbiology and biotechnology , mycobacterium , mycobacterium tuberculosis , gene , tuberculosis , bacteria , medicine , computer science , pathology , artificial intelligence
sacB expression is lethal to mycobacteria in the presence of sucrose. It can therefore serve as a counter‐selectable marker for positive selection of gene replacement events as demonstrated in the fast‐growing Mycobacterium smegmatis . With this methodology, a sucrose counter‐selectable vector was used to deliver, into the Mycobacterium bovis BCG genome, an inactivated copy ( ureC::Km ) of the ureC gene encoding the mycobacterial urease. A two‐step selection procedure on 2% sucrose allowed the positive selection of gene exchange mutants. This technique should thus be extremely useful for the genetic analysis of pathogenic mycobacteria.