The predominant strain of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infecting people in Europe, the Middle East and northern Africa derived from a single sub-Saharan ancestor, a team of international researchers reported this week in mBio®, the online open-access journal of the American Society for Microbiology.
CA-MRSA refers to MRSA infections occurring in healthy people with no recent hospitalizations. The infections, which are typically skin infections, can be transmitted through close person-to-person contact or contact with a contaminated item like a towel or clothing.
"With increasing levels of CA-MRSA reported from most parts of the Western world, there is a great interest in understanding the origin and factors associated with the emergence of these epidemic lineages," said lead study author Marc Stegger, PhD, of the Department of Microbiology and Infection Control at the Statens Serum Institut in Denmark. "Our study determined that a single descendant of a methicillin-sensitive ancestor circulating in sub-Saharan Africa rose to become the dominant CA-MRSA clone in Europe, the Middle East and north Africa."
In Europe, the predominant CA-MRSA strain belongs to a family called clonal complex 80 (CC80), which are resistant to the antibiotics kanamycin/amikacin, tetracyclin and fusidic acid, in addition to beta-lactams. It was first identified sporadically in the late 1990s, but has since been identified throughout northern Africa, the Middle East and Europe, with only sporadic reports from Asia, Australia and South America.
For the study, Stegger and colleagues at 19 other institutions around the world analyzed 97 S. aureus CC80 samples from 22 countries in Europe, North Africa, sub-Saharan Africa, the Middle East and Asia isolated between 1993 and 2010. Twenty-three samples were sensitive to methicillin while 74 were resistant to methicillin. The investigators performed whole genome sequencing, a technique that determines the complete DNA sequence of an organism's genetic material at a single time, and other tests to trace the origin, evolution and dissemination pattern of the European CA-MRSA clone CC80.
Within the samples, the team identified two distinct groups of S. aureus: a methicillin-sensitive clone from sub-Saharan Africa that was susceptible to all antibiotics, and the rest from all other areas that were MRSA and most often resistant to other antibiotics. Studying family trees among the bacteria, they found that the European CC80 clone evolved from the strain from sub-Saharan Africa. They also noted that in the transition from a methicillin-sensitive line to a CA-MRSA clone, the bacteria simultaneously acquired two highly specific genetic elements making them resistant to methicillin and became resistant to fusidic acid.
The methicillin-sensitive S. aureus resided in sub-Saharan Western Africa, potentially as a result of the local human migration patterns, Stegger said. The investigators hypothesize that CC80 moved to other countries starting in the mid-1980s due to several factors, including increased migration from sub-Saharan Africa in search of better economics, and as a result of an increase in European tourism to this region of Africa, he said. The simultaneous acquisition of methicillin and fusidic acid resistance determinants and their stability in the European CA-MRSA could be a result of a higher selective pressure in North Africa and Europe.
The study was supported by Pfizer and the Foundation pour la Recherche Médicale.
mBio® is an open access online journal published by the American Society for Microbiology to make microbiology research broadly accessible. The focus of the journal is on rapid publication of cutting-edge research spanning the entire spectrum of microbiology and related fields. It can be found online at http://mbio.asm.org.
The American Society for Microbiology is the largest single life science society, composed of over 39,000 scientists and health professionals. ASM's mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.
Jim Sliwa | Eurek Alert!
Researchers simplify tiny structures' construction drip by drip
12.11.2018 | Princeton University, Engineering School
Mandibular movement monitoring may help improve oral sleep apnea devices
06.11.2018 | Elsevier
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
15.11.2018 | Earth Sciences
15.11.2018 | Physics and Astronomy
15.11.2018 | Physics and Astronomy