In addition to hospitals as a source of infection, other facts also contribute to the increasing development of germs against which drugs no longer work well. Antibiotics are often prescribed for conditions that could also be treated with home remedies or for which antibiotics do not help at all (for example, viral infections such as colds).
To be on the safe side, some doctors also prescribe an antibiotic that attacks a wide range of pathogens (broad-spectrum antibiotic) when a more specific effective narrow-spectrum antibiotic would also be sufficient.
Rapid spread of resistant germs
The trend of prescribing antibiotics frequently and in an untargeted manner is leading to an increase in resistance. For example, tuberculosis pathogens against which conventional therapy with a three-drug combination is ineffective are increasingly spreading in Eastern Europe. Open borders and the desire to travel are also contributing to the fact that resistant pathogens are spreading more rapidly worldwide than in the past.
But many patients are also helping the bacteria to become better equipped. They don’t take the antibiotics for the entire prescribed period, but only until they feel better. At that point, however, the already weakened pathogens can recover and then improve their still weak resistance. And the next time, the drugs no longer help.
The same applies if the dosage is changed arbitrarily or if opened packs are reused “as needed” or passed on to others without consulting the doctor. It should also be noted that a package of antibiotics does not always have to be used up completely. Antibiotic should be taken for exactly as long as the doctor has prescribed.
Sewage plant, cow and co.
Resistant bacteria can enter sewage treatment plants through the hospital wastewater system. Whether and to what extent they are killed there or can transfer their resistance genes to harmless water bacteria has not yet been clearly clarified. In the latter case, these would then in turn reach humans via drinking water.
What is certain, however, is that the uncontrolled use of antibiotics in animal breeding is dangerous. The drugs, which are fed not only for therapy but also as a preventive measure or to promote growth, lead to resistant bacteria that can also endanger humans via the food chain.
Although restrictions have been in place in EU countries since 2005, this has not solved the problem worldwide. For example, over 40 percent of poultry salmonellae are now resistant to at least one antibiotic. If humans become infected with such resistant salmonella, they cannot be treated with that antibiotic.
Antibiotic-resistant cells in genetic engineering.
Little known and noticed: Antibiotic-resistant cells are used in genetic engineering for research purposes. As so-called marker genes – so named because they are intended to mark genetically modified (transformed) cells – they are placed on a culture medium soaked with the antibiotic of interest.
While all the susceptible cells die, those that have taken up the marker gene survive – and with them the desired gene, which is supposed to give the plant a new trait.
Gene transfer feared
Meanwhile, there are fears that the bacteria could take up genetic material from the genetically modified plants and incorporate it into themselves – and thus become resistant to the corresponding antibiotic themselves. Such “horizontal gene transfer” is theoretically possible wherever already decomposed plant material meets large quantities of bacteria: in compost, in silage, in the gastrointestinal tract of humans and animals.
Although such gene transfer is very unlikely, it cannot be ruled out. Thus, in the EU release directive of fall 2002, the use of antibiotic resistance markers has been significantly restricted, but not generally banned.