Featured Research

from universities, journals, and other organizations

Scientists Sequence Genome Of Strep Throat, Scarlet Fever Bacterium

Date:
April 11, 2001
Source:
NIH/National Institute Of Allergy And Infectious Diseases
Summary:
Scientists have completed sequencing the genome of Streptococcus pyogenes, a bacterium that causes a wide variety of human diseases. The "rap sheet" on this organism, also known as group A streptococci or GAS, stretches long: GAS infection can lead to strep throat, scarlet fever, the skin infection impetigo, pneumonia, acute kidney inflammation, toxic shock syndrome, blood "poisoning," acute rheumatic fever, rheumatic heart disease, and the flesh-eating disease known as necrotizing fasciitis.

Scientists have completed sequencing the genome of Streptococcus pyogenes, a bacterium that causes a wide variety of human diseases. The "rap sheet" on this organism, also known as group A streptococci or GAS, stretches long: GAS infection can lead to strep throat, scarlet fever, the skin infection impetigo, pneumonia, acute kidney inflammation, toxic shock syndrome, blood "poisoning," acute rheumatic fever, rheumatic heart disease, and the flesh-eating disease known as necrotizing fasciitis.

"This exceptionally virulent organism is difficult to study because it infects only humans and very few animal models of group A strep diseases exist," says Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID). "We need to know more about how group A strep interact with humans to cause so many different illnesses. The genetic sequence should shed light on these questions and pave the way for better treatment and prevention."

"Infection with this bacterium occurs worldwide, and acute rheumatic fever is the major cause of heart disease in children of developing countries," says Fran Rubin, Ph.D., a respiratory diseases program officer at NIAID. "This is one reason why sequencing this organism is so critical." Several million cases of strep throat and impetigo occur each year in the United States. In addition, in 1999 GAS infection led to 9,400 more serious illnesses such as toxic shock syndrome or necrotizing fasciitis in the United States. These invasive diseases occur when GAS get into parts of the body where bacteria are not usually found, such as the blood and muscles.

The sequencing project, supported by NIAID, was carried out by researchers at the University of Oklahoma Health Sciences Center. Their findings appear in the April 10 issue of the Proceedings of the National Academy of Sciences.

The single, circular chromosome containing the bacterium's genetic material is more than 1.8 million DNA base pairs long, reports Joseph J. Ferretti, Ph.D., a molecular biologist at the University of Oklahoma and head of the genome sequencing team. The particular strain of S. pyogenes that Dr. Ferretti and his colleagues examined, designated SF370, was isolated from the infected wound of a patient and can cause invasive diseases such as streptococcal toxic shock syndrome or necrotizing fasciitis. Preliminary analysis of its estimated 1,752 genes includes the following observations:

* The genome contains more than 40 possible virulence genes. "We didn't know about the existence of many of these genes," said Dr. Ferretti. "This new knowledge will broaden our understanding of how this organism causes disease."

* Specific genes may allow GAS to mimic certain molecules in people it infects. For example, one GAS gene codes for a protein similar to the collagen found in human connective tissue. Dr. Ferretti speculates that when the immune system attacks this streptococcal protein, it may also mistakenly attack connective tissue, resulting in rheumatic fever.

* The genome contains four sections inserted by bacteriophages, viruses that infect bacteria and splice their genes into the bacterial DNA. Some of these virally acquired genes code for "superantigen-like proteins," which can provoke immune system responses that lead to toxic shock. The presence of these viral genes strongly suggests that bacteriophages can spur GAS to evolve into new and more dangerous strains, Dr. Ferretti says.

The sequence information should aid efforts to develop vaccines against GAS, notes Dr. Rubin. NIAID-supported research has led to the development of several GAS vaccine candidates in various stages of testing. "We expect the sequence will reveal new antigens, possibly proteins on the bacterium's surface, that would also be good vaccine candidates."

NIAID is a component of the National Institutes of Health (NIH). NIAID supports basic and applied research to prevent, diagnose, and treat infectious and immune-mediated illnesses, including HIV/AIDS and other sexually transmitted diseases, tuberculosis, malaria, autoimmune disorders, asthma and allergies.

Reference: J Ferretti et al. Complete genome sequence of an M1 strain of streptococcus pyogenes. Proceedings of the National Academy of Sciences. 98 (8): 4658-63 (2001).

NIAID is a component of the National Institutes of Health (NIH). NIAID conducts and supports research to prevent, diagnose and treat illnesses such as HIV disease and other sexually transmitted diseases, tuberculosis, malaria, asthma and allergies. NIH is an agency of the U.S. Department of Health and Human Services.


Story Source:

The above story is based on materials provided by NIH/National Institute Of Allergy And Infectious Diseases. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute Of Allergy And Infectious Diseases. "Scientists Sequence Genome Of Strep Throat, Scarlet Fever Bacterium." ScienceDaily. ScienceDaily, 11 April 2001. <www.sciencedaily.com/releases/2001/04/010411081719.htm>.
NIH/National Institute Of Allergy And Infectious Diseases. (2001, April 11). Scientists Sequence Genome Of Strep Throat, Scarlet Fever Bacterium. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2001/04/010411081719.htm
NIH/National Institute Of Allergy And Infectious Diseases. "Scientists Sequence Genome Of Strep Throat, Scarlet Fever Bacterium." ScienceDaily. www.sciencedaily.com/releases/2001/04/010411081719.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins