Sequencing reveals genetic diversity in hospital-acquired bacterium
Using genome sequencing, National Institutes of Health (NIH) scientists and their colleagues have tracked the evolution of the antibiotic-resistant bacterium Klebsiella pneumoniae sequence type 258 (ST258), an important agent of hospital-acquired infections.
While researchers had previously thought that ST258 K. pneumoniae strains spread from a single ancestor, the NIH team showed that the strains arose from at least two different lineages. The investigators also found that the key difference between the two groups lies in the genes involved in production of the bacterium's outer coat, the primary region that interacts with the human immune system.
Their results, which appear online in Proceedings of the National Academy of Sciences, promise to help guide the development of new strategies to diagnose, prevent and treat this emerging public health threat.
ST258 K. pneumoniae is the predominant cause of human infections among bacteria classified as carbapenem-resistant Enterobacteriaceae (CRE), which kill approximately 600 people annually in the United States and sicken thousands more. Most CRE infections occur in hospitals and long-term care facilities among patients who are already weakened by unrelated disease or have undergone certain medical procedures.
In the new study, scientists from the NIH's National Institute of Allergy and Infectious Diseases (NIAID) and their colleagues sequenced the complete genomes of ST258 K. pneumoniae strains collected from two patients in New Jersey hospitals. By comparing these reference genomes with gene sequences from an additional 83 clinical ST258 K. pneumoniae isolates, the scientists found that the strains divided broadly into two distinct groups, each with its own evolutionary history.
Further analysis revealed that most differences between the two groups occur in a single "hotspot" of the genome containing genes that produce parts of the bacterium's outer shell. The investigators plan to further study how these genetic differences may affect the bacterium's ability to evade the human immune system.
The findings from this study highlight the wealth of information that can be gained from genome sequencing. They also demonstrate the importance of sequencing to the surveillance and accurate tracking of bacterial spread.
Study collaborators included NIAID-funded scientists from Public Health Research Institute and New Jersey Medical School-Rutgers University, as well as researchers from Case Western Reserve University, the Houston Methodist Research Institute and Hospital System and NIAID's Rocky Mountain Laboratories, where the comparative genome sequencing took place.
ARTICLE: F DeLeo et al. Molecular dissection of the evolution of carbapenem-resistant ST258 Klebsiella pneumoniae. Proceedings of the National Academy of Sciences DOI:10.1073/PNAS.1321364111 (2014).
Frank R. DeLeo, Ph.D., chief of NIAID's Laboratory of Human Bacterial Pathogenesis, is available to comment on the study.
CONTACT: To schedule interviews, please contact Ken Pekoc, (301) 402-1663, email@example.com.
NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov.
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov/.
NIH...Turning Discovery Into Health®
Ken Pekoc | EurekAlert!
Faster detection of pathogens in the lungs
24.06.2016 | Universität Zürich
How yeast cells regulate their fat balance
23.06.2016 | Goethe-Universität Frankfurt am Main
Physicists in Innsbruck have realized the first quantum simulation of lattice gauge theories, building a bridge between high-energy theory and atomic physics. In the journal Nature, Rainer Blatt‘s and Peter Zoller’s research teams describe how they simulated the creation of elementary particle pairs out of the vacuum by using a quantum computer.
Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The...
A year and a half on the outer wall of the International Space Station ISS in altitude of 400 kilometers is a real challenge. Whether a primordial bacterium...
Researchers at Case Western Reserve University have developed a way to swiftly and precisely control electron spins at room temperature.
A physics experiment performed at the National Institute of Standards and Technology (NIST) has enhanced scientists' understanding of how free neutrons decay...
Chemically the same, graphite and diamonds are as physically distinct as two minerals can be, one opaque and soft, the other translucent and hard. What makes...
09.06.2016 | Event News
24.05.2016 | Event News
20.05.2016 | Event News
24.06.2016 | Materials Sciences
24.06.2016 | Physics and Astronomy
24.06.2016 | Physics and Astronomy