Navigation Links
The tiny difference in the genes of bacteria

It is based on detecting short, repetitive DNA segments in the genome of bacteria. Every single bacterial strain has such characteristic repeats. "With this method we are able to identify bacterial strains as well as clarify their genetic relationships. Furthermore, we can show how new pathogenic variants develop," says Manfred Hfle, researcher at the HZI. The results have now been published in the current issue of the scientific journal "Applied and Environmental Microbiology". The work is part of the two European Union funded projects "Healthy Water" and "AQUA-chip". Manfred Hfle is coordinator of both projects that deal with various aspects of the microbiological safety of both, drinking water and sea water.

Various bacteria that live in drinking water or sea water can cause severe human diseases. One of them are vibrios: its species Vibrio cholerae is more commonly known as the causative agent of Cholera that spread in Europe until the 20th century. Interestingly, not all Vibrio cholerae strains are pathogenic to humans. Only those strains cause severe diarrhoea known as Cholera that produce a certain bacterial toxin which attacks the intestinal wall. A less known, though also dangerous member of the genus Vibrio, is Vibrio parahaemolyticus. It is a highly contagious pathogenic germ with only a dozen ingested bacteria causing severe diarrhoea. This strain is a threat for the pacific region and reached the east coast of the United States in the 21st century. Since the end of the 1990s, Vibrio parahaemolyticus epidemics have led to thousands of cases of illness in Chile. In the future, due to ballast water or climate change, the species may also gain importance in Europe. As in the Cholera bacterium, various Vibrio parahaemolyticus strains exist with varying infectivity. Distinguishing those strains has been a challenge until now.

The newly developed method makes it now possible to characterize and distinguish hundreds of bacteria strains in a short time. The method is based on the existence of short, repetitive DNA segments in the genome of all living species. As in a tandem bike, those segments are lined up on the DNA strand, called "tandem repeats". They are characteristic for every bacterial strain. To identify a certain strain, the HZI researchers use short DNA fragments, marked with certain dyes. Each dyed DNA fragment recognizes a single tandem repeat, binding at it. As a result, the researchers receive, for example, six red fragments binding a tandem of six repetitions. Then, the researchers analyzed the tandem repeats marked with dyed fragments: Every bacteria strain differs in pattern and size of the measured tandem repeats.

"With this method, we are able to differentiate more then 120 Vibrio parahaemolyticus strains," says Manfred Hfle. This is important for infectious diseases in which it is necessary to know which strain is the causative agent. Further information are whether it is just one or more strains and where they derive from. The latter can help to prevent spreading of the disease with corresponding sanctions. "The intake of Vibrio parahaemolytics often occurs through raw clams that have filtered contaminated sea water. With this method, we are able to say from which clam species the germ originates." The new technique can also be used to characterize other bacterial pathogens and to investigate how pathogenic bacteria evolve in the environment. "Hereby, this high resolution method makes an important contribution towards a fast and precise recognition of microbial pathogens with pandemic potential."


Contact: Dr. Bastian Dornbach
Helmholtz Association of German Research Centres

Related biology news :

1. St. Jude influenza survey uncovers key differences between bird flu and human flu
2. Claims of sex-related differences in genetic association studies often not properly validated
3. Genetic differences in clover make one type toxic
4. For honey bee queens, multiple mating makes a difference
5. Analysis of breast and colon cancer genes finds many areas of differences between tumors
6. Worms take the sniff test to reveal sex differences in brain
7. Choosing dry or wet food for cats makes little difference
8. Tiny genetic differences have huge consequences: McGill researchers
9. Sex differences in the brains serotonin system
10. Negligent, attentive mouse mothers show biological differences
11. Defining DNA differences to track and tackle typhoid
Post Your Comments:
(Date:11/26/2015)... DUBLIN , Nov. 26, 2015 Research ... of the "Capacitive Fingerprint Sensors - Technology and ... --> --> ... market, especially in smartphones. The fingerprint sensor vendor Idex ... fingerprint sensor units in mobile devices and of the ...
(Date:11/20/2015)... 20, 2015 NXTD ) ("NXT-ID" ... the growing mobile commerce market and creator of the ... , was recently interviewed on The RedChip Money ... this weekend on Bloomberg Europe , Bloomberg Asia, ... --> NXTD ) ("NXT-ID" or the "Company"), a ...
(Date:11/19/2015)... Nov. 19, 2015  Based on its in-depth analysis ... recognizes BIO-key with the 2015 Global Frost & Sullivan ... & Sullivan presents this award to the company that ... the needs of the market it serves. The award ... and expands on customer base demands, the overall impact ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... 2015 The Global Genomics ... professional and in-depth study on the current state ... ) , The report ... definitions, classifications, applications and industry chain structure. The ... markets including development trends, competitive landscape analysis, and ...
(Date:11/24/2015)... Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: HALO ... New York on Wednesday, December 2 at ... , president and CEO, will provide a corporate overview. ... at 1:00 p.m. ET/10:00 a.m. PT . ... will provide a corporate overview. --> th Annual ...
(Date:11/24/2015)... , Nov. 24, 2015  Clintrax Global, Inc., a worldwide ... Carolina , today announced that the company has set a ... a 391% quarter on quarter growth posted for Q3 of 2014 ... and Mexico , with the establishment of ... December 2015. --> United Kingdom and ...
(Date:11/24/2015)... --> --> ... by Transparency Market Research, the global non-invasive prenatal testing ... 17.5% during the period between 2014 and 2022. The ... Analysis, Size, Volume, Share, Growth, Trends and Forecast 2014 ... to reach a valuation of US$2.38 bn by 2022. ...
Breaking Biology Technology: