University of East Anglia

New study to give insight into public health risks of ESBL E. coli..

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New project investigates public health risks of ESBL E.Coli to develop intervention plans to reduce infections caused by these bacteria.

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A new study by Public Health England (PHE) and funded by the Department of Health will, for the first time, establish the most significant reservoirs of a strain of antibiotic resistant bacteria known as ESBL-positive E. coli that cause human illness in the UK.

Its findings will help to develop intervention strategies in efforts to reduce the numbers of infections such as urinary tract infections or blood poisoning, caused by these bacteria.

The research is being led by PHE with key collaborators from the Animal Health and Veterinary Laboratories Agency, The University of Cardiff, The University of East Anglia, The University of Glasgow, Queen Mary University of London, and Health Protection Scotland.

The study will look at sewage, farm slurry and raw meat to determine whether there are any potential risks to human health in a number of different reservoirs of these bacteria. It will also look at stool samples from patients who have no symptoms of illness (asymptomatic carriage) to see whether the bacteria is in their gut (colonisation).

E. coli is a bacterium that lives in the guts of humans and many other animals. Colonisation of the gut by E. coli is perfectly normal and is harmless, although some other types cause diarrhoea. However, E. coli is also the commonest cause of urinary tract and bloodstream infections, which usually require antibiotic treatment.

Not all types of ESBL-positive E. coli bacteria cause human disease, and the contribution to human disease made by resistant strains from animals, meat and environmental sources is not well understood.

Resistant strains of E. coli are an increasing problem, reducing the number of antibiotics that a doctor can use for treatment. Many of the resistant strains produce enzymes called ESBLs (Extended-Spectrum Beta-Lactamases), which make them resistant to most penicillin-like antibiotics. E. coli with ESBLs can also be found in food animals, raw retail meat, sewage and river water, but whether these reservoirs pose any public health risk is poorly understood.

Professor Neil Woodford, Head of the Antimicrobial Resistance and Healthcare Associated Infections Reference Unit at PHE, said:

The risks posed to human health by resistant E. coli from non-human reservoirs are not fully understood. This study will help to disentangle this complex interrelationship.

Treatment of infections caused by resistant E. coli can be difficult, which is why we need to understand the risks better. Having said that, we want to reassure the public that presence of these bacteria in the gut does not require antibiotic treatment and is usually temporary. Most colonized people never develop an infection caused by the resistant strain.

This study is very important because its results will help to shape future intervention strategies to reduce the spread of these antibiotic-resistant strains of bacteria and to reduce the numbers of infections that they cause.

Notes to editors

  1. The amount of the funding from the Department of Health is £500,000 and the study is spread over three years. The study will cover different elements.
  2. The first piece of research will look for ESBL-positive E. coli in 20-25,000 stool samples collected in five different geographical areas (London, East Anglia, North West, Scotland and Wales), which will determine rates of harmless gut carriage.
  3. Secondly, sewage samples will be collected from various sites throughout each of the five regions and numbers of ESBL-positive E. coli will be measured in each sample.
  4. Our third study will seek ESBL-positive E. coli in samples of farm slurry and from retail raw meats collected in each geographical region.
  5. In the final part of the study, the ESBL-positive E. coli collected from the different sample types and in each region will be compared with those isolated from bloodstream infections to determine whether there are any genetic similarities between the resistant strains from sewage, animals, retail raw meat, and those isolated from human faeces and blood.
  6. E. coli are bacteria that are commonly found in the gut of both people and animals where they live harmlessly. Some other strains can cause illness, including food poisoning, urinary tract infections and bloodstream infections.
  7. ESBL enzymes were first described in the 1980s and during the 1990s were mainly seen in Klebsiella species found in hospitals mostly in intensive care units. Since early 2000s, they have become a global problem in E. coli.
  8. The cycle of antibiotic resistance is complex with interlinking elements between antibiotic use and people, livestock, pets, sewage and the environment.

 

Source: www.gov.uk

 

Targeted vitamin D testing recommended in Australasia.

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Vitamin D testing should not be done by routine screening but should be used only in people with clear signs of deficiency, or who are at risk for deficiency, for whom treatment is likely to be of benefit, according to a position statement from the Royal College of Pathologists of Australasia.

The statement recommends that vitamin D should be measured as 25-hydroxyvitamin D (25OH-D) and argues that an assay that measures only 25OH-D3 is sufficient for use in Australia and New Zealand. Patients should be monitored by the same laboratory after treatment because vitamin D assays vary.

After reviewing available scientific literature, a working party from the College advised against routine screening for vitamin D deficiency in adults (including pregnant women), healthy infants, and children. “As the main source of vitamin D is UVB sunlight exposure, vitamin D levels are correlated with time spent outdoors, exercise, and other aspects of a healthy lifestyle including bodyweight”, says Professor Yee Khong, President of the College.

The working group believes that testing healthy individuals would identify a substantial subgroup of patients with low 25OH-D concentrations, who would then be given treatment and repeat testing, without evidence that they would benefit from vitamin D supplementation. Khong warns, “The quality of evidence for health benefits of an adequate vitamin D status is highly variable and trials to improve this evidence are underway”.

William Fraser (University of East Anglia, Norwich, UK), believes that the statement is useful, but he cautions that it is based on the situation in Australia and New Zealand. “Some of the broad statements made would not be applicable in other countries throughout the world. The recent guideline published by the National Osteoporosis Society is much more applicable in the UK and other countries where vitamin D2 is present in the food chain, is freely available as a supplement, or is used as a prescribed medication.”

The Australasian group suggests that the target concentration for serum 25OH-D should be greater than 50 nmol/L at the end of winter. Serum 25OH-D concentrations should be retested no earlier than 3 months after commencement of supplementation with vitamin D. Once a desirable target has been achieved, no further testing is needed unless risk factors change.

Fraser questions the recommendation to measure only 25OH-D3 when the statement notes that D2 supplementation could be being used by some individuals tested. “It is a relatively short time since Australia moved from prescribing D2supplementation to D3 supplementation, and I am left wondering if D2 is totally absent from the food and supplement chain.”

Source: Lancet

Cancer cell enzymes shown to act as ‘good cops.

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Enzymes released by cancerous cells have a protective function and are not one of the “bad guys”, say researchers from the University of East Anglia.

Their study found the MMP-8 enzyme sent a signal to the immune system to attack the tumour.

Patients whose breast tumours have more of this enzyme seem to do better.

Cancer Research UK said the research provided “very early clues” as to how the enzyme might recruit cells to fight breast cancer.

Scientists from UEA worked with clinicians at the Norfolk and Norwich University Hospital to look in detail at the patterns of MMPs in breast tumours from patients.

Their study, published in the Journal of Biological Chemistry, reveals that the matrix metalloproteinase-8 enzyme (MMP-8) could be acting as the ‘good guy’ by alerting the immune system to the location of the tumour.

It had been thought that the production of MMPs by breast cancer cells helped to promote cancer growth.

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MMP-8 acts as a sort of ‘find me’ signal to the immune system, which then becomes activated to attack the tumour”

Prof Dylan Edwards, lead researcher from UEA’s School of Biological Sciences, said that if breast cancer cells produce MMP-8 it causes them to produce two other inflammatory factors (IL-6 and IL-8) that have previously been shown to promote cancer.

“They were once thought to act like ‘molecular scissors’ to snip away at the scaffolding structures outside cells and clear a path for the cancer cells to invade and spread to other organs.

“However, breast tumour cells that over-produce MMP-8 don’t survive long-term – the enzyme stops them growing,” he said.

“We now think that in tumours, MMP-8 acts as a sort of ‘find me’ signal to the immune system, which then becomes activated to attack the tumour, which may help to explain its protective function.”

Drugs used to treat cancer in the 1990s, which blocked these enzymes, failed in the clinic, he said, and this new research may explain why.

It is still not known exactly how MMP-8 causes IL-6 and IL-8 to be activated.

Finding this out will be an important step forward which will help direct further research.

Dr Emma Smith, senior science information officer at Cancer Research UK, said: “This study provides very early clues as to how the MMP-8 protein might actually play the role of a ‘good cop’ and recruit immune cells to fight breast cancer.

“And, rather than seeing the MMP-8 protein as a ‘bad cop’ in breast cancer, recent research has shown that levels of this protein are raised in women who do relatively well.

“Yet, until now, we haven’t known why this should be the case.

“But these are early findings from cells grown in a lab, and more research is needed to see if the molecules found by the scientists alert immune cells to cancers in women.”

Source: BBC

Hawksbill turtles’ monogamous sex life revealed.

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The sex lives of critically endangered hawksbill turtles have been revealed by scientists studying the animals in the Seychelles.

Previously, little had been understood about the mating habits of the turtles, which live underwater and often far out at sea.

Researchers were surprised to find that the turtles are mainly monogamous, with females storing sperm from one male and using it to fertilise multiple egg clutches.

The study, led by researchers from the University of East Anglia, Norwich, UK, was published in the online journal Molecular Ecology.

“Sperm storage” is found in animals including reptiles, birds and some turtles, tortoises and terrapins.

Females can store viable sperm from multiple males for long periods of time, meaning that their egg clutches are sometimes fertilised by more than one father.

Researchers carried out DNA testing from hawksbill turtle hatchlings on Cousine Island in the Seychelles to identify how many males were involved in fertilising eggs during a breeding season.

The tests revealed a monogamous mating system: most egg clutches were sired by just one male, and no males had fertilised more than one female during the 75-day season.

“We were surprised that they were so monogamous because actually… genetic monogamy is actually the exception in most animals, not the rule,” said research team member Dr David Richardson.

The findings show that “there are plenty of males out there” for females to mate with.

“It’s very unlikely that it’s just a few males hanging around offshore”, said Dr Richardson. “We think they’re mating with males a long way away, wherever they’re normally foraging and feeding which can be all over the western Indian Ocean,” he added.

The number of hawksbill turtle males contributing to the next generation is important for the species’ survival because it results in higher levels of genetic variation.

Genetic variability “means [the turtles] can respond to new threats, new diseases or anything that comes along,” explained Dr Richardson.

Hawksbill turtles were identified as Critically Endangered by the International Union for the Conservation of Nature after years of being hunted for their shells, which were prized in the now illegal decorative tortoiseshell trade.

Found in tropical waters around the world, females turtles gather at onshore nesting sites such as Cousine Island every few years to lay around five clutches of eggs during the season.

Mating often takes place out at sea, but according to the study, by testing DNA samples from hatchlings on the island, the researchers were able to gather information that would have been impossible from observation alone.

Dr Richardson told BBC Nature that this study, combined with independent reports of hawksbill turtle numbers rising, indicates that “in terms of conservation… maybe we are in a better place than we thought.”

The team hopes their study may help conservationists working on Cousine Island to understand more about the lives of the animals and to focus their efforts.

Source:BBC