New MRSA strain

An international study has revealed that a new strain of the MRSA has made a leap from food animals to humans. Scientists from 20 institutions have conducted a research project focusing on the MRSA CC398 strain, known as pig MRSA or livestock-associated MRSA due to its prevalence among farm workers.

The study was led by Translational Genomics Research Institute (TGen).

Whole genome sequencing has shown that it was most likely an antibiotic-susceptible strain in humans in the past before transferring to food animals, where it became resistant to tetracycline and methicillin due to routine antibiotic use among animals to prevent staph infections.

This excessive application of antibiotics has caused the disease to rapidly evolve and spread back to humans.

The research was published in PLoS on-line and was titled “Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact”.

The introduction to the paper reads:

“The presence of Livestock Associated MRSA (LA-MRSA) in humans is associated with intensity of animal contact. It is unknown whether the presence of LA-MRSA is a result of carriage or retention of MRSA-contaminated dust. We conducted a longitudinal study among 155 veal farmers in which repeated nasal and throat swabs were taken for MRSA detection. Periods with and without animal exposure were covered.”

The reference is:

Graveland H, Wagenaar JA, Bergs K, Heesterbeek H, Heederik D (2011) Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact. PLoS ONE 6(2): e16830. doi:10.1371/journal.pone.0016830

For further details see: PLoS One

Posted by Tim Sandle