Superbugs face a new foe

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      A few weeks ago, the Journal of Clinical Microbiology published a paper about the prevalence of a superbug on Vancouver’s Downtown Eastside. Six Vancouver researchers studied a sample size of 301 intravenous-drug users. The superbug MRSA—known in the scientific world as methicillin-resistant Staphylococcus aureus—was present in 18.6 percent of them. That was up from just 7.4 percent of intravenous-drug users testing positive for MRSA in a similar experiment conducted in 2000.

      The more recent study helped focus national attention on antibiotic-resistant bacteria, which, up until then, were primarily seen as a problem within hospitals. But new research conducted at UBC offers some hope of defusing the power of the so-called superbugs, both within hospitals and in the community. The answer could come through the use of naturally occurring compounds called peptides, which consist of two or more amino acids.

      So what’s the problem with MRSA? According to Bob Hancock, a UBC professor of microbiology and immunology, MRSA and other staphylococcus bacteria cause infections of varying severity. They can range from a cut that won’t heal to deep-seated bone infections that spread throughout the body. Hancock told the Georgia Straight that it’s difficult to persuade drug addicts, who often have compromised immune systems, to remain in hospital for a couple of weeks for the “mainstay” MRSA treatment, a drug called vancomycin.

      “Right now, there is literally only a couple of antibiotics that you can use,” he said. “Both of them are relatively expensive.”

      Last year, the Straight published a story about how Hancock and UBC microbiologist Brett Finley were using peptides to stimulate the body’s “innate immunity” to fight off infections. They published their findings in the journal Nature Biotechnology, and they continue to work in this area with the help of a US$8.7-million grant from the Bill & Melinda Gates Foundation. Hancock suggested that peptides could one day be given to vulnerable hospital patients to help prevent infections.

      “There is no reason why it couldn’t work on any kind of disease, to tell the truth, but we’ve got a long way to go before we can demonstrate that,” he said.

      Hancock also told the Straight that researchers in his UBC lab are now using sophisticated computer programs to pioneer more targeted approaches to superbugs like MRSA and VRE (vancomycin-resistant Enterococcus). This approach, he said, involves using peptides as “straight antibiotics” rather than as immune boosters.

      Researchers in his lab have developed a very broad spectrum of peptides, and some, he said, are demonstrating “really good activity against at least most of the superbugs now”.

      “I’m talking about MRSA as one of them,” Hancock said. He noted that his lab’s research is now being reviewed, which occurs before the findings can be published in a scientific journal.

      This use of peptides as antibiotics raises the spectre of an entirely new avenue being developed to fight infectious diseases. Scientists have known for years that peptides can kill bacteria, but the difficulty came in figuring out how to create amino-acid sequences to kill mutating pathogens that develop resistance. Hancock praised Artem Cherkasov, a UBC assistant professor of infectious diseases, for accelerating research in this area with the use of artificial-intelligence systems. “It was really his contribution that made the critical difference there,” Hancock said.

      He said Cherkasov helped create a program that uses days of computer time to predict what new peptides need to be developed. “Literally, the computer has been able to go from a couple of thousand peptides that we made to looking at 90 million permutations of peptides—and telling us which ones are the most likely to be successful,” Hancock said. “And the computer is considerably more accurate than our previous rational approaches were.”

      The Gates foundation insists that any discoveries from its funding must be made available to developing countries, so there’s a good prospect that if this approach proves to be successful, treatments will be available for the world’s poor.

      Hancock has already won numerous prestigious scientific awards, including being named the 2006 Canadian health researcher of the year by the Canadian Institutes of Health Research. The prize was named after UBC’s deceased Nobel laureate Michael Smith.

      When asked if Hancock foresees himself and other UBC researchers ever winning the Nobel Prize in medicine for their research on peptides, he laughed it off and said that no scientist ever expects that to occur. “For me, I’m really excited about the fact that I think we have really come up with a new way of treating infections,” he said. “It’s exciting. I’m excited, believe me.”

      This may not come soon enough for those already suffering the ravages of antibiotic-resistant bacterial diseases. But it provides some reason to hope that scourges such as tuberculosis, syphilis, and MRSA might not claim quite so many victims in the future.

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