MRSA Strains Can Affect Humans and Livestock

Melissa Ward PhD CIIE Research Fellow Centre for Immunity, Infection and Evolution University of Interview with:
Melissa Ward PhD
CIIE Research Fellow Centre for Immunity, Infection and Evolution
University of Edinburgh


Medical Research: What is the background for this study? What are the main findings?

Dr. Ward: We studied a strain of the bacterium Staphylococcus aureus known as CC398, which can colonise and cause MRSA infection in humans and livestock. People and animals generally harbour genetically distinct variants of CC398, but we found human isolates, including a small number from Scottish hospitals, which were more similar to the livestock strains. Such isolates were resistant to a larger number of antibiotics than the CC398 strain which typically circulates in humans. By looking at the genetic sequences of strains from across the globe, we also inferred that CC398 has entered Scotland on multiple occasions.

Medical Research: What should clinicians and patients take away from your report?

Dr. Ward: Our findings emphasise the need for continued surveillance and infection control of MRSA in hospitals, as well as strict biosecurity practices in the food production industry. Responsible use of antibiotics by clinicians and patients antibiotics is of utmost importance.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Ward: Whole genome sequencing studies have the potential to transform our understanding of the spread of bacteria and antibiotic resistance. Future studies with more densely sampled data could inform targeted control measures for preventing bacterial transmission, predicting the emergence of particularly virulent strains and devising antibiotic usage strategies to limit levels of resistance.


Time-Scaled Evolutionary Analysis of the Transmission and Antibiotic Resistance Dynamics of Staphylococcus aureus Clonal Complex 398
Ward MJ, Gibbons CL, McAdam PR, van Bunnik BA, Girvan EK, Edwards GF, Fitzgerald JR, Woolhouse ME

Appl Environ Microbiol. 2014 Sep 19. pii: AEM.01777-14. [Epub ahead of print]

Last Updated on November 5, 2014 by Marie Benz MD FAAD