Antibiotics changed the face of medicine since their introduction in the 1940s. Before antibiotics came into widespread use, if a person accidentally scraped their hand and the wound became infected, there would have been a 1 in 10 chance that they would lose the limb. Antibiotics changed that.

However, the overuse and misuse of antibiotics have led to several bacterial pathogens becoming notoriously resistant to them. Therefore, scientists have been looking for alternate ways to treat bacterial infections. One such approach is bacteriophage therapy.

Bacteriophages are viruses that prey on bacteria. They infect their target bacterium, multiply, and break it open, thereby killing it. So, can we send in these sneaky viral hunters to kill bacteria that can't be killed by antibiotics?

Last year, researchers in South Korea showed that a novel bacteriophage they isolated from hospital sewage water (yes, you read that right) was active against 17 out of 40 antibiotic-resistant strains of A. baumannii that they tested. These researchers infected wax moth larvae and mice with antibiotic-resistant A. baumannii followed by treatment with the bacteriophage. The moth larvae and mice that were given the bacteriophage survived much longer than the ones that were infected but not treated. In fact, 100% of the mice infected with A. baumannii and treated with the bacteriophage survived, whereas mice that did not receive bacteriophage treatment died within five days of infection.

Mice and moths, sure. How about humans?

Last month, researchers in Australia enrolled 14 critically ill patients with bacterial sepsis caused by drug-resistant S. aureus bacteria into a safety trial for bacteriophage therapy. These patients were given a cocktail of phages with activity against drug-resistant S. aureus strains, along with the standard regimen of antibiotics to treat the infection. Phage therapy did not cause any adverse reaction in these patients and was associated with a reduction in bacterial burden and less inflammation.

Much needs to be done before bacteriophage therapy can become mainstream in humans. However, this study is an important step forward in understanding if bacteriophage therapy will be our ally in the war against drug-resistant bacteria.