Epinephrine Stimulates Mycobacterium tuberculosis Growth and Biofilm Formation

The human stress hormones catecholamines play a critical role in communication between human microbiota and their hosts and influence the outcomes of bacterial infections. However, it is unclear howM. tuberculosissenses and responds to certain types of human stress hormones. In this study, we screened several human catecholamine stress hormones (epinephrine, norepinephrine, and dopamine) for their effects onMycobacteriumgrowth. Our results showed that epinephrine significantly stimulated the growth ofM. tuberculosisin the serum-based medium as well as macrophages. In silico analysis and molecular docking suggested that the extra-cytoplasmic domain of the MprB might be the putative adrenergic sensor. Furthermore, we showed that epinephrine significantly enhancesM. tuberculosisbiofilm formation, which has distinct texture composition, antibiotic resistance, and stress tolerance. Together, our data revealed the effect and mechanism of epinephrine on the growth and biofilm formation ofM. tuberculosis, which contributes to the understanding of the environmental perception and antibiotic resistance ofM. tuberculosisand provides important clues for the understanding of bacterial pathogenesis and the development of novel antibacterial therapeutics.Keywords:M. tuberculosis;M. smegmatis;epinephrine;mprB;biofilm;antibiotic resistance