ֱ̽ of Cambridge - MRSA /taxonomy/subjects/mrsa en Reducing the rise of antibiotic resistance /stories/antibiotic-resistance <div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Rising resistance to antibiotics is a worrying prospect, but a success story happening across the farms of the UK gives hope that something can be done.</p> </p></div></div></div> Mon, 22 Nov 2021 12:00:01 +0000 lw355 228251 at MRSA contamination found in supermarket sausages and minced pork /research/news/mrsa-contamination-found-in-supermarket-sausages-and-minced-pork <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/sausages.jpg?itok=Fn6QqLHx" alt="Sausages (cropped)" title="Sausages (cropped), Credit: Ross Elliott" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>In February, a team of researchers funded primarily by the Medical Research Council bought and analysed a total of 103 (52 pork and 51 chicken) pre-packaged fresh meat products, labelled as being of UK farm origin, from supermarkets in five different locations across in England.<br /><br />&#13; All of the meat products were frozen at -20 °C and sent to the Department of Veterinary Medicine at the ֱ̽ of Cambridge for testing. After thawing, researchers disinfected the exterior packaging before removing the meat. They then tested a 10g sample of meat from each packet and screened for MRSA. Two of the pork samples – one from sausages, one from minced pork – tested positive for MRSA; the sausage sample contained two strains of the bacteria.<br /><br />&#13; In collaboration with the Wellcome Trust Sanger Institute an analysis of the genetic make-up of the bacteria and confirmed the presence of antibiotic resistant genes. ֱ̽analysis showed that the bacteria belonged to a type of MRSA known as LA-MRSA CC398, which has emerged over the last few years in continental Europe, particularly in pigs and poultry, but was not previously believed to be widely distributed in the UK.<br /><br />&#13; In many countries, LA-MRSA CC398 represents an occupational risk for those in close contact with livestock, particularly pigs and veal calves. Humans in contact with pigs (farm workers, abattoir workers and veterinarians, etc.) have significantly higher rates of the bacteria in their nasal carriage, according to epidemiological studies, for example. Other studies have revealed an association between clinical disease resulting from LA-MRSA CC398 infection and recent contact with pigs or pig farms. As with other MRSA, this type may be responsible for serious illness following wound or surgery site infections, although many people will carry MRSA on their skin or in their noses without showing signs of disease.<br /><br />&#13; ֱ̽researchers stress that adequate cooking (heating above 71°C) and hygienic precautions during food preparation should minimise the likelihood of transmission to humans via contaminated pork. However, they argue that the discovery of MRSA in pork identifies a potential way that the bacteria can spread from farms to the wider population.<br /><br />&#13; While human contamination of carcasses or meat products in the abattoir or at the meat packing plant may occur, there is good evidence that these isolates are of animal origin – possibly through the use of antibiotics to treat or control infection in livestock.<br /><br />&#13; As the tests use a highly sensitive method of detection of bacterial contamination, the numbers of MRSA bacteria present may be low. ֱ̽researchers say that as the two infected samples contained processed pork (sausages and minced pork), they cannot rule out that the meat packing plants from which the MRSA from this study originated also handle imported meat. If this were the case, it is conceivable that cross-contamination might have occurred between non-UK to UK sourced meat.<br /><br />&#13; Dr Mark Holmes from the Department of Veterinary Medicine at the ֱ̽ of Cambridge says: “This is the first time that MRSA has been detected in retail meat products in the UK. ֱ̽public should not be overly worried by this as sensible food precautions and good hygiene should prevent its spread. It’s also usually pretty harmless and only causes health problems if it infects someone in poor health or gets into a wound.<br /><br />&#13; “However, this does suggest that MRSA is established in our pig farms and provides a possible route of transmission from livestock, through those in direct contact with pigs, into the wider population.”<br /><br />&#13; Dr Des Walsh, Head of Infections and Immunity at the MRC, added: “Studies like this are crucial not just to reveal concerns to human health through contaminated livestock, but to show resistance to antibiotics is a problem growing far beyond just humans. To win the fight against antimicrobial resistance, we need an all hands on deck approach, and that’s why we’ve teamed up with leading experts in biological, social and others sciences in a joint initiative designed to find new solutions, fast.”<br /><br />&#13; ֱ̽research was funded by the Medical Research Council, with additional support from the Alliance to Save our Antibiotics. ֱ̽results of the study are published in the online journal <em>Eurosurveillance</em>.<br /><br />&#13; Dr Holmes was recently awarded <a href="http://www.mrc.ac.uk/news-events/news/5million-boost-to-superbug-researchers/">a further £1.58 million from the MRC</a> to look into the effects of antibiotic use on the entire population of animal gut flora, not just the disease causing bacteria. His work, using research in pigs, will help scientists understand the evolution of antibiotic resistance and help to make better choices about how to reduce the spread of antimicrobial resistance on farms.<br /><br /><em><strong>Reference</strong><br />&#13; Hadjirin, NF et al. <a href="https://www.eurosurveillance.org/content/10.2807/1560-7917.ES2015.20.24.21156">Detection of livestock-associated methicillin-resistant Staphylococcus aureus CC398 in retail pork, United Kingdom, February 2015</a>. Eurosurveillance</em></p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>A survey carried out earlier this year has found the first evidence of the ‘superbug’ bacteria Methicillin-Resistant Staphylococcus Aureus (MRSA) in sausages and minced pork obtained from supermarkets in the UK. However, researchers stress that this does not pose a significant immediate risk to the public.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"> ֱ̽public should not be overly worried by this as sensible food precautions and good hygiene should prevent its spread</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Mark Holmes</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://www.flickr.com/photos/ross_elliott/4568919576/" target="_blank"> Ross Elliott</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Sausages (cropped)</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="https://creativecommons.org/licenses/by/4.0/" rel="license"><img alt="Creative Commons License" src="https://i.creativecommons.org/l/by/4.0/88x31.png" style="border-width:0" /></a><br />&#13; ֱ̽text in this work is licensed under a <a href="https://creativecommons.org/licenses/by/4.0/" rel="license">Creative Commons Attribution 4.0 International License</a>. For image use please see separate credits above.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/attribution">Attribution</a></div></div></div> Thu, 18 Jun 2015 14:56:43 +0000 cjb250 153542 at Using genome sequencing to track MRSA in under-resourced hospitals /research/news/using-genome-sequencing-to-track-mrsa-in-under-resourced-hospitals <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/141208-mrsa.jpg?itok=egOWHEbw" alt="Micrograph of Methicillin-Resistant Staphylococcus aureus (MRSA)" title="Micrograph of Methicillin-Resistant Staphylococcus aureus (MRSA), Credit: NIAID" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Researchers from the ֱ̽ of Cambridge have used genome sequencing to monitor how the spread of methicillin-resistant<em> Staphylococcus aureus</em> (MRSA) occurs in under-resourced hospitals. By pinpointing how and when MRSA was transmitted over a three-month period at a hospital in northeast Thailand, the researchers are hoping their results will support evidence-based policies around infection control.</p>&#13; <p>MRSA is a common cause of hospital-acquired infections, with the largest burden of infections occurring in under-resourced hospitals in the developing world. Whereas genome sequencing has previously been applied in well-resourced clinical settings to track the spread of MRSA, how transmission occurs in resource-limited settings is unknown. In a <a href="https://dx.doi.org/10.1101/gr.174730.114" target="_blank">new study</a> published today (9 December) in the journal <em>Genome Research</em>, researchers used genome sequencing to understand the spread of MRSA in a hospital with high transmission rates.</p>&#13; <p>“In under-resourced hospitals and clinics, formal screening procedures for MRSA are not in place,” said Professor Sharon Peacock of the ֱ̽ of Cambridge and the Wellcome Trust Sanger Institute, who led the research. “Filling gaps in our understanding of how MRSA spreads in such settings is important, since this not only highlights the problem but also provides direction to interventions that tackle this and other hospital-based pathogens.”</p>&#13; <p> ֱ̽team of researchers from the UK, Thailand and Australia monitored all patients on two intensive care units (ICUs) at a hospital in northeast Thailand over a three-month period in order to track how and when MRSA was transmitted. During this time, five staff members and 46 patients tested positive at least once, which represented 16% of adult and 34% of paediatric patients. </p>&#13; <p>Conventional bacterial genotyping approaches do not provide enough discrimination between closely-related MRSA strains to be able to pinpoint transmission from one person to another, but whole genome sequencing addresses this problem. A total of 76 MRSA populations, or isolates, were sequenced, including up to two repeat isolates from patients who tested positive for MRSA in the first screen. None of the patients or staff members who tested positive for MRSA were asymptomatic carriers. </p>&#13; <p>By conventional typing, all of the MRSA identified belonged to sequence type 239, the dominant MRSA lineage worldwide. But, based on sequence data, there was considerable genetic diversity – including the presence or absence of clinically important genes such as those coding for antiseptic resistance and antibiotic resistance.</p>&#13; <p>“A striking result from sequence data was the presence of multiple distinct clades, which suggests that several different variants of MRSA were circulating through the hospital at the same time,” said Peacock. “We also confirmed numerous transmission events between patients after admission to the ICU, and identified a ‘super-spreader’ in each unit.”</p>&#13; <p>“Studies such as this provide information to help inform policy,” said Peacock, who is a member of the Department of Medicine and the Department of Pathology, and a Fellow of St John’s College. “It also highlights – in a concrete way – the importance of infection control including effective implementation of hand-washing, which is the most effective way to control MRSA.”</p>&#13; <p>Following the results of the study, the hospital has implemented a comprehensive hand-washing policy, a project which is being overseen by Ben Cooper, one of the paper’s co-authors.</p>&#13; <p> ֱ̽research was funded by the Medical Research Council.</p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Whole genome sequencing of MRSA from a hospital in Asia has demonstrated patterns of transmission in a resource-limited setting, where formal screening procedures are not feasible.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">This study highlights – in a concrete way – the importance of infection control including effective implementation of hand-washing, which is the most effective way to control MRSA</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Sharon Peacock</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="https://www.flickr.com/photos/niaid/8436193898/in/photolist-a4RLq5-9y4sDM-j4vREz-j4MspC-dRtGwW-dQorNR-bpCfQR-fyXRic-a2Ltvs-dQjFSx-a2HASi-j4uLGn-p2NgtV-9yy9Lu-456Vk-draSwB-9y7kCs-a5tw3L-bzHVKx-4bAWxg" target="_blank">NIAID</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Micrograph of Methicillin-Resistant Staphylococcus aureus (MRSA)</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p> ֱ̽text in this work is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/">Creative Commons Licence</a>. If you use this content on your site please link back to this page. For image rights, please see the credits associated with each individual image.</p>&#13; <p><a href="http://creativecommons.org/licenses/by-nc-sa/3.0/"><img alt="" src="/sites/www.cam.ac.uk/files/80x15.png" style="width: 80px; height: 15px;" /></a></p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div><div class="field field-name-field-license-type field-type-taxonomy-term-reference field-label-above"><div class="field-label">Licence type:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/taxonomy/imagecredit/attribution">Attribution</a></div></div></div> Tue, 09 Dec 2014 18:00:00 +0000 sc604 141532 at March of the superbugs /research/features/march-of-the-superbugs <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/features/130212-cow-credit-jelles-on-flickr.jpg?itok=gSVbbsVN" alt="" title="Cow, Credit: JelleS on flickr" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Every so often, research laboratories and hospitals testing patients for the superbug methicillin-resistant Staphylococcus aureus (MRSA) have come across an oddity: a strain that appeared to be MRSA because it was resistant to antibiotics but one that tested negative with the ‘gold standard’ molecular test. ֱ̽quirky cases were so infrequent that they were usually filed away for future analysis or disregarded. Until, that is, PhD student Laura Garcia-Alvarez from Cambridge’s Department of Veterinary Medicine had the tenacity to look a little further at a bacterial strain she had spotted in cows’ milk.</p> <p>MRSA first appeared in 1961 and epidemic strains of this difficult-to-treat bacterium have since spread worldwide in hospitals and the community. In the farming world, MRSA causes bovine mastitis – an infection of cows’ udders – affecting both animal welfare and milk yields.</p> <p>Garcia-Alvarez was working with Dr Mark Holmes on bovine mastitis when she came across one of the ‘curious anomalies’. ֱ̽strain was resistant to antibiotics but in the standard molecular test was negative for the presence of mecA – the gene responsible for methicillin resistance. She had the isolates retested and then sequenced at the Wellcome Trust Sanger Institute.</p> <p>It turned out that she had discovered a new strain of MRSA. Its antibiotic resistance is carried not by mecA but by mecC, a gene that is so genetically dissimilar to mecA that it can’t be picked up by the standard molecular test used to define MRSA but only by DNA sequencing.</p> <p>As Holmes and Garcia-Alvarez began to spread the information to colleagues around Europe, it soon became clear that this phenomenon was not confined to cows: others had found the unusual samples in humans. “We started to get calls from hospitals and research groups who had come across a small number of human MRSA strains that behaved differently,” said Holmes. “Within a few weeks, we had a further 50 isolates. This meant that what we were looking at was a human problem too.”</p> <p>Garcia-Alvarez, who at the time was a student on the Department’s postgraduate training in infectious disease dynamics programme, described how finding the same new strain in both humans and cows was worrying, although no cause for immediate alarm: “Pasteurisation of milk will prevent any risk of infection via the food chain. In the wider UK community, less than 3% of individuals carry MRSA – typically in their noses – without becoming ill.”</p> <p>“Nonetheless,” added Holmes, “MRSA presents a major challenge to the control of infectious diseases. Finding a new strain – studying its prevalence, how it confers antibiotic resistance and how it’s transmitted – can tell us enormous amounts about the origins and evolution of antibiotic resistance.”</p> <h2> New understanding</h2> <p>Since the discovery, Holmes’ team has been investigating the prevalence of the strain in human and animal populations – and the potential for passing the strain between species – in partnership with Cambridge’s Department of Medicine, the Sanger Institute and the Moredun Research Institute (Scotland), and funded by the Medical Research Council.</p> <p>One of their first steps was to develop a better genetic test, one that also detected the new strain. ֱ̽timing was fortuitous. Moves to help hospitals identify MRSA more quickly have resulted in the development of automated systems based on genetic testing. Because the standard genetic test does not detect the new strain, the scientists have now developed a protocol that will pick up both strains.</p> <p>Moreover, their recent research has shown that additional MRSA strains have emerged that possess other mechanisms of antibiotic resistance: “We’ve found about 40 human MRSA isolates that don’t have a mecA or a mecC gene, and we are trying to establish why these are resistant to methicillin-family antibiotics. In retrospect, it was incredibly lucky that the original isolate we investigated happened to have a genetic variation in a known gene that could be picked up by whole genome sequencing.”</p> <p>To identify how mecC confers antibiotic resistance, Holmes collaborated with Professor Alexander Tomasz at Rockefeller ֱ̽, New York. They discovered that the gene is more resistant than mecA to cefoxitin (one of the newer classes of antibiotics): “Inappropriate use of antibiotics in human and veterinary medicine has favoured the selection and growth of antibiotic-resistant microorganisms,” explained Holmes. “Our finding suggests that an increased use of this drug may have driven emergence of the new strain.”</p> <p>“We also now know that the new strain is found in almost every species that we’ve studied, including domestic cats and dogs, wild rats, deer, a rabbit, a common seal, sheep and a chaffinch. ֱ̽bacterium may have lost factors that restricted it to certain species, or gained pan-host virulence factors that make it better able to colonise multiple species. We need to know how and why this has happened to understand the emergence of bacterial pathogens from animals and their dissemination into human populations.”</p> <p>Now, their latest research has tracked transmission of the superbug, providing the first direct evidence of transmission of the new strain between livestock and humans.</p> <p> ֱ̽researchers capitalised on a growing trend to use increasingly rapid and affordable DNA sequencing for tracking the transmission of pathogens. This technique is helping scientists to look for differences at the level of single letters in the genetic code as a means to map the direction of infection – from patient to patient, and from one animal species to another. ֱ̽team investigated two cases of mecC MRSA in Danish farmers. ֱ̽strains circulating in the farmers’ livestock and those isolated from the patients only differed by a small number of letters – strong evidence that the farmers had acquired their infections from their animals, in one case a sheep and in another a cow.</p> <p>“ ֱ̽ability to confirm animal-to-human transmission in virtual real time using this technology can’t be underestimated,” said Holmes. “High-throughput DNA sequencing is going to revolutionise clinical microbiology by enabling targeted epidemiological follow-up and infection control.”</p> <h2> Nearing the precipice</h2> <p>Mastitis is the most common infectious disease of dairy cattle, affecting the welfare of cows and, according to one estimate, costs the UK dairy industry around £170 million per year. Its control and treatment relies on the use of millions of doses of therapeutic and prophylactic antibiotics every year. “Our research on MRSA is pointing to the fact that although we are not on the precipice of having the whole system collapse through selection of bugs that are even more resistant or having husbandry systems that make it impossible to eliminate them, we are closer to the precipice than we would like to be,” said Holmes. “As it is, S. aureus is considered impossible to eliminate in dairy herds – you have to live with it once you’ve got it. “Farmers and veterinarians are in a constant battle to improve the health of dairy cows, yet farming cannot be sustained at these levels if it is generating these types of resistance. Moreover, we can’t predict how these bacterial strains will evolve – they could become more resistant, more virulent or better able to jump between species.”<br /> Holmes views the interface between veterinary medicine and human medicine as crucial to understanding infectious diseases such as MRSA: “There is very little research on S. aureus mastitis in cows in comparison to research into it as a human pathogen, and yet now we’re beginning to see exactly the same organism being found in people and in cows. This means that we should be thinking about the epidemiology of disease control and the development of antibiotic resistance in both species. Understanding how new strains emerge will help us to understand the growing public health problem of antibiotic resistance.”</p> <p>For more information, please contact <a href="mailto:louise.walsh@admin.cam.ac.uk">Louise Walsh</a> at the ֱ̽ of Cambridge Office of External Affairs and Communications.</p> </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Scientists who recently discovered a new strain of superbug have now tracked its transmission between animals and humans.</p> </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">We can’t predict how these bacterial strains will evolve – they could become more resistant, more virulent or better able to jump between species</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Mark Holmes</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/" target="_blank">JelleS on flickr</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Cow</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="http://creativecommons.org/licenses/by-nc-sa/3.0/"><img alt="" src="/sites/www.cam.ac.uk/files/80x15.png" style="width: 80px; height: 15px;" /></a></p> <p>This work is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/">Creative Commons Licence</a>. If you use this content on your site please link back to this page.</p> </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Wed, 13 Feb 2013 09:38:50 +0000 admin 65612 at New strain of MRSA discovered /research/news/new-strain-of-mrsa-discovered <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/110603-cowsweb.jpg?itok=87OqbHBM" alt="Cow" title="Cow, Credit: Royalty-free image Collection by Flickr" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>Scientists have identified a new strain of methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) which occurs both in human and dairy cow populations.</p>&#13; <p> ֱ̽study, led by Dr Mark Holmes at the ֱ̽ of Cambridge, identified the new strain in milk from dairy cows while researching mastitis (a bacterial infection which occurs in the cows’ udders).</p>&#13; <p> ֱ̽new strain’s genetic makeup differs greatly from previous strains, which means that the ‘gold standard’ molecular tests currently used to identify MRSA - a polymerase chain reaction technique (PCR) and slide agglutination testing - do not detect this new strain. ֱ̽research findings are published today in the journal <em> ֱ̽Lancet Infectious Diseases</em>.</p>&#13; <p>Dr Laura García-Álvarez, first author of the paper, who discovered the new strain while a PhD student at the ֱ̽ of Cambridge’s Veterinary School, said: “To find the same new strain in both humans and cows is certainly worrying. However, pasteurization of milk will prevent any risk of infection via the food chain. Workers on dairy farms may be at higher risk of carrying MRSA, but we do not yet know if this translates into a higher risk of infection. In the wider UK community, less than 1% of individuals carry MRSA – typically in their noses – without becoming ill.”</p>&#13; <p> ֱ̽scientists discovered the antibiotic resistant strain while researching <em>S. aureus</em>, a bacterium known to cause bovine mastitis. Despite the strain being able to grow in the presence of antibiotics, when they attempted to use the standard molecular tests available – which work by identifying the presence of the gene responsible for methicillin resistance (the <em>mecA</em> gene) - the tests came back negative for MRSA.</p>&#13; <p>When Dr Matt Holden and a research team at the Wellcome Trust Sanger Institute sequenced the entire genome (decoding all of the genes in the bacteria’s DNA) they realised that the new strain possessed unconventional DNA for MRSA.  They found that the new strain does have a <em>mecA</em> gene but with only 60% similarity to the original <em>mecA</em> gene. Unfortunately, this results in molecular tests (which identify MRSA by the presence of the <em>mecA</em> gene) giving a false negative for this strain of MRSA.</p>&#13; <p>Subsequent research revealed that the new strain was also present in humans. During the study, the new strain was found in samples from Scotland, England and Denmark (some from screening tests and others from people with MRSA disease). It has since been identified in Ireland and Germany. Additionally, by testing archived <em>S. aureus</em> samples, the researchers have also identified a recent upward trend in the prevalence of the antibiotic resistant bacteria.</p>&#13; <p>Dr Mark Holmes said: “ ֱ̽majority of MRSA testing in British hospitals is performed by seeing if the bacteria will grow in the presence of antibiotics, typically oxacillin and cefoxitin, rather than methicillin - which is now no longer manufactured. This type of testing detects both the new MRSA and conventional MRSA.</p>&#13; <p>“However, it is important that any of the MRSA testing that is based on detection of the <em>mecA</em> gene - i.e. PCR based testing, or slide agglutination testing - be upgraded to ensure that the tests detect the new <em>mecA</em> gene found in the new MRSA. We have already been working with public health colleagues in the UK and Denmark to ensure that testing in these countries now detects the new MRSA.”</p>&#13; <p> ֱ̽new research also raises questions about whether cows could be a reservoir for the new strains of MRSA.</p>&#13; <p>Dr Holmes added: “Although there is circumstantial evidence that dairy cows are providing a reservoir of infection, it is still not known for certain if cows are infecting people, or people are infecting cows. This is one of the many things we will be looking into next.</p>&#13; <p>“Although our research suggests that the new MRSA accounts for a small proportion of MRSA – probably less than 100 isolations per year in the UK, it does appear that the numbers are rising. ֱ̽next step will be to explore how prevalent the new strain actually is and to track where it is coming from. If we are ever going to address the problem with MRSA, we need to determine its origins.”</p>&#13; <p>Scientists at the Health Protection Agency (HPA) co-authored this paper, providing the analysis of the human samples of the new strain. Dr Angela Kearns, head of the HPA’s Staphylococcus Reference Laboratory said: “There are numerous strains of MRSA circulating in the UK and the rest of Europe. Even though this new strain is not picked up by the current molecular tests, they do still remain effective for the detection of over 99 per cent of MRSAs. This new strain can be picked up by another type of test, which has shown to be effective in trials in the UK and elsewhere in Europe.</p>&#13; <p>“This is a very interesting find and the HPA is currently involved in further research to screen a wider population of MRSA samples to ascertain how prevalent it is. It’s important to remember MRSA is still treatable with a range of antibiotics and the risk of becoming infected with this new strain is very low.”</p>&#13; <p>With funding from the Medical Research Council, the researchers will next be undertaking prevalence surveys in people and in dairy cattle in the UK to determine how much new MRSA is present in these populations. They will also be performing an epidemiological study on farms to identify any factors that may be associated with infection by the new MRSA, to look for further new MRSA strains, and to explore the potential risks of the new strain to farm workers.</p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Antibiotic resistant bacteria found in both humans and dairy cows.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Although our research suggests that the new MRSA accounts for a small proportion of MRSA – probably less than 100 isolations per year in the UK, it does appear that the numbers are rising. ֱ̽next step will be to explore how prevalent the new strain actually is and to track where it is coming from. If we are ever going to address the problem with MRSA, we need to determine its origins.</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Dr Mark Holmes, Department of Veterinary Medicine at the ֱ̽ of Cambridge</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/" target="_blank">Royalty-free image Collection by Flickr</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Cow</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="http://creativecommons.org/licenses/by-nc-sa/3.0/"><img alt="" src="/sites/www.cam.ac.uk/files/80x15.png" style="width: 80px; height: 15px;" /></a></p>&#13; <p>This work is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/">Creative Commons Licence</a>. If you use this content on your site please link back to this page.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Fri, 03 Jun 2011 09:10:27 +0000 gm349 26276 at Stopping superbugs in their tracks /research/news/stopping-superbugs-in-their-tracks <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/mrsacredit-matt-holden-wt-sanger-institute.jpg?itok=T6Hz_h4G" alt="MRSA" title="MRSA, Credit: Matt Holden, WT Sanger Institute" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><div>&#13; <div>&#13; <p>Hundreds of millions of patients around the world are affected by healthcare-associated infections each year, although the true scale of their global burden and impact on health remains unknown because of the difficulty in gathering reliable data. In developing countries, the problem of such infections is compounded by the fact that the pathogens involved are frequently resistant to the antibiotics available.</p>&#13; <p>Reducing mortality and morbidity from healthcare-associated infections depends on effective prescribing policies based on information provided by diagnostic microbiology, as well as prevention through improved hygiene such as frequent hand washing. ‘One of the major difficulties in resource-poor countries,’ says Professor Sharon Peacock, from the Departments of Medicine and Pathology, ‘is the lack of even simple diagnostic microbiology in many hospitals. As a result, many pathogens go unrecognised.’</p>&#13; <p>Having spent most of the past decade working in resource-restricted areas of south-east Asia, Professor Peacock believes that researchers can help tackle this problem using technology at two ends of the spectrum. ‘By supporting the development of low-cost, sustainable diagnostic microbiology laboratories to identify pathogens, information is generated to guide prescribing and highlight the need for infection control. This also provides bacterial strain collections that can then be examined using cutting-edge tools to define transmission pathways of important pathogens at local, national and global levels.’</p>&#13; <h2>&#13; Detective work</h2>&#13; <p> ֱ̽antibiotic-resistant MRSA ‘superbug’ has a deservedly high profile across the developed world but is barely on the radar in developing countries. For example, until recently, there had been no documented report of MRSA in Cambodia. This isn’t because the country has remained completely free of the pathogen but simply because there were no facilities to detect its presence. Now, the Angkor Hospital for Children in Western Cambodia has such a laboratory, the development of which was supported by a team led by Professor Peacock while working at the Wellcome Trust-Mahidol ֱ̽-Oxford Tropical Medicine Research Unit in Thailand, where she continues to support research following her move to Cambridge in 2009.</p>&#13; <p>Within a month of opening, the first child with MRSA infection was identified. And, with continued support from Cambridge- and Thailand-based researchers, the laboratory has recently reported that MRSA causes infection in both the hospital and the community, and is being carried by a proportion of the population.</p>&#13; <p> ֱ̽impact of detecting these and other multi-resistant pathogens is potentially huge, explains Professor Peacock: ‘Such information alerts healthcarers and policy makers of the possibility of infection with these organisms and the risk of treatment failure using the readily available antimicrobial drugs, as well as supporting the need for hand washing to reduce spread among hospital patients’.</p>&#13; <h2>&#13; Tracking the global spread of multi-resistant pathogens</h2>&#13; <p>As highlighted by a study published this year in <em>Science</em> magazine, cutting-edge technology also has an important role to play. In this study, Professor Peacock was part of a team led by the Wellcome Trust Sanger Institute at Hinxton, Cambridge, which developed high-throughput genome sequencing to study the transmission of a single clone of MRSA that has become disseminated across much of the world.</p>&#13; <p>Existing techniques were unable to discriminate between individual strains, but genome sequencing showed that no two strains were genetically identical. ֱ̽beauty of the technique is that it allows healthcare officials to see how MRSA, or any other pathogen, can evolve and spread – from person to person, from hospital to hospital, and from country to country.</p>&#13; <p>Professor Peacock’s research is continuing to use this sophisticated technology to inform better infection control of MRSA, and other pathogens, in hospital settings. ‘Being able to feed this information back to hospitals,’ she explains, ‘is key for interventions to be targeted with precision and according to need.’</p>&#13; </div>&#13; <div>&#13; <p>For more information, please contact Professor Sharon Peacock (<a href="mailto:sjp97@cam.ac.uk">sjp97@cam.ac.uk</a>) at the Departments of Medicine and Pathology. Professor Peacock chairs the <a href="https://www.infectiousdisease.cam.ac.uk/">Cambridge Infectious Disease Initiative</a>, one aim of which is the development and translation of research in developing countries.</p>&#13; </div>&#13; </div>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p>Work in resource-restricted healthcare settings in south-east Asia is defining the transmission of hospital ‘superbugs’ using low-tech diagnostics and high-tech tools.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">One of the major difficulties in resource-poor countries is the lack of even simple diagnostic microbiology in many hospitals. As a result, many pathogens go unrecognised.</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Professor Sharon Peacock</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/" target="_blank">Matt Holden, WT Sanger Institute</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">MRSA</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="http://creativecommons.org/licenses/by-nc-sa/3.0/"><img alt="" src="/sites/www.cam.ac.uk/files/80x15.png" style="width: 80px; height: 15px;" /></a></p>&#13; <p>This work is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/">Creative Commons Licence</a>. If you use this content on your site please link back to this page.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Mon, 01 Nov 2010 14:10:52 +0000 bjb42 26100 at Superbug detective /research/discussion/superbug-detective <div class="field field-name-field-news-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><img class="cam-scale-with-grid" src="/sites/default/files/styles/content-580x288/public/news/research/news/speacock1.jpg?itok=PIkdG49i" alt="Sharon Peacock" title="Sharon Peacock, Credit: ֱ̽ of Cambridge" /></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p>On returning to the UK after seven years in Thailand researching infectious diseases, Cambridge's new Professor of Clinical Microbiology, Sharon Peacock, has taken up with an 'old friend', as she resumes her long-standing research interest in the bacterium <em>Staphylococcus aureus</em>, particularly the MRSA strains that have become resistant to the antibiotic drug methicillin. ֱ̽increasing incidence of antibiotic resistance in such bacteria is a global health threat. Her expertise is helping to drive a programme of research that will track and block routes of transmission for these 'superbugs'.</p>&#13; <p>Based within the Departments of Medicine and Pathology, and working closely with the Health Protection Agency and the Wellcome Trust Sanger Institute, Professor Peacock has recently returned from the Mahidol-Oxford Tropical Medicine Research Unit in Thailand. There, she directed a wide-ranging programme of bacterial disease research focused on prevalent diseases in South-East Asia. This included clinical treatment trials, diagnostic test development and the molecular epidemiology of several bacteria.</p>&#13; <p>Professor Peacock has also had a long-term interest in MRSA, which over the past four decades has spread around the world and is resistant to many of the antibiotics commonly used in hospitals. ‘Tracking how MRSA spreads can be likened to playing detective since it’s all about trying to identify and follow specific strains of bacteria as they move globally, between countries and between individuals,’ she explained. ‘It’s important that we can do this because measures can then be introduced to further reduce transmission in settings where the bacteria pose the greatest problem such as hospitals.’</p>&#13; <p>Through a collaboration with the Wellcome Trust Sanger Institute, her research has already had a dramatic impact on moving forward the detective story: in 2004, the genome of the MRSA strain that is a common cause of hospital-based infection in the UK was sequenced; and in January 2010, a new method for tracking transmission routes based on the rapid sequencing of genetic differences between strains was published in Science. Her focus now is to translate these research tools from the laboratory into the clinical setting, so that preventive interventions can then be targeted with precision and according to need</p>&#13; <p><strong>What’s the best piece of advice you’ve ever been given?</strong></p>&#13; <p>‘Make it hard, but make it look easy’; in other words, challenge yourself, but don’t let on that it’s so difficult. I’ve always tried not to settle into a comfort zone for very long before I’m looking for the next challenge, and the one after that.</p>&#13; <p><strong>Have you ever had a Eureka moment?</strong></p>&#13; <p>Yes – when I realised that what I really wanted to be was a doctor. But, at the time, I was six months into student nurse training, and having left school at 16 almost empty handed and without the O-levels I needed to study medicine. It was only when I saw how enthralling the whole diagnostic process was – taking a history, examining the patient, carrying out investigations, and reaching a diagnosis – that I knew that’s what I wanted to do. I had a very long way to go to achieve it. I did my O-levels at night school, then my A-levels part-time while working as a nurse to fund myself. It was quite difficult to get into ֱ̽ to study medicine because of this unusual background, but Southampton ֱ̽ gave me the opportunity. I haven’t really had a Eureka moment since – I’ve just been trying to achieve what I set out to do all those years ago!</p>&#13; <p><strong>If you could wake up tomorrow with a new skill, what would it be?</strong></p>&#13; <p>Wouldn’t it be good to wake up and realise you could run a marathon? I’m a very keen spinner – it’s a fitness regimen using a specially designed stationary bike – and I’d love to have the fitness of a marathon runner.</p>&#13; <p><strong>What is your favourite research tool?</strong></p>&#13; <p>There’s no doubt that access to information on the scale the internet provides has revolutionised the way we do our work. It’s hard to imagine that, when I was a medical student, finding scientific articles involved a trip to the library and locating the right volume of Index Medicus on a bookshelf, all to provide what PubMed does at the touch of a button. ֱ̽other major research tool for me is the advent of high-throughput sequencing technology, and the speed with which we can now sequence genomes and tell individual strains of bacterial pathogens apart, some of which may only differ at a few bases of DNA. It’s an incredibly powerful tool in the battle against the spread of bacteria.</p>&#13; <p><strong>What will the future look like in 2050?</strong></p>&#13; <p>Antibiotic resistance in bacteria is a result of the widespread use of antibiotics over recent decades. Unless we embark on a better global vision for conserving the efficacy of current drugs by limiting their use, this will be a major problem in the future. However, we’ll have a better genetic understanding of bacterial pathogens and based on this I hope that we’ll be able to identify weaknesses that can be targeted with a new generation of antibiotics. And, crucially, many of the technologies that are now becoming available for diagnosing and tracking disease will be translated into cost-effective clinical tools. Even in the face of rising antibiotic resistance, we’ll have the front-line measures to understand and reduce bacterial transmission and limit the spread of infection.</p>&#13; </div></div></div><div class="field field-name-field-content-summary field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even"><p><p> ֱ̽expertise of Cambridge's new Professor of Clinical Microbiology, Sharon Peacock, is helping to drive a programme of research that will track and block routes of transmission for superbugs.</p>&#13; </p></div></div></div><div class="field field-name-field-content-quote field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even">Tracking how MRSA spreads can be likened to playing detective since it’s all about trying to identify and follow specific strains of bacteria as they move globally, between countries and between individuals.&quot;</div></div></div><div class="field field-name-field-content-quote-name field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Sharon Peacock</div></div></div><div class="field field-name-field-image-credit field-type-link-field field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/" target="_blank"> ֱ̽ of Cambridge</a></div></div></div><div class="field field-name-field-image-desctiprion field-type-text field-label-hidden"><div class="field-items"><div class="field-item even">Sharon Peacock</div></div></div><div class="field field-name-field-cc-attribute-text field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p><a href="http://creativecommons.org/licenses/by-nc-sa/3.0/"><img alt="" src="/sites/www.cam.ac.uk/files/80x15.png" style="width: 80px; height: 15px;" /></a></p>&#13; <p>This work is licensed under a <a href="http://creativecommons.org/licenses/by-nc-sa/3.0/">Creative Commons Licence</a>. If you use this content on your site please link back to this page.</p>&#13; </div></div></div><div class="field field-name-field-show-cc-text field-type-list-boolean field-label-hidden"><div class="field-items"><div class="field-item even">Yes</div></div></div> Sat, 01 May 2010 00:00:00 +0000 bjb42 25989 at