Dynamic Persistence of Antibiotic-Stressed Mycobacteria

All About Noise How individual cells behave within a larger “average” population can be surprising. Wakamoto et al. (p. 91 ) developed a method for investigating the consequences of phenotypic variability in single mycobacterial cells exposed to the pro-drug, isoniazid. Isoniazid needs to be activated by bacterial catalase. In the isoniazid–mycobacterium system, random fluctuations in catalase activity were important for cell survival. Because catalase is essential, it cannot be ablated; however, catalase activity pulsed randomly in the mycobacteria. Thus, a subpopulation of individual cells manage to avoid being killed by the activated antibiotic.