MRSA Infection

MRSA Strains in Horses

Comparative molecular analysis substantiates a zoonotic potential of equine Methicillin- resistant Staphylococcus aureus (MRSA) -- Walther et al., 10.1128/JCM.01626-08 -- Journal of Clinical Microbiology.

Despite the increasing importance of Methicillin-resistant Staphylococcus aureus (MRSA) in veterinary medicine, knowledge about the epidemiology of these pathogens in horses is still poor. The phylogenetic relationship of strains from human and equine origin has been addressed before, usually by analyzing results of common standard classification methods for MRSA. This work intends to go beyond the base line of typing procedures in order to comparatively characterize equine and human MRSA strains of similar phylogenetic background. Additionally to MLST, PFGE, spa typing, SCCmec typing and a PCR for PVL detection, a microarray analysis of altogether 185 structural, virulence-associated and resistance loci was applied. As a result, the clonal complex (CC) 8 was absolutely predominant (16) in 19 investigated equine MSRA strains. Of CC8, 13 strains belonged to sequence type (ST) 254, three others to ST8. This genotype has been isolated from different equine patients in various regions over several years, substantiating the apparent predominance of CC8 STs in MRSA strains of horses worldwide. Beyond that, comparatively investigated human strains of ST254 displayed indistinguishable molecular typing results to those of equine origin. Two further equine strains (ST22, ST1117) showed similarity to ST22 human strains (CC22). One equine strain was of ST398, a genotype recently described to be frequently isolated from specimens of pigs and pig farmers. These data provide evidence for the adaptation to more than one mammalian species of certain MRSA genotypes, reflecting their extended host spectrum.

Vets are MRSA reservoir

AVMA backgrounder cautions practitioners about risks of MRSA - November 15, 2008.

The publication says veterinarians are at risk of becoming MRSA reservoirs. About 6.5 percent of practitioners who attended the 2005 American College of Veterinary Internal Medicine Forum and volunteered for testing were colonized with MRSA. None had been recently hospitalized or previously had the infection diagnosed. Of those volunteers, about 4.4 percent of small animal practitioners and about 15.6 percent of large animal practitioners were colonized. About one percent of the general public is colonized with MRSA and 30 percent with Staphylococcus, according to information from CDC spokeswoman Nicole Coffin. The AVMA backgrounder says veterinarians need to practice proper hygiene and educate others who come into contact with infected animals how to minimize risks. To read the publication, go to www.avma.org, click on the Reference tab, and follow the Animal Health link. FAQ sections are available through links on the side of the full article.

MRSA in Pigs Infecting Farmers

HighWire Press -- Medline Abstract.

We compared the prevalence of human and animal methicillin-resistant Staphylococcus aureus (MRSA) at pig farms in The Netherlands, and related this to individual and farm-level characteristics. More than half of the farms investigated (28/50) had MRSA in pigs or stable dust and about one third (15/50) of person(s) were identified as MRSA carriers. Human carriage was found only on farms with MRSA-positive pigs or dust. MRSA strains in human samples were the same spa-type as found in pigs and all were not typable by pulsed-field gel electrophoresis (NT-MRSA). Multivariate analyses showed that risk factors for human MRSA carriage were: working in pig stables (OR 40, 95% CI 8-209) and the presence of sows and finishing pigs (OR 9, 95% CI 3-30). Veterinary sample collectors sampling the pigs showed transient MRSA carriage only during the day of the farm visit. Working in pig stables with MRSA-positive pigs poses a high risk for acquiring MRSA, increasingly so when contact with live pigs is more intensive or long lasting.

Local health officials say MRSA is now being tracked

Local health officials say MRSA is now being tracked | KLEW CBS 3 - News, Weather and Sports - Lewiston, ID - Lewiston, Idaho | News.

Some of the contaminated ground pork found in a recent investigation by Fisher Broadcasting television stations was purchased in Lewiston. Because of legal concerns, where the contaminated pork was purchased can't be revealed. Pork products were purchased at three Lewiston supermarkets. The store where the MRSA was found is being notified. North Central District Health Department Staff Epidemiologist Donna Anderson said Friday, that MRSA has been identified in the Valley since the 90s, but only now is the state starting to track it. "Well we don't really know how much MRSA is in our community because it is not one of those things that is reportable as far as skin infections go," said Anderson. "The State of Idaho in the year 2008, we now have requirements for reporting invasive MRSA, that is MRSA that is found in a normally sterile site. For example blood, or spinal fluid, if MRSA is found in those sites, then it's reportable." Anderson said MRSA could also be picked up from surfaces like handrails and shopping carts. As far as food-borne MRSA, she said the key is keeping wounds covered, washing hands and thoroughly cleaning kitchens.

MRSA and animals: zoonosis or humanosis

Link: Methicillin-resistant Staphylococcus aureus and animals: zoonosis or humanosis? -- Morgan, 10.1093/jac/dkn405 -- Journal of Antimicrobial Chemotherapy.

Methicillin-resistant Staphylococcus aureus (MRSA) is increasing worldwide. Occasionally, animals are colonized or infected incidentally with human strains. Recently, however, new strains of MRSA emerging from within the animal kingdom, particularly in pigs, are causing human infection. MRSA has been reported in species as diverse as companion animals, horses and pigs, through to chinchillas, bats and parrots. In contrast, whereas strains of community-associated MRSA, the majority of which carry genes encoding Panton–Valentine leucocidin, are spreading rapidly in human populations, only sporadic cases have been reported in animals to date. Although MRSA has been found in some meat products, the implications for human infection through consumption are unclear. This review examines the epidemiology of MRSA in animals and human attendants/owners, the diagnosis and management of MRSA colonization, infection and infection control strategies in animals.

Genome-Wide Analysis of Ruminant Staphylococcus aureus

Link: Genome-Wide Analysis of Ruminant Staphylococcus aureus Reveals Diversification of the Core Genome -- Ben Zakour et al. 190 (19): 6302 -- The Journal of Bacteriology.

Staphylococcus aureus causes disease in humans and a wide array of animals. Of note, S. aureus mastitis of ruminants, including cows, sheep, and goats, results in major economic losses worldwide. Extensive variation in genome content exists among S. aureus pathogenic clones. However, the genomic variation among S. aureus strains infecting different animal species has not been well examined. To investigate variation in the genome content of human and ruminant S. aureus, we carried out whole-genome PCR scanning (WGPS), comparative genomic hybridizations (CGH), and the directed DNA sequence analysis of strains of human, bovine, ovine, and caprine origin. Extensive variation in genome content was discovered, including host- and ruminant-specific genetic loci. Ovine and caprine strains were genetically allied, whereas bovine strains were heterogeneous in gene content. As expected, mobile genetic elements such as pathogenicity islands and bacteriophages contributed to the variation in genome content between strains. However, differences specific for ruminant strains were restricted to regions of the conserved core genome, which contained allelic variation in genes encoding proteins of known and unknown function. Many of these proteins are predicted to be exported and could play a role in host-pathogen interactions. The genomic regions of difference identified by the whole-genome approaches adopted in the current study represent excellent targets for studies of the molecular basis of S. aureus host adaptation.

ST398 reaches Iran

Link: Antimicrobial Resistance of Old and Recent Staphylococcus aureus Isolates from Poultry: First Detection of Livestock-Associated Methicillin-Resistant Strain ST398 -- Nemati et al. 52 (10): 3817 -- Antimicrobial Agents and Chemotherapy.

The susceptibilities of 12 antimicrobial agents for two collections of Staphylococcus aureus, isolated in the 1970s and in 2006 from poultry, were determined. For eight antibiotics, the percentage of resistance was significantly higher in the recent isolates. Ten recent isolates were methicillin resistant and had spa types t011 and t567, belonging to multilocus sequence type 398. This is the first report of "livestock-associated" methicillin resistant S. aureus from healthy poultry.

Pets an MRSA source

Link: Spotlight on Research.

So far, it’s clear that humans and pets can be colonized with the MRSA bacteria, said John R. Middleton, an associate professor of food animal medicine and surgery at the University of Missouri. That doesn’t mean they’ve got active infections, just that they’re carriers of the germs that are resistant to most frontline antibiotics. An ongoing study of some 600 people-pet households across the U.S. showed that staph aureus germs were present in nearly 28 percent of people and about 13 percent of pets. About 10 percent of households had both a human and an animal colonized. MRSA, the drug-resistant strain, was detected in more than 5 percent of humans and about 3 percent of dogs and cats, Middleton said

Pets an MRSA source

Link: Spotlight on Research.

So far, it’s clear that humans and pets can be colonized with the MRSA bacteria, said John R. Middleton, an associate professor of food animal medicine and surgery at the University of Missouri. That doesn’t mean they’ve got active infections, just that they’re carriers of the germs that are resistant to most frontline antibiotics. An ongoing study of some 600 people-pet households across the U.S. showed that staph aureus germs were present in nearly 28 percent of people and about 13 percent of pets. About 10 percent of households had both a human and an animal colonized. MRSA, the drug-resistant strain, was detected in more than 5 percent of humans and about 3 percent of dogs and cats, Middleton said

New pet visit guidelines aim to control infections

Link: New pet visit guidelines aim to control infections -- Bryden 179 (4): 317 -- Canadian Medical Association Journal.

No llamas, reptiles or ponies allowed. Those might seem altogether sensible, if not self-evident restrictions when talking about hospitals and long-term care facilities. Yet, there have been instances in which those or even more exotic and unusual species have been brought into North American hospitals and long-term care facilities, putting patients at higher risk of infection, or even injury, and prompting the development of a new set of evidence-based guidelines for animal-assisted interventions in health care facilities (Am J Infect Control 2008;36:78-85). The guidelines propose that health care facilities place "age, origin, behaviour, diet and health" restrictions on animals involved in health care interventions, while implementing outright bans on some species, including lizards, salamanders, non-human primates, rats, hedgehogs, prairie dogs and species that have not been litter-trained or "for which no other measures can be taken to prevent exposure of patients/residents to animal excrement."

MRSA growing more resistant in chickens

Link: Antimicrobial resistance of old and recent Staphylococcus aureus isolates from poultry: first detection of livestock-associated methicillin-resistant strain ST398 -- Nemati et al., 10.1128/AAC.00613-08 -- Antimicrobial Agents and Chemotherapy.

The susceptibilities of two collections of Staphylococcus aureus isolated in 1970s and 2006 from poultry were determined to 12 antimicrobial agents. For 8 antibiotics the percentage of resistance was significantly higher in the recent isolates. Ten recent isolates were MRSA and had spa types t011 and t567 belonging to multi-locus sequence type 398. This is the first report of the "livestock-associated" MRSA from healthy poultry.

Pig MRSA found in Poultry

Link: Antimicrobial resistance of old and recent Staphylococcus aureus isolates from poultry: first detection of livestock-associated methicillin-resistant strain ST398 -- Nemati et al., 10.1128/AAC.00613-08 -- Antimicrobial Agents and Chemotherapy.

The susceptibilities of two collections of Staphylococcus aureus isolated in 1970s and 2006 from poultry were determined to 12 antimicrobial agents. For 8 antibiotics the percentage of resistance was significantly higher in the recent isolates. Ten recent isolates were MRSA and had spa types t011 and t567 belonging to multi-locus sequence type 398. This is the first report of the "livestock-associated" MRSA from healthy poultry.

MRSA & Animals - Who do they get it from?

Link: Staphylococcus aureus host specificity: comparative genomics of human versus animal isolates by multi-strain microarray -- Sung et al. 154 (7): 1949 -- Microbiology.

Staphylococcus aureus is a commensal and pathogen of several mammalian species, particularly humans and cattle. We aimed to (i) identify S. aureus genes associated with host specificity, (ii) determine the relatedness of human and animal isolates, and (iii) identify whether human and animal isolates typically exchanged mobile genetic elements encoding virulence and resistance genes. Using a well-validated seven-strain S. aureus microarray, we compared 56 UK S. aureus isolates that caused infection in cows, horses, goats, sheep and a camel with 161 human S. aureus isolates from healthy carriers and community acquired infections in the UK. We had previously shown that human isolates are clustered into ten dominant and a few minor lineages, each with unique combinations of surface proteins predicted to bind to human proteins. We found that the animal-associated S. aureus clustered into ten lineages, with 61 % assigned to four lineages, ST151, ST771, ST130 and ST873, that were unique to animals. The majority of bovine mastitis was caused by isolates of lineage ST151, ST771 and ST97, but a few human lineages also caused mastitis. S. aureus isolated from horses were more likely to cluster into human-associated lineages, with 54 % of horse-associated S. aureus assigned to the human clusters CC1, CC8 and CC22; along with the presence of some multi-drug resistant strains, this suggests a human origin. This is the most comprehensive genetic comparison of human versus animal S. aureus isolates conducted, and because we used a whole-genome approach we could estimate the key genes with the greatest variability that are associated with host specificity. Several genes conserved in all human isolates were variable or missing in one or more animal lineages, including the well-characterized lineage specific genes fnbA, fnbB and coa. Interestingly, genes carried on mobile genetic elements (MGEs) such as chp, scn and sak were less common in animal S. aureus isolates, and bap was not found. There was a lot of MGE variation within lineages, and some evidence that exchange of MGEs such as bacteriophage and pathogenicity islands between animal and human lineages is feasible, but there was less evidence of antibiotic resistance gene transfer on the staphylococcal cassette chromosomes (SCC) or plasmids. Surprisingly, animal lineages are closely related to human lineages and only a handful of genes or gene combinations may be responsible for host specificity.

Health Protection Agency calls for vigilance over Pig MRSA

Link: Health Protection Report | News Archives | 20 June 2008.

Health Protection Scotland recently reported three cases of the so-called pig strain of Community MRSA (ST398) occurring in humans during 2007 [1]. These were the first such cases in the UK and all three individuals were treated successfully. Increasing colonisation of pig stocks in continental Europe with the ST398 strain of MRSA, albeit without any manifest signs of infection, has been recognized for several years. More recently - after the first human case was reported in 2003 in the Netherlands - routine testing of pigs for the bacterium has been carried out in Belgium, Denmark, Germany, Spain and the Netherlands to monitor its emergence and spread. The EU Commission has required all member states to monitor MRSA levels in pig stocks since January 2008 and plans to publish EU-wide data in 2009. Human cases of ST398 remain relatively rare, occurring mainly as a result of contact with farm animals, most commonly pigs, with some being detected in those working with chickens, cattle or horses. Current evidence suggests the ST398 strain probably originated in animals but, in some instances, it can be transferred to humans in close contact with animals carrying the MRSA strain. To identify any further human cases of pig-related MRSA (ST398), the HPA reiterates the need for continued vigilance by diagnostic laboratories in England and Wales on Community-associated MRSA [2].

MRSA in animals - different genetic roots

Link: Genome-wide analysis of ruminant Staphylococcus aureus reveals diversification of the core genome -- Ben Zakour et al., 10.1128/JB.01984-07 -- The Journal of Bacteriology.

Staphylococcus aureus causes disease in humans and a wide array of animals. Of note, S. aureus mastitis of ruminants, including cows, sheep and goats, results in major economic losses worldwide. Extensive variation in genome content exists among S. aureus pathogenic clones. However, the genomic variation among S. aureus strains infecting different animal species has not been well examined. To investigate variation in the genome content of human and ruminant S. aureus we carried out whole genome PCR scanning (WGPS), comparative genomic hybridizations (CGH), and directed DNA sequence analysis of strains of human, bovine, ovine, and caprine origin. Extensive variation in genome content was discovered including host- and ruminant-specific genetic loci. Ovine and caprine strains were genetically allied whereas bovine strains were heterogeneous in gene content. As expected, mobile genetic elements such as pathogenicity islands and bacteriophages contributed to the variation in genome content between strains. However, differences specific for ruminant strains were restricted to regions of the conserved core genome, which contained allelic variation in genes encoding proteins of known and unknown function. Many of these proteins are predicted to be exported and could play a role in host-pathogen interactions. The genomic regions of difference identified by the whole-genome approaches adopted in the current study represent excellent targets for studies of the molecular basis of S. aureus host-adaptation.

UK Government downplays PIG MRSA threat

Link: Defra casts doubt on link to MRSA - Meat News & Industry Knowledge - Meatinfo.co.uk.

Defra has questioned the accuracy of newspaper reports linking three identified cases of MRSA in humans in Scotland to pigs. A spokesperson for Defra told MTJ: “We are not aware of any direct link between these patients and livestock. DH/Health Protection Scotland would need to provide further information on these cases.” It also pointed to 940 clinical isolates of staphylococcus aureus from cattle that were tested by the Veterinary Laboratories Agency in 2006/07 and proved negative for MRSA. Defra added that an EU survey of breeding pigs is in progress to assess the prevalence of MRSA and of salmonella in Great Britain. It started in January 2008 and will conclude in December 2008. Once the survey is complete and the results have been analysed, Defra said, it will give a representative picture of the situation across the GB breeding pig population. “The provisional results to date are negative for MRSA, but the survey is still in progress,” it added.

MRSA bacteria found in USA pigs

Link: Potentially fatal bacteria found in pigs, farmworkers.

Last week, the Seattle P-I's "Secret Ingredients" blog disclosed that Tara Smith, an assistant professor at the University of Iowa Department of Epidemiology, and her graduate researchers found MRSA in more than 70 percent of the pigs they tested on farms in Iowa and Illinois. In what is apparently the first testing of swine for MRSA in the U.S., Smith and her team swabbed the noses of 209 pigs on 10 farms. They also found the bacteria among livestock workers employed by those hog operations. On Friday, at the annual meeting of the American Society for Microbiology in Boston, Abby Harper, one of Smith's graduate assistants, presented the results of the study on farmworkers. She said she and Michael Male tested 20 workers at the Iowa swine farms and found that 45 percent carried the same MRSA bacteria as the pigs. Smith said she is working with collaborators in Minnesota, Ohio, North Carolina and other areas to examine more swine farms. "We're going to be looking at conventional, free-range and organic or antibiotic-free pigs," she said. "We will be paying special attention to the antibiotics that are being used, because there are indications that the tetracycline used in swine farming may be the cause of the spread of MRSA," she explained. A link between increased use of antibiotics and an increased incidence of MRSA is being hotly debated.

MRSA from pigs discovered by campaigners

Link: MRSA from pigs has passed to humans and could be in the food chain| News | This is London.

Until recently, there were no reported cases in Britain. But Government laboratories in Scotland have discovered three cases in humans, none of whom work with pigs. This raises the possibility the superbug is being passed between humans or is reaching consumers buying pork on the High Street. The cases were revealed after pressure from campaigners at the Soil Association. Its experts became aware of an unusual case of MRSA in Scotland and asked the Scottish MRSA Reference Laboratory to carry out further tests. It found the MRSA involved was the strain found in pigs and that there were at least two other cases. Richard Young, the Soil Association's policy adviser, said: 'The Government had plenty of opportunities to take steps to keep this MRSA out, but it failed to take them. 'It is has been burying its head in the sand. It is an absolute disgrace.'

Fears grow that MRSA variant has entered food chain in UK

Link: Fears grow that MRSA variant has entered food chain - Health News, Health & Wellbeing - The Independent.

British people have been infected for the first time by an animal variant of MRSA, the hospital superbug that infects more than 4,000 patients a year. Scientists revealed yesterday that three patients in separate hospitals were infected with the ST398 strain, which is found in factory-farmed pigs in the Netherlands. None of the humans had a close association with farm animals, raising the possibility that the superbug has entered the food chain. Most cases of the ST398 strain have been spread to people in close contact with animals such as farmers, vets and abattoir workers, but cooks may be infected if bacteria on their hands entered a cut or a wound. MRSA has been found in pigs in the Netherlands, Denmark, Belgium and Germany and in other farm animals such as chickens and cattle. The strain – which has caused skin infections and rare heart and bone problems in humans – is believed to have spread among pigs that were fed antibiotics to spur growth and protect them from disease. A survey by the Dutch authorities in 2006 found traces of the bug in 20 per cent of pork products, 21 per cent of chicken meat and 3 per cent of beef.

MRSA strain in pigs caught by one in 5 working with them

Link: HighWire Press -- Medline Abstract.

In 2007, 678 pigs of all age groups out of 347 different farms from Lower Saxony and Northrhine-Westphalia and 86 persons occupationally exposed to pigs were investigated for their nasal colonisation with methicillin-resistant Staphylococcus areus (MRSA) by the Field Station for Epidemiology of the University of Veterinary Medicine Hannover and the Robert Koch-Institute. At the individual animal level, a frequency of positive results of 13% (n = 85 positive animals) and at the herd level, a frequency of positive results of 18% (n = 62 positive herds) were found. All isolates were assigned to the Multilocus Sequence Typing Type ST398. Within MRSA-positive herds, there were more MRSA-negative than MRSA-positive animals. Among the occupationally exposed persons (veterinarians, laboratory personnel and meat inspection personnel), 20 persons (23%) showed a nasal colonisation with MRSA ST398. A quite strong association between the intensity of the contact to pigs with the frequency of nasal colonisation in the occupationally exposed persons was detected. None of the animals or the humans nasally colonised by MRSA ST398 showed any clinical symptoms of a staphylococcal infection. Conclusions are drawn on the herd and intra-herd prevalence of the nasal colonisation of pigs with MRSA ST398 in pigs, but especially on which questions need to be addressed by further research.

EU investigating MRSA in pigs

Link: Animals: MRSA: 12 May 2008: Written answers (TheyWorkForYou.com).

Jonathan R Shaw (Parliamentary Under-Secretary (Marine, Landscape and Rural Affairs) and Minister for the South East), Department for Environment, Food and Rural Affairs; Chatham & Aylesford, Labour) | Hansard source Methicillin-resistant Staphylococcus aureus (MRSA) has not been detected in farmed livestock in the UK and there is no current evidence that food-producing animals form a reservoir of infection in the UK. The organism has been isolated from dairy cows, pigs and chickens outside the UK, as well as in companion animals (including cats, dogs and horses) both in the UK and elsewhere. Ongoing monitoring of the international picture is being maintained. A 12-month long study to provide an initial overview of the presence of MRSA in breeding pig herds across Europe began in January 2008. This is being carried out under Community legislation. It is anticipated that the results of this study will be published in mid 2009 and that they will inform the direction of future work by DEFRA. DEFRA's Antimicrobial Resistance Co-ordination (DARC) Group continues to provide guidance on policy relating to antimicrobial resistance. The membership of the DARC Group reflects a partnership approach and includes representatives from many organisations involved in both human and animal health throughout the UK. DARC created a MRSA sub-group in 2005, through which DEFRA is assisting and encouraging various initiatives relating to MRSA from the Bella Moss Foundation (a UK registered charity promoting awareness of MRSA in animals), industry and the veterinary profession. DEFRA has funded research to better understand the epidemiology of MRSA in companion animals and livestock and any role it may play in human infections.

Antimicrobial resistance--animals and the environment

Link: The 2008 Garrod Lecture: Antimicrobial resistance--animals and the environment -- Lord Soulsby of Swaffham Prior, 10.1093/jac/dkn183 -- Journal of Antimicrobial Chemotherapy.

The evolution of resistance to microbes is one of the most significant problems in modern medicine, posing serious threats to human and animal health. The early work on the use of antibiotics to bacterial infections gave much hope that infectious diseases were no longer a problem, especially in the human field. However, as their use, indeed over-use, progressed, resistance (both monoresistance and multiresistance), which was often transferable between different strains and species of bacteria, emerged. In addition, the situation is increasingly complex, as various mechanisms of resistance, including a wide range of β-lactamases, are now complicating the issue. The use of antibiotics in animals, especially those used for growth promotion, has come in for serious criticism, especially those where their use should be reserved for difficult human infections. To lend control, certain antibiotic growth promoters have been banned from use in the EU and the UK. Antimicrobial resistance is not confined to bacteria but occurs in viruses, protozoa and helminths. In many of these, the mechanism of resistance is unknown, and hence their control is still in question. It is likely, however, that the mechanisms are no less complicated than those pertaining to bacteria.

10% 0f dogs MRSA carriers?

Link: Beware of Fido: chief vet warns of the risk of disease transmission - Times Online.

Some 10 per cent of dogs are thought to carry the superbug MRSA. Research by a team at Liverpool University Veterinary School showed that many dog owners appeared unaware of, or unconcerned about any health risks from their pet. According to a survey of 260 households in a semi-rural town in the South Wirral, where most pets were labradors or Jack Russells, almost 20 per cent of the animals slept in the bedroom and 14 per cent on a person’s bed. Dr Landeg’s warning also coincides with a review of pet travel rules on the Continent by the European Commission.

Cat reinfects owner with MRSA

Link: The Bay Area Reporter Online | Keeping you and your pets healthy.

Include on that list the overly-hyped infection MRSA, methicillin-resistant Staphylococcus aureus. The family cat was the source of a recurring MRSA infection in an otherwise healthy German woman, according to a report published in the New England Journal of Medicine in March. The woman developed multiple deep skin abscesses caused by MRSA. She was treated but the infection came back. Screening found the bug in the nose of other family members, even though they had no signs of active infections. They were treated, but the mother s abscesses came back. In desperation the doctor swabbed the throats of the three family cats, and one of them came back positive for MRSA. The bacteria sample from the cat had the same patterns of drug resistance seen in the mother. The animal was treated and so was the woman. This time her sores cleared up for good. She was no longer being reinfected by others in the household. Veterinarians first noticed MRSA in the milk of a cow in 1972, but reports of the infection in all types of animals really have exploded in the last five years, said Jeff Bender, a professor of veterinary public health at the University of Minnesota. "Typically pets clear this rather rapidly, in a couple of weeks, as long as there is not reinfection," said J. Scott Weese, a professor at the Ontario Veterinary College at the University of Guelph, in Canada. "If you see long-term colonization, usually it is because it is passing between different individuals in the household, humans or animals."

Beware of the dog: you may catch MRSA

Link: Beware of the dog: you may catch MRSA - Times Online.

They might be man’s best friend, but dogs should be sold with a health warning, a study suggests. Letting a dog lick your face, picking up its mess or allowing it to sleep on your bed could put you at risk of catching salmonella, campylobacter or MRSA. Research commissioned by the Department for Environment, Food and Rural Affairs (Defra) from the University of Liverpool Veterinary School, has identified health risks in the interaction between man and dog. The findings, published in The Veterinary Record, may enrage the country’s 6.5 million dog owners. Men, in particular, may have to learn cleaner habits because it seems they have a problem picking up dog mess. Risks of infection from dog to Man at present are low.

Doctors urge caution over hospital animal visits

Link: The Canadian Press: Hedgehogs bad, Labradors good: group issues new advice for hospital pet visits.

Hedgehogs, prairie dogs, non-human primates and alpacas shouldn't be making rounds in hospitals and long-term care facilities, according to new infection control advice for popular animal visitation programs. Therapy animals shouldn't be permitted access to patients' bathrooms, where they could pick up bugs like Clostridium difficile by licking surfaces or drinking from toilet bowls. And animals at high risk of carrying salmonella - turtles and dogs fed a raw food diet - should be barred from participating in animal therapy programs, the guidelines say. The lengthy list of recommendations, recently published in the American Journal of Infection Control, was the product of a consensus conference held in Toronto in January 2007. The conference, which drew in animal and human health experts, therapy animal program operators and infection control specialists, was sponsored by the Public Health Agency of Canada and the University of Guelph's Centre for Public Health and Zoonoses. (Zoonoses are the diseases that move back and forth between two-and four-legged animals.) The idea behind the guidelines is to minimize the risk that visiting animals will spread more than love as they make their way from patient to patient.

11% Dutch pork is contaminated with MRSA bacteria

Link: Pig Progress | Pig News | 11% pork is contaminated with MRSA bacteria.

A recent study carried out by the risk department of the Dutch Food and Consumer Product Safety Authority (VWA) revealed that 11% of meat products in the retail sector is contaminated with the hospital bacteria ‘MRSA’. In 84% of the cases, the nt-MRSA (non-typable MRSA), which affects pigs, calves and livestock farmers is present. MRSA is the name given to a group of bacteria that belong to the Staphylococcus aureus (SA) family of bacteria. The people who are most at risk of becoming either colonised or infected with MRSA are those in close contact with people who may be carrying the bacteria, for example in hospital wards that care for ill people. Nt-MRSA is a clone of MRSA. According to the Authority, meat does not contribute to the spread of the bacteria, which is resistant to most antibiotics. However, nt-MRSA can be spread where livestock is kept.

Pig MRSA spreading into humans in Holland

Link: First outbreak of methicillin-resistant Staphylococcus aureus ST398 in a Dutch hospital, June 2007.

In June 2007, MRSA was cultured from a diabetic foot ulcer of a patient on a surgical ward. Subsequent screening of contacts among patients and healthcare workers revealed four additional patients with MRSA infection and/or colonisation and five healthcare workers who carried MRSA. Two of the five affected patients (one with prostate carcinoma and one with a diabetic foot) were successfully decolonised with mupirocin nasal ointment, chlorhexidine wash, and treatment with trimetoprim/rifampicin. A further colonised patient with a gastro-intestinal malignancy and two patients with infected diabetic foot ulcers remained colonised, despite several decolonisation regimens. Of 238 healthcare workers who were screened, five were colonised in the nose and/or throat and had no skin conditions. All five have been treated with mupirocin nasal ointment and chlorhexidine wash and successfully decolonised. All strains were resistant to tetracycline and non-typable by PFGE. Spa-typing showed that all strains were spa-type t567. This spa-type corresponds to MLST type 398, a type previously found in pigs. None of the patients had had contact with pigs or veal calves. One healthcare worker lived on the grounds of a pig farm but neither she nor her partner came into contact with pigs themselves. While we presume that this health care worker was the source of the infection, this could not be proven. Permission to sample the pigs on this farm was not granted. Conclusions The NT-MRSA strain responsible for this outbreak was spa-type t567, which corresponds to MLST type ST398, the clonal complex to which most of NT-MRSA strains belong. This outbreak shows that transmission on a larger scale than a one-on-one transmission between caretaker and patient can occur with NT-MRSA in a hospital setting.

MRSA spreading from Animals to Humans

Link: HighWire Press -- Medline Abstract.

In 2003 in the Netherlands, a new methicillin-resistant Staphylococcus aureus (MRSA) strain emerged that could not be typed with Sma1 pulsed-field gel electrophoresis (NT-MRSA). The association of NT-MRSA in humans with a reservoir in animals was investigated. The frequency of NT-MRSA increased from 0% in 2002 to >21% after intensified surveillance was implemented in July 2006. Geographically, NT-MRSA clustered with pig farming. A case-control study showed that carriers of NT-MRSA were more often pig or cattle farmers (pig farmers odds ratio [OR] 12.2, 95% confidence interval [CI] 3.1-48.6; cattle farmers OR 19.7, 95% CI 2.3-169.5). Molecular typing showed that the NT-MRSA strains belonged to a new clonal complex, ST 398. This study shows that MRSA from an animal reservoir has recently entered the human population and is now responsible for >20% of all MRSA in the Netherlands.

Human and animal MRSA Differences

Link: Bacteriological Characteristics of Staphylococcus aureus Isolates from Humans and Bulk Milk -- Hata et al. 91 (2): 564 -- Journal of Dairy Science.

The aim of this study was to clarify the epidemiological association and bacteriological characteristics of human and animal Staphylococcus aureus isolates. Pulsed-field gel electrophoresis showed that pulsotypes (PT) of isolates from bulk milk differed from PT from human isolates, suggesting that there is no epidemiological association between isolates from these 2 sources. The absence of a common PT could result from the lack of contact between the sources. Methicillin-resistant S. aureus from human secretions and S. aureus from bulk milk in Japan consisted of 1 and 2 dominant clusters, respectively, whereas methicillin-susceptible S. aureus from humans consisted of assorted clusters. Isolates belonging to the dominant clusters showed the coagulase serotype, the capsule serotype, detection of exotoxin genes, and antimicrobial susceptibility. Isolates from bulk milk did not show the penicillin-binding protein 2a gene, and 252 of 275 isolates belonging to the 2 dominant clusters of bulk milk were susceptible to ampicillin, cefazolin, erythromycin, chloramphenicol, oxacillin, and vancomycin. Moreover, the LukM/LukF'-PV leukotoxin gene was detected in 233 of 275 isolates belonging to the dominant clusters in bulk milk isolates. These results support the hypothesis that a number of factors play a role in the adaptation of S. aureus isolates to specific hosts.

Antibiotic resistance found in wild birds

Link: Medical News Today News Article.

In the latest issue of the journal Emerging Infectious Diseases, Swedish researchers report that birds captured in the hyperboreal tundra, in connection with the tundra expedition "Beringia 2005," were carriers of antibiotics-resistant bacteria. These findings indicate that resistance to antibiotics has spread into nature, which is an alarming prospect for future health care. The scientists took samples from 97 birds in northeastern Siberia, northern Alaska, and northern Greenland. These samples were cultivated directly in special laboratories that the researchers had installed onboard the icebreaker Oden and were further analyzed at the microbiological laboratory at the Central Hospital in V�xj�, Sweden. "We were extremely surprised," says Bj�rn Olsen, professor of infectious diseases at Uppsala University and at the Laboratory for Zoonosis Research at the University of Kalmar. "We took samples from birds living far out on the tundra and had no contact with people. This further confirms that resistance to antibiotics has become a global phenomenon and that virtually no region of the earth, with the possible exception of the Antarctic, is unaffected." The researchers' hypothesis is that immigrating birds have passed through regions in Southeast Asia, for example, where there is a great deal of antibiotics pressure and carried with them the resistant bacteria to the tundra.

MRSA trebles in Holland due to pig infection

Link: HighWire Press -- Medline Abstract.

In The Netherlands, patients exposed to pigs or veal calves were recently shown to be at high risk of methicillin-resistant Staphylococcus aureus (MRSA) carriage. In Amphia Hospital (Breda, The Netherlands), 32% of patients in this risk group were shown to carry MRSA. This resulted in a 3-fold increase in the annual MRSA incidence.

1 in 5 Dutch MRSA cases linked to Pigs

Link: MRSA of Animal Origin in Humans | CDC EID.

In 2003 in the Netherlands, a new methicillin-resistant Staphylococcus aureus (MRSA) strain emerged that could not be typed with Sma1 pulsed-field gel electrophoresis (NT-MRSA). The association of NT-MRSA in humans with a reservoir in animals was investigated. The frequency of NT-MRSA increased from 0% in 2002 to >21% after intensified surveillance was implemented in July 2006. Geographically, NT-MRSA clustered with pig farming. A case–control study showed that carriers of NT-MRSA were more often pig or cattle farmers (pig farmers odds ratio [OR] 12.2, 95% confidence interval [CI] 3.1–48.6; cattle farmers OR 19.7, 95% CI 2.3–169.5). Molecular typing showed that the NT-MRSA strains belonged to a new clonal complex, ST 398. This study shows that MRSA from an animal reservoir has recently entered the human population and is now responsible for >20% of all MRSA in the Netherlands.

Cow staph a rare strain

Link: Multilocus sequence typing of Staphylococcus aureus isolates recovered from cows with mastitis in Brazilian dairy herds -- Rabello et al. 56 (11): 1505 -- Journal of Medical Microbiology.

Staphylococcus aureus is a major pathogen associated with bovine mastitis, one of the most important infectious diseases occurring in dairy cattle herds worldwide. In the present study, S. aureus isolates recovered from cows with mastitis in dairy herds located in the south-east of Brazil were genotyped by PFGE and multilocus sequence typing (MLST). PFGE identified 60 pulsotypes (PTs), which were found to be distributed among six clonal complexes (CCs) by MLST. All PTs with similarity percentages greater than 65 % belonged to the same CC. Most of the PTs belonged to CC126 (n=28) and CC97 (n=19), which were represented by 91 % of the isolates. These CCs have also been recovered from cows with mastitis in countries located in different continents, but they have rarely been isolated from human specimens. Few isolates were represented by PTs belonging to CCs that are frequently isolated from human specimens (CC1, CC5 and CC30). These data reinforce the hypothesis that a limited number of S. aureus CCs are responsible for most bovine mastitis cases internationally. Specific features of the specialized clones should be studied for use as future targets of mastitis control measures.

A tale of pigs, people, and a shared germ

Link: A tale of pigs, people, and a shared germ - The Boston Globe.

Both the pigs and the people on the Ontario farms tended to harbor one of two strains. The first is the same type of MRSA that has been infecting swine in Europe and spreading to humans. It's called ST398. The second predominant strain is called USA100, and it has been most often associated with human cases of MRSA, suggesting the pigs caught it from the people. Research has shown that three of every four newly emerging diseases in the world have their roots in the animal kingdom. A prime culprit is the pig. Swine have long been recognized as remarkably efficient incubators for germs - and for the ability to take parts of germs from different species and reassemble them into dangerous, novel viruses and bacteria.

Canadian researchers find drug-resistant Staph in pigs, pig farmers

Link: The Canadian Press: Canadian researchers find drug-resistant Staph in pigs, pig farmers.

Canadian researchers have found two major strains of the superbug MRSA on pigs - and pig farmers - in southwestern Ontario, the first time the pathogen has been reported in food animals in North America. One of the strains, they believe, passed from people to pigs. But the other, first seen in pigs in the Netherlands in 2003, seems to have originated in animals and moved into people. The senior author of the work said the findings don't cast in doubt the safety of meat produced on Ontario pig farms. But they do suggest pig farms could serve as sources of methicillin-resistant Staphylococcus aureus infections for people who work on them or live on them. "The big public health concern in my mind is whether we might end up in the same situation as they have in Europe with this starting to become an important community pathogen," said senior author Dr. Scott Weese, a veterinarian at the Ontario Veterinary College in Guelph who specializes in the antibiotic resistant bugs that pass back and forth between people and animals.

MRSA infecting Horses

Link: HighWire Press -- Medline Abstract.

This study evaluated factors associated with MRSA colonization at the time of admission to a veterinary teaching hospital. A case-control study evaluating historical factors was performed. Previous colonization of the horse, previous identification of colonized horses on the farm, antimicrobial administration within 30 days, admission to the neonatal intensive care unit, and admission to a service other than the surgical service were risk factors for community-associated colonization. A better understanding of risk factors for MRSA colonization is important to elucidate the epidemiology of this emerging veterinary and zoonotic pathogen, and to design evidence-based infection control programs.

Vet surgeries may be MRSA superspreaders

Link: HighWire Press -- Medline Abstract.

Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the tracheostomy tube of an 18-month-old castrated male Golden Retriever in the intensive care unit (ICU) of the Ontario Veterinary College. This prompted an investigation of MRSA colonization in other animals in the ICU. Clinical Findings-On day 1 of the investigation, MRSA was isolated from nasal swabs obtained from 2 of 10 animals (2/7 dogs and 0/3 cats), including the index case. Subsequently, MRSA was isolated from 3 of 12 animals on day 9; 3 of 9 animals on day 13; and none of 14, 5, and 6 animals on day 20, 27, and 78, respectively. Overall, MRSA was isolated from 6 of 26 (23%) animals during the outbreak period (4/22 dogs and 2/4 cats). The apparent incidence of MRSA acquisition in the ICU from days 1 through 13 was 20% (5/25 animals).

MRSA in Horses - A growing problem

Link: The Horse: Methicillin-resistant Staphylococcus aureus: A Review.

Like methicillin-susceptible S. aureus, MRSA can colonize horses without causing any problems. Studies have reported carriage rates of 0-5% in horses in the general population, but on some farms the prevalence can exceed 50%. Colonized horses may never have any problems with MRSA, but they are more likely to develop an MRSA infection under certain conditions. Colonized horses are also of concern because they can transmit MRSA to other horses and people. Clinical MRSA infections can occur as sporadic cases or outbreaks. A wide range of infections can develop. In horses in the general population, skin and soft tissue infections (including wound and surgical site infections) and joint infections are most common. In hospitalized horses, surgical site infections predominate. Invasive device (i.e., intravenous catheter) site infections and bloodstream infections can also occur, as well infections at a variety of other sites. Despite the obvious concerns about MRSA, it can be a treatable condition. In a multicenter study, over 80% of horses with MRSA infections survived, although they tended to have prolonged hospital stays and often required additional surgeries. While MRSA strains are resistant to many drugs, acceptable antibiotic options usually exist. The key to proper and successful management is early diagnosis of MRSA so that appropriate therapy can be instituted.

PCR best for detecting Animal MRSA

Link: HighWire Press -- Medline Abstract.

Conclusions: As MRSA of animal origin may display atypical phenotypes, PCR appears to be more reliable for detection of methicillin resistance in animal strains. Significance and Impact of the Study: The study stresses the need for implementing the methods of screening S. aureus from food of animal origin for methicillin resistance.

Pets May Carry Bacteria Deadly to Humans

Link: FOXNews.com - Pets May Carry Bacteria Deadly to Humans - Science News | Current Articles.

While evidence that points to pets helping to infect humans is so far slim, Kottler and University of Missouri-Columbia colleagues Leah Cohn and John Middleton announced today they will study the issue, which is hinted at in some previous research. "There are multiple case reports of humans with infection with MRSA when the household pet was also found to have MRSA," Cohn told LiveScience. "Sometimes, the human infection could not be successfully eradicated until the animal was also treated." Studies have been relatively small and somewhat inconclusive, however. For instance, a small 2005 British study of a vet facility, detailed in the journal Emerging Infectious Diseases, "suggests that dogs can act as reservoirs of MRSA, which can pose a public health risk to owners and veterinary staff."

Pets could be source of multiresistant bacteria infections in humans

Link: Pets could be source of multiresistant bacteria infections in humans, MU researchers investigate.

“This study will help us evaluate the various risk factors associated with this problem,” said Middleton, an associate professor of food animal internal medicine. “Are pets a risk factor" This study will help us track where the disease started and determine what questions the physician should be asking if a patient is diagnosed with MRSA.” ### Currently, the Mizzou researchers, aided by J. Scott Weese, an assistant professor at the University of Guelph Ontario Veterinary College in Canada, are taking samples from 750 to 800 pairs of owners and pets. To date, they have collected about 500 samples and are sorting them into three groups: human healthcare workers and pets, veterinary healthcare workers and pets, and non-healthcare professionals and pets. The study is being funded by the American College of Veterinary Internal Medicine Foundation and the MU Department of Veterinary Medicine and Surgery.

Antimicrobials, animal healthm and human infection

Link: Antimicrobials and animal health: a fascinating nexus -- Soulsby 60 (1): i77 -- Journal of Antimicrobial Chemotherapy.

The widespread use of antibiotics in the human, animal and horticultural fields raises the concerns of the acquisition of resistance by commensal organisms in waste materials from hospitals, farms, fisheries and food-processing plants. Reservoirs of Antibiotic Resistance (ROAR) network, which is part of the Alliance for the Prudent Use of Antibiotics, is concerned with environmental spread of resistance in commensal organisms and the transfer of this between commensals and pathogens. Resistant-enteric bacteria have been found in wildlife (wild rodents) where no contact with domestic livestock or medicine is evident. Whether such infections are manifestations of environmental contamination as envisaged by ROAR or are natural resistant populations existing independent of antibiotic usage in man and animals is unclear at present.

MRSA in Pigs - Not just a Dutch problem

Link: HighWire Press -- Medline Abstract.

Meticillin-resistant Staphylococcus aureus (MRSA) was unexpectedly isolated from a pig used for streptozotocin-induced diabetes research. To investigate the possible source of the MRSA isolate, nasal swabs were obtained from the animal herd, and from animal holding rooms, and veterinary and research staff involved in the handling of the animals. Overall, four MRSA isolates were cultured from three pigs and from a clinician/scientist. Two were ST22-MRSA-IV, a human strain type associated with epidemic spread. The other two were ST398-MRSA-V, a strain type associated with pigs. Thus, care should be taken to prevent cross-transmission of MRSA.

No meat testing yet.....

Link: Methicillin Resistant Staphylococcus...: 10 Jul 2007: Written answers (TheyWorkForYou.com).

Dawn Primarolo (Minister of State, Department of Health) | Hansard source holding answer 9 July 2007 The Food Standards Agency (FSA) has received no reports of incidents of methicillin resistant Staphylococcus aureus (MRSA) contamination in United Kingdom produced meat. No testing for Staphylococcus aureus is required in UK slaughterhouses nor in other European Union slaughterhouses. Meat from third countries is subject to import controls, but is not routinely tested for Staphylococcus aureus FSA and other organisations provide advice on personal hygiene and proper handling, storage and cooking of meat to minimise contamination by micro-organisms. Proper cooking will destroy MRSA.

(The cooking issue is a bit moot .... meat handling could spread the infection - MRSA Watch)

UK to test farm animals for MRSA

Link: Livestock: Methicillin Resistant...: 10 Jul 2007: Written answers (TheyWorkForYou.com).

Jonathan R Shaw (Parliamentary Under-Secretary (and Minister for the South East), Department for Environment, Food and Rural Affairs) | Hansard source MRSA has not been detected in farmed livestock in the UK and there is no current evidence that food-producing animals form a reservoir of infection in the UK. The organism has been isolated from dairy cows, pigs and chickens outside the UK and an ongoing assessment of the international picture is being maintained. The European Food Safety Authority is looking at the issue of MRSA in food-producing animals and considering what surveillance and other actions would be most appropriate for EU member states to undertake to address the issue. The UK is actively participating in the development of these proposals.

New staph infection could spread in meat

Link: Straight Goods

Retail meat from pigs, chickens and other livestock could be infected with a "superbug" strain of methicillin-resistant Staphylococcus aureus (MRSA), according to a UK study released today. The prospect of MRSA in the food chain could spark off another consumer reaction against meat products, already suffering from a bad perception due to past outbreaks of bird flu, food-and-mouth disease and bovine spongiform encephalopathy (BSE). In the Netherlands, the MRSA strain has been found in 20 percent of pork, 21 percent of chicken and 3 percent of beef on sale to the public, the UK's Soil Association stated in the study.

Cattle have MRSAstrains emerging

Link: HighWire Press -- Medline Abstract.

Two isolates were methicillin-resistant S. aureus (MRSA). One of them was a clonal complex 8 MRSA related to the epidemic MRSA strain Irish 01. The other one belonged to ST398/spa-type 34 resembling a newly emerging MRSA strain which has been described to occur in humans as well as in domestic animals. The presence of these two strains highlights the possibility of transfers of S. aureus strains between different host species.

Dutch pig farmers are MRSA carriers

Link: Meatinfo.co.uk.

Dutch producers have hit back at claims by the Soil Association that a new strain of the superbug MRSA has developed among intensively farmed animals on the Continent. The SA is calling on the government to test UK livestock and meat for the bug and claimed there was a serious human health threat in the Netherlands, where 40% of Dutch pigs and 50% of Dutch pig farmers have been found to carry farm-animal MRSA, with the risk it could spread to the UK. It blames the new strain of MRSA on high levels of antibiotics used in intensive farming. Richard Young, SA policy adviser, said: "This new type of MRSA is spreading like wildfire across Europe, and we know it is transferring from farm animals to humans with serious health impacts. Concerned scientists have referred to this as 'a new monster'. Fortunately, it has not yet been found in UK livestock or imported meat, but then neither the government nor the Food Standards Agency (FSA) are looking for it."

No MRSA in UK pigs

Link: Defra acts on MRSA in animals threat.

A Dutch microbiologist, Sander Leenders, called for research to be extended to all Holland's livestock sectors. The bacteria has been found in several people working on poultry farms. In the United Kingdom, Defra says MRSA (Meticillin-Resistant Staphylococcus aureus) is an emerging issue in veterinary medicine. But though it has been isolated from dairy cows, pigs and chickens outside the United Kingdom there is no current evidence that food-producing animals form a reservoir of infection in this country. The organism has not been detected in farmed livestock in this country.