AIMMS researchers discover mechanism of increased virulence of Mycobacterium tuberculosis

The results of the research, led by Prof. Wilbert Bitter (Molecular Microbiology), are described in Nature Microbiology.

02/02/2018 | 11:26 AM

Tuberculosis is often regarded as a problem of the past, but is in fact the most deadly infectious disease worldwide with 1.7 million annual deaths. Although tuberculosis is among one of the most widespread and deathly infectious diseases, researchers at VU/VUMC have demonstrated that this bacteria even limits itself in its virulence. The bacterium has a substantial amount of proteins on its surface, the so-called PE and PPE proteins, that reduces damage to its host. Apparently, the bacterium benefits from a reduced/delayed virulence.


In recent years new tuberculosis strains are being spread around the world that do not produce these surface proteins and which have therefore become highly virulent. The research group led by Prof. Wilbert Bitter report in Nature Microbiology on a single mutation (deletion of the ppe38 locus) that is responsible for the loss of protein secretion. They also showed that ppe38 loss is directly linked to increased virulence of these new tuberculosis strains.

This finding is important, as the development of hyper virulent tuberculosis strains makes the fight against tuberculosis even more urgent. Furthermore, with the mutation in hand, hyper virulent strains can be identified quickly.

International collaboration

This research is the result of an international collaboration between research groups from The Netherlands, South-Africa, France, Mexico and Saudi Arabia.