The National Institutes of Health Office of Technology Transfer this month disclosed several new licensing opportunities related to molecular diagnostics using PCR or other nucleic acid amplification and analysis technologies.
All of the assays were developed in laboratories at the US Centers for Disease Control and Prevention. The licensing opportunities include two assays for detecting or discriminating between bacteria that cause Legionnaires' disease; assays for tuberculosis, noroviruses, and dengue virus; and a broad nucleic acid amplification technique for diagnostic test development.
The first technology is a real-time PCR assay capable of detecting all Legionella species and discriminating L. pneumophila from other Legionella species. According to an abstract describing the technology, Legionnaires' disease is typically difficult to diagnose because it confers no unique clinical features or symptoms.
The assay, according to the abstract, is faster than immunoassays; less laborious than current Legionnaires' diagnostics; is rapid, sensitive, and specific; may curtail misdiagnosis associated with serological testing; and is readily adaptable to kit form.
NIH said the assay is in early-stage development and that in vitro data is available. The technology is described in PCT Patent Application No. PCT/US2009/06841 and US Patent Application No. 13/140,922.
The second assay for Legionnaires' disease, developed by a different CDC laboratory, is a real-time multiplex PCR test to diagnose and identify Legionella strains. Specifically, the assay comprises five sets of primers targeting L. bozemanii, L. dumoffii, L. feeleii, L. lonbeachae, and L. micdadei, and corresponding probes.
According to the technology's abstract, each probe is labeled with a different fluorophore, which allows the detection of a particular strain in a single-tube reaction. Thus, the presence of any one of the five pathogenic non-pneumophila strains of Legionella can be rapidly ascertained from clinical or environmental samples.
The assay is described as being in the pre-clinical stage with in vitro data available, and is described in PCT Patent Application No. PCT/US2013/030217 and US Patent Application No. 13/895,898.
Meantime, CDC scientists have developed a rapid, sensitive, and specific real-time assay based on real-time PCR and high-resolution melt analysis that is capable of detecting the presence of Mycobacterium tuberculosis and determining its resistance profile to antibiotics such as rifampin and isoniazid.
According to the technology's abstract, there are currently few assays available capable of both detecting M. tuberculosis and determining its drug resistance. The CDC assay incorporates multiple fluorescent chemistries, can discriminate M. tuberculosis complex strains from non-MTBC strains within five hours of obtaining DNA, and is more cost-efficient and less complex than culturing and sequencing methods, the researchers claim.
The assay is described as early stage with in vitro data available. The technology is described in PCT Patent Application No. PCT/US2011/035217 and US Patent Application No. 13/695,935.
The fourth recently available technology is a specific and sensitive assay based on TaqMan real-time PCR to detect noroviruses in clinical and environmental specimens. The assay can rapidly detect and distinguish norovirus strains from genogroups I and II, which are responsible for the majority of human infections, according to an NIH abstract describing the technology.
Additionally, the assay is multiplexed with an internal extraction control virus — coliphage MS2 — to help validate results. According to NIH, this assay is particularly useful because norovirus cannot be grown in cell culture and enzyme immunoassays lack the necessary sensitivity.
The NIH said the assay is in the pre-clinical stage with in vitro data available. The technology is described in PCT Patent Application No. PCT/US2012/065269.
CDC scientists have also developed a multiplex real-time PCR assay that, prior to seroconversion, selectively detects dengue virus — the cause of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome — in biological or other fluid media such as whole blood, plasma, or serum.
According to a technology abstract, the primers and probes of the assay are sufficiently specific to amplify and detect all four dengue virus serotypes. The assay is already approved by the US Food and Drug Administration, and may provide an improved method to rapidly and accurately serotype dengue virus in clinical and research settings, the inventors claim.
The NIH said that both in vitro and human in vivo data are available for this assay, which is described in PCT Patent Application No. PCT/US2012/061828.
The final technology is a simple, target-specific isothermal nucleic acid amplification technique called genome exponential amplification reaction, or GEAR.
This method uses a set of four primers, two inner and two outer, according to an abstract of the technology. The outer primer pair targets three specific nucleic acid sequences at a constant 60°C, while the inner pair of primers accelerates and improves the sensitivity of the assay.
According to NIH, the GEAR technique is an improvement over loop-mediated isothermal amplification, or LAMP, in three ways. First, the GEAR method uses two Tab primers targeting three genomic regions, while corresponding LAMP primers target four regions. Further, GEAR features complementary 5' ends between the forward and reverse primers and does not require a second set of outer primers, while LAMP requires two outermost primers.
The GEAR method can be performed in a relatively inexpensive water bath or heating block, with fluorescent detection of amplification products, making it suitable for low-resource settings. It is also a single-tube assay, thus eliminating the need for thermal cyclers or gel electrophoresis, and can be performed at temperatures exceeding 60°C, thus increasing specificity and sensitivity, NIH said.
The agency noted that the technique can provide both qualitative and quantitative analysis of nucleic acids and may be amenable to low-cost diagnostics for malaria, tuberculosis, and other infectious diseases.
The assay is in the pre-clinical stage with in vitro data available, and is described in PCT Patent Application No. PCT/US2012/049784.
The aforementioned and other technologies available for licensing can be found on the NIH OTT website.