Escherichia coli – Engineering Evil

From friend to foe: How benign bacteria evolve to virulent pathogens

Contact: Isabel Gordo igordo@igc.gulbenkian.pt 351-214-407-915 Public Library of Science

Bacteria can evolve rapidly to adapt to environmental change. When the “environment” is the immune response of an infected host, this evolution can turn harmless bacteria into life-threatening pathogens. A study published on December 12 in PLOS Pathogens provides insight into how this happens.

Isabel Gordo and colleagues from the Instituto Gulbenkian de Ciencia in Oeira, Portugal, have for the first time devised an experimental system to observe and study the evolution of bacteria in response to encounters with cells of the mammalian immune system. They found that in less than 500 bacterial generations (or 30 days), the bacteria became more resistant to being killed by immune cells and acquired the ability to cause disease in mice. Continue reading “From friend to foe: How benign bacteria evolve to virulent pathogens”

Bacteria adapt and evade nanosilver’s sting

08 May 2013

Researchers from UNSW have cautioned that more work is needed to understand how micro-organisms respond to the disinfecting properties of silver nano-particles, increasingly used in consumer goods, and for medical and environmental applications.

Although nanosilver has effective antimicrobial properties against certain pathogens, overexposure to silver nano-particles can cause other potentially harmful organisms to rapidly adapt and flourish, a UNSW study reveals.

This result, published in the journal Small, could have wide-reaching implications for the future use of nanosilver as an antimicrobial agent with biomedical and environmental applications.

“We found an important natural ability of a widely occurring bacteria to adapt quite rapidly to the antimicrobial action of nanosilver. This is the first unambiguous evidence of this induced adaptation,” says co-author Dr Cindy Gunawan, from the UNSW School of Chemical Engineering.

Using an experimental culture, UNSW researchers observed that nanosilver was effective in suppressing a targeted bacteria (Escherichia coli), but that its presence initiated the unexpected emergence, adaptation and abnormally fast growth of another bacteria species (Bacillus).

The efficacy of nanosilver to suppress certain disease-causing pathogens has been well-documented, and as a result, it has become widely used in medicine to coat bandages and wound dressings. It also has environmental uses in water and air purification systems, and is used in cosmetics and detergents, and as a surface coating for things like toys and tupperware.

But the researchers say this exploitation of nanosilver’s antimicrobial properties have “gained momentum due in part to a lack of evidence for the potential development of resistant microorganisms”.

“Antimicrobial action of nanosilver is not universal and the widespread use of these products should take into consideration the potential for longer-term adverse outcomes,” says Gunawan.

The researchers say these adverse impacts could be more pronounced given the near-ubiquitous nature of the Bacillus bacteria, which originate from airborne spores, and because the resistance trait can potentially be transferred to the genes of other micro-organisms.

“For the medical use of nanosilver, this implies the potential for reduced efficacy and the development of resistant populations in clinical settings,” says co-author Dr Christopher Marquis, a senior lecturer from the UNSW School of Biotechnology and Biomolecular Sciences.

“This work suggests caution in the widespread use of nanosilver and the requirement for much deeper research into the antimicrobial mechanisms, the extent of adaptability and the molecular basis or genetics of cell defence against the antimicrobial activity.”

Media Contact: Myles Gough, UNSW Media Office, (02) 9385 1933

Special E. Coli Bacteria Produce Diesel On Demand

Apr. 22, 2013 — It sounds like science fiction but a team from the University of Exeter, with support from Shell, has developed a method to make bacteria produce diesel on demand. While the technology still faces many significant commercialisation challenges, the diesel, produced by special strains of E. coli bacteria, is almost identical to conventional diesel fuel and so does not need to be blended with petroleum products as is often required by biodiesels derived from plant oils.

This also means that the diesel can be used with current supplies in existing infrastructure because engines, pipelines and tankers do not need to be modified. Biofuels with these characteristics are being termed ‘drop-ins’.

Professor John Love from Biosciences at the University of Exeter said: “Producing a commercial biofuel that can be used without needing to modify vehicles has been the goal of this project from the outset. Replacing conventional diesel with a carbon neutral biofuel in commercial volumes would be a tremendous step towards meeting our target of an 80% reduction in greenhouse gas emissions by 2050. Global demand for energy is rising and a fuel that is independent of both global oil price fluctuations and political instability is an increasingly attractive prospect.”

E. coli bacteria naturally turn sugars into fat to build their cell membranes. Synthetic fuel oil molecules can be created by harnessing this natural oil production process. Large scale manufacturing using E. coli as the catalyst is already commonplace in the pharmaceutical industry and, although the biodiesel is currently produced in tiny quantities in the laboratory, work will continue to see if this may be a viable commercial pathway to ‘drop in’ fuels.

Rob Lee from Shell Projects & Technology said: “We are proud of the work being done by Exeter in using advanced biotechnologies to create the specific hydrocarbon molecules that we know will continue to be in high demand in the future. While the technology still faces several hurdles to commercialisation, by exploring this new method of creating biofuel, along with other intelligent technologies, we hope they could help us to meet the challenges of limiting the rise in carbon dioxide emissions while responding to the growing global requirement for transport fuel.”

http://www.sciencedaily.com/releases/2013/04/130422154911.htm

The first caffeine-‘addicted’ bacteria

Contact: Michael Bernstein m_bernstein@acs.org 202-872-6042 American Chemical Society

Some people may joke about living on caffeine, but scientists now have genetically engineered E. coli bacteria to do that — literally. Their report in the journal ACS Synthetic Biology describes bacteria being “addicted” to caffeine in a way that promises practical uses ranging from decontamination of wastewater to bioproduction of medications for asthma.

Jeffrey E. Barrick and colleagues note that caffeine and related chemical compounds have become important water pollutants due to widespread use in coffee, soda pop, tea, energy drinks, chocolate and certain medications. These include prescription drugs for asthma and other lung diseases. The scientists knew that a natural soil bacterium, Pseudomonas putida CBB5, can actually live solely on caffeine and could be used to clean up such environmental contamination. So they set out to transfer genetic gear for metabolizing, or breaking down, caffeine from P. putida into that old workhorse of biotechnology, E. coli, which is easy to handle and grow.

The study reports their success in doing so, as well as use of the E. coli for decaffeination and measuring the caffeine content of beverages. It describes development of a synthetic packet of genes for breaking down caffeine and related compounds that can be moved easily to other microbes. When engineered into certain E. coli, the result was bacteria literally addicted to caffeine. The genetic packet could have applications beyond environmental remediation, the scientists say, citing potential use as a sensor to measure caffeine levels in beverages, in recovery of nutrient-rich byproducts of coffee processing and for the cost-effective bioproduction of medicines.

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The author and co-authors acknowledge financial support from the University of Texas at Austin and the University of Iowa.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Ikea chocolate cake contaminated by SEWAGE: Officials in China destroy two tonnes of confectionary after disgusting discovery

Chinese authorities found cake contained high levels of coliform bacteria
Nearly two tons of the chocolate almond cake was destroyed last year
The company was caught up in the horsemeat scandal last week

By Steve Nolan

PUBLISHED: 09:37 EST, 5 March 2013 | UPDATED: 10:57 EST, 5 March 2013

Almost two tons of cake imported by Swedish firm Ikea to China have been destroyed after authorities found it contained bacteria present in sewage.

Quarentine officials in Shanghai confirmed that 1,872kg of chocolate almond cake imported by the company contained excessive levels of coliform bacteria which is found in human faeces.

The news comes just a week after Ikea became embroiled in the horsemeat scandal.

Food scandal: Cake imported to China by Swedish firm Ikea failed to meet food hygiene standards, officials have said

The company had to withdraw meatballs from 24 countries last week over fears that they could contain horse DNA.

Ikea spokesman Ylva Magnusson said that the cakes were destroyed in November and December but the company’s head office had only found out about it on Monday.

She said: ‘The product was stopped and destroyed. So none of the cakes made it to our restaurants.’

She added that the supplier has tested the same batch of almond cakes and found no presence of E. coli or human intestinal bacteria.

The cake, which is made by a Swedish supplier, is sold in Ikea stores in the majority of countries that it operates in.

A statement released by Ikea said that the product has now been withdrawn from 23 countries – but added that the UK and Ireland are not affected.

It read: ‘Traces of coliform bacteria have been found in two isolated production batches of Almond cake with chocolate and butterscotch, produced for the Restaurant, from one supplier in Sweden.

‘There is no health risk associated with consuming this product.

‘The production batches have, as per safety and quality routines, been tested for bacteria that can cause health issues, such as E.coli, and none of these pathogen bacteria have been found.’

Coliform bacteria can be found in soil, vegetation, water and everyday human environments, as well as in the faeces of humans and warm-blooded animals.

Not on sale: The firm had already had to remove meatballs from 24 countries because it was feared that there could be horse DNA in them

The Shanghai quarantine bureau said this week that Kraft cream cheese and 2.7 tons of Nestle chocolate bars also were among dozens of imported products destroyed in its latest round of quality inspections.

Chinese authorities have stepped up food inspections in recent years after a series of scandals over fake or shoddy goods.

The Nestle chocolate apparently contained too much sorbitol, a sweetener that in large amounts can cause bowel problems, the agency said in a statement.

Plantain and broccoli fibers may block key stage in Crohn’s disease development

2010 study posted for filing

Contact: Emma Dickinson edickinson@bmjgroup.com 44-207-383-6529 BMJ-British Medical Journal

Translocation of Crohn’s disease Escherichia coli across M-cells: Contrasting effects of soluble plant fibers and emulsifiers

Plantain and broccoli fibres may block a key stage in the development of the inflammatory bowel disorder, Crohn’s disease, suggests preliminary research published online in Gut.

The causes of Crohn’s disease are thought to be a mix of genetic and environmental factors, one of which is very likely to be diet.

The disease is significantly less common in developing countries, where fibrous fruit and vegetables are dietary staples, and its incidence has recently risen rapidly in Japan, in tandem with the increasing adoption of a more Westernised diet.

One of the key stages in the development of Crohn’s is invasion of the cells lining the bowel (epithelial cells) by bacteria, particularly a “sticky” type of Escherichia coli, so the researchers looked at dietary agents that might influence this process.

They cultured M (microfold) cells, bowel lining cells that are the common entry point for invading bacteria that cause diarrhoea – a process known as translocation.

The researchers tested whether preparations of plant soluble fibres prepared from leeks, apples, broccoli, and plantains, and the fat emulsifiers polysorbate 60 and 80, commonly used in processed food manufacture, could alter E coli translocation across M cells.

Plantain and broccoli fibres (5 mg/ml) reduced translocation of E. coli by between 45% and 82%, while leek and apple fibres had no noticeable impact. By contrast, the emulsifier polysorbate 80 substantially increased translocation.

These results were then confirmed in tissue samples taken from patients undergoing surgery for other gut disorders.

The findings suggest that supplementing the diet with broccoli/plantain fibres might prevent relapse of Crohn’s disease, say the authors.

They go on to add that the results could have further implications for the treatment of Crohn’s disease as many enteral feeds contain emulsifiers, which may account for the variable response to this type of treatment.

Cinnamon is lethal weapon against E. coli O157:H7

Contact: Angela Dansby aldansby@ift.org 312-782-8424 x127 Institute of Food Technologists

When cinnamon is in, Escherichia coli O157:H7 is out. That’s what researchers at Kansas State University discovered in laboratory tests with cinnamon and apple juice heavily tainted with the bacteria. Presented at the Institute of Food Technologists’ 1999 Annual Meeting in Chicago on July 27, the study findings revealed that cinnamon is a lethal weapon against E. coli O157:H7 and may be able to help control it in unpasteurized juices.

Lead researcher Erdogan Ceylan, M.S., reported that in apple juice samples inoculated with about one million E. coli O157:H7 bacteria, about one teaspoon (0.3 percent) of cinnamon killed 99.5 percent of the bacteria in three days at room temperature (25 C). When the same amount of cinnamon was combined with either 0.1 percent sodium benzoate or potassium sorbate, preservatives approved by the Food and Drug Administration, the E. coli were knocked out to an undetectable level. The number of bacteria added to the test samples was 100 times the number typically found in contaminated food.

“This research indicates that the use of cinnamon alone and in combination with preservatives in apple juice, besides its flavoring effect, might reduce and control the number of E. coli O157:H7,” concluded Ceylan, a Ph.D. graduate assistant at K-State. “Cinna-mon may help protect consumers against foodborne bacteria that may be in unpasteurized juices and may partially or completely replace preservatives in foods to maintain their safety,” he said.

“If cinnamon can knock out E. coli O157:H7, one of the most virulent foodborne microorganisms that exists today, it will certainly have antimicrobial effects on other common foodborne bacteria, such as Salmonella and Campylobacter,” noted Daniel Y.C. Fung, Ph.D., professor of Food Science in the Department of Animal Sciences and Industry at K-State, who oversaw the research.

Last year, Fung and Ceylan researched the antimicrobial effects of various spices on E. coli O157:H7 in raw ground beef and sausage and found that cinnamon, clove, and garlic were the most powerful. This research led to their recent studies on cinnamon in apple juice, which proved to be a more effective medium than meat for the spice to kill the bacteria.

“In liquid, the E. coli have nowhere to hide,” Fung noted, “whereas in a solid structure, such as ground meat, the bacteria can get trapped in the fat or other cells and avoid contact with the cinnamon. But this cannot happen in a free-moving environment.”

Regardless of the K-State findings, people who are at greater than normal risk for foodborne diseases– namely the elderly, young children, or immune-compromised– would be urged to avoid drinking unpasteurized juices or unthoroughly cooked hamburgers, which may contain harmful microorganisms.

For a copy of the study presented at IFT’s Annual Meeting, contact Angela Dansby at 312-82-8424 x127 or via e-mail at aldansby@ift.org .

###Founded in 1939, IFT is a non-profit scientific society with 28,000 members working in food science, technology and related professions in industry, academia and government. As the society for food science and technology, IFT brings sound science to the public discussion of food issues

Reposted for Filing 1999 Data

Feeding cattle byproduct of ethanol production causes E. coli 0157 to spike

K-State researchers findings on E. coli

MANHATTAN, KAN. — Ethanol plants and livestock producers have created a symbiotic relationship. Cattle producers feed their livestock distiller’s grains, a byproduct of the ethanol distilling process, giving ethanol producers have an added source of income.

But recent research at Kansas State University has found that cattle fed distiller’s grain have an increased prevalence of E. coli 0157 in their hindgut. This particular type of E. coli is present in healthy cattle but poses a health risk to humans, who can acquire it through undercooked meat, raw dairy products and produce contaminated with cattle manure.

“Distiller’s grain is a good animal feed. That’s why ethanol plants are often built next to feedlots,” said T.G. Nagaraja, a professor of diagnostic medicine and pathobiology at K-State’s College of Veterinary Medicine.

Through three rounds of testing, Nagaraja said the prevalence of 0157 was about twice as high in cattle fed distiller’s grain compared with those cattle that were on a diet lacking the ethanol byproduct.

“Feeding cattle distiller’s grain is a big economic advantage for ethanol plants,” Nagaraja said. “We realize we can’t tell cattle producers, ‘Don’t feed distiller’s grain.’ What we want to do is not only understand the reasons why 0157 increases, but also find a way to prevent that from happening.”