Salicylic acid is a plant hormone best known for its use as a key ingredient in pain relievers, anti-acne preparations and medications for skin conditions. We also consume mild doses of salicylic acid when we eat fruits and vegetables. Researchers, including scientists from Vetmeduni Vienna, have now shown that the multifaceted compound can also have an unpleasant side effect. Salicylic acid forms complexes with iron, an important trace element. Laboratory tests showed that iron limitation strongly promotes the formation of biofilms by S. aureus. This allows the bacteria to persist in our respiratory tract possibly causing infections. Published in Frontiers in Microbiology.
Staphylococcus aureus (S. aureus ) can colonize the upper respiratory tract of around one quarter of the human population. As an opportunistic bacteria S. aureus usually does not harm its host. If the host is healthy and the bacteria obtain sufficient nutrients, the bacteria remain quiet and are kept under control by the immune system. They may, however, become active in response to infections by another pathogen or illness weakening the host immune system.
The regular consumption of salicylic acid, or its consumption in higher doses, could unexpectedly promote and prolong bacterial colonization, as shown by a joint study conducted by Monika Ehling-Schulz’s group from the Institute of Microbiology, Vetmeduni Vienna, together with the research group of Fernanda Buzzola from the University of Buenos Aires. The research stays were in part funded by the Mobility Programme for Scientific and Technological Cooperation between Austria and Argentina.
Salicylic acid deprives the body of iron and triggers a defence mechanism in the bacteria
Iron is an important trace element for the human body and plays an essential role in blood formation. The metabolism of many bacteria, including S. aureus, also depends on the availability of iron molecules. Salicylic acid forms complexes with iron ions in the blood and so deprives not only us but also the staphylococcal bacteria of this element.
S. aureus modifies its metabolism if it obtains no or only insufficient iron. The microorganism reacts to the changed – from its perspective, negative – conditions through the intensified formation of a biofilm, a sort of layer of slime formed by the aggregation of individual bacteria, as Tom Grunert of the Institute for Microbiology at Vetmeduni Vienna explains. The accelerated biofilm production allows the bacteria to survive for an even longer period under unfavourable living conditions.
This increased biofilm formation is promoted by the regular or increased consumption of salicylic acid. As pain relief medication, this compound is usually not taken regularly. However, it also is a component of anti-acne preparations and certain exfoliate products, which are often used for a longer period of time. Since salicylic acid is found in fruits and vegetables, people who follow a mostly vegetarian diet might also affected. “These people consume a small dose of the substance virtually every day,” says Grunert. The use of certain medications further increases the iron limitation. Taken orally, salicylic acid enters the blood circulation and forms there complexes with the iron ions.
Enhanced biofilm formation after consumption of salicylic acid in experimental settings
The research team demonstrated this effect in a laboratory experiment. “We first confirmed that salicylic acid, which is known for its capacity to form iron complexes, really does ‘capture’ the iron that is important for the staphylococcal bacteria,” says Grunert. The formation of the bacterial biofilm was then demonstrated through different doses of salicylic acid. “We grew a staphylococcal culture in a special, iron-rich medium – a nutrient solution – in a laboratory dish.” The addition of salicylic acid resulted in a further increase of biofilm. Moreover, the treatment of mice with salicylic acid demonstrably resulted in prolonged colonization of the nasal mucosa by S. aureus.
“We were able to show that the frequent consumption of salicylic acid as well as a vegetarian diet can promote the colonization of the upper respiratory tract by S. aureus, which may contribute to staphylococcal infections that are long lasting and more difficult to treat” explains Grunert.
The article “The Active Component of Aspirin, Salicylic Acid, Promotes Staphylococcus aureus Biofilm Formation in a PIA-dependent Manner” by Cristian Dotto, Andrea Lombarte Serrat, Natalia Cattelan, María S. Barbagelata, Osvaldo M. Yantorno, Daniel O. Sordelli, Monika Ehling-Schulz, Tom Grunert and Fernanda R. Buzzola was published in Frontiers in Microbiology.
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Institute of Microbiology
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-2469
Science Communication / Corporate Communications
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1165
Mag.rer.nat Georg Mair | idw - Informationsdienst Wissenschaft
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences