MRSA bug linked to livestock is found in hospitals
A University of Edinburgh study has suggested that an MRSA bug in UK hospitals can be traced back to a type of bacteria found in farm animals.
Researchers say a drug-resistant bacteria carried by some livestock, MRSA strain staphylococcus aureus CC398, has been found in patients.
The study shows it has been transmitted to humans on "many occasions".
It provides new evidence that the livestock-associated CC398 strain could spread in hospitals.
People and humans generally harbour distinct variants of CC398, which the team say evolved from the same original bacteria. However, the study shows the livestock-associated strain can be transmitted to humans.
CC398 from farm animals is resistant to some common antibiotic drugs, which could make it harder to treat. Scientists say the strain's enhanced drug resistance in livestock is likely to be the result of widespread use of antibiotics on farms.
Hospital and nursing home patients are at increased risk of MRSA infection, but healthy people in the wider community can also become infected with some strains.
University of Edinburgh scientists studied the evolution of the CC398 strain using a complex genetic analysis technique.
It is the first time researchers have unravelled the full genetic code of the CC398 strain from the UK and compared these with published genetic data on CC398 infections from humans and livestock around the world.
The scientists say that CC398 has entered the UK on several occasions since the mid 1940s, though the original source of the bacteria remains unclear.
Lead researcher Dr Melissa Ward said: "Our findings emphasise the need for strict biosecurity practices in the food production industry, as well as continued surveillance and infection control of MRSA in hospitals. Responsible use of antibiotics in healthcare settings and agriculture is of utmost importance."