Bacteria shut down their mutant ‘cousins’

"This means we can start to think about the population of microbes as another set of knobs you could turn to fight infection," says Vernita Gordon. (Credit: mostly*harmless/Flickr)

A dangerous type of bacteria can not only block their own growth, but also the growth of their antibiotic-resistant mutants.

The discovery might lead to better ways to fight bacteria that are becoming increasingly resistant to antibiotic treatments.

“This means we can start to think about the population of microbes as another set of knobs you could turn to fight infection,” says Vernita Gordon, assistant professor of physics at University of Texas at Austin.

Life-threatening infections

The bacteria, Pseudomonas aeruginosa, frequently cause pneumonia in hospital patients and life-threatening infections for cystic fibrosis patients and people with HIV and chronic wounds. Part of a class of pathogenic bacteria that are becoming increasingly antibiotic-resistant, they include E. coli, a leading cause of urinary tract infections, and N. gonorrhoeae, which causes gonorrhea.

Findings from the study, published in the journal Interface, show that these bacteria produce a byproduct that can change the pH balance in ways that help suppress the antibiotic-resistant bacteria among them.

The finding supports the notion of adding a base (a substance with higher pH) to certain inhaled treatments that can be given along with antibiotics, for example in cystic fibrosis patients.


This would help tamp down antibiotic resistance, while allowing doctors to lower the dosage of antibiotics that are toxic at high doses and that produce serious side effects like deafness and kidney damage.

“Her results suggest that, for certain types of infections, formulation of an antibiotic that creates an alkaline environment at the source of infection could be effective,” says Bryan Davies, associate professor with the university’s Center for Infectious Disease, who was not involved with the study.

ExxonMobil, the University of Texas at Austin, and the university’s physics department funded the work.

Source: University of Texas at Austin