New antibiotics for superbugs are critically needed to save lives, Canadian and U.S. infectious disease experts warn.

When the Infectious Diseases Society of America reviewed progress on development of new drugs this week, it found only two new antibiotics had been approved since 2009.

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[Progress] remains alarmingly slow," Dr. Barbara Murray of the University of Texas Medical School at Houston and her co-authors from the society concluded in the May 15 issue of the journal Clinical Infectious Diseases.

Antibiotics kill bacteria but the fast-growing microbes fight back by becoming resistant â€” a vicious cycle.

Both biological and economic factors hinder the development of new antibiotics, Murray said. Yet new drugs are needed for resistant infections that continue to increase in frequency, causing significant illness and mortality, the society noted. 

In the short term, the group aims to create sustainable global antibacterial drug research with the ultimate goal of developing 10 new, safe and effective antibiotics by 2020.

Prof. Gerry Wright, scientific director of the Michael G. DeGroote Institute for Infectious Disease Research, is one of the researchers hunting for new antibiotics. At the McMaster University professor's lab, scientists are looking for new ammunition to kill bacteria.

"We have spent several years hunting around Canada and around the world to isolate new bacteria and pull out from them as many compounds as we can," Wright said from Hamilton, Ont.

Wright is using new technology that can screen hundreds of compounds at the same time. He hopes it will speed up the challenging search.

"Bacteria have been on the planet for almost 4 billion years," he said. "In that time, they've been interacting with their environments and interacting with each other. They have been making molecules to try and poison each other. They are used to detoxifying chemicals, they are used to trying to avoid them."

Tax credits proposed for antibiotic makers 

Wright's team has some promising leads on potential antibiotics, but they can't find a drug company willing to spend the money to get the drugs to market.

"Funding is the challenging thing," Wright lamented.

'One would like to think that the pharmaceutical industry has motives in mind that are to benefit health care and human kind in general. Sadly, I think their bottom line is a business.' —Dr. Andrew Simor, Sunnybrook Health Sciences Centre

The infectious disease society found that most of the large drug companies have left the antibiotic business. The group has proposed tax credits to encourage the remaining pharmaceutical companies to conduct the expensive clinical trials needed to test antibiotic candidates.

Murray explained why her group believes incentives are needed. "If you're developing a drug that somebody's going to take for 20 years or for five days, there's more economic potential benefit for one that's going to be used for a chronic disease rather than acute disease."

Dr. Andrew Simor, head of microbiology at Toronto's Sunnybrook Health Sciences Centre, agrees.

"One would like to think that the pharmaceutical industry has motives in mind that are to benefit health care and human kind in general. Sadly, I think their bottom line is a business," said Simor, who has no shares or interest in the pharmaceutical industry.

The biggest infection risk is in hospitals, where it's estimated at least one in 10 hospitalized patients will get a bacterial infection, Simor said. He calls antibiotic resistance a significant public health threat that "leaves us in a real bind."

Antibiotic resistance is a global problem that all hospitals need to be vigilant about, Simor suggested.

The society said it's important to preserve current antibiotics through strong stewardship and infection prevention.

With files from CBC's Kelly Crowe and Melanie Glanz