Isolation and identification of a staphylococal strain with an anti-mycobacterial activity and study of it’s mode of action

Abstract

The resistance of mycobacteria to the clinical applied antibiotics poses a serious problem to deal with the infections they cause. So, the search for new antibiotics active against these bacteria becomes urgent. We report here the isolation from a Moroccan biotope of a bacterial strain secreting an active substance of protein nature that inhibits the growth of several mycobacterial species (Mycobacterium smegmatis; M. aurum A+;M. vaccae; M. bovis BCG andM. kansasii). PCR amplification and DNA sequecing of the 16S ribosomal RNA gene allowed the identification of this strain asStaphylococcus haemolyticus. Moreover, the substance produced by this strain was able to lyse the wall ofM. smegmatis and to extract its genomic DNA indicating that it acts probably, like others anti-mycobacterial antibiotics, on this envelope. The identification and characterisation of the active substance would open the way for further technological and therapeutic investigations.