from APA | 11:38, February 12, 2019
As a result of one antibiotic therapy This can lead to bloody diarrhea and abdominal cramps. This pp haemorrhagic colitis associated with an antibiotic is from Intestinal Klebsiella oxytoca bacterium and the toxins it produces. How these bacteria or their enterotoxins damage the human intestine when they get too much Researcher of Graz BioTechMed studied.
When antibiotics are given due to infections, drugs not only fight infectious agents but also kill bacteria of the natural intestinal flora. This can be one dramatic imbalance in microbes in the intestine. So u.a. The growth of antibiotic-resistant Klebsiella oxytoca bacteria, which is invisible to healthy people, is preferred by antibiotics. The penicillin-resistant intestinal dwelling, usually kept under control from the rest of the intestinal flora, can grow excessively and ultimately dominate the entire intestinal flora.
Researchers of. T Grazer BioTechMed-Verbund of the University and Med-University Graz Several years ago, cell cultures of mice have shown that certain strains of this bacterium produce metabolic products that are toxic to intestinal mucosal cells. What exactly happens is there Team around Ellen Zechner (University of Graz) and Christoph Högenauer (Med-University Graz) It is now observed for the first time on the basis of intestinal cells of the human organism and in the American journal PNAS * published. According to Ellen Zechner, "the processes we observe from model organisms in the laboratory are a huge challenge in affirming one-to-one in the human cranium."
Toxic substances in perfect teamwork
The team has shown that the bacterium produces two different intestinal-based intestinal cells derived from intestinal rinses and stool samples:One of them destroys host cell DNA and the other blocks their cell division process., wrote the first author of Graz Katrin Unterhauser of the Institute of Molecular Biosciences at the University of Graz. According to Unterhauser, the two metabolites make perfect teamwork. Tilimycin thus specifically attacking human DNA and thus can cause damage to the genetic material of the cell. Tilivallin It defines an important step in the process of cell division, which in turn causes malformations. As a result, the barrier between the intestinal bacteria and the human body is not maintained: the result is one severe intestinal inflammation with bloody diarrhea.
"Now we know for sure that these two toxins cause colitis and we know their goals", says Unterhauser at the request of APA. The results may facilitate both the specific diagnosis of haemorrhagic colitis and the alleviation of the undesirable side effects of antibiotics.
If the clinical picture appears, it is crucial to immediately stop the causative antibiotic. This allows the intestinal flora to regenerate and leads to a reduction of Klebsiella oxytoca to harmless extent.
Unterhauser, L. Pöltl, G. Schneditz, Ch. Högenauer, E. Zechner et al .: "Klebsiella oxytoca enterotoxins tilimycin and tilivalline have different DNA damage to the host and microtubule stabilizing activities." )