Uni develops test for antibiotic resistance

Researchers are developing a rapid test to detect antibiotic-resistant bacteria

06/27/2014

The increasing spread of antibiotic-resistant agents is not only a growing problem in German hospitals. „In Europe, deaths associated with antimicrobial resistance are estimated to be around 25,000 people per year“, reports the Swiss University of Freiburg. A newly developed test procedure could help identify certain resistant bacteria within a very short time and, if necessary, initiate necessary countermeasures.

Together with the institute INSERM in Paris, Professor Patrice Nordmann and dr. Laurent Poirel, who is working at the Department of Microbiology of the Medical Institute of the University of Freiburg, the new one „Rapid diagnostic test“ developed. This recognizes „Multidrug resistance to broad-spectrum antibiotics and is capable of the bacterial strains of Acinetobacter baumannii, a particularly dreaded in clinical routine pathogens“, within two hours, the University of Freiburg reports. The researchers also believe that the use of this diagnostic test could help to better control the spread of certain antimicrobial resistance.

Drastic increase in antibiotic resistance
Overall, the antibiotic resistance of bacteria has increased significantly in recent years, but the situation is particularly dramatic, according to the Swiss scientists „Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii).“ Here often would „veritable treatment dead ends“ emerge. Even broadband antibiotics, such as cephalosporins, or carbapenems, which are often the last treatment option as antibiotics of the last generation, are already powerless against certain bacterial strains, according to the University. By the increasing development of these resistances would also „new methods of medicine of the 21st century, which are particularly dependent on efficient antibiotic therapies,“endangered.

Resistant bacteria hydrolyze antibiotics
Certain bacteria can hydrolyze antibiotics and thus prevent their effectiveness, the researchers report. Based on this process, Prof. Nordmann and Dr. med. Poirel has already developed two rapid diagnostic test methods that can be used to detect resistant enterobacteria and Pseudomonas aeruginosa. „With the third method, the new CarbAcineto NP test, researchers are now able to detect the carbapenemase activity of Acinetobacter baumannii, which is systematically associated with a multi-resistance of these bacterial strains to antibiotics“, the message of the University of Freiburg continues.

Proof within two hours
According to the researchers, the test is based on the „Properties of the acidification that occurs in the enzymatic hydrolysis of the carbapenem imipenem when cleaved by a carbapenemase.“ This changes the pH and the environment becomes more acidic, which can be seen with the help of the test. The pH indicator shows a color change from red to yellow. „The detection of this carbapenemase activity is possible both in isolated bacteria as well as (directly) at any infection sites“, the researchers write further. The result is available within two hours, while other diagnostic procedures currently require at least 24 hours, usually even 72 hours. The sensitivity as well as the accuracy of this new test method is given by the scientists with almost 100 percent.

Important contribution in the fight against antibiotic-resistant pathogens
The researchers conclude, „that the development of the CarbAcineto NP test is an important contribution to the fight against the emergence of antibiotic resistance.“ The test is simple to perform, inexpensive and inhibits their spread by detecting multidrug-resistant bacterial strains. „Last but not least, the test allows a targeted selection among the few available therapies for patients with such infections“, write to Professor Patrice Nordmann and dr. Laurent Poirel, whose current study also in the trade magazine „Journal of Clinical Microbiology“ has been published. (Fp)