Researchers use mass spectrometry to detect norovirus particles

Apr 07, 2006

Scientists have used mass spectrometry for decades to determine the chemical composition of samples but rarely has it been used to identify viruses, and never in complex environmental samples. Researchers at the Johns Hopkins Bloomberg School of Public Health recently demonstrated that proteomic mass spectrometry has the potential to be applied for this purpose. Using a two-step process, researchers successfully separated, purified and concentrated a norovirus surrogate from a clinical sample within a few hours. Nanospray mass spectrometry was used to demonstrate the feasibility of detecting norovirus particles in the purified concentrates.

Human norovirus is responsible for an estimated 23 million cases of gastrointestinal illness in the United States each year. This pathogen is a particular problem aboard cruise ships. The researchers believe that their mass spectrometric method could potentially be used for biodefense and public health preparedness as a tool for rapidly detecting norovirus--a category B bioterrorism agent--and other viral public health threats. The study is published in the April 2006 edition of Applied and Environmental Microbiology.

In simplified terms, mass spectrometry is essentially a scale for weighing molecules. A laser turns a sample into ionized particles, which are then accelerated in a vacuum toward a detector. The time lapsed prior to registering on the detector helps researchers determine the mass--or weight--of the particles. By targeting characteristic particles, or peptides, belonging to the viral coat protein, the virus can be positively identified by matching the results to entries in genetic databases.

In the Hopkins study, the researchers analyzed a stool sample treated with virus-like particles, which closely resemble norovirus but are noninfectious. Using mass spectrometry, the researchers were able to detect the norovirus capsid protein down to levels typically found in clinical specimens from sick individuals.

"This is the first report of the use of mass spectrometry for the detection of norovirus," said David R. Colquhoun, lead author of the study and research fellow with the Johns Hopkins Center for a Livable Future. "This is a significant step towards using mass spectrometry as an environmental surveillance tool for the detection of pathogenic human viruses in complex environmental samples such as human and animal waste."

Typically, bacteria and viruses are identified by cultivation on selective media and cell lines. However, this process does not work for human norovirus, which cannot be cultured outside the human body.

Rolf Halden, PhD, assistant professor in the Department of Environmental Health Sciences and senior author of the study, pointed out that proteomic mass spectrometry is appealing because it has the potential to identify different types and strains of viruses regardless of whether their presence is suspected or not. "Unlike other processes, we do not need to know what we are looking for in advance. Any pathogen whose genetic information is contained in online genetic databases represents a suitable potential target. This makes the technique ideal for situations where you have an emerging infectious agent or pathogenic strain, such as in a potential terrorist attack," said Halden.

Source: Johns Hopkins University Bloomberg School of Public Health

Explore further: 'NanoSuit': Researchers use nano-coating to allow for electron microscopy of living insects

add to favorites email to friend print save as pdf

Related Stories

Modular disability aids for world's poorest

21 minutes ago

Brunel University London design engineering student Cara O'Sullivan's final year project aims to help developing countries make their own disability aids using modular components.

New tattoos discovered on Oetzi mummy

31 minutes ago

With the aid of a non-invasive photographic technique, researchers at the EURAC-Institute for Mummies and the Iceman have been able to show up all the tattoos on the man who was found preserved in a glacier, ...

Particle physicists discuss JUNO neutrino experiment

57 minutes ago

The construction of the facilities for the JUNO neutrino experiment has been initiated with an official groundbreaking ceremony near the south Chinese city of Jiangmen. Involved in the Jiangmen Underground ...

Cellular memory of stressful situations

58 minutes ago

Stress is unhealthy. The cells use therefore a variety of mechanisms to deal with stress and avert its immediate threat. However, certain stressful situations leave marks that go beyond the immediate response; ...

Recommended for you

Holes in valence bands of nanodiamonds discovered

Jan 28, 2015

Nanodiamonds are tiny crystals only a few nanometers in size. While they possess the crystalline structure of diamonds, their properties diverge considerably from those of their big brothers, because their ...

Demystifying nanocrystal solar cells

Jan 28, 2015

ETH researchers have developed a comprehensive model to explain how electrons flow inside new types of solar cells made of tiny crystals. The model allows for a better understanding of such cells and may ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.