Researchers studied LA, San Francisco, Chicago, New York and Raleigh-Durham
The rates of community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) varied dramatically among academic medical centers in California, New York, Illinois and North Carolina, suggesting there is not a uniform change in the "national epidemic" of the "superbug" that has generated extensive public health concern over the past decade, according to a new study.
Dr. Brad Spellberg, LA BioMed infectious disease specialist, says dramatic differences in the incidence and rate of change in the number of MRSA and MSSA infections indicate ongoing, fundamental changes in bacterial ecology.
Credit: LA BioMed
The study, published online ahead of print in the journal Clinical Infectious Diseases, surveyed hospital records of 4,171 cases of MRSA and MRSA-related infections between 2008 and 2011 in five medical centers located in Los Angeles, San Francisco, Chicago, New York City and Raleigh-Durham, NC.
The rates of MRSA acquired in the community declined 57% from 2008-2011 in the Los Angeles medical center. In contrast, CO-MRSA rates tripled at the New York medical center, while the rates remained stable in San Francisco, Chicago and Raleigh-Durham. At the same time, the rates for a MRSA-related infection, methicillin-susceptible S. aureus (MSSA), tended to change in the opposite direction from MRSA rates.
Since MRSA and MSSA rates moved in opposite directions, the authors concluded: "Enhanced infection control efforts are unlikely to account for such variation in community onset infection rates"
"These dramatic differences in the incidence and rate of change in the number of MRSA and MSSA infections indicate ongoing, fundamental changes in bacterial ecology, which need further study to protect public health," said Brad Spellberg, MD, a Los Angeles Biomedical Research Institute (LA BioMed) infectious disease specialist and senior author of the study. "Fully understanding MRSA, MSSA and other antibiotic-resistant infections is essential to finding new approaches to save the lives and protect the health of our patients here and around the world."
First recognized in the early 1960s, MRSA became a major public health concern in the late 1980s because it had become endemic in most U.S. hospitals. In the 1990s, a new wave of the antibiotic-resistant staph infections acquired in the community swept the nation. These were not caused by bacteria that had escaped from the hospital. They were MSSA strains with a novel resistance element. These MSSA strain types, especially the ones with a genetic background known as USA 300, were highly virulent. Driven by the emergence of USA300, the incidence of MRSA infections rose dramatically in the 2000s.
In the mid-1990s, Los Angeles and Chicago were among the first regions in the country to be affected by the emergence of MRSA acquired in the community. The "epidemic" of these community-acquired antibiotic-resistant infections only recently reached New York, leading researchers to conclude that the relatively stable incidence of CO-MRSA in Chicago and the decline in Los Angeles will begin to be seen in East Coast cities in the near future.
"This study also found that more than half the MRSA cases involved the most virulent form of the bacteria, bacterium with the USA300 genetic background. But the incidence varied from 35% at one hospital to 80% at another," said Dr. Spellberg. "All these differences in rates suggest that the epidemiology and other factors of antibiotic resistance vary greatly, requiring further study to fully understand antibiotic-resistant bacteria."
Dr. Spellberg is the author of the book, "Rising Plague," which examined the rise of antibiotic resistant infections and the failure to develop new antibiotics to combat them. The other researchers engaged in the study were: Arnold S. Bayer, Loren G. Miller and Raul Macias-Gil, LA BioMed; Michael Z. David, Robert S. Daum, Alison Baesa, Susan Boyle-Vavra and Julia Sieth, University of Chicago; Henry F. Chambers and Joann Volinski, University of California, San Francisco; Vance G. Fowler, Jr. and Thomas H. Rude, Duke University Medical Center, and Belinda Ostrowsky and Philip Gialanella, Montefiore Medical Center/Albert Einstein College of Medicine in New York.
About LA BioMed
Founded in 1952, LA BioMed is one of the country's leading nonprofit independent biomedical research institutes. It has approximately 100 principal researchers conducting studies into cancer, inherited diseases, infectious diseases, illnesses caused by environmental factors and much more. It also educates young scientists and provides community services, including prenatal counseling and childhood nutrition programs. LA BioMed is academically affiliated with the David Geffen School of Medicine at UCLA and located on the campus of Harbor-UCLA Medical Center. For more information, please visit http://www.LABioMed.org
Laura Mecoy | Eurek Alert!
New antibody analysis accelerates rational vaccine design
09.08.2018 | Scripps Research Institute
Distrust of power influences choice of medical procedures
01.08.2018 | Johannes Gutenberg-Universität Mainz
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Information Technology
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences