Attacking drug-resistant bacteria by crippling their energy source

bacteria
The drug PEG-2S inhibits a nontraditional target: a sodium pump that supplies energy to many bacteria.

Although the threat of drug-resistant bacteria is rising, no new class of antibiotics has been approved in 30 years. Canadian researchers believe they've found a solution: attacking drug-resistant bacteria via a pathway that many of them share.

A team from St. Boniface and the University of Manitoba is targeting a sodium pump called NQR, which supplies energy to more than 20 different pathogenic bacteria, according to a statement.

“New drugs are not being approved because they share the same target to which the bacteria are developing resistance,” said Grant Pierce, a professor of physiology and pathophysiology at the University of Manitoba, in a statement. "We have not only defined a new and effective target, we have designed a drug to attack it without affecting normal cells."

The researchers tested their drug, PEG-2S, in Chlamydia trachomatis bacteria. It blocks the pump, inhibiting the growth and proliferation of the bacteria, they said. Because it only affects bacterial cells that have the NQR pump, it does not harm healthy cells. The findings are published in the Canadian Journal of Physiology and Pharmacology.

Each year, 2 million people are infected by antibiotic-resistant bacteria, with at least 23,000 people dying from these infections annually, the CDC says. Because a number of bacteria rely on the NQR pump for energy, PEG-2S could be a boon in the fight against drug-resistant bacteria.

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“The first pathogen our research team studied … has confirmed that NQR is a good target, and it is shared by many bacteria in need of a more effective antibiotic,” Pierce said.

This research marks the latest example of science aimed at combating drug-resistant bacteria by outsmarting the bugs rather than trying to directly kill them. Another recent example of that approach was reported by scientists at Rockefeller University, who are sidestepping antibiotic-resistance by creating a new class of immune-boosting treatments. Dubbed “lysibodies,” their therapy is a hybrid of antibodies and lysins, which bind to carbohydrates found on cell walls. This combination molecule attaches to the carbohydrates displayed on bacterial cells—which the immune system does not normally recognize—and triggers nearby immune cells to destroy the bacteria.

The Canadian team is now working on different variations of their drug candidate, and they hope to “tailor” PEG-based drugs to each individual bacterium that contains the NQR pump, said Pavel Dibrov, a professor in the University of Manitoba’s faculty of science.