Genetic tools in pathogenic nocardioform actinomycetes

Nocardioform actinomycetes are Gram-positive bacteria with high G+C content. Several species of Mycobacterium, Corynebacterium, Nocardia and Rhodococcus are important human or animal pathogens. Transposon mutagenesis and homologous recombination are powerful genetic tools used for the identification of pathogenicity determinants. Transposable elements with potential application to mutagenize pathogenic nocardioform actinomycetes are described. Homologous recombination experiments which have been recently achieved in mycobacteria and related actinomycetes are commented on.