Navigation Links
Curbing C. difficile's toxin production
Date:9/5/2007

BOSTON (Sept. 5, 2007) As if being admitted to the hospital werent bad enough, patients, once admitted, are at higher risk of becoming infected with a superbug bacterium, Clostridium difficile (C. difficile). The toxins produced by C. difficile kill human intestinal cells by causing them to burst open, allowing the bacteria to use them as fuel. This results in severe diarrhea and, in rare cases, death. Abraham Linc Sonenshein, PhD, and colleagues from the Department of Molecular Biology and Microbiology at the Tufts University School of Medicine (TUSM) and the Sackler School of Graduate Biomedical Sciences at Tufts, have discovered how a protein called CodY regulates the genes that control production of the dangerous toxins. Understanding the relationship between CodY and C. difficile is an important step toward the development of a drug that may prevent hospital patients from falling ill.

The C. difficile bacteria only produce toxins when they are in need of food, explains Sonenshein, professor of microbiology at TUSM and corresponding author on the paper to be published in Molecular Microbiology. We found that the CodY protein, in essence, monitors the hunger level of C. difficile, preventing toxin production when the bacteria have enough to eat. Sonenshein, along with first author Sean Dineen, PhD, and other Tufts colleagues developed a series of experiments to investigate the importance of CodY and how this protein communicates to bacteria that it is time to search for new sources of food.

The researchers first developed a mutant strain of C. difficile bacteria that does not make the protein CodY, and compared the amount of toxin produced by the mutant strain of bacteria to the amount of toxin produced by normal bacteria. The mutant strain produced much higher levels of toxin. The presence of CodY seems to tell the bacterial cells that they are well-fed and there is no reason to make toxin that kills intestinal cells for fuel. Lack of CodY activity, however, indicates to the bacteria that they are lacking key nutrients and that it is time to make the toxins they need to get food from the host cells.

To determine how CodY tells the bacteria not to make toxins, Sonenshein and colleagues removed DNA from the bacteria, and observed the interaction of the DNA and the CodY protein in vitro. They found that CodY targeted the region of the bacterial chromosome that includes the toxin genes. When CodY senses that the cell has enough nutrients, it binds to this gene region, and prevents the bacterium from making toxin, says Sonenshein. Conversely, when food is scarce, the CodY protein does not bind to these genes, allowing C. difficile to make the toxins needed to attack intestinal cells.

Knowing what turns on, and more importantly, what turns off the toxin-producing genes in C. difficile opens the door for treatment and prevention options. It is possible that, based on our findings, a new drug could be developed that would trick CodY into thinking there is enough fuel for the bacteria, causing CodY to remain bound to the toxin gene region and thus suppressing toxin production.


'/>"/>

Contact: Siobhan Gallagher
Siobhan.Gallagher@tufts.edu
617-636-6586
Tufts University, Health Sciences
Source:Eurekalert

Related biology news :

1. Defensins neutralize anthrax toxin
2. Green catalyst destroys pesticides and munitions toxins, finds Carnegie Mellon University
3. Tetanus toxin found to have therapeutic properties
4. Structures of marine toxins provide insight into their effectiveness as cancer drugs
5. Prenatal exposure to marine toxin causes lasting damage
6. UCSD study finds anthrax toxins also harmful to fruit flies
7. Scientists design potent anthrax toxin inhibitor
8. Anthrax inhibitor counteracts toxin, may lead to new therapeutics
9. Scientists reveal how deadly toxin hijacks cells
10. Scientists develop a way to make the deadliest toxin known even more toxic
11. Yale researchers find environmental toxins disruptive to hearing in mammals
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/23/2016)... , March 23, 2016 ... erhöhter Sicherheit Gesichts- und Stimmerkennung mit Passwörtern ... (NASDAQ: MESG ), ein führender ... das Unternehmen mit SpeechPro zusammenarbeitet, um erstmals ... Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, im Rahmen ...
(Date:3/22/2016)... and SANDY, Utah , March ... operates the highest sample volume laboratory in ... and UNIConnect, leaders in clinical sequencing informatics and molecular ... of a project to establish the informatics infrastructure for ... NSO has been contracted by the Ontario Ministry ...
(Date:3/18/2016)... -- --> --> Competitive ... Unmanned Vehicles, Physical infrastructure and Perimeter Surveillance & Detection Systems ... security market and the continuing migration crisis in the ... has led visiongain to publish this unique report, which ... defence & security companies in the border security market ...
Breaking Biology News(10 mins):
(Date:4/26/2016)... (PRWEB) , ... April 27, 2016 , ... ... of Lewis Roca Rothgerber Christie LLP as an associate in the firm’s Intellectual ... and international electrical, mechanical and electromechanical patent applications. He has an electrical engineering ...
(Date:4/26/2016)... ... April 26, 2016 , ... The European Patent Office (EPO) ... of three finalists for the European Inventor Award 2016 in the category "Non-European countries." ... announced at a ceremony in Lisbon on June 9th. , The human capacity to ...
(Date:4/26/2016)... ... 2016 , ... Mr. Palmer created the RPO business for Ceridian and lead ... managed services contract in the U.S. intelligence community with The SI (a Lockheed Martin ... Younger, founder of Accolo. “We are growing and his experience guiding our expansion ...
(Date:4/26/2016)... ... ... BioFactura, Inc ., a biopharmaceutical research and manufacturing company, announced today the ... significant oversubscription of the original $1.5M target. The funds will be used to ... , Chief Executive Officer and President, Darryl Sampey founded BioFactura in 2004 ...
Breaking Biology Technology: