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The Best Way to Consume Antibiotics; A New Way For Exosome Extraction

Researchers at the Kazan Federal University create a panel to monitor the state of the intestinal microflora during therapy of Helicobacter pylori infection, which is associated with many cases of gastric and duodenal ulcers, gastritis, duodenitis, and stomach cancer.

Scientists are trying to establish the roles of separate representatives on the intestinal microbiota and the way they change after taking the medication. According to the genome-sequencing (decoding of the genome) of 200 intestinal contents samples, scientists were able to identify about 300 markers that vary in response to antibiotics. The project started in 2014 under the federal target program “Research and development on priority directions of scientific and technological complex of Russia for 2014-2020”.

Tatyana_Grigoryeva Tatyana Grigoryeva

“Under the terms of subsidies within the framework of the federal program, we have to collect 250 samples of intestinal contents, including 100 samples from the control group and 150 from patients with Helicobacter pylori infection and various associated diseases, - Senior Researcher of the Institute of Fundamental Medicine and Biology of Kazan Federal University, Tatyana Grigoryeva. - It should be noted that this is the umbrella project. Three more projects on related subjects were supported within the Federal Program – besides, our colleagues and partners from the Medical University of Tomsk and two Moscow Research Centers help us with the collection of materials and data processing. The subject of their projects is “Study of the microbiota and its pathologies in other diseases including chronic obstructive pulmonary disease, alcoholism, Crohn’s disease”.

Kazan scientists have calculated the “weak” and “strong” types of intestinal microflora of a human being and tracked, which groups of micro-organisms disappear, and which are beginning to dominate the intestinal microflora with antibiotics, as well as determined how antibiotic resistance genes in microorganisms increase in number, and what risks human beings run, when taking medications.

“On the basis of the data obtained we managed firstly, to come to the conclusion that initially people, regardless of whether they are healthy or sick, have very various in its composition microbiota, - Grigoryeva says. - Therefore, it’s very difficult to determine the groups of microorganisms, which could describe the state of the human microflora as normal or abnormal. There are too many individual features. And of course, 200 samples are not enough to classify both healthy and sick people into groups”.

However, there are general patterns. Changes occur during treatment with antibiotics - in this case, certain groups of microorganisms of human intestinal simply disappear.

The status of intestinal microbial communities was evaluated by researchers using methods that come in biomedicine from the environment. This is an index of Shannon, the so-called diversity index, and Bray Curtis metric, which evaluates the taxonomic distance between one community and another state after taking antibiotics. Considering these distances (that is, how the community has changed in comparison to its original state), the authors ranked patients with severe, moderate and low side effects of drug therapy on the intestinal microflora.


“But only about 20% of patients had severe changes in community structure after the use of antibiotics, - Tatyana Grigoryeva notices. - We don’t know how to treat this yet. We should keep in mind that some patients initially had a damaged intestinal microflora. For example, one and not the most useful part of the community dominated and the community itself was narrow, undeveloped. In this case, the antibiotics could influence positively not only eliminating the Helicobacter pylori and other related pathogens or microbes atypical for gut.

It’s very pleasing that there are people whose microflora didn’t suffer greatly from the hard, two-week antibiotic treatment.

It deserves attention - we hope to calculate the “weak” and “strong” enterotype, when antibiotics may be contraindicated, or rather, when you first need to take the intestines rehabilitation course, and take antibiotics only after that. Besides, we are interested in stable communities in which the microbiota won’t undergo drastic changes in response to pharmaceuticals”.

The ultimate goal of researchers is to develop the diagnostic panel for assessment of the condition of the intestinal microflora during therapy of Helicobacter pylori, applicable in clinical practice. Currently, the researchers have published their findings in the scientific journal “Genes and cells”, “Antibiotics and Chemotherapy”, they also filed an application for publication in the Journal of Bionanoscience. The scientists received an offer on the full text of the report publication from “Gastroenterology” journal.

In the meantime, a graduate of the Faculty of Natural Sciences, Novosibirsk State University, Lada Purvinsh is developing a versatile method of isolating exosomes from large volumes of biological fluids. Various diseases (cancer, in particular) are diagnosed with the help of exosomes, besides, they are used as a means of medicine delivery.

According to Lada Purvinsh, the project essence (the work on the project began under the direction of the researcher from the laboratory of repair enzymes of the Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Sergei Sedykh) consists in the development of exosome isolation technology, and subsequently in the production and sale of sets for their release. The process itself consists of the following stages: ultrafiltration, ultracentrifugation and gel filtration. Scientists will also take into account the types and volumes of biological fluids.

“The peculiarity of our technology and the set being developed will be the fact that clean separation will be carried out from any biological fluids, including such “complex” ones as homogenates of tissues and milk, - Lada Purvinsh explains. - The systems introduced at the market nowadays enables to separate exosomes from the blood plasma mainly, culture-based and cerebrospinal fluids, urine”.

With the ability to handle large volumes of liquid, the technology will be useful for pharmacological companies using exosomes for targeted medicine delivery.

Lada Purvinsh notes that the target audience of the product is clinics and research laboratories. The project is at the stage of research and development work. About three million rubles are required for the initial phase of its development.


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