Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The tiny difference in the genes of bacteria

02.07.2009
Researchers from Helmholtz Center for Infection Research, Germany, develop new method for better diagnostic of diarrhea-causing 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 Höfle, 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 Höfle 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 Höfle. 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."

Article: Multiple-Locus Variable-Number Tandem-Repeat Analysis for Clonal Identification of Vibrio parahaemolyticus Isolates by Using Capillary Electrophoresis. Erika Harth-Chu, Romilio T. Espejo, Richard Christen, Carlos A. Guzmán, and Manfred G. Höfle. Appl. Environ. Microbiol. 2009; 75: 4079-4088

Dr. Bastian Dornbach | EurekAlert!
Further information:
http://www.helmholtz-hzi.de

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Devils Hole: Ancient Traces of Climate History

24.05.2017 | Earth Sciences

Discovery of a Key Regulatory Gene in Cardiac Valve Formation

24.05.2017 | Life Sciences

A CLOUD of possibilities: Finding new therapies by combining drugs

24.05.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>