This new killer antibiotic beats deadly bacteria by targeting their defence system

(Photo: Getty)

(Photo: Getty)

Antibiotic-resistant bacteria are one of the biggest public health threats facing us today. Drugs that were effective at warding off infections decades ago are now less potent because the bacteria they were designed to kill have developed defence mechanisms. According to the Centers for Disease Control in Atlanta, antibiotic-resistant bacteria cause more than two million illnesses in the U.S. every year and 23,000 deaths. (Canadian data isn’t available, but the infection and mortality rates are likely comparable.) “We’re in a serious jam,” says Gerry Wright, director of the Michael DeGroote Institute for Infectious Disease Research at McMaster University. “Our access to antibiotics to control disease is at a crisis point.”

One solution? New antibiotics. Many pharmaceutical companies have abandoned the antibiotic space (there are easier and faster ways to turn a profit), but Cubist Pharmaceuticals in Massachusetts is plowing $400 million into research and development this year that could help address the problem.

The traditional approach was to develop antibiotics to simply kill bacteria, but their growing resistance is forcing researchers to consider entirely new methods. One approach used by Cubist is to target the enzymes produced by drug-resistant bacteria that degrade antibiotic agents and render them useless. Its new two-pronged drug inhibits the enzyme and allows the antibiotic agent to destroy the bacteria. “When you put these two things together, you’ve got a novel new drug,” says Steve Gilman, the company’s chief scientific officer. The drug, with the unwieldy name ceftolozane/tazobactam, has completed Phase 3 clinical trials and could prove particularly effective in dealing with pseudomonas—bacteria usually acquired in hospitals that cause serious interabdominal and urinary tract infections, ultimately resulting in death in some cases.

Further down the road is something called CB-618, which Gilman describes as “tazobactam on steriods.” The drug targets a wider variety of defence mechanisms used by antibiotic-resistant bacteria and can be used in more situations. The company hopes CB-618 can ultimately be deployed against nasty bacteria known as carbapenem-resistant Enterobacteriaceae, or CRE—“nightmare bacteria” that kill about half the people who contract bloodstream infections.