Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Comeback of an abandoned antibiotic: Trimethoprim is more effective than expected

19.03.2014

Scarlet fever and infections of the skin and throat are often caused by a bacterium called Streptococcus pyogenes.

In less-developed countries, inexpensive and well-tolerated antibiotics for therapy are often not available. Scientists of the Helmholtz Centre for Infection Research (HZI) in Braunschweig, Germany, have discovered that trimethoprim may provide an option.


Scientists use the zone of inhibition test to study antibiotic resistance of bacteria. The wafers contain an antibiotic that inhibits growth of sensitive bacteria in their vicinity. HZI/Bergmann und Nitsche-Schmitz

Contrary to a long-held belief, the bacteria are not generally resistant to this agent. In their recent publication, the scientists demonstrated that there are three potential pathways for the development of resistance - meaning that streptococci can easily become resistant to the antibiotic and pass on this trait quickly.

The common bacterium Streptococcus pyogenes is responsible not only for scarlet fever, a childhood disease presenting with characteristic skin rash, but also for many suppurative infections of the skin. The infection can be associated with serious consequences such as acute rheumatic fever and inflammation of the kidneys.

In Germany, physicians usually prescribe penicillin, an antibiotic. In less-developed countries, penicillin is not always an option though. Firstly, penicillin is often not available and secondly, co-infections, i.e. concurrent infections, by another bacterium called Staphylococcus aureus occur and this microorganism is often no longer susceptible to the action of penicillin.

A group of scientists directed by Dr Patric Nitsche-Schmitz of the HZI entered into cooperation with the German National Reference Center for Streptococci in Aachen, Germany, to investigate if the antibiotic trimethoprim can be helpful in these scenarios.

Trimethoprim inhibits an enzyme of folic acid metabolism called dihydrofolate reductase, which plays an important role in bacterial growth. Trimethoprim thus prevents bacteria from proliferating in the body. In the past, doctors advised against the use of this medication for treatment of streptococcal infections.

The underlying reasoning was the wide-spread belief that the bacteria are already resistant to this agent, a misconception, as is becoming increasingly more evident. The reason for this mistake is that early studies used a culture medium that reduces the anti-microbial effect of trimethoprim. 

The scientists from Braunschweig investigated samples from infected patients from Germany and India for resistance to trimethoprim. The majority of the samples were sensitive to the agent. "This shows that trimethoprim is indeed effective in many cases of Streptococcus pyogenes infection," Nitsche-Schmitz said. 

The focus of his team was also on samples, in which the bacteria failed to respond to the agent. They discovered two types of resistance. "Spontaneous mutations can occur in the gene for dihydrofolate reductase rendering trimethoprim no longer able to attack the changed enzyme, which means it becomes ineffective," Nitsche-Schmitz explained.

The team from Braunschweig detected a specific mutation in this gene in many samples, which renders streptococci resistant. In addition, bacteria can transfer copies of changed variants of the dihydrofolate reductase gene to other bacteria. This process called horizontal gene transfer allows resistance to spread very rapidly. The scientists found two genes of this type to be further causes of insensitivity.

The study shows that the antibiotic trimethoprim is a therapeutic option for Streptococcus pyogenes infections in some geographical regions of the world. The frequency of resistance is much lower than previously believed and the medication is inexpensive, stable and effective in Staphylococcus aureus co-infections.

"However, it is like a sword that can loose its sharpness quickly," Nitsche-Schmitz said. "We found three causes for the rapid spread of resistance. It is important that trimethoprim, like all antibiotics, is not prescribed without need and that patients take the agent in accordance with the instructions given."

Original publication:
René Bergmann, Mark van der Linden, Gursharan S. Chhatwal and D. Patric Nitsche-Schmitz
Factors that cause trimethoprim resistance in Streptococcus pyogenes
Antimicrobial Agent and Chemotherapy, 2014, doi: 10.1128/AAC.02282-13

The research group "Microbial interactions and processes" investigates the interplay of micro-organisms in complex communities made up of millions of cells and hundreds or even thousands of species. The group employs new methods for the identification of bacteria and the characterisation of bacterial activities in its work.

The Helmholtz Centre for Infection Research (HZI)
Scientists at the Helmholtz Centre for Infection Research in Braunschweig, Germany, are engaged in the study of different mechanisms of infection and of the body’s response to infection. Helping to improve the scientific community’s understanding of a given bacterium’s or virus’ pathogenicity is key to developing effective new treatments and vaccines.
http://www.helmholtz-hzi.de

Weitere Informationen:

http://www.helmholtz-hzi.de/en/news_events/news/view/article/complete/comeback_e... - This press release on www.helmholtz-hzi.de

Dr. Birgit Manno | Helmholtz-Zentrum

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Supercomputing helps researchers understand Earth's interior

23.05.2017 | Earth Sciences

Study identifies RNA molecule that shields breast cancer stem cells from immune system

23.05.2017 | Life Sciences

Turmoil in sluggish electrons’ existence

23.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>