New research suggests that the rapid rise of antibiotic resistance correlates with oral ingestion of antibiotics, raising the possibility that other routes of administration could reduce the spread of resistance. The manuscript appears online ahead of print in the journal Antimicrobial Agents and Chemotherapy.
"For more than 40 years, a few doses of penicillin were enough to take care of deadly bacterial infections," says Hua Wang of the Ohio State University, Columbus, a researcher on the study. But since the 1980s, antibiotic resistance has been spreading rapidly, disabling once-powerful agents, leaving increasing numbers of patients to suffer, and even to die.
In earlier research, the investigators found a large cache of antibiotic resistance genes carried by nonpathogenic bacteria in many ready-to-consume food items. They also reported rapid development of resistant bacteria in infants who had not been exposed to antibiotics, shortly after birth, suggesting the gastrointestinal tract played a critical role in spreading resistance.
In the new research, the researchers inoculated lab mice with either Enterococcus species or Escherichia coli carrying specific resistance genes. The mice were then given tetracycline or ampicillin antibiotics, either orally, or via injection. Oral administration of antibiotics resulted in rapid rise of resistance genes as measured in the mice' feces. Resistance spread much less, and more slowly when the mice received antibiotics via injection.
The researchers also found that antibiotic resistance genes were not detectable in mice that had not been inoculated with bacteria containing antibiotic resistance genes, regardless of the route of antibiotic administration.
The human death toll from resistance, Wang says, is much higher than the 90,000 figure provided by the Centers for Disease Control and Prevention. The difference is due to the fact that bacterial inf
|Contact: Jim Sliwa|
American Society for Microbiology