الله أكبر....ولله الحمد
لن أتكلم كثيرا .....أقرأوا
Humble fly may be super bug's match
The advertising jingle has Louie the fly singing "I'm bad and mean and mighty unclean".

Being dirty is hardly surprising, given where flies hang out. But what do flies have that stops them from being overrun by infections?

This thought occurred to PhD student Joanne Clarke and her colleagues at the Department of Biological Sciences at Macquarie University, as they discussed where the next generation of antibiotics might come from.

"Most antibiotics were originally isolated from bacteria," Clarke said. "But we've pretty much exhausted these."

As Clarke and her supervisors, Professor Andrew Beattie and Associate Professor Michael Gillings, said in Australasian Science magazine: "Microbes that produce an antibiotic may not be sensitive to that particular antibiotic, otherwise they would kill themselves.


"Consequently it seems likely that for every antibiotic produced [from bacteria], there is at least one natural mechanism of resistance."

And that's the big problem. Bacteria are increasingly resistant to the present range of antibiotics, the so-called "super bugs".

The idea of looking to insects for new ones is that the bacteria which cause us so many problems won't have the genes to resist them, yet.

Insects are a likely source of antimicrobials not only because of where they live, but how they live. For example, in the close confines of a hive, one sick individual could wipe out the entire colony if there wasn't some way of controlling the spread of disease.

Clarke studied insects from "pretty yucky" environments.

"I looked at the sheep blowfly, the common housefly and the vinegar fly," she said. "I used the Queensland fruit fly as a control because it lays its eggs in fresh fruit."

Clarke tested material extracted from the flies on four microbes: candida yeast, E.coli, golden staph and a common soil bacterium, all of which are known to cause infections in humans.

Clarke found that adults from each test species of fly produced something which prevented all the different microbes from growing.

"I also looked at the different life stages of the flies," she said. "I predicted there wouldn't be much expression of antibiotics in pupae because they have a protective casing - they're not feeding and don't come into contact with other flies - and, in general, that's what I found."

The logical next step would be to isolate and identify the chemicals in the fly extract. But, as is increasingly the case in science, the path is not going to be smooth.

"Although industry very generously funded my PhD project for three years, they chose not to renew the funding," Clarke said. "Unless someone else funds the research, it stops at this point."


This story was found at: http://www.smh.com.au/articles/2003...2591671953.html


============
The new buzz on antibiotics

The surface of flies is the last place you would expect to find antibiotics, yet that is exactly where a team of Australian researchers is concentrating their efforts.

Working on the theory that flies must have remarkable antimicrobial defences to survive rotting dung, meat and fruit, the team at the Department of Biological Sciences, Macquarie University, set out to identify those antibacterial properties manifesting at different stages of a fly’s development.

"Our research is a small part of a global research effort for new antibiotics, but we are looking where we believe no-one has looked before,” said Ms Joanne Clarke, who presented the group’s findings at the Australian Society for Microbiology Conference in Melbourne this week. The project is part of her PhD thesis.

The scientists tested four different species of fly: a house fly, a sheep blowfly, a vinegar fruit fly and the control, a Queensland fruit fly which lays its eggs in fresh fruit. These larvae do not need as much antibacterial compound because they do not come into contact with as much bacteria.

Flies go through the life stages of larvae and pupae before becoming adults. In the pupae stage, the fly is encased in a protective casing and does not feed. "We predicted they would not produce many antibiotics," said Ms Clarke.

They did not. However the larvae all showed antibacterial properties (except that of the Queensland fruit fly control).

As did all the adult fly species, including the Queensland fruit fly (which at this point requires antibacterial protection because it has contact with other flies and is mobile).

Such properties were present on the fly surface in all four species, although antibacterial properties occur in the gut as well. "You find activity in both places," said Ms Clarke.

"The reason we concentrated on the surface is because it is a simpler extraction.”

The antibiotic material is extracted by drowning the flies in ethanol, then running the mixture through a filter to obtain the crude extract.

When this was placed in a solution with various bacteria including E.coli, Golden Staph, Candida (a yeast) and a common hospital pathogen, antibiotic action was observed every time.

"We are now trying to identify the specific antibacterial compounds," said Ms Clarke. Ultimately these will be chemically synthesised.

Because the compounds are not from bacteria, any genes conferring resistance to them may not be as easily transferred into pathogens. It is hoped this new form of antibiotics will have a longer effective therapeutic life.

المصادر
http://www.abc.net.au/science/news/stories/s689400.htm
http://www.smh.com.au/cgi-bin/commo...2591671953.html


فليسمع الكفرة الذين يطعنون في الحديث ليل نهار
فليسمع الشيعة الذين يطعنون بأبي هريرة رضى الله عنه راوي الحديث...

و اظن أن الأبحاث مستمرة لكي يصلوا إلى معنى الحديث بالحرف...

والحمد لله الغرب الكفرة ينصرون ديننا وهم لا يدرون..

الله المستعان



منقول من منتدي بن مريم
http://www.ebnmaryam.com/vb/showthread.php?t=4190