Rapid Pathogen Detection In A Box 6
DawnAlan writes: "The University of South Florida has developed (biosensor assays to detect pathogens in record time. The technology is a marriage of engineering and biology. The biosensor uses optical fibers and a laser to generate a signal for each sample tested. This signal indicates the presence or absence of biological agents." (Read more below.)
"Major applications include monitoring of pathogens for food safety in meat and beverage packaging facilities as well as surveillance for biological warefare agents (BWA) in the field for the protection of military personnel. In the wake of Desert Storm the Department of Defense has increased funding for research and education to prepare U.S. military personnel and civilians in the case of a bioterrorism event. The USF biosensor contributes to this effort."
Amen! (Score:1)
Is there any chance of this being used in general patient diagnosis eg. from blood samples? For example, if a determination can be made quickly as to what bacteria/virus a person is infected with, an appropriate treatment can be started sooner. I don't know if this is even relevant, but I am curious.
Re:The article didn't mention how it works! (Score:1)
IAA biologist. DNA probing, especially in whole bacteria, takes more than 20 minutes, and won't do what you're talking about. The only thing you could do is to have several strands that would indicate different bacteria and label them with different fluorescent dyes. This would be messy, especially in the field.
The boon for food safety is obvious, but the boon in removing the fangs of bio-warfare is just as great. If you can detect a spray of bugs on the battlefield or in the New York subway, identify them by species in 20 minutes and have a readout of their genetic modifications (antibiotic resistance genes, etc.) in another 20,
umm... no. sorry. not now, anyway. DNA sequencing is kind of a bitch. first, you have to get the DNA out of the bugs and then amplify it with PCR.
To do PCR, you have to cut up the DNA and put the pieces in a bacterial vector. (bacteria have a circular piece of DNA called a plasmid. You can stick a short [2500 bp] piece of your DNA into it). Now you can sequence the DNA. This is accomplished by separating the two strands and placing them in a reaction phial with all of the enzymes and the nucleotide triphosphates, as well as some that are altered in such a way that DNA polymerisation does not continue once one is attached. What ends up happening is that you get strands that are of all lengths. You also tag these altered nucleotides with a fluorescent dye so they show up differently on the gel.
The gel is the limiting factor. It takes a lot of space to resolve the different length strands, so you can only read about 300 bp per gel. If you need more than that, you have to do the whole process over again.
To sequence a bacterium will take a couple of weeks, using equipment that is most definately not portable.
A Welcome Device (Score:1)
Of course, it'll be nicer when a dozen years from now, every butcher shop in the country has one. I can hear Sam the Butcher offering to check the rib roast for Alice before he serves her up the meat! ;)
Of course it goes without saying that no amount of devices like this can replace throughly cooking and washing your food before you eat it. Don't use the same knife on the salad that you used to cut the chicken, etc.
Nice, but doesn't solve underlying problem. (Score:1)
However I think that in some ways it's solving the wrong problem.
Why should your food get contaminated (e.g. with E. Coli.) in the first place? To me it shows bad practices - handling etc.
For example,
1) in the US cattle are fed grain. Cows don't digest grain well - this gives them a more acidic stomach. This creates an environment where acid resistant bacteria can develop.
2) Cattle (and other animals) are slaughtered in a very messy way - entrails spilled everywhere, contaminating meat.
And then there's the British BSE thingy, scrapie (dunno why this is underplayed - maybe because they don't mince sheep into patties to feed humans), etc.
Various stuff like this create a high risk environment when it comes to having contaminated or unsafe food.
Having to have a sensor at the end of the chain just to detect whether it's safe or not doesn't sound like a good direction for the food industry to head in.
Same goes for that gamma irradiation scheme.
I'd call the end results fuel, not food. And I'd rather eat food, please.
I don't think we should look at food the way the food industry does currently.
Trouble is those that don't engage in such dubious stuff can't compete - it's not cheap to treat livestock and food with proper respect.
Cheerio,
Link.
The article didn't mention how it works! (Score:1)
If it can detect a few hundred organisms in 20 minutes, that is not enough time to grow them or do anything else that depends on reproducing them. The only other technology I'm aware of that could do that is the use of fluorescently-labelled DNA probes to detect the pathogen DNA directly. It seems likely, to me (IANAbiologist) anyway, that this could detect both bacteria and DNA-based viruses.
The boon for food safety is obvious, but the boon in removing the fangs of bio-warfare is just as great. If you can detect a spray of bugs on the battlefield or in the New York subway, identify them by species in 20 minutes and have a readout of their genetic modifications (antibiotic resistance genes, etc.) in another 20, you could be giving people treatment serum, vaccines or antibiotics before the first person falls ill. A bio-attack becomes a call for mobilizing the public health brigades for mass vaccinations, and few if any ever use a hospital bed. Death toll: close enough to zero to ignore. Saddam Hussein's bio-war labs become useless. I like this.
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Re:The article didn't mention how it works! (Score:1)