Researchers Turn “Good” Bacteria Against “Bad” Bacteria

A new technology from Tel Aviv University will make it possible to insert ‘good’ bacteria into the body or into diverse environmental niches for the purpose of injecting toxins and eliminating ‘bad’ bacteria.

Researchers believe that the breakthrough, which can be suited to target different kinds of bacteria, may become a biological replacement for antibiotics whose efficacy has been on the decline in recent years.

The World Health Organization recently defined bacteria resistance to antibiotics as one of the most significant dangers to public health and food safety.

In the TAU study, researchers ‘borrowed’ a toxin injection system – known as a Type 6 Secretion System – from a pathogenic bacterium and introduced it into a ‘friendly’ bacterium, Vibrio natriegens. This ‘friendly’ bacterium is not harmful to humans or animals and can survive and reproduce under a variety of conditions. The injection system is similar to a poisoned arrow shot from a bacterium towards neighboring bacteria.

Toxins carried on the arrow then mediate the elimination of competing bacteria. With the help of a central regulator protein that they identified, researchers were able to produce an ‘operating switch’ for the system and cause it to ‘turn on’ only in response to recognizing desirable environmental conditions. In addition, researchers proved it possible to control the type and amount of toxins that are loaded on the arrow, thus adjusting the system’s killing range.

Dr. Dor Salomon explains, “The system that we built allows us to engineer ‘good’ bacteria that can recognize pathogenic bacteria, attack them with toxins and neutralize them. We know how to change and control every component in the system and create a bacterium that neutralizes different strains of bacteria. This is proof of feasibility, showing that we have the knowledge and ability to create bacteria that take advantage of this killing system and may serve as antibiotic treatments. Such bacteria could replace the classic antibiotics that we currently use in a variety of scenarios.”

According to Dr. Salomon, researchers created the prototype in a bacterium occurring naturally in salt water. Therefore, it is particularly efficient at neutralizing bacteria that are pathogens found in fish and other marine creatures used for food.

“Since we want to avoid pouring antibiotics into aquaculture farms, a biological solution such as the one we have developed is an effective alternative. Moreover, our system can also be adapted to treat pathogenic bacteria in humans, farm animals, plants and the environment,” he added.