Reprogrammed bacteria able to detect cancer

Bacteria to detect cancer

Reprogramming bacteria to detect cancer

The fight against cancer has risen to a fever pitch in the last decade, with new research avenues increasing almost by the day. If we are to believe Ray Kurzweil and the singularity folk, the specter of cancer may soon be a thing of the past. Lending credence to such optimism, new research by a team at MIT and UC San Diego employs genetically engineered bacteria to detect cancer, and perhaps someday treat it as well. Enlisting the help of bacteria in the battle against cancer may prove key in turning the tables on this awful menace.

The basis for this new form of cancer diagnosis is the unusual relationship between cancer and bacteria. Whereas healthy human tissue will aggressively fight off most bacterial infestations, the immune system within tumors has been compromised by the many mutations taking place there, and so bacteria accumulate in them at a higher-than-normal rate. The researchers exploited this characteristic to devise a means of detecting tumors long before other methods could catch them.

By removing a snippet of DNA programming found in fireflies and transferring it to a harmless form of E. Coli bacteria, the researchers were able to cause these bacteria to fluoresce at the critical concentrations that occur within tumors. The analogy would be to that of creating a flashlight that automatically turns on when it finds a tumor. The ability to detect tumors as small as one cubic millimeter makes this one of the most sensitive diagnostic tools to date. In treating cancer, early detection is pivotal, since the sooner a tumor is detected, the easier it is to contain and eliminate.

But before letting out a collective sigh of relief, it should be kept in mind that this method has only been successfully applied to liver cancers. Early on in the study, the researchers realized the orally ingested bacteria would not reach sufficient concentrations throughout the whole body to successfully detect all tumors therein. For instance, the blood brain barrier prevents the bacteria from entering the human brain as would be necessary for this method to detect brain tumors. The liver, however, proved an exception, in that the E. Coli bacteria in question naturally occurs there and would multiply rapidly in the presence of a tumor.

Despite its limitations, this is nonetheless a significant development. Many tumors that begin in the colon quickly spread to the liver, where they prove difficult to detect and go on to infect other parts of the body. Therefore, catching liver cancer early can play a key role in preventing cancers in many other place of the body.

The scientists involved in the study, including Tal Danino and Arthur Prindle, are now hopeful that the same bacteria can be programmed to fight cancer as well. The goal is to engineer the bacteria to cause genetic disruption of cancer cell function, deliver drugs, or signal the immune system to destroy the cancer itself. In the future, the cup of yogurt you have in the morning may not only improve digestive health, but simultaneously track down and eliminate cancers growing within the body.

 

Source:  extremetech.com

 

Bacteria exploit proteins to trigger potentially lethal infections

New research by scientists at the University of York sheds light on how bacteria exploit human proteins during infections:

bacteria exploit proteins

bacteria exploit proteins

 

 

A research team led by Professor Jennifer Potts, a British Heart Foundation Senior Research Fellow in York’s Department of Biology, studied how Staphylococcus aureus, which can cause life-threatening human infections, attach to two proteins fibronectin and fibrinogen found in human blood.

The human proteins play important roles in clot formation and wound healing and the bacteria appear to exploit them during the process of infection. Scientists had earlier shown that the binding sites for fibrinogen and fibronectin on the S. aureus protein FnBPA appear to “co-operate” in causing the dangerous heart infection infective endocarditis and the latest research suggest how the process occurs. The researchers, who included Vaclav Stemberk and Dr Richard Jones at York and Dr Ruth Massey, a microbiologist at the University of Bath, used X-ray crystallography, biophysical techniques and bacterial assays to investigate the process.

In research published in the Journal of Biological Chemistry, they solved the three dimensional structure of the bacterial protein FnBPA in complex with a small part of the human protein fibrinogen. This work showed that the fibrinogen binding site on FnBPA is close to, but not overlapping with, the binding site for fibronectin.

They then studied the binding of the two human proteins simultaneously to FnBPA and found that binding of fibronectin appears to block binding of fibrinogen to the bacterial protein. It appears that regulation of binding arises due to the close proximity of the fibrinogen and fibronectin binding sites on the bacterial protein and the large size of the human proteins. While the research provides the first biophysical evidence in support of the co-operation previously observed in the infection studies, it is still not clear how these two observations are linked. The scientists are planning further studies.

Professor Potts said: “Bacteria have evolved various mechanisms to exploit human proteins to cause infection. Understanding these mechanisms might not only lead to the development of new therapeutics but can also provide important information regarding the normal role of these human proteins in the body.”

Dr Sanjay Thakrar, Research Advisor at the British Heart Foundation, which co-funded the study, said: “The bacteria studied can cause a wide range of infections including the potentially fatal heart infection known as infective endocarditis.

“This study showed how this bacterium interacts with proteins found in our blood, which may give us an insight into how these deadly heart infections occur. This is an important step towards developing new treatments, but more research is needed to fully understand this interaction.”

 

Source:   eurekalert.org

Diet Quickly Alters Gut Bacteria

A New Diet Quickly Alters Gut Bacteria:

 

A New Diet Quickly Alters Gut Bacteria

A New Diet Quickly Alters Gut BacteriaGut clock regulates when we’re hungry

 

The types of bacteria in your gut today may be different tomorrow, depending on what kinds of food you eat, a new study suggests.

In the study, participants who switched from their normal diet to eating only animal products, including meat, cheese and eggs, saw their gut bacteria change rapidly — within one day.

While the participants were on the animal-based diet, there was an increase within their guts in the types of bacteria that can tolerate bile (a fluid produced by the liver that helps break down fat), and a decrease in bacteria called Firmicutes, which break down plant carbohydrates.

 

Gut bacteria also tended to express (or “turn on”) different genes during the animal-based diet, ones that would allow them to break down protein. In contrast, the gut bacteria of another group of participants who ate a plant-based diet expressed genes that would allow them to ferment carbohydrates.

The differences between the gut bacteria of the people on the plant-only and animal-only diets “mirrored the differences between herbivorous and carnivorous mammals,” the researchers wrote in the study published today (Dec. 11) in the journal Nature.

Researchers knew that a person’s diet affects his or her gut bacteria, but it wasn’t clear just how quickly this happens.

The researchers said they were surprised by their results. “We weren’t at all sure it was going to happen this quickly in humans,” said study researcher Lawrence David, an assistant professor at Duke University’s Institute for Genome Sciences and Policy.

The findings suggest “the choices that people make on relatively short time scales … could be affecting the massive bacterial communities that live inside of us,” David said.

The study also adds evidence to the idea that human diets — acting through the gut bacteria — influence the risk of certain diseases. People on the animal-based diet had higher levels of a bacterium called Bilophila wadsworthia, which grows in response to bile acids and has been linked with inflammatory bowel disease in mice, according to the study.

This finding supports a link between dietary fat (from animal fat), bile acids and an increase in growth of microbes that may affect the risk of inflammatory bowel disease, the researchers said.

People who ate the plant-based diet saw fewer changes in the abundance of bacterial species in their gut than people who ate the animal-based diet. This may have, in part, been due to the fact that humans produce bile acids in response to eating animal products, and bile acids, in turn, influence bacterial growth, according to the researchers.

The study included 10 people (six men and four women) ages 21 to 33. One of the participants was a lifelong vegetarian who switched to eating only animal products, such as eggs and cheese (but not meat), for the study. Participants stuck to their diet for five days, and gave stool samples each day for analysis.

While previous studies have looked at changes in gut bacteria in response to diet, most of these collected samples on a weekly or monthly basis, because it is difficult to recruit volunteers willing to give samples daily, David said.

Because the study was small, the researchers are cautious about generalizing their results to the population as a whole. But “the changes we saw appeared to be uniform across these subjects, suggesting that if we were to recruit more people, we would see similar results,” David said.

The study was a collaboration between researchers at Duke, Harvard University, Boston Children’s Hospital and the University of California, San Francisco.

Researchers Discover Bacteria Produces Pure Gold

Researchers Discover Bacteria That Produces Pure Gold:

Researchers Discover Bacteria That Produces Pure Gold

Researchers Discover Bacteria That Produces Pure Gold

Gold was produced by a bacteria that, according to researchers at Michigan State University, can survive in extreme toxic environments and create 24-karat gold nuggets. Pure gold. Maybe this critter can save us all from the global economic crisis? Of course not—but at least it can make Kazem Kashefi—assistant professor of microbiology and molecular genetics—and Adam Brown—associate professor of electronic art and intermedia—a bit rich, if only for the show they have put together. Kashefi and Brown are the ones who have created this compact laboratory that uses the bacteria Cupriavidus metallidurans to turn gold chlroride—a toxic chemical liquid you can find in nature—into 99.9% pure gold. Accoding to Kashefi, they are doing “microbial alchemy” by “something that has no value into a solid [in fact, it the toxic material they use does cost money. Less than gold, but still plenty], precious metal that’s valuable.” The bacteria is incredibly resistant to this toxic element. In fact, it’s 25 times stronger than previously thought. The researchers’ compact factory—which they named The Great Work of the Metal Lover—holds the bacteria as they feed it the gold chloride. In about a week, the bacteria does its job, processing all that junk into the precious metal—a process they believe happens regularly in nature. So yes, basically, Cupriavidus metallidurans can eat toxins and poop out gold nuggets. It seems that medieval alchemists were looking for the Philosopher’s Stone—the magic element that could turn lead to gold—in the wrong place. It’s not a mineral. It’s a bug.