People use antibiotics far too often, with the result that pathogenic bacteria are becoming more and more resistant to these drugs. However, there is also another cause of increasing resistance, which has now been uncovered by Würzburg scientists who research infectious diseases.
Many infections that used to mean certain death can nowadays usually be overcome quickly by taking a few tablets. This is all thanks to antibiotics. So, it is all the more disturbing to physicians and patients alike that many pathogenic bacteria are becoming increasingly resistant to antibiotics.
From a colony of Staphylococcus aureus bacteria (middle, orange), groups that produce an antibiotic (white) and groups that are resistant to this antibiotic (periphery, yellow) gradually develop.
(Photo: Daniel Lopez)
This is particularly problematic in hospitals when bacteria spread that have become resistant to several antibiotics at the same time: these pathogens can be life-threatening for older and vulnerable patients. Sometimes such bacteria can be found in so-called biofilms on medical instruments or implants: they settle there in relatively large colonies inside a shared protective shell, which makes them even less receptive to drugs.
How is it that bacteria are becoming increasingly resistant? “It is because they come into contact with antibiotics too often and develop defense mechanisms,” according to the scientifically accepted explanation. Resistance is partly encouraged by the fact that physicians prescribe antibiotics too frequently and often even without good reason and by the fact that the agents are often mixed with food prophylactically in factory farming.
Competition between bacteria leads to resistance
Würzburg researchers have now discovered another way in which bacteria can become resistant – and surprisingly it has nothing to do with antibiotics used by humans. “Resistance already arises when competing bacteria live together in large numbers and in confined spaces,” says Dr. Daniel Lopez from the Research Center for Infectious Diseases at the University of Würzburg.
The scientists discovered this during experiments with Staphylococcus aureus bacteria, which are not resistant to antibiotics. They kept the bacteria under the conditions that prevail in a biofilm, i.e. numerous individuals in a confined space with a limited supply of nutrients.
A small evolution takes place in the biofilm
In this environment the Staphylococci become rivals and experience a kind of small-scale evolution: individual bacteria that are suddenly able to produce antibiotics through spontaneous mutations have the advantage. They keep the competition at a distance and multiply successfully. It is normal for bacteria to produce antibiotics themselves: even “in the wild” they use these agents to assert themselves against other bacteria, and many commonly prescribed antibiotics are derived from bacterial antibiotics.
In the biofilm created by the Würzburg researchers, the initial bacteria did not meekly surrender to this attack: they in turn developed mechanisms to defend themselves against the antibiotics, rendering themselves resistant. After just five days, there were three very distinctive groups of bacteria in the biofilm: the “harmless” original bacteria, the antibiotics producers, and the antibiotic-resistant group. This is reported by the Würzburg researchers in the current issue of the journal “Cell”.
Biofilms as breeding grounds for resistance
“Biofilms can therefore be breeding grounds for resistance without coming into contact with antibiotics from outside,” says Daniel Lopez. Consequently, hospitals should take even more care than they already do to prevent and combat biofilms. As their next step, the Würzburg researchers want to find out further details about what happens in biofilms. They are particularly interested in whether and how the ominous resistance development processes can be prevented.
“Evolution of Resistance to a Last-Resort Antibiotic in Staphylococcus aureus via Bacterial Competition”, Gudrun Koch, Ana Yepes, Konrad U. Förstner, Charlotte Wermser, Stephanie T. Stengel, Jennifer Modamio, Knut Ohlsen, Kevin R. Foster, and Daniel Lopez, Cell, Vol. 158, Issue 5, p1060–1071, 28. August 2014, DOI: 10.1016/j.cell.2014.06.046
Dr. Daniel Lopez, leader of the junior research group “Bacterial Cell Differentiation”, Research Center for Infectious Diseases, University of Würzburg, T +49 (0)931 31-83831, email@example.com
Daniel Lopez’s homepage: http://www.imib-wuerzburg.de/research/lopez/group-leader
Robert Emmerich | idw - Informationsdienst Wissenschaft
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research