Medicines Developed new environmentally friendly antibiotics

New antibiotics should reduce the environmental impact

The accumulation of antibiotics in the environment is a massive problem, mainly because it leads to the increased development of resistant pathogens. Scientists at Leuphana University Lüneburg have now developed an antibiotic that does not accumulate in the environment and thus can prevent the development of resistance.

The scientists focused their research on the broad-spectrum antibiotic ciprofloxacin, which is widely used and after medical use - like other antibiotics also - largely unchanged in the environment. There, the drugs remain active and even the development of resistant pathogens is promoted by small concentrations of the drug, the team led by Professor Dr. med. Klaus Kümmerer from Leuphana University. The scientists have therefore developed an antibiotic of this class of substances, which is rendered ineffective by natural decomposition processes in the environment.

Conventional antibiotics accumulate in the environment and promote the development of resistant pathogens. Scientists have now developed a new antibiotic that disintegrates after use and is significantly more environmentally friendly. (Image: denisismagilov / fotolia.com)

Enrichment of antibiotics in the environment

According to the experts, around 33 tonnes of the active ingredient ciprofloxacin are used in Germany in human and veterinary medicine every year - and the number is rising. However, ciprofloxacin does not decompose in the environment after leaving the body and is not biodegraded. Instead, the active substance enriches itself in waters, their sediments or sewage sludge. With the use of sewage sludge as a fertilizer, ciprofloxacin can also be found in soils. In addition, the active ingredient is introduced by the use in animal husbandry directly with the manure in the soil.

Demand for degradable active ingredients

Even low levels of ciprofloxacin in soils or sediments and waters can contribute to the spread of resistance, according to the researchers. In addition, ciprofloxacin - similar to other active pharmaceutical ingredients - absorbed by food plants. In order to reduce the environmental pollution and risk of antibiotics, active ingredients must be used that are biodegradable and disintegrate. Here is the answer of the Lüneburg scientists "Benign by Design". An approach in which new molecules are engineered to end up being more environmentally friendly.

Five years of research

The scientists focused their work on the active substance ciprofloxacin, as it is used frequently and remains in the environment for a particularly long time. For five years, they have been developing ciprofloxacin to develop an antibiotic that "disintegrates after its medicinal use and is no longer active," according to the University's announcement. For this we first had to "get to know the molecule very well", emphasizes Dr. med. Christoph Leder from Leuphana University.

Functioning agents now available

The challenge was to so cleverly destabilize the chemical bonds of the drug that they remain sufficiently stable in the blood, but disintegrate after they pass through the body. This has been achieved by the scientists and the newly developed active ingredients have already been patented by Leuphana University. Professor Kümmerer emphasizes that active ingredients are now available that work in the test tube. However, there is still no finished drug. This is now the task of potential partners in the pharmaceutical industry.

Klärprozess an incubator for resistant bacteria

The need for biodegradable antibiotics is great. To clarify, Dr. Leder, that with ciprofloxacin alone seven times the volume of water of Lake Constance would be required "to dilute the amount used in Germany annually to a harmless concentration." Particularly problematic is the effect of antibiotics in waste water, the expert said, referring to earlier study results. Because the bacteria of the wild type are indeed attacked by the drugs, but the resistant mutants do not react and can continue to divide. Thus, the entire process of purification becomes an "incubator for resistant bacteria" Leather. According to the latest findings, significantly lower concentrations than previously thought are an advantage for the mutated bacteria.

Degradability in the environment as an approval criterion

Professor Kümmerer and colleagues hope, in view of their current study results, that in the future the degradability of antibiotics and other active pharmaceutical ingredients in the environment will become an approval criterion, as the feasibility has now been demonstrated. Overall, the success can be a "game changer", because "new molecules also open up new market opportunities, especially if, as in this case, they have built their environmental compatibility right from the start," emphasizes Professor Kümmerer. (Fp)