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!
Natural metabolite can suppress inflammation
01.07.2016 | ITMO University
Benign bacteria block mosquitoes from transmitting Zika, chikungunya viruses
01.07.2016 | University of Wisconsin-Madison
Densified regions with drastically reduced internal motion either act as crystal precursors or cluster and frustrate all further dynamics
Glasses are neither fluids nor crystals. They are amorphous solids and one of the big puzzles in condensed matter physics. For decades, the question of how...
Since the completion of the human genome an important goal has been to elucidate the function of the now known proteins: a new molecular method enables the investigation of the function for thousands of proteins in parallel. Applying this new method, an international team of researchers with leading participation of the Technical University of Munich (TUM) was able to identify hundreds of previously unknown interactions among proteins.
The human genome and those of most common crops have been decoded for many years. Soon it will be possible to sequence your personal genome for less than 1000...
3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...
R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.
In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...
High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!
In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...
30.06.2016 | Event News
28.06.2016 | Event News
09.06.2016 | Event News
01.07.2016 | Physics and Astronomy
01.07.2016 | Earth Sciences
01.07.2016 | Medical Engineering