Eating red meat could make your body more vulnerable to a dangerous bacterial toxin, according to a new study. A sugar molecule, Neu5Gc, found in beef, lamb, pork, and unpasteurized milk can attach itself to the cells lining the human intestines and act as a magnet for toxins produced by certain strains of E. coli, often carried in the same meats. The result is bloody diarrhea and sometimes death. “This uncovered the first example of bacterium causing disease in humans by targeting a molecule which is incorporated into our bodies through what we eat,” [ABC Science] says researcher Travis Beddoe.
The study, published in Nature [subscription required], was conducted in petri dishes using mouse tissues and human cells. The scientists tested human gut and kidney cells steeped in these sugar molecules and discovered that the toxin was about seven times more likely to bind to these cells if the sugar was present. It is still “not clear how to extrapolate this precisely to the human body,” [Science News] says co-author Ajit Varki. That is, researchers don’t know exactly what it means for human health yet. (more…)
A “sustainable chemical” company called Genomatica has developed a way to use sugar and genetically engineered bacteria to produce a common industrial chemical that’s usually produced using petroleum, and which is found in everything from Spandex to car bumpers. By using sugar from sugar cane as a feedstock, industrial chemical companies can get a cheaper alternative to petroleum-derived chemicals, while investing in processes that are less polluting and nontoxic, said Genomatica CEO Chris Gann [CNET].
Genomatica produces the chemical, 1,4-butanediol (BDO), by feeding pure glucose derived from sugarcane to E. coli bacteria, which has been engineered to produce BDO. “We have engineered the organism such that it has to secrete that product in order for it to grow,” says [company president] Christophe Schilling…. “The interests of the organism are aligned with our interests: It grows faster when it produces more” [Scientific American].
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Villagers living deep in the Guyanese rain forest have developed resistance to an antibiotic they’ve never taken, and a malaria drug may be to blame. Researchers say the malaria drug is chemically similar to a type of widely used antibiotic, and they believe that the E. coli bacteria in the villagers’ guts evolved a broad resistance to both medications.
Antibiotic resistance is a major problem in Western countries, where strains of disease-causing bacteria such as Staphylococcus have adapted to beat some of the most commonly-used drugs. However, for a resistant strain to develop, bacteria usually need to be exposed to the drug involved [BBC News]. In this case, researchers say that a cheap malaria medication called chloroquine is similar enough to the antibiotic ciprofloxacin to allow the E. coli to develop defenses to the unknown drug.
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