#Food safety Returns To Nature (ISNS) Outbreaks of foodborne diseases carried by bacteria can be a nuisance at best and deadly at worst.
Bacteriophages are viruses that specifically attack bacteria. These phages as researchers call them have evolved alongside bacteria
and become very good at what they do. Scientists are interested most in lytic phages viruses that inject their DNA into a bacterium
and then hijack the cell s machinery to make new copies of the virus. The copies eventually burst through bacterium s membrane killing it
and attack neighboring cells. Recently a team of researchers at Purdue University in West Lafayette Indiana developed a cocktail of different phages that was extremely effective against Escherichia coli o157:
H7 the pathogen that was estimated to have caused more than 63000 illnesses and 2138 hospitalizations between 2000 and 2008 in the U s. The researchers mixed a cocktail of three phages
They found that the combination eliminated over 99%of E coli O157: H7 on spinach stored at room temperature.
One product called Listshield sold by Intralytix controls Listeria monocytogenes and can be applied directly to poultry meat.#
they only target bacteria. It s highly unlikely that they will ever evolve to cause diseases for humans or animals.
The bacteria on the other hand are highly virulent.##oe Phages are not human pathogens. The bacteria are the human pathogens#said Paul Ebner a professor of animal sciences at Purdue
and the lead author of the E coli study. Sulakvelidze added that phage bio-control products are an alternative to chemical washes
and irradiation two mechanisms commonly used to kill bacteria in ready-to-eat food products. Phages are much more specific usually one phage targets only one species of bacteria.
They kill the pathogenic bad#bacteria while leaving the naturally occurring good#bacteria intact making a more nutritious product.
Researchers are also looking into ways to treat bacterial infections in livestock using phages but Sulakvelidze said that results from these tests are inconclusive so far.
However if phages prove successful in this way it would greatly reduce the need for antibiotics in livestock
and potentially eliminate the need to treat food products with phages. Naturally there is also a push to find a use for phages in humans.
Antibiotic resistance in bacteria is a crisis. According to the Centers for Disease Control and Prevention each year in the United states at least two million people become infected with bacteria that are resistant to antibiotics
and at least 23000 people die each year as a direct result of these infections.##Phages are a hopeful alternative.
Phage therapy was the big thing in the 19 20s and 30s#said Jason Gill a microbiologist at Texas A&m University in College Station who was involved not in the study.
But now that many bacteria are resistant to one or more antibiotics phages are making a comeback.
Bacteria can become resistant to phages as well. But one type of bacteria usually only develops resistance to one or two types of phages
which is why researchers use a cocktail. The probability that one type of bacteria can become resistant to multiple phages at once is extremely low according to both Gill and Ebner.
But numerous obstacles obstruct the path to phage therapy in humans in the U s. Regulations make phages difficult to patent.
or destroy the bacteria the fastest#said Ebner. Hope still abounds for phages though.##oethey re the most abundant organism you can find in nature.
Instead makers likely fermented this cheese using microbes such as Lactobacillus and Saccharomycetaceae yeasts which are used commonly to make the still-popular fermented dairy beverage known as kefir.
and found that the chemical and bacterial composition matched the snacks buried with the mummies.
I remember thinking that bacteria was a bad word. It represented something that should be avoided at all costs.
In fact our intestines have more than 500 types of bacteria. Some are beneficial and some are not.
Our diet and lifestyle can help to keep the balance of good and bad bacteria in check.
One way to do this is to consume beneficial bacteria also known as probiotics. The World health organization defines probiotics as live microorganisms which
For example some research shows that two common types of beneficial bacteria Lactobacilli and Bifidobacteria may regulate cancer growth
Here are three ways to increase your body's beneficial bacteria-load naturally. 1. Eat more yogurt.
You may be wondering how beneficial bacteria can survive in your body. How do these microorganisms eat?
whether you feed the good bacteria or the bad ones. Beneficial bacteria thrive on things like fiber
while harmful bacteria thrive on sugars and alcohols. So consume more fiber-packed foods such as leafy greens oatmeal and whole grains.
Healthy Bites appears weekly on Live Science. Deborah Herlax Enos is certified a nutritionist and a health coach
when there are research companies around the world spending millions to create products containing patented strains of probiotic bacteria for targeting specific ailments.
But it was reported recently that probiotic bacteria found in common fermented foods such as yogurt can reach the gut in high numbers increasing the likelihood of beneficial effects from consuming these foods.
Although all this doesn t prove that probiotics confer a health benefit the study authors speculate that probiotic bacteria
This helps prevent bacteria from building up. According to Dr. Margaret Culotta-Norton a dentist in Washington D c. and former president of the D c. Dental Society this also helps babies become used to having something in their mouths
Methane-producing bacteria in wetlands thrive when there's more water. Greenhouse Gases: The Biggest Emitters (Infographic) One mystery in the global methane record is why Asia's strong economic growth
One study by researchers at University of California Berkeley found that anarcardic acid is effective at killing the bacteria that causes acne as well as that which causes tooth decay and the erosion of tooth enamel.
A search of plant genome databases found them to contain no genes comparable to those of certain bacteria known to make the gas.
Those bacteria are needed to break down grass and other delicacies in her fibrous diet but could also pose an infection risk.
Insects can become resistant to individual insecticides in much the same way as bacteria develop resistance to antibiotics.
One of the most common'pyramided'crops on the market is cotton that produces two different'Bt'toxins made naturally by the bacterium Bacillus thuringensis.
Proprietary bacteria then ingest the gases and produce ethanol says chief marketing officer Wesley Bolsen.
and gasoline-producing bacterial reactors to new methods for making light-emitting diodes and synthetic enzymes for capturing carbon dioxide from industrial emissions.
Research has shown how dirty piglets obtain'friendly'bacteria that help them to develop healthy immune systems later in life.
They also indicate that manipulating gut bacteria early in life might reduce allergies and other autoimmune diseases, says Denise Kelly, a gut immunologist at the University of Aberdeen, UK and one of the study's authors.
The study found that 90%of bacteria in the guts of the outdoor piglets came from the phylum Firmicutes.
Most of these were known lactobacillaceae for their health-promoting effects, and for their ability to limit intestinal pathogens such as Escherichia coli and Salmonella.
In contrast, the Firmicutes bacteria made up less than 70%and just more than 50%of the gut flora in indoor and isolated bred pigs respectively.
The pigs also had much smaller proportions of bacteria from the lactobacillaceae family. The team also found that the differences in gut microbial communities affected the expression of genes associated with the piglets'immune system.
Animals raised in the isolated environment expressed more genes involved in inflammatory immune responses and cholesterol synthesis,
according to research showing that dirty piglets pick up'friendly'bacteria that help them to develop robust immune systems later in life.
The study found that 90%of bacteria in the guts of the outdoor piglets came from the phylum Firmicutes.
Most of these were Lactobacillaceae, a family of bacteria known for their ability to limit intestinal pathogens such as Escherichia coli and Salmonella species. By contrast,
Firmicutes made up less than 70%of the gut flora in indoor pigs and slightly more than 50%of that in isolated pigs.
Pigs from these cleaner environments also had much smaller proportions of bacteria from the Lactobacillaceae.
patients with Crohn's also have reduced overall bacterial diversity, similar to the outdoor pigs, suggesting that the results might not extrapolate directly to human disease.
researchers have engineered a bacterium that can convert a form of raw plant biomass directly into clean, road-ready diesel.
a modified Escherichia coli bacterium that can make biodiesel directly from sugars or hemicellulose, a component of plant fibre (see page 559).
and then short-circuited E coli's internal machinery for producing large fatty-acid molecules, enabling them to convert precursor molecules directly into fuels and other chemicals.
The team then inserted genes from other bacteria to produce enzymes able to break down hemicellulose.
such as analysis tracing mailed Bacillus anthracis spores back to a single-spore batch in Ivins's lab at the US ARMY Medical Research Institute of Infectious diseases in Fort Detrick, Maryland.
The crop carries a gene from the bacterium Bacillus thuringiensis (Bt), and was developed by Mahyco-Monsanto Biotech, a joint venture between the Jalna-based Maharashtra Hybrid Seed Company and the US seed giant Monsanto,
Environmental groups and some countries have had longstanding concerns about the risk of genes spreading from crops to bacteria and increasing bacterial antibiotic resistance.
and concluded that the risk of transfer of antibiotic resistance from plants to bacteria was remote,
and that bacteria resistant to the antibiotics were already present in soil, animals and humans.
Q fever, caused by Coxiella burnetii bacteria, is harboured in mammals, birds and even insects. It can trigger abortions in goats and sheep and causes flu-like symptoms and sometimes pneumonia in humans.
cut down on the amount of bacteria in the goats'milk and afterbirth during lambing season the following year1.
whether one fast-spreading strain of the bacteria is causing human cases of the disease.
The french agricultural research institute, will start by looking at how the bacteria spreads in mice.
from understanding how the bacteria are distributed at such a large scale to correlating measurements of BACTERIAL DNA levels in bulk milk tank samples with infection rates.
Soil bacteria could yield drug to treat roundworm: Nature Newsa bacterial protein used in a common pesticide kills intestinal parasitic roundworms in mice
The new approach, published today in PLOS Neglected Tropical Diseases1, uses crystal proteins from the soil bacterium Bacillus thuringiensis (Bt.
This bacterium is a natural soil predator of nematodes, says author Raffi Aroian from the University of California,
San diego. The bacterium can kill the worm, he adds, and it has a great track record for safety around vertebrates.
which are engineered to produce pest-killing toxins from the bacterium Bacillus thuringiensis, use less insecticide. Increased planting of herbicide-tolerant crops may also have reduced the use of many herbicides that linger in soil and waterways
In 1997, the Chinese government approved the commercial cultivation of cotton plants genetically modified to produce a toxin from the bacteria Bacillus thuringiensis (Bt) that is deadly to the bollworm Helicoverpa armigera.
The bacteria Bacillus thuringiensis israelensis (Bti) is now the most commonly used microbicide to control mosquitoes worldwide
a variety of aubergine modified to produce a protein from the Bacillus thuringiensis (Bt) bacterium that is toxic to insect pests.
In ongoing experiments, Hawlena is getting intriguing results by looking at the different kinds of soil bacteria that thrive on stressed or unstressed grasshopper corpses.
whether the physiological effects of stress on grasshoppers scale up to plants, soil, bacteria and onwards,
Nature Newsscientists in Uganda will next week start field trials of a banana variety genetically engineered to resist a bacterial disease that has been decimating crops across Central africa.
The bananas have a gene from green pepper to protect against banana Xanthomonas wilt (BXW which costs farmers in Africa's Great lakes region an estimated half a billion dollars every year.
The crops produce a toxin that is made naturally by the bacterium Bacillus thuringiensis called Bt toxin.
coaxing digesting bacteria to work harder and longer and to produce new hydrocarbon products. It's not a lack of interest or a lack of feedstock or anything like that,
caused by the bacterium Coxiella burnetii, can trigger abortions in goats and sheep and cause flu-like symptoms and sometimes pneumonia in humans.
Nature Newsa slime mould long thought to hunt bacteria as prey turns out to have unexpected abilities: according to researchers in Texas, some of the amoebae are actually farmers,
husbanding their bacterial'crops'much as some ant species farm fungus. As social amoebae, slime moulds are bizarre creatures that live as individual singled-celled organisms while feeding,
But now, a selection of the soil-dwelling species Dictyostelium discoideum have been shown to husband their bacterial food source.
By prudently harvesting the bacteria and then migrating with them, the amoebae are seed able to a new food source at their destination.
shows that this'bacterial husbandry'is similar to the behaviour of other social animals, such as fungus-farming ants although compared to the ants,
It was thought previously that slime moulds were strictly predators of bacteria, forming the multicellular slug when scant food supplies prompted a move to new hunting grounds.
and noticed that some of these seemed to have bacteria in their reproductive structures, alongside their spores.
The team showed that the bacteria carried by the amoebae had the potential to initiate new populations in the lab,
The researchers dubbed the bacteria-carrying amoebae, which made up one-third of all clones in the wild population,'
If they then end up in an area that lacks sufficient edible bacteria, they can rely on their own supply to seed a new population for harvest.
Dictyostelium farmers seem sometimes to benefit from their husbandry skills even in natural soil that harbours a variety of bacteria,
because they can bring along bacteria of their choice, just as humans plant seeds in areas with naturally growing vegetation.
When the researchers compared the success of the farmers and non-farmers in areas of abundant edible bacteria
However, it would be interesting to know to what extent they allow the bacteria to proliferate at the new location.
including viruses, bacteria and fungi some novel that, alone or in combination, might push a bee colony into precipitous decline.
The pathogens include bacteria and viruses that cause smallpox, the plague, anthrax, Ebola and foot-and-mouth disease.
Nature Newswomen, beansprouts, cucumbers, bacteria, cows: the cast of the current European Escherichia coli outbreak is already a crowd.
Enter the phage. Bacteriophages are viruses that infect bacteria, and they are star players in the chain of events that led to this outbreak.
Bacterial infections often originate from contaminated food, but it is now about six weeks since the start of this outbreak and the trail is going cold.
It's hard to be sure of the culprit but this simply serves to highlight the importance of understanding how infectious bacteria get into the food chain in the first place.
Case-control studies of patients in the German outbreak pointed to salad vegetables and both cucumbers and beansprouts have been suspects.
It is possible that the vegetables were contaminated with bacteria originally carried in soil or water;
but the more likely source of the bacteria is animals. Pathogenic E coli are passed typically to humans from ruminant animals (cows or sheep) via faecal contamination in the food chain or through consumption of raw milk or meat products.
But how do pathogenic E coli arise in the first place? This is where bacteriophage come in. The bacterium in this outbreak, currently recognised as strain O104:
H4, makes Shiga toxin, which is responsible for the severe diarrhoea and kidney damage in patients
whose E coli infections develop into haemolytic uremic syndrome (HUS). The genes for the Shiga toxin are not actually bacterial genes,
but phage genes being expressed by infected bacteria. So when an E coli bacterium gets infected with a Shiga-toxin-producing phage,
it becomes pathogenic to humans. Our use of antibiotics may be helping those viral genes to spread.
If bacteria are exposed to some types of antibiotics they undergo what is called the SOS response,
which induces the phage to start replicating. Active replication of the phage causes the bacterial cells to burst open,
which releases the phage. It also releases the toxin, which is why antibiotics are used not usually to treat E coli infections (see'Europe's E coli outbreak:
time for the antibiotics?'.'One of the many unusual characteristics of strain O104: H4 is that it has resistance genes to multiple classes of antibiotics.
This suggests that wherever the bacteria have come from there has been selective pressure to resist antibiotics.
Heather Allison, a microbiologist at the University of Liverpool, UK, and David Acheson, a managing director for food safety at consulting firm Leavitt Partners in WASHINGTON DC, agree it is plausible that exposure to antibiotics in agricultural use
Massachusetts, studying the molecular pathogenesis of Shiga-toxin-producing E coli in the 1990s. He says they saw Shiga-toxin-producing phage transfer between E coli in response to sub-therapeutic levels of the antibiotic ciprofloxacin in vitro and in the intestines of mice.
They do it in the laboratory, he says, but it's hard to show it happens in the environment.
from the European Reference Laboratory for verotoxin-producing E coli in Rome, Italy (verotoxin is another name for Shiga toxin).
And the gut is one place in which the phage move between different bacteria, and new pathogenic bacterial strains emerge.
Shiga toxins have been causing diarrhoeal disease in humans for centuries the bacterial genus Shigella and the Shiga toxins were named first for Kiyoshi Shiga,
a Japanese medical doctor who identified the bacterium during an outbreak of dysentery in Japan in 1897.
According to Allison, Shiga-toxin producing phage probably picked up the genes encoding Shiga toxin from these bacteria,
and since the 1980s have been spreading these virulent genes to other bacteria, including many strains of E coli.
We are seeing more and more Shiga-toxin-producing strains says Alison Weiss, microbiologist at the University of Cincinnati in Ohio.
How have Shiga-toxin-producing phage spread so widely in just a few decades? Allison says they have unusual characteristics that make them very successful.
They infect bacteria by binding to a protein called Bama on the surface of many bacterial cells,
Weiss adds that carrying the phage also provides a survival advantage for the host bacteria.
Once the bacteria are out in the environment say in manure they are fed on by other microbes
giving these bacteria an advantage. Not only are more E coli strains being infected with Shiga toxin, but it seems to be moving into different classes of bacteria.
The genome of strain O104: H4 has been sequenced, and it shares many genes with enteroaggerative E coli (EAEC) strains.
EAEC strains are associated not typically with zoonotic infections, and EAEC and Shiga toxin is a very unusual combination,
says Caprioli. This increased movement of Shiga-toxin-producing phage means that even more unusual and dangerous strains could be on the horizon.
German E coli outbreak caused by previously unknown strain: Nature Newsthe bacterium responsible for the current outbreak of enterohaemorrhagic Escherichia coli (EHEC) infections in Germany is a strain that has never before been isolated in humans.
The discovery, announced today by the food safety office of the World health organization (WHO) in Geneva, Switzerland,
Scientists in Germany are feverishly analysing the genome sequence of the bacterium, and have found clues as to how this strain
The bacteria are relatively unusual in that they produce extended-spectrum à Â-lactamases enzymes that render the bacteria resistant to many different antibiotics.
Patients with E coli infections are treated not typically with antibiotics anyway, because the bacteria are thought to respond to the medication by increasing production of the Shiga toxin,
which can lead to the life-threatening complication haemolytic-uremic syndrome. But antibiotic resistance might have helped the bacteria to survive
and persist in the environment. EHEC outbreaks usually only last around two weeks, but this outbreak has been going on
the bacteria are still infecting people. That source remains a mystery. A case-control study of female patients
but not the bacteria responsible for the ourbreak themselves. Fresh vegetables are still the prime suspect
but Flemming Scheutz, head of THE WHO Collaborative Centre for Reference and Research on Escherichia and Klebsiella in Copenhagen, suggests that the bacteria might not have originated in the food chain at all.
In addition to the antibiotic-resistance genes, the bacteria contain a gene for resistance to the mineral tellurite (tellurium dioxide.
Some strains of bacteria may have evolved resistance to tellurium during its historical medical use, or after its use in the mining and electronics industries increased its presence in the environment.
The ongoing genetic characterization of the strain might also reveal why the bacteria is mostly infecting adults,
an adhesion protein that allows the bacteria to attach to cells in the gut. Eae-negative E coli have been associated specifically with adult infections before
although it is still unclear why this particular protein is more effective in adult guts than in those of children.
Gad Frankel, a microbiologist at Imperial College London, suspects that the genome of this strain will reveal more information about the adherence mechanisms of E coli.
Some pathogenic bacteria don't just stick to cells in our guts, they also have active adherence mechanisms to stick to some vegetables,
The bacterium Agrobacterium tumefaciens which can cause tumours on plants shuttled foreign genes into plant genomes.
And Agrobacterium is not essential either; foreign genes can be fired into plant cells on metal particles shot from a'gene gun'.
Now we can foresee this loophole getting wider and wider as companies turn more to plants and away from bacteria and other plant-pest organisms.
Nevertheless, Agrobacterium is still industry's tool of choice for shuttling in foreign genes, says Johan Botterman, head of product research at Bayer Bioscience in Ghent, Belgium.
But Agrobacterium isn't suitable for some new techniques. Many companies are developing'mini-chromosomes'that can function in a plant cell without needing to be integrated into the plant's genome.
unlike the near-random scattering generated by Agrobacterium. In 2009 researchers at Dow Agrosciences in Indianapolis, Indiana,
which has added genes from the Bacillus thuringiensis bacterium, making the plant produce toxins that confer resistance to some insect pests.
Friendly bacteria move in mysterious ways: Nature Newsmany yoghurts are loaded with live bacteria, and labelled with claims that consuming these microorganisms can be good for your health.
But a study published today shows that such yoghurts have only subtle effects on the bacteria already in the gut
and do not replace them. Nathan Mcnulty, a microbiologist at Washington University in St louis, Missouri, recruited seven pairs of identical twins,
and asked one in each pair to eat twice-daily servings of a popular yoghurt brand containing five strains of bacteria.
nor affected the make-up of the local bacterial communities. Jeffrey Gordon, the microbiologist at Washington University who led the study,
We were only giving several billion bacterial cells in total to the twins, who harbour tens of trillions of gut microbes in their intestines,
Mcnulty also fed the five bacterial strains from the yoghurt to'gnotobiotic'mice animals raised
As with the twins, the yoghurt bacteria did not change the composition of the rodents'resident communities.
the activity of genes that allow the native bacteria to break down carbohydrates did increase. One of the five yoghurt strains Bifidobacterium animalis lactis also showed a similar boost in its ability to metabolize carbohydrates.
The study, which was funded by the US National institutes of health and Danone Research, the research arm of the food company that makes some probiotic yoghurts,
because there is so much variety in the bacteria in the yoghurts and in the people who consume them,
or sequence their bacterial genes at enough depth. We should reserve the judgement on the effects of probiotics in humans until broader and deeper studies are carried out,
However, he cautions that there are limits to studying mice with human gut bacteria because different species have their own specifically evolved sets.
the researchers determined the different kinds of bacteria present, as well as the identity of thousands of microbial genes.
Wei's team found that samples from both groups contained previously unknown genes produced by Clostridium bacteria,
Margulis pioneered the now-accepted idea that the eukaryotic cell originated in fusions between different bacteria;
organelles such as mitochondria and chloroplasts were originally free-living bacteria before they were absorbed by another cell.
Yasuo Yoshikuni and his colleagues at the Bio Architecture Lab in Berkeley, California, engineered the bacterium Escherichia coli
and have turned to different feedstocks including switchgrass, the succulent plant jatropha, cyanobacteria and green algae. However, producing biofuels from sugar cane
So using Vibrio splendidus, a marine microbe that can digest brown seaweed, Yoshikuni and his team isolated a biochemical pathway that breaks down alginate.
They inserted the genes responsible into a strain of E coli, which could then digest the alginate into simple sugars.
This strain of E coli could, in theory, be engineered to produce a variety of other useful chemicals and fuels."
because overuse of the drugs is"likely to contribute to cephalosporin-resistant strains of certain bacterial pathogens.
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