Can Predatory Bacteria Succeed Where Antibiotics Fail?

There are predators in the bacterial world that consume other bacteria, much as predators attack prey in the animal world. A team led by researchers at the University of Medicine and Dentistry of New Jersey-New Jersey Dental School suggests that some of these predator microbes might be put to work against disease-causing bacteria that have become resistant to antibiotics. Their findings have been published online by the Journal of Applied Microbiology.

Lead author Daniel Kadouri, PhD, an assistant professor of oral biology at New Jersey Dental School, and his team focused on two bacteria: Micavibrio aeruginosavorus and Bdellovibrio bacteriovorus. Kadouri says the two microorganisms were chosen because they are true predators. They actually have to consume other bacteria in order to complete their life cycles, notes Kadouri. They have a great ability to seek out other bacteria, invade them, grow in or on them, and kill them.

The researchers found that in a laboratory environment, M. aeruginosavorus was able to reduce populations of 57 of 89 bacteria examined. B. bacteriovorus reduced 68 forms of bacteria out of 83 tested. The bacteria effectively attacked include Klebsiella pneumoniae, a cause of lung infection; Pseudomonas aeruginosa, which can be fatal for patients suffering from the lung disorder cystic fibrosis; and Acinetobacter, which in its drug-resistant form can produce extremely hard-to-treat infections in wounds.

Kadouri hopes that one day medical practitioners can use these predator bacteria to supplement antibiotic drugs in treating life-threatening infections. We have been living with bacteria all our lives, he reminds us. There are bacteria in and on us, and they are a part of our ecology. When we eat yogurt and cheese, for example, we are eating bacteria. Kadouri adds that the predator bacteria he is examining are among the many bacteria in our environment that are considered harmless to humans.

A big unknown at the moment is whether predator bacteria can have the same effect on harmful microbes inside the human body as they do in the lab. It is possible that the human immune system would neutralize these bacteria before they could do their beneficial work. But if that problem can be avoided, or solved, Kadouri is confident that a new disease-fighting tool may one day be put into use.