Abstract
The treatment of tuberculosis is extremely long. One of the reasons why Mycobacterium tuberculosis elimination from the organism takes so long is that in particular environmental conditions it can become tolerant to drugs and/or develop persisters able to survive killing even from very high drug concentrations. Tolerance develops in response to a harsh environment exposure encountered by bacteria during infection, mainly due to the action of the immune system, whereas persistence results from the presence of heterogeneous bacterial populations with different degrees of drug sensitivity, and can be induced by exposure to stress conditions. Here, we review the actual knowledge on the stress response mechanisms enacted by M. tuberculosis during infection, which leads to increased drug tolerance or development of a highly drug-resistant subpopulation.
Highlights
Tolerance and persistence: two words often used as synonyms, but indicating deeply different concepts and biological phenomena (Kussell et al, 2005)
Persistence is characterized by the onset of bacterial subpopulations, which are extremely resistant to drug concentrations several times higher than the minimal inhibitory concentration (MIC), with the rest of the population remaining sensitive (Kussell et al, 2005; Brauner et al, 2016)
We review the actual knowledge about the mechanisms of drug tolerance and persistence to drugs in M. tuberculosis, underlining their vast complexity
Summary
Tolerance and persistence: two words often used as synonyms, but indicating deeply different concepts and biological phenomena (Kussell et al, 2005). Tolerance and Persistence in Mycobacteria entire bacterial population upon exposure to a peculiar and often stressful environment (Figure 1; Brauner et al, 2016; Meylan et al, 2018) This does not involve the selection of resistant mutants, but is usually due to a reduction of metabolism that leads to growth rate slowdown upon encountering specific environmental conditions. Persistence can be considered as a social behavior used by a bacterial community to guarantee the survival of at least a minority of its members toward incoming stress conditions, through the preventive development of heterogeneous subpopulations with different physiologic characteristics Such a heterogeneity can be obtained by deterministic or stochastic mechanisms. We review the actual knowledge about the mechanisms of drug tolerance and persistence to drugs in M. tuberculosis, underlining their vast complexity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
