Salon.com features an interesting article about Methicillin-resistant Staphylococcus aureus that focuses on the origins of MRSA and how it is spreading to humans.  Following is an excerpt from the article:

Recently, something about MRSA — and its epidemiology — has been changing in ways that suggest that those changes could be taking place among livestock. Traditionally considered a disease picked up in hospitals, MRSA is now being seen more and more often in the community. And it doesn’t appear that the hospital-acquired strains have just left the hospital and gone feral. The community-acquired strains of MRSA are genetically different. They’re new. And though there is as of yet no definitive proof identifying livestock as the source of the major new MRSA strains, there is a growing body of evidence that suggests animals are, at minimum, reservoirs for other new strains now infecting humans.

Those studies done to date in Europe and Canada on MRSA give some credence to the involvement of livestock in MRSA’s mutation. Hospitals in the Netherlands, for example, have had fantastic success at controlling MRSA. They employ a "search and destroy" policy, using aggressive screening, strict infection-control procedures, and severe restrictions on the quantity of antibiotics dispensed. They have managed to keep MRSA rates far below those in the rest of Europe. Dutch rates are so low, in fact, that Dutch hospitals list a previous visit to a foreign hospital as an MRSA risk factor.

Read the full article here.