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Pfizer takes its shot at a vaccine for evasive MRSA superbug

Kathrin Jansen is a microbiologist with at least two breakthrough vaccines to her name: she brought the cervical cancer vaccine Gardasil to market for Merck and helped develop the $4 billion a year pneumonia and meningitis vaccine Prevnar 13 for Pfizer. Jansen's next vaccine success could come by taming the superbug MRSA, a drug-resistant bacterium that she has seen ravage a healthy man up close and personally. Methicillin-resistant Staphylococcus aureus infects an estimated 53 million people globally and costs more than $20 billion a year to treat. In the United States alone, MRSA kills 20,000 Americans each year, exceeding annual deaths from AIDS. Jansen watched the infection unfold two years ago when visiting her stepfather, who was in the hospital for a hip replacement. The man in the bed next door died soon after MRSA attacked the vascular graft in his leg. “He went in healthy and died very quickly,” recalls Jansen, senior vice president of vaccine research and early development at Pfizer Inc, the world's largest drug maker. She says the experience steeled her resolve to develop an effective vaccine that could prevent such deaths. But Staphylococcus aureus has proven a tenacious adversary. In the past decade, vaccine candidates by Nabi Biopharmaceuticals and Merck & Co Inc failed in costly, late-stage clinical trials. Now, led by Jansen, Pfizer is taking a shot. Competitors, including vaccine giants GlaxoSmithKline, Novartis and Sanofi, are, too. And while the race could lead to a viable vaccine, potentially worth billions in sales, critics say companies may be risking costly failure with so much work on a bacterium that is still barely understood. 'Bag of trouble' Staph has been living in and on its human hosts for centuries. At any given time, 25 to 35 percent of individuals will test positive for staph, often with no symptoms. But the bacterium can cause a range of diseases from boils and impetigo to raging blood infections and deadly bacterial pneumonia. The discovery of penicillin in 1928 gave doctors a way to defeat staph infections, but overuse and misuse gave rise to drug-resistant staph. Methicillin was developed to overcome drug-resistance, but by the 1960s, staph evolved new defenses to overcome this more powerful version of penicillin. Thus began the decades-long battle against methicillin-resistant staph, now the most common cause of hospital-acquired infections that is increasingly spreading into army barracks, prisons and daycare centers. Dr. Bill Gruber, a Pfizer senior vice president who led clinical trials for Prevnar 13 and is running the company's Staph aureus trials, thinks of the bacterium as “a little bag of trouble.” “Basically, it has a number of different toxins and defenses to try to defeat you.” That may explain why vaccines from Nabi and Merck failed. Both tried to defeat this bug by attacking on just one front. The vaccine by Nabi, now Biota Pharmaceuticals, focused only on the sugar capsule the bacteria make to hide from the immune system, while Merck's focused on a single protein that helps staph gets its nutrition. Neither lived up to expectations. “We've learned that just focusing on one target of Staph aureus might not be sufficient,” said Dr. Buddy Creech, an infectious diseases expert at Vanderbilt University. It takes stamina Jansen has been working on a Staph aureus vaccine for the past decade, first at Merck, then at Wyeth, and now at Pfizer. The East German-born scientist - who fled to the West in 1960 and earned her PhD in biology at Philipps University in Marburg - says it takes stamina to develop a successful vaccine, a process that can take 15 years or more. With the cervical cancer vaccine Gardasil, which had 2012 sales of $1.6 billion, it took 14 years from lab bench to government approval. “That's actually a fast development program,” she said. With Staph aureus, it took eight years from the first experiments to human safety trials. Now, it could take another seven to 10 years to wind up clinical trials, putting the team about midway through the process. Pfizer's initial vaccine targeted three mechanisms key to staph's survival and ability to cause disease. Two of those focused on sugar capsules. The third attacks a mechanism called “clumping factor,” which allows bacteria to stick to proteins when they enter the body. But Jansen's team wanted one more point of attack. They added a fourth antigen, a protein that allows the bacterium to steal manganese - a key nutrient - from host cells. The result is a four-antigen vaccine that generates antibody responses at distinct points of the life cycle of the bug. The company is testing this in Phase 1/Phase 2 trials in healthy adults in the United States. If Pfizer gets the results they hope for, likely later this year, the company expects to meet with regulators to iron out a plan for larger trials involving thousands of individuals. Initially, the vaccine would be aimed at preventing infections in millions of people globally who need elective procedures such as a hip replacement. Ultimately, it could be used to protect people at risk in the broader community. Rival vaccines Pfizer is furthest along, but the large, untapped market, estimated to be worth $3 billion to $4 billion a year, has drawn interest from several companies. GlaxoSmithKline has been quiet about its approach. The drugmaker had been partnering with Nabi's failed StaphVax candidate, and in 2009 bought another Nabi candidate called PentaStaph for $46 million. Company researchers declined to discuss their program, but Glaxo spokeswoman Melinda Stubbee confirmed the company has a four-component vaccine in Phase 1 development. “We are still evaluating the data and haven't yet announced plans to present the data or to pursue further development,” she said. NovaDigm Therapeutics, a private company based in Grand Forks, North Dakota, is developing a single-antigen vaccine that targets both staph and yeast infections caused by the fungus Candida. Other rivals with early-stage programs include Novartis, which has a vaccine in Phase 1 trials, and Sanofi, which is partnering with privately held biotech Syntiron. Although academic researchers applaud these efforts, they say companies may be rushing into trials too soon, especially when so much is unknown about how staph interacts with people. “Our development of Staphylococcal vaccines has predated an adequate understanding of the human response to infection,” Creech said. For instance, it is still not clear whether a Staph aureus vaccine that protects against skin infections will also protect individuals from bloodstream infections. It may be that instead of preventing infection, some vaccines will merely blunt infection. Dr. Robert Daum, who leads the MRSA Research Center at the University of Chicago Medical Center, doubts any of the current candidates will make it into widespread use. “I am convinced we need a vaccine. I'm just not sure anyone knows how to make one yet.” Jansen, who knows Daum, said she understands his skepticism. “I'm a microbiologist. I know bacteria pretty well. They are very potent adversaries.” She says there's a reason the company was not the first out of the gate. “We wanted to make sure that we looked under all the rocks and found what we needed to find.” Tests in animals and people suggest the vaccine induces production of antibodies that defeat staph's defenses and kill the bacteria. “To our knowledge, we are the only ones who have demonstrated very, very robust killing responses.” That was enough for Jansen. “We essentially said, 'That's it. We put it together as best as we know how. Now is the time to test it.'”source : http://www.foxnews.com/health/2013/05/23/pfizer-takes-its-shot-at-vaccine-for-evasive-mrsa-superbug/

Dogs bring swarm of bacteria into your home

Your loyal pooch may be bringing a whole world of bacteria into your home but don't panic. Research suggests that exposure to a wide variety of microbes may be good for us. A new study reveals that homes with dogs have greater bacterial diversity than canine-free dwellings. Dog-related diversity is particularly high on television screens and pillowcases, the researchers found. “When you bring a dog into your house, you are not just bringing a dog, you are also introducing a suite of dog-associated [microbe] taxa directly into your home environment, some of which may have direct or indirect effects on human health,” the researchers wrote today (May 22) in the journal PLOS ONE. [5 Wacky Things That Are Good For You] Microbes around us The microbes in our environment are the subject of increased interest by scientists, thanks to studies revealing how intertwined human lives are with those of the single-celled. Skin microbes, for example, may be key for warding off disease. And the load of microbes living in the human gut may influence everything from immunity to obesity. North Carolina State University biologist Rob Dunn and his colleagues wanted to step back from the body to better understand the microbes in our environment at large. They gave 40 families a home-sampling kit and asked them to swab down nine locations in their houses: a kitchen cutting board, a kitchen counter, a refrigerator shelf, a toilet seat, a pillowcase, a television screen, the main door's exterior handle and the upper trim on both an interior door and on an exterior door. The researchers then examined the microbial DNA from the swabs to detect different families of microscopic tenants living on these surfaces. All told, the 40 homes harbored 7,726 different types of bacteria. The most common were Proteobacteria, Firmicutes and Actinobacteria, all families containing a wide range of species. Types of bacteria tended to differ by location: Kitchen environments (cutting boards, counters and shelves) had similar colonies from home to home, as did frequently touched surfaces (toilet seats, pillowcases, door handles) and rarely cleaned surfaces (door trims and television screens). “This makes sense,” Dunn said in a statement. “Humans have been living in houses for thousands of years, which is sufficient time for organisms to adapt to living in particular parts of houses. We know, for example, that there is a species that only lives in hot-water heaters. We deposit these bacterial hitchhikers in different ways in different places, and they thrive or fail depending on their adaptations.” Bacteria related to human skin were found most frequently on pillowcases and toilet seats as were bacteria commonly found in human feces. Bacteria from leaves and produce were found most often on door trims and also on kitchen surfaces. Bacteria from the soil were found across the home, but were most common on the exterior door trim, the researchers found. Doggie diversity Dunn and his colleagues next looked for variables that would alter bacterial communities from home to home, such as the presence of cats, children, carpet and other factors. The only one they found that made any difference was whether or not the family had a pet dog. Pillowcases and TV screens of dog-owning families had 42 percent and 52 percent more microbial groups, respectively, than pillowcases and TV screens of non-dog-owning families. This extra diversity, unsurprisingly, was made up largely of bacteria known to live on dog fur. (Other factors, such as the level of humidity in a home, could also influence microbe diversity, the researchers wrote, but they were unable to measure those factors in this study.) Dog owners shouldn't ship Fido off to the countryside for fear of nasty bacteria, though. In fact, the family pet may be a boon to health. Previous studies have found that pregnant women who live in homes with dogs are less likely to have children with allergies. Scientists speculate that the reason might be an exposure to greater numbers of microbes that keeps the immune system from turning on the body. “Our study provides evidence to robustly support this assumption,” Dunn and his colleagues wrote. The researchers are planning to process samples from a total of 1,300 homes across the United States to look for geographic differences in microbial roommates. Copyright 2013 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.source : http://www.foxnews.com/health/2013/05/23/dogs-bring-swarm-bacteria-into-your-home/

Feet contain most fungi on body, new research shows

A new map of the fungal species lurking on human skin reveals the most diverse communities can be found on — you guessed it — the bottom of the feet. Genetic sequencing found the fungal genus Malassezia dominated on most of the core body regions and arms. The heel, toenail and toe web (skin between the toes), by contrast, supported highly varied fungal communities. Imbalances in these populations may lead to athlete's foot and other fungal diseases, the researchers say. The skin serves as a barrier to pathogenic microorganisms, but is also home to a rich array of harmless microbes. Until now, most efforts to study the skin's microorganisms have focused on bacterial species, but fungi (which are a distinct biological group) form a significant part of these skin communities. Feet love fungi In the study, scientists took skin scrapings from 10 healthy adults at 14 different sites on the body. They sequenced the DNA from the swabs. In addition, the researchers isolated more than 130 fungal strains from the genera Malassezia, Penicillium and Aspergillus, and grew them in the lab.   The genus Malassezia, which may cause dandruff, was the most abundant type of fungus at all 11 core-body and arm sites, results showed. These areas included the inner elbow, palm, space between the eyebrows, back of the head, nostril and forearm, among other spots. Core-body sites, such as the chest and abdomen, had the fewest types of fungi, ranging from two to 10 genera. The three foot sites — heel, toenail and toe web — contained much greater fungal diversity, with populations of Malassezia¸ Aspergillus, Cryptococcus, Rhodotorula and Epicoccum, among others. Overall, the heel had the most diverse fungal makeup, with about 80 fungal genera. One study participant had an especially diverse array of fungi. This person had taken a course of oral antifungal medication for a toenail infection seven months prior to the study. The unusual fungal diversity suggests that either an imbalance in the fungal community was causing the stubborn toenail infections, or that changes in the microbe composition due to the medication continued even seven months after stopping treatment, the researchers say. The results demonstrate that human skin is capable of harboring a highly varied fungal population. When fungi go awry The researchers also sequenced bacteria on the skin. The results confirmed previous findings for skin bacterial makeup in healthy people. In contrast to fungal populations, the most diverse bacterial populations were found on the arms. The person with abnormal fungal diversity appeared to have a normal distribution of bacteria. The study of the skin's native fungi has important implications for infection and disease. About 20 percent of the study participants showed signs of possible foot fungal infections, and previous studies have shown up to 60 percent of healthy people may harbor such infections. Fungal infections affect 29 million North Americans. Several factors influence the prevalence of fungal infections, including population and climate. Antifungal medications can have dangerous side effects, and new treatments that target fungal imbalances are needed, the researchers say. The findings were reported online May 22 in the journal Nature.  source : http://www.foxnews.com/health/2013/05/22/feet-contain-most-fungus/

What do we eat? New food map will tell us

Do your kids love chocolate milk? It may have more calories on average than you thought. Same goes for soda. Until now, the only way to find out what people in the United States eat and how many calories they consume has been government data, which can lag behind the rapidly expanding and changing food marketplace. Researchers from the University of North Carolina at Chapel Hill are trying to change that by creating a gargantuan map of what foods Americans are buying and eating. Part of the uniqueness of the database is its ability to sort one product into what it really is - thousands of brands and variations. Take the chocolate milk. The government long has long classified chocolate milk with 2 percent fat as one item. But the UNC researchers, using scanner data from grocery stores and other commercial data, found thousands of different brands and variations of 2 percent chocolate milk and averaged them out. The results show that chocolate milk has about 11 calories per cup more than the government thought. The researchers led by professor Barry Popkin at the UNC School of Public Health, are figuring out that chocolate milk equation over and over, with every single item in the grocery store. It's a massive project that could be the first evidence of how rapidly the marketplace is changing, and the best data yet on what exact ingredients and nutrients people are consuming. That kind of information could be used to better target nutritional guidelines, push companies to cut down on certain ingredients and even help with disease research. Just call it “mapping the food genome.” “The country needs something like this, given all of the questions about our food supply,” says Popkin, the head of the UNC Food Research Program. “We're interested in improving the public's health and it really takes this kind of knowledge.” The project first came together in 2010 after a group of 16 major food companies pledged, as part of first lady Michelle Obama's campaign to combat obesity, to reduce the calories they sell to the public by 1.5 trillion. The Robert Wood Johnson Foundation agreed to fund a study to hold the companies accountable, eventually turning to UNC with grants totaling $6.7 million. Aided by supercomputers on campus, Popkin and his team have taken existing commercial databases of food items in stores and people's homes, including the store-based scanner data of 600,000 different foods, and matched that information with the nutrition facts panels on the back of packages and government data on individuals' dietary intake. The result is an enormous database that has taken almost three years so far to construct and includes more detail than researchers have ever had on grocery store items - their individual nutritional content, who is buying them and their part in consumers' diets. The study will fill gaps in current data about the choices available to consumers and whether they are healthy, says Susan Krebs-Smith, who researches diet and other risk factors related to cancer at the National Cancer Institute. Government data, long the only source of information about American eating habits, can have a lag of several years and neglect entire categories of new types of products - Greek yogurt or energy drinks, for example. With those significant gaps, the government information fails to account for the rapid change now seen in the marketplace. Now more than ever, companies are reformulating products on the fly as they try to make them healthier or better tasting. While consumers may not notice changes in the ingredient panel on the back of the package, the UNC study will pick up small variations in individual items and also begin to be able to tell how much the marketplace as a whole is evolving. “When we are done we will probably see 20 percent change in the food supply in a year,” Popkin says. “The food supply is changing and no one really knows how.” For example, the researchers have found that there has been an increase in using fruit concentrate as a sweetener in foods and beverages because of a propensity toward natural foods, even though it isn't necessarily healthier than other sugars. While the soda and chocolate milk have more calories on average than the government thought, the federal numbers were more accurate on the calories in milk and cereals. Popkin and his researchers are hoping their project will only be the beginning of a map that consumers, companies, researchers and even the government can use, breaking the data down to find out who is eating what and where they shop. Is there a racial divide in the brand of potato chips purchased, for example, and what could that mean for health? Does diet depend on where you buy your food - the grocery store or the convenience store…