* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download RED HERRING | Bacteria Talk and Manipulate
Survey
Document related concepts
Trimeric autotransporter adhesin wikipedia , lookup
Microorganism wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Phospholipid-derived fatty acids wikipedia , lookup
Horizontal gene transfer wikipedia , lookup
Sarcocystis wikipedia , lookup
Disinfectant wikipedia , lookup
Triclocarban wikipedia , lookup
Bacterial cell structure wikipedia , lookup
Human microbiota wikipedia , lookup
Marine microorganism wikipedia , lookup
Quorum sensing wikipedia , lookup
Transcript
RED HERRING | Bacteria Talk and Manipulate Wednesday, October 12, 2005 Search the site Log in | Join the RH community - it's FREE Industries Capital Industries Biosciences Bacteria Talk and Manipulate Communications Computing Scientists learn bacteria species communicate, and adjust their conversations to block or Energy Entertainment & Media spread human infection. Internet & Services September 30, 2005 Security & Defense Venture Capital Bacteria may be single-cell creatures, but they’re far from dumb: They not only can talk to each other, but some Profiles species can also manipulate other species’ behavior to block or spread infection in humans. Q&A Regions That’s the latest discovery from a group of Princeton University molecular biologists whose findings on the Briefings science of bacterial communication appear in the current issue of the journal Nature. The results could have Metrics important implications for designing better antibiotics. Blog Bacteria talk to each other by secreting chemical signals called pheromones, or autoinducers, into the Research environment, where they can be sensed by other bacteria cells. When this happens, it changes the behavior of Newsletters the cells that pick up the signal by turning on and off combinations of their genes. Events The trick is called quorum sensing. It allows bacteria to coordinate the behavior of whole colonies, giving them some of the characteristics of multicellular organisms. Chemical Census Subscribe Now Customer Service Advertisement - ADVERTISEMENT - When the chemical signal induces another bacterium to produce the same chemical, it can be used to sense the population density. For example, a species called Pseudomonas aeruginosa, which can cause devastating infections in cancer and AIDS patients, can - MARKETS NYSE NSDQ S&P increase in number without harming its host. 7325.41 -55.40 2036.63 -24.46 1177.90 -6.97 However, quorum sensing allows the bacteria Delayed 20 mins. to monitor their population density. When they hit a threshold great enough to overcome the immune system, the bacteria cells change to become aggressive. “Quorum sensing-controlled processes are often crucial for successful bacterial–host relationships—both symbiotic and pathogenic,” said the paper. Manipulating the Signal Most autoinducers are produced to communicate with bacteria of the same species. However, one autoinducer, known as AI-2, is produced and detected by many different species. For this reason it is widely believed to facilitate communication between species. http://www.redherring.com/Article.aspx?a=13803&hed=Bacteria+Talk+and+Manipulate (1 of 3)10/12/2005 12:01:14 PM RED HERRING | Bacteria Talk and Manipulate In the study, Karina Xavier, a postdoctoral fellow at Princeton University’s Howard Hughes Medical Institute, demonstrated this theory by mixing a common gut bacteria called Escherichia coli with a bioluminescent marine bacteria called Vibrio harveyi, which uses quorum sensing to coordinate bacteria cells to glow when they hit a threshold density. Her findings confirmed that both species responded to AI-2 produced by another species. Another experiment showed that E. coli could take advantage of the common language to confuse the marine species. It ate up enough AI-2 to dim the glow of the marine species, fooling it into thinking its population numbers had dropped. Finally, Dr. Xavier mixed E. coli with the bacterial species that causes cholera and would naturally mix with it in a human gut. The cholera-producing species, called Vibrio cholerae, uses quorum sensing to tell when its population has increased sufficiently to make it worth moving on to infect another human. When the population reaches this threshold, the chemical signal tells V. cholerae to detach from the intestine walls and stop producing toxins. Again, E. coli managed to block the V. cholerae signal. “Consumption of the signal could be a mechanism that allows one kind of bacteria to block another kind of bacteria from counting how many neighbors they have and, in turn, properly controlling its behavior,” said Bonnie L. Bassler, a professor of molecular biology at Princeton. “You can imagine that, in niche one, the bacteria we consider good guys might be using AI-2 and winning. And unfortunately, in niche two, the bad guys might be using AI-2 and winning,” she added. And this could add another layer of complexity to antibiotic prescription and design. The Princeton team is currently trying to develop molecules that interfere with a bacterium’s ability to detect and produce AI-2. “A more far-out strategy is to develop therapies that enhance the growth of AI-2 consumers at the expense of bacteria that rely on AI-2 for counting to turn on virulence,” Professor Bassler told RedHerring.com, adding that this strategy is still some way off. “We try to manipulate the manipulators!” RELATED ARTICLES RECENT ARTICLES Guts • • • • • • If you take a look at the Red Herring Top 50 Private companies, and our Ten to Watch, you'll notice there's something... No guts, no glory "Are you crazy?" is always a fun question to ask a CEO who's laid out his or her business plan before you. Especially when... RED HERRING Sponsors http://www.redherring.com/Article.aspx?a=13803&hed=Bacteria+Talk+and+Manipulate (2 of 3)10/12/2005 12:01:14 PM Celldex Buys Lorantis, Alteris Genentech Q3 Profit up 56% UCLA Makes Cheap Solar Cells KKR Buys Accellent for $1.27B Firm Lifted by Cancer Vaccine Nascar: Women’s Health Central RED HERRING | Bacteria Talk and Manipulate Articles | Blog | Research | Newsletters | Events New User Registration | Search | About Us | Letter from the Editor | Advertising Info | Magazine Customer Service | Contact Us | Careers | © 1993-2005 Red Herring, Inc. All rights reserved. http://www.redherring.com/Article.aspx?a=13803&hed=Bacteria+Talk+and+Manipulate (3 of 3)10/12/2005 12:01:14 PM RSS feeds