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BAD BUGS, NO DRUGS ; Our Dwindling Pill Arsenal Can't Fight New Germs

Posted on: Thursday, 2 March 2006, 12:00 CST

By Avery Comarow

Many of the germs that make us sick are mutating under pressure of antibiotics into toxic new strains that are not easily treatable.

And drug research to find new antibiotics to fight these bugs is lagging -- in part because the new antibiotics take too much time and money to develop.

December 2005 brought fresh evidence that we are losing the bacteria battle: Clostridium difficile, a microbe that can cause serious digestive illness and death in vulnerable patients in hospitals and nursing homes but rarely bothers healthy adults outside health care settings, was blamed by the U.S. Centers for Disease Control and Prevention for doing just that in four states.

As if that wasn't bad enough, a couple of weeks later, the Journal of the American Medical Association suggested that we have aided the resourceful C. difficile by dosing ourselves with pills like Pepcid and Prilosec that prevent severe heartburn, or reflux, by lowering the acidity of the stomach's gastric juices.

That acidity, noted the authors, keeps the upper part of the digestive tract bug free. By reducing the acidity, the pills lowered the barrier.

Such news was just the latest in a string of misadventures that illuminate the uncommon adaptive power of bacteria. Until about 25 years ago, most disease-causing germs stood little chance against the stream of antibiotics that had emerged from laboratories during the 1940s and '50s. Top researchers at large pharmaceutical companies truly believed that the days of infectious disease were over.

But the flow of unique new classes of antibiotics ebbed and died in the 1960s. Resistant strains of microbes that had crumbled obediently at the touch of drugs like vancomycin appeared. Now some 2 million hospital patients a year get bacterial infections; about 90,000 of them die.

The National Institute of Allergy and Infectious Diseases estimates that more than 70 percent of the bacteria that cause these infections are resistant to one or more antibiotics. That complicates care, inflating the cost of treating an infected patient. And so reports such as these are piling up:

* Military service members injured in Iraq and Afghanistan increasingly are coming home with Acinetobacter baumannii, a potent microbe that causes pneumonia and blood infections, in their wounds. Plucked straight from soil or water, the bug is naturally resistant, often to multiple antibiotics. Sometimes physicians have to turn to coliston, a drug rarely used since the 1960s because of the high chance of injuring the kidneys and nervous system.

* Gonorrhea used to be easily treatable with penicillin, but the bacterium responsible, Neisseria gonorrhoeae, long ago shrugged it off. Now the newer quinolone class of antibiotics such as Cipro and Floxin, which became the drugs of choice, are being defeated in the U.S. and in Australia, Canada, Great Britain and Hong Kong. It has gotten so bad, J. Todd Weber, director of the CDC's office of antimicrobial resistance, wrote in a JAMA editorial in November (2005), that the usefulness of quinolone drugs to treat and control gonorrhea "is being lost worldwide because of increasing resistance."

* Resistant strains of bacteria usually confined to hospitals are finding their way into local communities. In 2003 and 2005, studies fingered Staphylococcus aureus, a microbe that is blamed for many serious heart and lung infections in hospitals and nursing homes and is resistant to the methicillin class of antibiotics, as the cause of outbreaks of skin abscesses in high school wrestlers in Indiana, members of a Colorado fencing club, and five players on the St. Louis Rams football team.

What has exacerbated matters is Americans' well-documented tendency to think they need an antibiotic for every cold or cough or child's sore throat or earache. And physicians tend to go along, arguing that they don't have time to educate patients on the folly of taking an antibiotic.

The larger the quantity of antibiotics prescribed, the greater the opportunity for bacteria to form resistant mutations. Yet in an analysis in JAMA published in November 2005, more than half of children who came to a doctor's office, a hospital outpatient department, or an emergency room between 1995 and 2003 because of a sore throat left with an antibiotic.

The solution to larger issues of antibiotic resistance is more and better drugs. If that doesn't happen, warns "Bad Bugs, No Drugs," a report issued in 2004 by a task force of the Infectious Diseases Society of America, whose 8,000 members are mostly physicians and scientists, the country -- and the world -- face a brewing crisis in which millions of people could die. "The shelf is very sparse," says John Bartlett, a physician who chaired the task force and is founding director of the Center for Civilian Biodefense Strategies at the Johns Hopkins School of Public Health, Baltimore, Maryland. "When we go on rounds every day, we are continually reminded that we're running out of drugs."

Why few new antibiotics are emerging, says George Talbot, a task force member and consultant to drug manufacturers, is simple: "Big companies decided that there are more fertile fields. They needed to have blockbuster drugs." Antibiotics are expensive to develop -- putting a new one on the market would cost at least $800 million and take as long as 10 years--and offer a lower return than that offered by medications for chronic illnesses, such as heart disease, Alzheimer's, and depression. The task force concluded that Congress has to give large pharmaceutical manufacturers a good reason, in the form of tax breaks and other financial carrots, to get back into antibiotic research and development. Several bills that would do so, however, languish in committee. And so a perfect storm well may be in the making, as microbes gain in strength while current antibiotics, unbolstered by reinforcements, are defeated one by one.

Source: Buffalo News

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