Bacteria Developing Resistance to New Antibiotics
Bacteria, which cause a wide variety of diseases in humans ranging from diarrhea to pneumonia, appear to be developing resistance to medicine’s arsenal of antibiotic drugs at an alarming rate around the world.
More types of bacteria are becoming resistant to antibiotics, and organisms already resistant to one drug are developing resistance to new drugs, according to a new government-sponsored study.
“You have to say it’s serious,” said Dr. Stuart B. Levy, a professor at the Tufts University School of Medicine who headed the study. “It’s an extremely serious public health problem.”
The first-of-a-kind, three-year study was funded by the National Institutes of Health to gauge the prevalence and causes of antibiotic resistance worldwide and explore possible solutions.
More than 100 health experts from 30 countries analyzed all available information and literature on antibiotic-resistant bacteria for the study, which was published in the Reviews of Infectious Diseases.
The researchers found the prevalence of resistant bacteria varied widely from country to country, ranging from between 20% and 70% of strains tested.
But in some countries, as much as 30% of prevalent strains of bacteria that cause diarrhea or pneumonia were found to be resistant to conventional antibiotics such as penicillin or tetracycline, Levy said.
Many forms of bacteria cause no disease in humans while others can cause serious illness and even death. In developing countries, bacterial infections are a major cause of disease.
Nearly all disease-causing bacteria can be treated with one or more antibiotics, but resistance raises concerns because it reduces the drugs available and sometimes leaves hard-to-find or expensive antibiotics as the only choice.
Although the level of resistance to the more standard antibiotics appears to have stabilized, the researchers found the level of resistance to newer drugs seems to be increasing.
“When you look at some of the newer antibiotics coming into the fields, you find there is an increase in resistance,” Levy said.
For example, one study found no evidence of resistance to the antibiotic trimethoprim in a type of salmonella bacteria in Britain in 1977. But by 1980, 24% of the bacteria in animals and 5% in humans were resistant.
The researchers attributed the increased resistance primarily to the overuse or misuse of antibiotics.
Overall, resistance was found to be more of a problem in developing counties than in developed countries, Levy said. He attributed that to poorer health and education systems in those areas.
“In the developing countries, this has become a big problem because they don’t have the financial resources for the alternative drugs,” Levy said.
Although the developed world uses more antibiotics overall, antibiotics represent a much greater percentage of all the drugs used in developing nations, the researchers found.
Antibiotics account for about 15% of all drugs used in the developed world compared to about 50% in the developing world.
“To find that they are not being used equally indicates that either there is a difference in the diseases being treated or a difference in the education of people using them,” Levy said.
He said that while bacteria resistance does not pose as immediate a problem in the United States, it should still be cause for concern.
“As the bacteria become more resistant to the newer drugs, there may be a limit to the amount of money or the amount of new drugs that can be found.”
The researchers recommended uniform collection and analysis of information on the prevalence of antibiotic resistance and detailed studies of how policies, laws and regulations in different countries encourage or discourage proper use of antibiotics.
They also recommended establishment or improvement of drug-regulation systems and development of strategies to promote safe and effective antibiotic use.
