Canadian scientists say they’ve discovered a new way to beat the world’s most notorious antibiotic resistant superbugs – a breakthrough they say could change the way doctors treat and beat drug-resistant infectious diseases.
According to researchers at McMaster University, combining existing antibiotics with another drug called pentamidine was found to be effective against Gram-negative bacteria, which are resistant to all antibiotics including the last resort drug colistin.
Pentamidine is an antiprotozoal drug and anti-fungal medication used to treat specific pneumonias and other conditions as determined by a physician, Drugs.com outlines.
Gram-negative bacteria is surrounded by an impenetrable outer shell and acts as a barrier to some the world’s most potent antibiotics. These type of infections can be deadly, especially in hospital settings.
“We were looking for agents that would disrupt the outer surface of this class of bacteria,” says Dr. Eric Brown, lead author of the study and professor of biochemistry at McMaster University. “And we found it, surprisingly, in an existing drug called pentamidine. It was a surprising finding to us that pentamidine could disrupt the outer surface but what it means is that pentamidine can now be combined with any one of a number of antibiotics that are otherwise not effective against Gram-negative bacteria.”
After testing 1,440 off-patient drugs, pentamidine was found to be effective against two of the three pathogens the World Health Organization (WHO) identified as being the most critical priority in developing new antibiotics. This is because the drug was found to have a molecule that shed the shell and allows antibiotics to enter and attack.
The two pathogens are acinetobacter baumannii and the enterobacteriaceae, both of which can cause serious infections in the lungs (like pneumonia), blood and brain, as well as urinary tracts and wound infections.
The therapy also had some impact on the third pathogen called pseudomonas aeruginosa, which is commonly associated with infection and inflammation due to wearing contact lenses and can cause scarring and vision loss, the Public Health Agency of Canada says.
The discovery was successful in lab mice but has not yet been tested on humans. It is not yet known when experimental human trials will begin.
As for what’s next, Brown says more research is needed to look in to potential side effects, ensure human safety and see what other drugs could possibly treat the other Gram-negative bacteria pentamidine couldn’t.
“Pentamidine wasn’t effective against all of the Gram-negatives so we’re now looking into further compounds that might be useful,” he says. “We’re always busy trying to come up with new ways. Innovation is so important and we have to keep discovering so we can stay one step ahead. We’ve had the upper hand for a relatively brief time in the course of human history over bacteria and that’s been the result of innovation and we really need to keep doing that.”
But while this is a victory for now, the constant evolution of these superbugs will only make this new therapy effective for a period of time. As for how long this type of treatment will be effect – only time will tell.
“These bugs have a very clever strategy for living in a dangerous world full of antibiotics and that’s to produce a lot of offspring to share genetic information,” Browns says. “If anybody tells you they’ve come up with an agent that is completely immune to evolution is not being honest with themselves… Resistance is not futile, it’s inevitable.”
The research was published Monday in the journal Nature Microbiology.