The bacteria battle

One of the most remarkable advances against disease and death was the invention of antibiotics, which led to a massive and immediate decline in death from infections. In a paper published last fall in a workshop report of the Institute of Medicine, Brad Spellberg, an associate professor of medicine at UCLA, noted that antibiotics led U.S. deaths to decline by about 220 per 100,000 population over 15 years, from the late 1930s to the early 150s. This period includes the introduction of penicillin.

By contrast, he reported, subsequent medical advances over the next 45 years resulted in only minor further reductions in deaths by infections—about an additional 20 per 100,000 people.

Antibiotics caused a revolution in medicine, and gave hope to millions of people who might otherwise have died from infections. They allowed the conduct of complicated and deeply invasive surgery, and organ transplants, which would not have been possible without effective antibacterial agents to deal with infections.

Spellberg recalls the words of Dr. Lewis Thomas, one of the most prominent physicians of the 20th century, on the arrival of the first antibiotics. In a memoir of his internship, Thomas wrote:

For most of the infectious diseases on the wards of Boston City Hospital in 1937, there was nothing that could be done beyond bed rest and good nursing care. Then came the explosive news of sulfanilamide, and the start of the real evolution in medicine. I remember the astonishment when the first cases of pneumococcal and streptococcal septicemia were treated in Boston in 1937. The phenomenon was almost beyond belief. Here were moribund patients, who would surely have died without treatment, improving ... within a matter of hours ... and feeling entirely well within the next day ... we became convinced, overnight, that nothing lay beyond reach for the future. Medicine was off and running.


But the antibiotic revolution seems to be running out of steam. The number of new antibiotic drugs has dwindled. Meanwhile, microbes continue to evolve, developing resistance to existing drugs. Some of these bacteria, like Methicillin-resistant Staphylococcus aureus, or MRSA, are lethal.

There are economic reasons why the drug pipeline has been drying up. Among them: pharmaceutical companies don’t get as high a return on investment for products taken for just a few weeks, compared to those for chronic disease, so there are not strong incentives to invest the millions of dollars in developing new antibiotics.

Now comes a report of a promising new approach. In a paper just published by Nature Chemistry, [abstract] a team of researchers has developed biodegradable nanoparticles, super-small particles which attack the microbe’s cell membrane “selectively and efficiently,” in effect poking holes in the membrane. They destroy the infection, without hurting healthy cells. In an article in the Wall Street Journal today describing the technology, James L. Hedrick of International Business Machines Corp., one of the researchers, said the destruction of the bacteria renders it unable to develop resistance to the nanoparticles. The paper says the technology can work against many different infections, including MRSA, which is responsible for some 19,000 hospital-stay related deaths per year in the United States. It hasn’t been tested yet in humans, but if further trials and research show it works, nanoparticles could eventually open a new avenue to fight a real and ongoing threat.

 

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