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:10/29/2015)... , October 29, 2015 ... biometric authentication company focused on the growing mobile ... wallet announces that StackCommerce, a leading marketplace to ... featuring the Wocket® smart wallet on StackSocial for ... ) ("NXT-ID" or the "Company"), a biometric authentication ...
(Date:10/27/2015)... , Oct. 27, 2015 In the present ... of concern for various industry verticals such as banking, ... to the growing demand for secure & simplified access ... ,sectors, such as hacking of bank accounts, misuse of ... equipment such as PC,s, laptops, and smartphones are expected ...
(Date:10/27/2015)... SAN JOSE, Calif. , Oct. 27, 2015 /PRNewswire/ ... human interface solutions, today announced that Google has adopted ... family of touch controller solutions to power its newest ... Nexus 6P by Huawei. --> ... ecosystem partners like Google to provide strategic collaboration in ...
Breaking Biology News(10 mins):
(Date:11/26/2015)... , England , November 26, 2015 ... Lightpoint Medical, an innovative medical device company specializing in imaging ... grant from the European Commission as part of the Horizon ... the company to carry out a large-scale clinical trial in ... -->      (Logo: , --> ...
(Date:11/25/2015)... LOS ANGELES and HOLLISTON, Mass. ... Regenerative Technology, Inc. (Nasdaq: HART ), a biotechnology ... announced that CEO Jim McGorry will present ... Tuesday, December 1, 2015 at 2:30 p.m. PT. The ... (link below) for 30 days. Management will also be ...
(Date:11/25/2015)... The Global Genomics Industry ... and in-depth study on the current state of ... ) , The report provides ... classifications, applications and industry chain structure. The Genomics ... including development trends, competitive landscape analysis, and key ...
(Date:11/24/2015)... DIEGO , Nov. 24, 2015 Halozyme Therapeutics, Inc. ... Healthcare Conference in New York on Wednesday, ... Helen Torley , president and CEO, will provide a corporate ... New York at 1:00 p.m. ET/10:00 a.m. PT ... and investor relations, will provide a corporate overview. --> ...
Breaking Biology Technology: