FAQ Infections & Antibiotics

Antibiotic resistance

Bacteria can be resistant to one or more antibiotics, that is, they develop resistance to the particular antibiotics. This resistance results from random mutations that confer a survival advantage on the affected bacterium when there is an appropriate selection pressure. Resistance then spreads rapidly. If the corresponding resistance genes are also located on plasmids (ring-shaped DNA structures), antibiotic resistance can also spread very rapidly between different species through an exchange of these plasmids. This is particularly the case when different bacterial species are found in the same environment, e.g. the soil, the intestines, waste water, biofilms, etc.

There are different types of antibiotic resistance, e.g.

  • primary resistance (an antibiotic lacks efficacy for certain bacteria)
  • secondary resistance (loss of efficacy of an antibiotic in a non-primarily resistant bacterium due to a mutation or an exchange of genetic material with others)
  • multidrug resistance is the absence of susceptibility of a bacterium to several antibiotics from different classes

Antibiotic resistance is a problem with grave consequences. It is therefore important to reduce the inappropriate use of antibiotics.

The unneccessary or incorrect use of antibiotics accelerates the development and spread of resistant bacteria. Every time antibiotics are taken, the pathogens and the intestinal flora are exposed to a selection pressure, that is, the development and spread of resistance is favoured. For this reason, antibiotics should not be used speculatively.

Bacterial infections should be treated with an adequately high dose of antibiotics over the shortest possible period. The antibioitc therapy used should target the actual pathogen present (antibiogram). Furthermore, it must be clarified as a matter of course whether the infection is actually bacterial in origin before prescribing an antibiotic.

If a course of antibiotics is not completed, this favours the survival of slightly resistant germs and further adaption to the antibiotic. What is important, therefore, is an exact diagnosis, a prescription-only requirement (this is not the case in many countries) and taking the antibiotic precisely in accordance with the doctor's instructions.

There is still a great deal of educational work required in human medicine, however. According to a 2013 Cochrane Library survey of 89 studies from 19 countries, up to 50 % of antibiotic use is inappropriate, leading to increased antibiotic resistance, lengthened hospital stays for patients and subsequently increased costs to patient, hospitals and commissioners (Davey P et al. Interventions to improve antibiotic prescribing practices for hospital inpatients. Cochrane Database of Systematic Reviews 2013, Issue 4. Art. No.: CD003543. doi:10.1002/14651858.CD003543. pub3. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003543.pub3/epdf ).

In the US, in 2010 to 2011, there was an estimated annual antibiotic prescription rate per 1000 population of 506, but only an estimated 353 antibiotic prescriptions were actually appropraite, demonstrating the need for establishing a goal for outpatient antibiotic stewardship (Fleming-Dutra KE et al. Prevalence of inappropriate antibiotic prescriptions among US ambulatory care visits, 2010–2011. JAMA. 2016;315(17):1864–1873. doi:10.1001/jama.2016.4151).

An antibiogram is a laboratory test to identify the susceptibility or resistance of bacterial pathogens to antibiotics. It should ideally be carried out before any antibiotic therapy is administered.

The tests determine whether bacteria can still grow in the presence of an antibiotic whilst also measuring the lowest concentration at which reproduction is prevented. They need about 16-20 hours to complete.

Rapid genetic methodes to identify existing resistance are based on confirming the presence of genetic sequences that confer resistance. They are considerably faster (about 5 hours) but only indicate the presence of genetic sequences and are not suitable for measuring the inhibitory concentrations.

to top

Heraeus Medical

You have come to the International website. Would you like to stay or be redirected to the US website?