Researchers from Children's Hospital Oakland Research Institute, Emory University, and Network Biosystems have been awarded a five-year grant from the National Institutes of Health to develop an assay for NetBio's integrated molecular testing system that will identify the biothreat pathogen Chlamydia psittaci and distinguish it from similar non-biothreat pathogenic organisms.
The grant, which is worth $1.2 million in its first year, marks the team's third NIH-funded project to help advance commercialization of NetBio's technology platform, called Genebench. The other two grants have covered the development of rapid, point-of-care diagnostics for Neisseria gonorrhoeae and Chlamydia trachomatis.
Deborah Dean, a researcher at Children's Hospital Oakland Research Institute, is principal investigator on the new grant, which is being administered by the National Institute of Allergy and Infectious Diseases. Additional PIs include Timothy Read, director of the Emory Georgia Research Alliance Genomics Center; and Richard Selden, executive chairman and chief scientific officer of NetBio.
According to recently published grant information, the researchers are developing the C. psittaci assay in response to "an urgent need to develop rapid sample-to-answer clinic- and field-deployable diagnostics for NIAID Category A, B, and C biothreat pathogens to protect both military and civilian populations."
The specific goal of the grant is to advance and validate NetBio's Genebench to identify Category B pathogen C. psittaci, which causes life-threatening respiratory diseases and has historically been a focus of bioweapons development as well as being a vastly understudied pathogen, the researchers wrote in their grant abstract.
The team also aims to detect non-biothreat pathogens that can cause pneumonia and are often confused with biothreat agents in clinical presentation. These pathogens include C. trachomatis, C. pneumoniae, Mycoplasma pneumonia, and Legionella pneumophila.
The researchers cited the original biodefense RFA assertion that medical diagnostics that can rapidly distinguish whether an individual is infected with a biological threat agent or a common infection with similar, generalized symptoms are of high priority.
There are currently few or no commercial diagnostics for these pathogens in the US, the researchers noted.
NetBio has been developing Genebench for several years. The platform uses core microfluidic electrophoresis and Sanger sequencing technology originally developed in partnership with Shimadzu; and also features proprietary nucleic acid sample prep, multiplexed PCR, laser detection, and integrated analysis software.
According to the scientists, the platform is a ruggedized instrument that accepts a biochip set that has been shown in preliminary studies to purify genomic DNA from clinical samples, amplify and electrophoretically separate it, and laser-detect and type C. trachomatis in about one hour from DNA purification to detection.
Under the NIAID grant, the scientists plan to sequence representative C. psittaci biothreat and non-biothreat atypical respiratory pathogens for robust primer selection; modify the biochip set to purify genomic DNA from human clinical nasopharyngeal swab and sputum samples; and use a primer-selection pipeline developed in Read's lab to identify primers for differentiating biothreat and non-biothreat atypical respiratory pathogens based on comparative genomics of available genomes and those sequenced during the course of the project.
The team will then use the primers to develop a multiplexed DNA amplification assay to distinguish each pathogen; and will evaluate the sensitivity, specificity, and positive and negative predictive value of the assay using spiked samples and clinical nasopharyngeal swabs and sputum samples, comparing the test to the few available commercial nucleic acid amplification tests for the target organisms and to highly sensitive in-house RT-PCR assays.
Eventually, the group plans to enter the assay into clinical trials and submit it for US Food and Drug Administration approval.
"A future goal will be to expand the assay to other biothreat respiratory pathogens," the researchers wrote. "We envision that the NetBio sample-to-answer assay will be used in ERs, MD offices, clinics, military facilities, hospitals, and the field to advance our understanding of the epidemiology of atypical respiratory diseases and best treatment strategies, which will inform biothreat preparedness."
Broadly used, the diagnostic will also be able to detect patients with common and biothreat infections, enabling early identification of an attack and rapid treatment of infected military and civilian populations.
In March, NetBio secured $1 million for the first year of a three-year, Phase II Small Business Innovation Research grant from NIH to continue developing Genebench for diagnosing and differentiating C. trachomatis strains, work that began in 2009 (PCR Insider, 3/22/2012).
And in 2011, the company won $300,000 from NIAID to develop the platform for gonorrhea diagnosis (PCR Insider, 9/8/2011).
NetBio's Selden said in March that the company is actually developing two versions of Genebench: one that will use electrophoretic separation and laser detection to identify multiple amplified targets; and one that will use integrated Sanger sequencing for detection. Both platforms would integrate similar sample prep and amplification steps.
Both systems are being designed for use at the point of care by non-technical users.
NetBio is also currently field testing a human forensic ID system based on the same core technology, which it plans to launch commercially later this year.