Researchers at the University of Alabama at Birmingham (UAB) have found that a toxic gas present in air pollution and tobacco smoke plays a significant role in triggering tuberculosis infection. For the study, researchers study focused on carbon monoxide (CO), a colourless, odourless gas present in tobacco smoke, and vehicle and manufacturing plant emissions. CO is also produced naturally in brushfires and volcanic gas. In the study, researchers showed that CO triggers Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, to shift from active infection to a drug-resistant dormant state. This is called latency, a global problem that results in tuberculosis escaping detection and treatment, and which contributes to overall tuberculosis transmission. "This is the first description of a role for CO in mycobacterial pathogenesis, and may explain why smoking and air pollution contributes to TB,' said Adrie Steyn, Ph.D., assistant professor in UAB's Department of Microbiology and lead author on the study. During the study, the researchers worked with Mtb cells under biosafe laboratory conditions and found Mtb proteins