The increasing fear of drug-resistant superbugs is leading to a growing push for the next generation of antibiotics.

A team from the Okinawa Institute of Science and Technology (OIST) Graduate University is focusing on B. bacteriovorus—a type of bacteria that is harmless to humans but lethal to other forms of bacteria including E. coli, Salmonella and Legionella—as a candidate to be genetically mutated for a potential use as an antibiotic.

B. bacteriovorus could potentially treat many different types of infections, but due to its unusual predatory nature and other features it is difficult to manipulate genetically.

“In the future, we want to control the predation of the bacteria--the timing and extent of predation,” Mohammed Dwidar, Ph.D., from the Nucleic Acid Chemistry and Engineering Unit and first author on the paper, said in a statement. “[At the moment] we lack the basic engineering tools in order to do this.”

During the study, the researchers used riboswitches—gene expression-controlling tools known to function well in other bacteria—to grasp a better understand and to manipulate the bacteria’s predation.

The way in which a gene is expressed follows a specific pathway—where DNA is converted into RNA through transcription, RNA is converted into proteins through translation and then the proteins carry out different functions. 

The riboswitch can start or stop the RNA from being translated into a protein by putting a riboswitch at the beginning of a strand of RNA and then activating it with a chemical.

The researchers inserted a riboswitch into flagellar sigma factor FliA—one of the genes thought to be important to B. bacteriovorus predatory behavior. They then activated it with the chemical theophylline and placed it in petri dishes with E. coli.

The modified B. bacteriovorus multiplied quicker in the presence of theophylline, which implies that the bacteria was consuming its prey faster.

The researchers also found other uses in manipulating B. bacteriovorus cells.

“People want organic food without chemicals,” Dwidar said. “The predatory bacteria may be a potentially safe alternative to antibacterial agents for some plant diseases.

“We can also use it for industry, for example, in water treatment plants,” he added.

The researchers now plan on studying the bacteria and decide what tools might be able to control its behavior to release its full antibiotic potential.

The study was published in ACS Synthetic Biology.