Features | Partner Sites | Information | LinkXpress
Sign In
JIB
GLOBETECH PUBLISHING
GLOBETECH PUBLISHING

Asparagine Metabolism Empowers Group A Streptococcus Infection

By BiotechDaily International staff writers
Posted on 30 Jan 2014
Image: Photomicrograph (900x) of Streptococcus pyogenes bacteria, viewed using Pappenheim\'s stain (Photo courtesy of the CDC - [US] Centers for Disease Control and Prevention).
Image: Photomicrograph (900x) of Streptococcus pyogenes bacteria, viewed using Pappenheim\'s stain (Photo courtesy of the CDC - [US] Centers for Disease Control and Prevention).
Image: Micrograph (H&E stain) of necrotizing fasciitis, showing necrosis (center of image) of the dense connective tissue, i.e., fascia, interposed between fat lobules (top-right and bottom-left of image) (Photo courtesy of Wikimedia Commons).
Image: Micrograph (H&E stain) of necrotizing fasciitis, showing necrosis (center of image) of the dense connective tissue, i.e., fascia, interposed between fat lobules (top-right and bottom-left of image) (Photo courtesy of Wikimedia Commons).
The bacteria that cause the frightening syndrome called "flesh-eating disease" have been found to be stimulated by the amino acid asparagine and inhibited by the chemotherapeutic enzyme asparaginase, which destroys asparagine.

Necrotizing fasciitis or NF, commonly known as "flesh-eating disease" is a rare infection of the deeper layers of skin and subcutaneous tissues, which quickly spreads across the fascial plane within the subcutaneous tissue. Individuals having compromised immune systems (due to conditions like diabetes, cancer, etc.) have greater risk of developing NF. It is a severe disease of sudden onset and is usually treated immediately with high doses of intravenous antibiotics. "Flesh-eating disease" is a misnomer, as the bacteria involved—most frequently Streptococcus pyogenes, or Group A Streptococcus (GAS)—do not actually "eat" the tissue. They cause the destruction of skin and muscle by releasing toxins, which include streptococcal pyogenic exotoxins.

Investigators at the Hebrew University of Jerusalem (Israel) reported in the January 16, 2014, issue of the journal Cell that during adherence to host cells, GAS releases streptolysin toxins, which create endoplasmic reticulum stress in the host cells. This stress causes an increase in the expression of the enzyme asparagine synthetase and the production of asparagine. The released asparagine is sensed by the bacteria, which induces altered expression of about 17% of the bacterial genes.

Asparaginase, a widely used chemotherapeutic agent, was found to block GAS growth in human blood and prevented GAS proliferation in a mouse model. To date asparaginase has not been used to treat GAS infections.

The Yissum Research Development Company (Jerusalem, Israel), the technology transfer arm of the Hebrew University of Jerusalem, has registered a patent for this discovery and is seeking commercial partners to help develop effective therapies against invasive Streptococcus infections.

Related Links:

Hebrew University of Jerusalem
Yissum Research Development Company



comments powered by Disqus

Channels

Drug Discovery

view channel
Image: Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells (Photo courtesy of the University of Texas, Austin).

Experimental Drug Kills Cancer Cells by Interfering with Their Ion Transport Mechanism

An experimental anticancer drug induces cells to enter a molecular pathway leading to apoptosis by skewing their ion transport systems to greatly favor the influx of chloride anions. To promote development... Read more

Therapeutics

view channel
Image: Liver cells regenerated in mice treated with a new drug (right) compared with a control group (center) after partial liver removal. Healthy liver cells are shown at left (Photo courtesy of Marshall et al, 2014, the Journal of Experimental Medicine).

New Drug Triggers Liver Regeneration After Surgery

Investigators have revealed that an innovative complement inhibitor decreases complement-mediated liver cell death, and actually stimulates postsurgery liver regrowth in mice. Liver cancer often results... Read more

Lab Technologies

view channel

Genome-Wide Mutation-Searching Computational Software Designed for Genomic Medicine

Analysis software cross-references a patient’s symptoms with his genome sequence to help physicians in the diagnosis of disease. This software was created by a team of scientists from A*STAR’s Genome Institute of Singapore (GIS), led by Dr. Pauline Ng. The research findings were published August 3, 2014, in the journal... Read more

Business

view channel

Partnership Established to Decode Bowel Disease

23andMe (Mountain View, CA,USA), a personal genetics company, is collaborating with Pfizer, Inc. (New York, NY, USA), in which the companies will seek to enroll 10,000 people with inflammatory bowel disease (IBD) in a research project designed to explore the genetic factors associated with the onset, progression, severity,... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.