Scientists Identify Newly Emerging Staph Strain
It is presently susceptible to methicillin but could acquire genes making it resistant, and it transmits efficiently from person to person.
Scientists from the National Institute of Allergy and Infectious Diseases and colleagues from Columbia University Medical Center and St. George's University of London have confirmed a newly emerging strain of Staphylococcus aureus bacteria has adapted to transmit efficiently among humans. The strain is currently susceptible to methicillin, but it could acquire genes that make it resistant, they reported.
The team used genome sequencing and household surveillance to pinpoint the strain; they plan to continue global surveillance of the new strain and to watch for molecular adaptations.
A methicillin-resistant S. aureus is livestock-associated (LA)-ST398 -- a cause of severe infections in people in Europe who have close contact with swine, but this bacterium does not transmit well person-to-person. The newly found variant of LA-ST398 "has emerged as a significant cause of community-associated infections in several countries, including the United States, Canada and China. The new strain primarily infects the skin and soft tissue, but it can cause more severe disease," according to NIAID, an NIH agency.
Samples from 332 households in northern Manhattan allowed them to determine that the new ST398-NM strain efficiently transmits from person-to-person. ST398-NM contains human-specific immune evasion genes and adheres well to human skin, increasing its ability to colonize and infect people.
The study was headed by Anne-Catrin Uhlemann, M.D., Ph.D., at Columbia. It complements a study that a different group of scientists published in mBio on Feb. 21. That study, also supported by NIH, focused on the evolution of the ST398 strain in livestock, including the effect of antibiotic use. Lance Price, Ph.D., and Paul Keim, Ph.D., at the Translational Genomics Research Institute in Flagstaff, Ariz., headed that study.