Researchers from the School of Biological Sciences, Monash University, have discovered that Mycobacteria, a bacterial group that cause tuberculosis (TB), leprosy, and Buruli ulcer, might utilise carbon monoxide (CO) to survive longer inside the human host.
During infection, these microbes are in a hostile environment with very few available nutrients. Thus anything they can do to get extra energy can be hugely advantageous.
“When microbial cells are starved of their preferred energy sources, one way they subsist is by scavenging gases such as carbon monoxide,” says co-lead author Paul Cordero, PhD student at Monash University, in a news release.
“They breakdown this gas into its fundamental components, which provide the cells just enough energy to persist.”
The enzyme carbon monoxide dehydrogenase allows Mycobacteria to obtain energy from carbon monoxide gas, reveals the researchers. They found that,while the energy gained is not enough to allow for growth, carbon monoxide consumption allowed mycobacteria to survive for longer periods of time.
“It has been known for years that Mycobacterium tuberculosis can use carbon monoxide, but nobody knew why,” says co-first author and PhD candidate Katie Bayly.
“Based on these findings, we predict that it uses this gas to its advantage to persist inside human lungs,” she said.
“Our immune cells actually make small amounts of carbon monoxide, which the bacterium may be able to use as an energy supply while dormant.”
Dormancy allows Mycobacterium tuberculosis to stay alive inside patients for years. This dormant infection usually has no symptoms, but can advance into full-blown TB, especially when people become immuno-compromised.
Researchers suggest that the new findings on survival mechanism of Mycobacteria could pave way for newer strategies to better fight diseases such as tuberculosis.
The study was published in the ISME Journal.