Antibiotics in manure a far-reaching impact on abundance of human pathogenic bacteria in soils

Since antibiotics are commonly used in animal husbandry, the implications for agricultural areas that are fertilized with the manure of these animals are of great interest. The study results confirmed the scientists’ hypothesis that the application of antibiotics has an effect on the composition of soil bacteria. “After repeated application of manure contaminated with antibiotics, we found a decrease in the bacteria that are important for good soil quality. This means a loss of soil fertility and thus in the long run a decline in crop yields,” said Professor Michael Schloter, head of Research Unit Environmental Genomics at Helmholtz Zentrum München. “Moreover, the number of microbes living in the soil that are harmful to humans increased under the experimental conditions of the study.”

Wide-reaching consequences for human health

“The increase in human pathogenic microorganisms in the environment has wide-reaching consequences for human health,” says Professor Schloter. “We are in continous contact with these microorganisms, and the probability of contracting an infection increases accordingly. This applies particularly to diseases of the respiratory system and the lungs, as bacteria are spread through the air and inhaled. Moreover, many of the bacteria are resistant to commonly used antibiotics, which often makes treatment more difficult. We must therefore urgently develop a new mindset as regards the use of antibiotics in animal husbandry.”