Featured Research

from universities, journals, and other organizations

New way to learn about -- and potentially block -- traits in harmful pathogens

Date:
January 18, 2012
Source:
Duke University Medical Center
Summary:
Researchers have developed a new way to identify the genes of harmful microbes, particularly those that have been difficult to study in the laboratory.

Electron micrograph of Chlamydia mutant bacteria inside of a cell. These particular mutant bacteria, colored red, are defective in secreting high levels of virulence proteins, seen here as the accumulating dark granules in between two bacterial membranes.
Credit: Bidong Nguyen, Duke Molecular Genetics and Microbiology

Researchers at Duke University Medical Center have developed a new way to identify the genes of harmful microbes, particularly those that have been difficult to study in the laboratory.

This new method uses chemicals to create mutant bacteria, followed by genomic sequencing to identify all mutations. By looking for common genes that were mutated in Chlamydia sharing a particular trait, the investigators were able to rapidly "zero in" on the genes responsible for that trait.

The approach is versatile and inexpensive enough that it could be applied to study a range of microorganisms, said Raphael Valdivia, PhD, an associate professor of molecular genetics and microbiology at Duke.

"We were able to learn about genes that allow Chlamydia to flourish in their hosts without the traditional, lengthy process of domesticating the pathogen to accept recombinant DNA," Valdivia said.

"Our approach marries classical microbiology techniques with 21st century genome-sequencing technologies. If you encounter a new dangerous microorganism and want to determine what genes are important, I think this represents an effective way to learn all we can, as fast as we can."

One of the goals in studying microbial pathogens that harm humans and animals is to locate and disrupt the genes required for infection, Valdivia said.

The microbe in this study, Chlamydia, is usually sexually transmitted, hides in human cells, and is a type of bacteria that must cause disease to be transmitted from one host to another. Chlamydia is the leading sexually transmitted infection and a risk factor for pelvic inflammatory disease and infertility.

Prior to this work, the function of many Chlamydia genes had to be inferred by their similarity to genes from other bacteria. "By isolating mutants that don't grow well inside cells and identifying the underlying mutations, we can learn a lot about how these genes contribute to disease," Valdivia said. "These are the activities we'd like to block."

"For us, this significantly accelerates the analysis of Chlamydia and importantly, should be applicable to many other microbes that have been difficult manipulate with recombinant DNA approaches," he said.

Valdivia suggested that even microbes associated with our normal intestinal flora, which are notoriously difficult to manipulate, are now open to exploration so that we can learn how their genes influence human health, including dietary disorders and inflammatory bowel disease.

The work was published on Jan. 9 in the early edition of the Proceedings of the National Academy of Sciences.

Valdivia also said that the new technique could help to create Chlamydia vaccines that have a combination of mutations that affect the pathogen's virulence. "That way we can cripple some aspects of the bacterium's ability to thrive intact in a host, while still allowing the bacterium to replicate enough to prime the im mune system against it."

The lead author was Bidong D. Nguyen of the Duke Department of Molecular Genetics and Microbiology.

This work was supported by funds from a Chancellor's Science Council Pilot Projects award from Duke University and funds from the NIH.


Story Source:

The above story is based on materials provided by Duke University Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. B. D. Nguyen, R. H. Valdivia. Virulence determinants in the obligate intracellular pathogen Chlamydia trachomatis revealed by forward genetic approaches. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1117884109

Cite This Page:

Duke University Medical Center. "New way to learn about -- and potentially block -- traits in harmful pathogens." ScienceDaily. ScienceDaily, 18 January 2012. <www.sciencedaily.com/releases/2012/01/120109155725.htm>.
Duke University Medical Center. (2012, January 18). New way to learn about -- and potentially block -- traits in harmful pathogens. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2012/01/120109155725.htm
Duke University Medical Center. "New way to learn about -- and potentially block -- traits in harmful pathogens." ScienceDaily. www.sciencedaily.com/releases/2012/01/120109155725.htm (accessed April 16, 2014).

Share This



More Health & Medicine News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. Video provided by Newsy
Powered by NewsLook.com
How Mt. Everest Helped Scientists Research Diabetes

How Mt. Everest Helped Scientists Research Diabetes

Newsy (Apr. 15, 2014) British researchers were able to use Mount Everest's low altitudes to study insulin resistance. They hope to find ways to treat diabetes. Video provided by Newsy
Powered by NewsLook.com
Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Carpenter's Injury Leads To Hundreds Of 3-D-Printed Hands

Newsy (Apr. 14, 2014) Richard van As lost all fingers on his right hand in a woodworking accident. Now, he's used the incident to create a prosthetic to help hundreds. Video provided by Newsy
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:
from the past week

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