Check Up: The bacteria are winning

Posted: January 22, 2013

The bacteria are gaining on us.

That was the gist of a conference last week involving a Nobel Prize-winning chemist and six local scientists at Drexel University, discussing the state of antibiotics research, especially the shortage of new drugs as old diseases keep gaining strength.

"If the bugs continue to evolve and we don't develop new compounds . . . I don't want to be dramatic about it, but more people will die," said University of Pennsylvania infectious-disease specialist Harvey Rubin. "It's a hidden epidemic."

Our understanding of how antibiotics work comes in part from Nobel laureate Ada Yonath, 73, who was on hand from her native Israel.

Yonath became her nation's first female Nobel laureate in 2009 by delineating the structure of the ribosome, a large molecule found in all living cells. Yonath described ribosomes as rapid protein-making factories that read instructions from genetic material. They make proteins in all creatures, from bacteria to humans.

Differences in ribosome structure can enable a drug to attack bacterial ribosomes without harming the human host. The molecular nuances Yonath found helped identify various Achilles' heels that scientists could exploit, and about 40 percent of antibiotics work this way.

But bacteria mutate quickly and evolve resistance over time to antibiotic attack.

Drexel infectious-disease specialist Jeffrey Jacobson cited a 50-year-old antibiotic, colistin, which had fallen out of favor for being too toxic. It has seen a recent comeback due to a lack of alternatives. "I'm even seeing colistin resistance now," he said. "It's hard to overstate the significance of this problem."

Several panelists cited a lack of funding on antibiotics by large drug firms. Antibiotics aren't as profitable as a drug for a chronic disease that requires a lifetime of pills.

Several also suggested that the government needs to do more. Jacobson envisioned a reward system, in which firms get a cash prize for developing a drug that is socially useful but not very profitable.

Without such actions, Rubin warned, many potential ideas will fall into a "valley of death," and wither away.

There have been some successes. In December, the government approved Sirturo to treat multi-drug-resistant tuberculosis. It was discovered by a unit of Johnson & Johnson. "This is not going to be a big moneymaker," Rubin said. "And it's a wonderful thing they did."

Drexel's Michele Kutzler said Yonath's work helped her and others create better DNA vaccines.

Instead of injecting the inactive form of a bug such as the flu virus into a person, this new class of vaccines uses only a genetic piece of the virus or bacteria. Then the recipient's ribosomes translate that into proteins that trigger an immune response.

DNA vaccines are "much safer, easy to manufacture, more stable, cost-effective, and you can . . . combine many different strains of the virus into one vaccine," Kutzler said. Vaccines for cancer treatment, HIV, and the flu are now in trials.

Donna Gentile O'Donnell, trustee emerita of Drexel's medical school, said she wanted to focus the event on antibiotic resistance, and noted that staffers of U.S. Sen. Robert Casey (D., Pa.) and U.S. Rep. Michael Fitzpatrick (R., Pa.) were on hand. "It's not a problem for legislators or scientists," she added. "It's everybody's problem."


Meeri Kim can be reached at meeri@alumni.upenn.edu or 857-205-6920.

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