Mini Medical School-Session III
New Strategies Needed On Bacteria Battleground
INDIANAPOLIS - Theirs is a crowded universe with billions of inhabitants, whole and diverse colonies claiming squatter's rights to the inside of the human body. For the most part, they live in remarkable harmony with their host; they reproduce and die in extraordinary anonymity. Sometimes, they revolt and leave their host with a runny nose. On rare occasions, they launch all-out war and the results can be deadly.
For decades, these have been fought off with antibiotics, drugs that search and destroy bacteria when their legions cause illnesses. However, certain strains of bacteria have adapted and developed shields, rendering some antibiotics virtually useless.
"Antibiotic resistant bacteria are becoming premier challenges in medical practice, and certainly getting a lot of hype in the media-some of it blown out of proportion-these days," said Richard B. Kohler, M.D., featured lecturer of Indiana University School of Medicine's Mini Medical School, Oct. 26.
Some diseases, such as tuberculosis and meningitis, loom as a serious threat because of the proliferation of antibiotic resistance, many health officials have warned.
Dr. Kohler, professor in the Department of Medicine and an expert on infectious diseases, described as examples two kinds of bacteria in the human body: Streptococcus salivaris, located in the mouth, largely benign and rarely the source of illnesses; and Streptococcus pneumoniae, occasionally found in the mouth, nose and throat, and prone to aggressive behavior. If aspirated into the lungs, Streptococcus pneumoniae can cause pneumonia and other respiratory-related illnesses. If it reaches the blood stream, it can cause meningitis.
Antibiotics, which came into use during World War II and continue to be a key weapon against bacterial maladies, are substances generally produced by organisms (real and synthesized) that have the power to inhibit or destroy other living organisms. Among the best-known antibiotics are penicillin, ampicillin and streptomycin.
But certain bacteria, over time, can build resistance to antibiotics. "They can alter their structures, they can make proteins that destroy or modify antibiotics, or they can create little pumps that are highly effective in removing antibiotic material," said Dr. Kohler, adding that multidrug resistant bacteria poses one of the most immediate threats to human health. These changes come about because the bacteria change their genes, either by mutating or by acquiring new genetic material from other bacteria.
For example, TB patients normally are isolated for a few weeks and treated with three main antibiotics, often isoniazid, rifampin and ethambutol. That drug therapy virtually is useless in combating the multidrug resistant TB cases erupting throughout Russia, according to recent news reports.
"Multidrug resistant TB, to me, represents a scary situation," Dr. Kohler said. "It is extraordinarily expensive to contain this organism. It is potentially devastating in developing countries and can rapidly spread to developed nations such as our own. Let's face it: the world is a smaller and much more mobile place than it use to be."
Dr. Kohler suggested several ways society and science could deal with antibiotic resistant bacteria. First, he said patients with highly infectious illnesses such as TB should be isolated and treated fully with all modern science has to offer. Second, new antibiotics can be developed. Third, the public should be encouraged to obtain flu and pneumonia shots. "Many people don't realize that flu vaccines can also protect them from other bacteria-related illnesses," he said.
Finally, there is another weapon in the war against antibiotic resistant bacteria, Dr. Kohler noted. "Decrease the use of antibiotics for sinusitis, ear infections, bronchitis, and colds," he said, adding that these and other similar minor conditions normally are healed by the body's immune system. "The more that antibiotics are used, the more likely bacteria are to develop ways to thwart them."
Contact: Joe Stuteville
317-274-7722
jstutevi@iupui.edu
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