Apr. 24, 2013 ? Antibiotic resistance is a global problem. The World Health Organisation (WHO) estimates that for tuberculosis alone multi-drug resistance accounts for more than 150,000 deaths each year. WHO warns of "a doomsday scenario of a world without antibiotics," in which antibiotic resistance will turn common infections into incurable killers and make routine surgeries a high-risk gamble.
Certain types of bacteria are a scourge of the hospital environment because they are extremely resistant to antibiotics and consequently difficult, if not impossible, to treat. This group of bacteria is classified as 'gram-negative' because their cells have a double membrane or outer layer, compared with gram-positive bacteria, which just have one outer layer.
Not only are these cells difficult to penetrate in the first instance, due to their double membrane, but they have effective 'pumps' which quickly reject anything that interferes with the activity of protein-building within the cell and the development of the protective cell wall.
This research, which was funded by the Wellcome Trust, gives for the first time a clear insight into how these protein components of the pump work together to transport an antibiotic from the cell.
Examples of gram-negative bacteria include those which cause food poisoning, meningitis, gonorrhoea and respiratory problems. Since the antibiotic is an interfering agent, many of these pathogenic bacteria use the membrane pumps to transport the medication out of the cell.
The pumps are made up of three different proteins within the cell that work together to bring about the movement. Research lead, Professor Adrian Walmsley from Durham University's School of Biological and Biomedical Sciences explained:
"Patients with bacterial infections are often treated with antibiotics, but since many strains are resistant to one or more of these drugs, clinicians often try to bring such infections under control by prescribing a combination of different types of antibiotics in the hope that they will override the resistance mechanisms. This sometimes works, but other times it does not. Pumps exacerbate this situation by reducing the effective concentration of the drug inside the cell. "
"By investigating how these pumps function, we have been able to identify the molecular events that are involved in binding and transporting an antibiotic from the cell. This advance in our understanding will ultimately aid the development of 'pump blockers'. This is important because these pumps often confer resistance to multiple, structurally unrelated, drugs; which means that they could also be resistant to new drugs which have never been used before."
Dr Vassiliy Bavro from the the Institute of Microbiology and Infection at the University of Birmingham said: "This study greatly expands our understanding of the mechanistic aspects of the pump function, and in particular challenges our previous concepts of energy requirements for pump assembly and cycling. By elucidating the intricate details of how these essential nanomachines come together, it also provides a new working model of their functional cycle in general, paving the way to development of novel approaches to disrupting their function."
Dr Ted Bianco, Acting Director of the Wellcome Trust, said: "A world without antibiotics is a world where simple surgery becomes a life-threatening procedure, where a scratch from a rose might prove fatal, and where diseases like tuberculosis return with a ferocity not seen in Britain since the Victorian era. This is why fundamental research to understand the mechanisms of antibiotic resistance is so important. Only when we know what we're up against can researchers begin to design new antibacterial agents to help us win the war against bacterial infections."
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Story Source:
The above story is reprinted from materials provided by Durham University.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Thamarai K. Janganan, Vassiliy N. Bavro, Li Zhang, Maria In?s Borges-Walmsley, Adrian R. Walmsley. Tripartite efflux pumps: energy is required for dissociation, but not assembly or opening of the outer membrane channel of the pump. Molecular Microbiology, 2013; 88 (3): 590 DOI: 10.1111/mmi.12211
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/9lrScfLULdA/130424222554.htm
taylor allderdice mixtape andrew bogut monta ellis wiz khalifa taylor allderdice mixtape reggie wayne taylor allderdice vincent jackson






Groupon’s VP of mobile, David Katz, says that it has been “business as usual” at the daily deals company since the dramatic departure of founder/CEO Andrew Mason. “We’re still just focused on shipping new stuff,” Katz told TechCrunch in an interview. Today, that includes news of updates to Groupon’s iPhone and Android apps: it is adding a universal search feature that will let consumers use the apps to search for Marketplace deals that are available nearby, covering not just local discounts that are time-sensitive but rolling offers that are not. The search feature lays the groundwork for a larger attack that publicly traded Groupon is making on mobile to stay competitive in location-based mobile services against the likes of Google, Yelp and Foursquare — with the latter just raising $41 million to position itself as a platform for local search, offering local deals as an added twist. On top of the new search updates, the Android app is now able to support tablets, the first time that it has been optimized for screens of up to 10 inches. With the search feature available now in the U.S., Groupon plans to turn the feature on across the rest of its mobile footprint this year, Katz says. And while the iPad app is not getting an update today, Groupon says that this week it is extending the number of countries where it will work. Belgium, Japan, Malaysia, South Africa and Switzerland are getting added, taking the total to 18 countries. That’s still a far cry from the 42 that Groupon supports with its iPhone app, but Katz says that they hope to reach parity “by the end of the year, if not sooner.” iOS usage, he says, “still dominates” on Groupon’s platform but the company’s move to roll out features like search internationally, into countries where Android is stronger than iOS, may see that balance changing, which is why it’s important for Groupon to not only keep updating that Android app but add tablet support as well. Groupon’s bid to “transition from being just daily deals into a more complete offering,” in Katz’s words, is so far showing some signs of paying off, with both mobile and non-time-specific Marketplace deals playing roles in that. About half of the company’s local transaction volume in North America is coming from its Deals Marketplace at the moment, and that deal bank (Groupon’s internal term for
Adobe has changed the way it sells technology used to enabled high-quality streaming services from TV networks and other video providers. With the launch of Adobe Primetime -- previously know as Project Primetime -- the technology company is providing a suite of tools for video delivery. And it's signed up a couple of big new clients for the suite of products.

