The term “silent pandemic” was coined in connection with the problem of antibiotic-resistant bacteria. What does this mean?
Katharina Schaufler: We use the term “silent pandemic” to describe a global, imminent health risk: More and more bacterial pathogens are becoming insensitive to existing antibiotics because they are being used excessively and sometimes incorrectly in human and veterinary medicine as well as in agriculture. Under this selection pressure, resistant strains are on the rise and spreading in hospitals, the community and the environment. Unlike COVID-19, this is not about a single pathogen whose spread is increasing, but about many different – in this case – bacterial pathogens. There is currently no acute crisis like the corona pandemic, but the burden of antibiotic-resistant bacteria is steadily increasing. Without consistent measures, which include the responsible use of antibiotics – i.e. antibiotic stewardship – as well as infection prevention and One Health surveillance, there is a much greater risk of infections that will be difficult to treat in the future.
Can the status quo be backed up with figures? How high is the current risk of people dying from infections as a result of antimicrobial resistance?
For Germany, it was estimated in 2019 that almost 10,000 people died from infections due to antimicrobial resistance. Deaths involving resistance were estimated at just over 45,000. The global estimates for 2019 were 1.27 million and 4.95 million, respectively. These figures show: Mortality associated with antimicrobial resistance is already relevant today.
So far, preventive measures have primarily focused on curbing the – sometimes uncritical and inflationary – use of antibiotics. You are looking at and investigating the problem in a wider context...
Yes, the HIOH has set itself the goal of thinking about health in a broader context. The use of antibiotics in human and veterinary medicine does not take place in a vacuum. We are therefore also interested in ecological aspects. Where and in what quantities are antibiotic-resistant or even multidrug-resistant bacteria detectable in the environment? How do they get there and what negative effects can such environmental pollution have? Are there reservoirs of resistant bacteria in wild animal populations? We are addressing these important questions.
Antimicrobial resistance can spread very quickly under certain circumstances. Perhaps you could briefly explain exactly how this happens?
Antimicrobial resistance is caused by spontaneous mutations, among other things. For example, as a result of a mutation, a bacterium develops the ability to pump antibiotics out of the cell. When such a bacterium divides, it passes on the resistance mechanism to its offspring. This is known as vertical gene transfer. In an environment containing antibiotics, the resistance mutation gives the bacteria in question a selection advantage and they will spread within the population.
In contrast, horizontal gene transfer involves an exchange of genetic material between bacteria of different strains or species. A so-called pilus forms between two bacterial cells, through which ring-shaped pieces of DNA – plasmids – containing genetic information are usually transferred from one cell to the other. Resistance genes can also be exchanged through this mechanism, which is known as conjugation. Other mechanisms of horizontal gene transfer that can significantly accelerate the spread of resistance are transformation and transduction, i.e. the uptake of free DNA or the transfer of DNA by bacteriophages.
