Title:Metagenomika – a velünk élő mikroorganizmusok megismerésének új megközelítése
SUMMARY Background: In our age, the information society, the computer based technologies, including the data analytical procedures are parts of each site of the life. Bioinformatics provides approaches for the knowledge gathering and update which were not imaginable two decades ago. Metagenomics is the area of bioinformatics which helps improve our knowledge about the composition of microbial species in the production or companion animals, human being or environment. Objectives: The present work describes the main steps of a metagenomics analysis. As an example, the metagenomics investigation of swine dysentery as an important animal disease is shown. Materials and methods: From three clinically diseased fattening pigs intestinal contents were sampled from three different sections of the gut (i.e. caecum, colon and rectum). All DNA was extracted from the samples, thereafter sequenced by next generation sequencing technology. The produced 1,782,466 reads were pooled and analysed. The reads were aligned to archea, bacteria and virus genome databases by the Kraken bioinformatics tool. The results of the alignments were visualized by the tool Krona. Results and Discussion: The presented case study helps the reader understand how metagenomics studies work and provide new professional knowledge on the microbiome of selected organs in different creatures. The proportions of the different taxa allow to have an insight to the microbial communities of the gut in the diseased animals. Beside this, a short review is presented to demonstrate the application possibilities of metagenomics in the field of animal health. Bioinformatics is an emerging area and it is very important to have knowledge –clinicians and researchers as well – about the methods, their possible results and the limitations. This work provides a simple introduction to metagenomics in the language of veterinarians.