A single strain of bacteria gave rise to the current national epidemic of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), according to new research published by scientists from the National Institute of Allergy and Infectious Diseases.
Previously, some researchers had proposed that various strains of the MRSA may have evolved to have similar characteristics. However,
this study's comparison of the genomes of 10 isolates of the USA300
strain of MRSA collected from patients from across the United States revealed few major genetic changes had occurred between the isolates,
suggesting that this single strain has given rise to the various isolates (Kennedy AD et al. Proc Natl Acad Sci U S A.10.1073/pnas.0710217105 [published online ahead of print January 23, 2008]).
Kuehn BM. Community-Acquired MRSA. JAMA. 2008;299(8):890. doi:10.1001/jama.299.8.890-a