研究人员使用质谱检测脓融病毒
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Public release date: 7-Apr-2006
Researchers use mass spectrometry to detect norovirus particles
New process could aid biodefense in rapidly detecting dangerous pathogens
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.
Researchers use mass spectrometry to detect norovirus particles
New process could aid biodefense in rapidly detecting dangerous pathogens
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.
