Discovery About Biofilm Could Benefit Cystic Fibrosis Patients

Signal producing biofilm has been isolated

A new discovery out of Indiana University-Purdue University Indianapolis finds a signal that controls when lung bacteria in Cystic Fibrosis (CF) patients start producing biofilm. Biofilm is a sticky thick secretion that protects the bacteria from attacks making them almost impossible to get rid of. The findings could lead to treatments that prevent bacteria from using this biofilm as a defense.

The Journal of Bacteriology published the study titled: The Pseudomonas Aeruginosa Magnesium Transporter MgtE Inhibits Type III Secretion System Gene Expression by Stimulating rsmYZ Transcription. It focused on the most common bacteria found in CF patients, Pseudomonas aeruginosa. P. aeruginosa is an aerobic, gram-negative pathogen that grows in CF patients as a result of infections.

Mucous secretions clog the airways which reduce the clearance of inhaled microbes leading to bacterial biofilm buildup. The buildup results in inflammation and chronic infections in CF patients. The more severe the lung disease the poorer a patient’s quality of life and life expectancy. Currently treatment for P. aeruginosa includes inhaled antibiotics and chronic suppressive therapy.

There is more to be learned about molecular signals

Gregory G. Anderson, a microbiologist and lead author of the study said they know much about the regulatory signaling involved in the bacterium telling itself to form biofilm. However, there is not much knowledge about the molecular signals telling the organisms of appropriate times and places to cluster. Specifically, signals from the environment, mucous in the lungs, to tell them to form biofilms.

The problem with biofilms is that once bacteria starts producing them, immune responses or antibiotics can reach them. This gives the bacteria freedom to grow and proliferate. In CF patients having CF doesn’t cause loss of lung function, but bacterial infections cause the gradual loss of lung function.

The study localized a protein that was on the surface of bacteria in the lungs, magnesium transporter (MgtE). MgtE is a key regulator of biofilm production. It recognized chemical surroundings like abnormal levels of mucus, found in CF patients lungs. In particular, MgtE responds to altered levels of magnesium. Clusters of bacteria form producing a slime-like from treatments like antibiotics. The clusters are extremely hard to attack and kill.

This study is the first of its kind

Researchers found that MgtE suppresses the activity of signaling pathways involved in the formation of biofilm. Anderson said, they have tied MgtE to biofilm signaling networks. This is the first time an external signal, mucus, and biofilm regulation have been identified. This will lead to research of ways to disrupt the formation of biofilm and find better treatments for chronic lung infections.

Read on to learn more about the implications of this new research and what it means for current and future cystic fibrosis patients.