Low levels of antibiotic exposure makes E.coli bacteria more drug resistant, find scientists.
E. coli bacteria in food and water supplies have been responsible for disease outbreaks and deaths around the world in recent years.
The current outbreak in Europe has sickened thousands of individuals and caused multiple deaths and life-threatening complications in hundreds of persons infected with a new strain of E. coli.
Bacterial resistance to commonly prescribed antibiotics is an enormous and growing problem, largely due to misuse of antibiotics to treat non-bacterial infections and environmental exposure of the bacteria to low levels of antibiotics used, for example, in agriculture.
In the new study, the authors studied the mechanisms by which E. coli acquire resistance to three common antibiotics: amoxicillin, tetracycline, and enrofloxacin.
They found that exposure to antibiotics at relatively low levels-below those needed to inhibit growth of the bacteria-are more likely to result in the development of antibiotic resistance.
"Exposure to low levels of antibiotics therefore clearly poses most risk," concluded the authors.
The study was published in Microbial Drug Resistance.