via News.

via PFGE diversity within the methicillin-resistant Staphylococcus aureus clonal lineage ST398 – 7thSpace Interactive.

ST398 appears to be less virulent and less transmissible than the community-associated strains of MRSA common in the United States, which have very low prevalence in the Netherlands. “The impact of ST398 on [human] public health may be limited,” Kluytmans writes, “but close monitoring of its evolution over time will be required.”

The strain’s presence in meat after slaughter—it has been found in beef, lamb, and chicken and other birds in addition to pork—raises uncertainties over the degree of its movement into the food chain. While staph species are known to cause staphylococcal food poisoning, MRSA ST398 to date lacks the toxin-producing genes that would produce similar illness.

The chief concern, Kluytmans writes, is the possibility that people preparing MRSA-contaminated meat for cooking will become colonized with the organism on their skin or mucous membranes, moving it into a broad new ecological niche and positioning it as a possible cause of further human infections.

via CIDRAP >> MRSA clone in food animals worrisome, expert says.

The highest level of MRSA positives was in Spain, in 51 per cent of breeding pig herds, followed by Germany, Belgium and Italy, research published by the European Food Safety Authority EFSA showed.

Despite the failure to find the ‘superbug’ in Britain, the Soil Association is calling for improved testing claiming it could ‘easily have been missed due to a poor testing method which had not been checked before the survey began’.

via Fears over rising MRSA levels in EU pigs | News | Farmers Guardian.

Methicillin-resistant S. aureus MRSA poses a serious threat to public health, since few drugs, or in the currently rare cases of vancomycin-resistant MRSA, no drugs are able to treat these infections. The arrival this week of ST398 at a US hospital signals the beginning of a potential clone war with the better recognized USA 200 or USA 300 MRSA clones.

via ST398 MRSA Clone Arrives in US Hospital This Week.

Bacteria have been discovered by researchers at the University and the Institute Laussanne Galli-Valerio, after sampling more than 100 farms. Pathogens have been detected in pigs and two cows that showed symptoms of inflammation of the udders. Also we have found that three people were carrying the bacteria, though they have not shown symptoms.

The strain detected is the ST398, which is resistant to the antibiotic group lactamina-beta, which is widely used in human medicine like penicillin and cephalosporins.

The MRSA was first detected in animals in 1972. We have already detected the presence of MRSA on farms in the U.S., Canada, Germany and Holland.

MRSA, (methicillin-resistant Staphylococcus aureus), or antibiotic-resistant staph, can be found anywhere in nature, according to Paul Ebner, a livestock microbiologist. While he said there has been an increase in the number of these infections and that pigs and other animals can be carriers, the vast majority of infections come from skin-to-skin contact with infected humans.

Making assumptions based on limited studies or information is a big jump and there is no proof to link MRSA in humans to pigs and pig operations at this time, said Ching Ching Wu, professor of veterinary pathobiology and head of microbiology in Purdue’s Animal Disease and Diagnostic Laboratory. Wu said there is more scientific evidence to support the spread of MRSA among humans and from humans to animals rather than from animals to humans.

A University of Iowa study mentioned in the Times column was a pilot study that looked at only two farms, and only one of them had the organism. Another Dutch study was also inconclusive, according to the Purdue experts.

via Purdue Experts On Livestock & Antibiotic Resistance – Cattle Network.

Researchers at Rhode Island Hospital, led by infectious diseases specialist Leonard Mermel, DO, ScM, set out to determine if retail beef, chicken and pork is contaminated with MRSA, vancomycin-resistant enterococci (VRE) and other antibiotic-resistant bacteria. To do so, meats from 10 supermarkets and butcher shops in the greater Providence area were obtained for a total of 36 samples (12 each of beef, chicken and pork).

Their findings indicated that only one of the 36 samples contained antibiotic-resistant bacteria, which was found in a sample of pork from one store. Of note, Staphylococcus aureus (methicillin-sensitive, not MRSA), was found in four of the 36 meat samples, which is consistent with previous reports. These findings do not indicate a cause for concern regarding meat purchased in the Providence area. The researchers, however, do urge the public to be sure to always cook meats to the recommended temperatures. This will reduce risk of illness if any bacteria is present.

Meat Evaluated For MRSA, VRE And Other Organisms In First Of Its Kind Study.

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.

HighWire Press — Medline Abstract.

Seemingly healthy animals are sometimes colonized with the bacteria, and there is evidence humans can both transmit it to animals and become colonized or infected from them. Infections have been reported in horses, dogs, cats, pet birds, cattle, and pigs, the backgrounder states.

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.

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