Staphylococcus aureus is a microorganism that colonizes the skin in 10-35% of healthy individuals. Methicillin-resistant S. aureus (MRSA) is characterized by clonal spread. MRSA clones are unequally distributed across the world and different clones are dominant at different times.
The MACOTRA project studied the interaction between MRSA, humans and the environment. We used mathematical model to gain a better understanding of MRSA dynamics.
A collection of ~300 MRSA strains was genetically characterized, highlighting antimicrobial genes possibly contributing to successful transmission. Different clones were successful in different countries, partly due to antimicrobial resistance gene carriage and antimicrobial usage. Antimicrobial resistance genes transferred easily between some isolates and we identified that bacteriophage – viruses of bacteria – were responsible. Evaluation of MRSA survival under dehydrated conditions or on a human skin mimic showed similar results for epidemic and sporadic MRSA. Survival on a dry environment could not explain success of different clones. Our study of nasal samples from volunteers showed that the bacterial composition of the nose was slightly different in S. aureus carriers compared to noncarriers. Mathematical models suggested that the established dominant clone in a particular country will be maintained as the dominant clone over time.
A main predictor of success was antimicrobial resistance, driven by antibiotic use. Other important factors for success were not identified yet. To enhance international epidemiological surveillance and subsequent data collection, we presented a proposal for harmonisation of MRSA surveillance.
- Margreet Vos, Erasmus MC University Medical Center, Netherlands (Coordinator)
- Jodi Lindsay, Institute of Infection and Immunity, St George’s, University of London, United Kingdom
- Gwenan Knight, Imperial College London, United Kingdom
- Leo Schouls, National Institute for Public Health and the Environment (RIVM), Netherlands
- Gerard Lina, Universite Claude Bernard Lyon 1, France
- Participation in International Society of Antimicrobial Chemotherapy (ISAC) webinar 10 March 2021: Regional and National MRSA Surveillance Programs Worldwide (program and webinar video)
- Novel algorithm and software to improve precision of DNA metabarcoding in microbiota analyses
- Dehydration model
- MACOTRA strain collection metadata database
- Epidemics, 2021. Understanding MRSA clonal competition within a UK hospital; the possible importance of density dependence.