The small difference in the genes of bacteria

It is based on the detection and repetitive short segments of DNA into the genome of bacteria. Each strain of bacteria this property several times. "With this method we are able to identify the bacterial strains and to clarify their genetic relationship. In addition, we can show how new pathogenic variants to develop, "says Manfred Höfle, a researcher at the HZI. The results were published in the latest issue of the journal Applied and Environmental Microbiology." The work is part of the Union of the two projects "water" and "Aqua-Chip." Manfred Höfle is project coordinator, with the various aspects of microbiological safety of drinking water and lake water. Several bacteria at the drinking water or water can cause severe disease in humans. One of them vibrios: the species of Vibrio cholerae is better known as the pathogen of cholera, which in Europe 20 century. It is interesting to note that all strains of Vibrio cholerae are pathogenic to humans. Only strains cause severe diarrhea known as cholera, a bacterial toxin that attacks the intestinal wall. A lesser known, but as dangerous member of the species is Vibrio Vibrio parahaemolyticus. It is highly contagious pathogens, which recorded a dozen bacteria cause severe diarrhea. This variety is a danger to the Pacific and on the east coast U.S. United in the 21st Century. Since late 1990, Vibrio parahaemolyticus outbreaks have resulted in thousands of cases of the disease in Chile. In the future, ballast water or climate change, nature can also Europe increasingly important. As with the cholera bacterium, Vibrio parahaemolyticus exist with different strains of infectivity. The distinction of these tribes is a challenge, until now.

The new method, it is now possible to characterize and distinguish it from hundreds of strains of bacteria in a short time. The method relies on the existence of repetitive short segments of DNA into the genome of all living species. As in a bicycle-tandem, the segments are available on the DNA strand, the "tandem repeats". They are characteristic of all bacteria. For the identification of a strain, researchers HZI the use of short DNA fragments of certain colors. Each DNA fragment recognizes a single colored tandem repeat mandatory. Consequently, researchers have, for example, six red authentic fragments of six tandem repeats. Then the researchers analyzed the tandem repeats, with the fragments color: All different bacteria in the root structure and size of the extent of tandem occasions.

"With this method we are able to distinguish more than 120 strains of Vibrio parahaemolyticus", says Manfred Höfle. This is important for infectious diseases for which it is necessary to know the load of the pathogen. For more information, if one or more tribes, and they are spreading. This may help to prevent the spread of the disease with the corresponding penalties. "The taking of Vibrio parahaemolytics often raw shellfish, contamination of water filtered. With this method, we can say, types of clams whose seed is originating." The new technology can also be used to characterize bacteria and other pathogens, to investigate how bacterial pathogens in the environment. "What this method of high resolution makes a significant contribution to a rapid and accurate detection of pathogens with pandemic potential."