Point-of-Care Test Identifies Bacterial and Viral Causes of Acute Respiratory Infections

A point-of-care test shows good sensitivity for identifying both bacterial and viral pathogens in patients with acute respiratory infections.

A point-of-care test has been found to correctly distinguish between bacterial and viral infections based on the host’s immune response, among patients with acute respiratory infections according to the results of a diagnostic study by team of US researchers.

Respiratory symptoms are the motive for a third of emergency room visits by both adult and paediatric patients. Acute respiratory infections due to either acute bronchitis, sinusitis, pneumonia and the common cold often present with overlapping symptoms leading to over-prescribing of antibiotics. Although multiplex PCR systems are available for the identification of bacterial and viral pathogens, an alternative strategy is to use a point-of-care test based on the host’s immune response to myxovirus resistance protein A (MxA) and C-reactive protein (CRP) in a finger-stick whole blood sample. To test the value of this approach in helping clinicians to decide on whether or not to prescribed antibiotics, in the present study, the US team examined the ability of the FebriDx® which is a rapid, point-of-care diagnostic test that is designed to aid in the differentiation of bacterial and viral acute respiratory infections. The test can provide a result within 10 minutes by identifying myxovirus resistance protein A, which is induced by type 1 interferon due to viral infections and CRP, a non-specific acute-phase protein produced in response to inflammation and infection. While CRP is not specific for bacterial infections, if only MxA levels are elevated (i.e., no change in CRP) this is indicative of a viral infection. Similarly, elevated CRP in the absence of MxA, indicates a bacterial infection.

The US team recruited patients from emergency departments and outpatient settings who presented with new-onset respiratory symptoms including rhinorrhoea, nasal congestion, sore, throat, hoarseness, cough or shortness of breath and a recent fever and an asymptomatic control group. The point-of-care test was administered to both groups of patients although the treating physicians were blind to the test results. The primary outcome was set as a bacterial or viral-associated systemic host response. In addition, patient samples were collected and analysed by multiplex PCR for either viral or bacterial identification and which served as independent assessment of the point-of-care test result.

Point-of-care test and bacterial or viral identification

A total of 520 symptomatic patients with a mean age of 35.3 (44.2% male) were included and 170 in the asymptomatic group.

Final diagnostic information was available for 496 individuals and of whom, 14.7% had a confirmed bacterial and 59.7% a viral infection with the remainder classed as negative. The point-of-care test correctly identified 93.1% of bacterial infections giving a sensitivity of 93.2% (95% CI 84.9 – 97%), a specificity of 88.4% (95% CI 85 – 91.1%) and a positive predictive value of 58.1%.

For viral infections, the point-of-care test had a sensitivity of 70.3% (95% CI 64.8 – 75.2%), a specificity of 88% (95% CI 82.8 – 91.8%) and a positive predictive value of 89.7%. Interestingly, none of the participants had a co-infection which was defined as both a bacterial and viral pathogen plus a host response based on the independent assessment.

The authors concluded that the rapid diagnostic point-of-care test could help inform clinicians when assessing for either bacterial or viral causes for acute respiratory infections.

Citation

Shapiro NI et al. Diagnostic Accuracy of a Bacterial and Viral Biomarker Point-of-Care Test in the Outpatient Setting JAMA Netw Open 2022

https://pubmed.ncbi.nlm.nih.gov/36255727/

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PRESS RELEASE: Nissui Pharma Solutions Launches its Mycoplasma Detection Kit in EMEA

Nissui Pharma Solutions (NPS), European subsidiary of Nissui Pharmaceutical Japan, commercialises contamination detection kit for the production of cell culture derived biopharmaceutical products. 

MycoFinder, our rapid mycoplasma detection kit, has been validated in accordance with the EP 2.6.7, USP 63 and JP 17 and is now commercially available throughout EMEA. MycoFinder uses real-time fluorescent PCR to ensure sensitive detection (below 10 CFU/mL) of mycoplasma. The kit is simple and quick to implement for product screening and batch release in laboratories where time is of the essence.

MycoFinder: sensitivity, simplicity and speed 

MycoFinder is in a PCR tube strip format with all the components of the Master Mix freeze-dried in each PCR tube. This allows preparation of PCR reactions in minutes, the Master Mix is resuspended simply by adding 25µL of DNA sample directly into the tubes. 

The kit is compatible with most commercially available thermocyclers due to two formats of PCR strips (white and clear). The ease of use of the MycoFinder kit, combined with the optimised Master Mix, results in PCR data in less than one hour.

For more information, please visit www.nissui-ps.com.

Christopher Tarabay

Commercial Director NPS

christopher.tarabay@nissui-ps.com

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DNA Nets Capture COVID-19 Virus in Low-Cost Rapid-Testing Platform

Tiny nets woven from DNA strands can ensnare the spike protein of the virus that causes COVID-19, lighting up the virus for a fast-yet-sensitive diagnostic test – and also impeding the virus from infecting cells, opening a new possible route to antiviral treatment, according to a new study.

Researchers at the University of Illinois Urbana-Champaign and collaborators demonstrated the DNA nets’ ability to detect and impede COVID-19 in human cell cultures in a paper published in the Journal of the American Chemical Society. 

“This platform combines the sensitivity of clinical PCR tests and the speed and low cost of antigen tests,” said study leader Xing Wang, a professor of bioengineering and of chemistry at Illinois. “We need tests like this for a couple of reasons. One is to prepare for the next pandemic. The other reason is to track ongoing viral epidemics – not only coronaviruses, but also other deadly and economically impactful viruses like HIV or influenza.”   

DNA is best known for its genetic properties, but it also can be folded into custom nanoscale structures that can perform functions or specifically bind to other structures much like proteins do. The DNA nets the Illinois group developed were designed to bind to the coronavirus spike protein – the structure that sticks out from the surface of the virus and binds to receptors on human cells to infect them. Once bound, the nets give off a fluorescent signal that can be read by an inexpensive handheld device in about 10 minutes.

The researchers demonstrated that their DNA nets effectively targeted the spike protein and were able to detect the virus at very low levels, equivalent to the sensitivity of gold-standard PCR tests that detect the virus’s genetic material but can take a day or more to return results from a clinical lab.

The technique holds several advantages, Wang said. It does not need any special preparation or equipment, and can be performed at room temperature, so all a user would do is mix the sample with the solution and read it. The researchers estimated in their study that the method would cost $1.26 per test.  

“Another advantage of this measure is that we can detect the entire virus, which is still infectious, and distinguish it from fragments that may not be infectious anymore,” Wang said. This not only gives patients and physicians better understanding of whether they are infectious, but it could greatly improve community-level modeling and tracking of active outbreaks, such as through wastewater.

In addition, the DNA nets inhibited the virus’s spread in live cell cultures, with the antiviral activity increasing with the size of the DNA net scaffold. This points to DNA structures’ potential as therapeutic agents, Wang said.

“I had this idea at the very beginning of the pandemic to build a platform for testing, but also for inhibition at the same time,” Wang said. “Lots of other groups working on inhibitors are trying to wrap up the entire virus, or the parts of the virus that provide access to antibodies. This is not good, because you want the body to form antibodies. With the hollow DNA net structures, antibodies can still access the virus.”

The DNA net platform can be adapted to other viruses, Wang said, and even multiplexed so that a single test could detect multiple viruses.

“We're trying to develop a unified technology that can be used as a plug-and-play platform. We want to take advantage of DNA sensors’ high binding affinity, low limit of detection, low cost and rapid preparation,” Wang said.

The National Institutes of Health supported this work through the Rapid Acceleration of Diagnostics program. The researchers will continue to work through the RADx program to explore and accelerate clinical applications for the DNA net platform.

Wang also is affiliated with the Holonyak Micro and Nanotechnology Lab and the Carl R. Woese Institute for Genomic Biology at Illinois.

The paper “Net-shaped DNA nanostructures designed for rapid/sensitive detection and potential inhibition of the SARS-CoV-2 virus” is available at https://pubs.acs.org/doi/10.1021/jacs.2c04835.

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OpGen, FIND Sign R&D Collaboration for Rapid Detection of AMR via Blood Culture

OpGen announced Tuesday it has signed a research and development collaboration agreement with FIND, a global alliance focused on bringing diagnostics throughout the developing world, for a feasibility study on the use of Unyvero A30 RQ platform for use in rapid pathogen ID and antimicrobial resistance (AMR) testing from blood culture samples in low- and middle-income countries (LMICs).

During the feasibility study, scientists at OpGen’s German subsidiary Curetis will work to develop a molecular testing panel with a comprehensive set of pathogen ID and AMR detection assays while also creating a simple, easy-to-perform workflow for testing using the blood culture systems available in target regions without the need for sample preparation. The collaboration’s goal is to find methods to adapt the A30 RQ platform—which is capable of test for up to 33 diagnostic targets from a single specimen—for use in environments often found in LMICs, such as those with continuous operation with unstable power grids.

“AMR is one of the most pressing health emergencies of our time, with the potential to undo decades of medical progress,” said Cecilia Ferreyra, director of AMR at FIND. “Simplifying blood culture systems so that the pathogen responsible for an illness and its resistance profile can both be identified quickly is crucial for halting and preventing this silent pandemic, especially in LMICs that bear the greatest burden of AMR.”

Based on the results of the feasibility study, co-funded by FIND with €700,000, which is anticipated to be completed by the end of the first quarter of 2023, OpGen and FIND will discuss the option of future collaboration and a commercialization agreement. Such a collaboration would be focused on bringing the Unyvero A30 RQ platform and the first products developed in the feasibility collaboration through the necessary clinical studies for marketing approval. Further, the two partners aim to develop the products that can be sold at a price point that will encourage the use of the tests to help address the unmet testing need for AMRs in LMICs.

OpGen noted that the platform, which uses a one-time use disposable cartridge and can deliver results in 30 to 90 minutes depending on the complexity of the test being run, is a good candidate for use in LMICs for rapid AMR detection due to the low cost of good associated with producing the assays.

“We are excited to partner with FIND, in demonstrating that our Unyvero A30 RQ platform is ideally suited to being used in LMICs for rapid detection of AMR which is a truly global issue that must be addressed in a multilateral and indeed global fashion,” said Oliver Schacht, president & CEO of OpGen in a press release. “The R&D contract and associated funding will support the required R&D efforts on our side and expedite such development.”

FIND (Foundation for Innovative New Diagnostics), based in Geneva, Switzerland, was created in 2003 at the World Health Assembly to address the pressing need for affordable diagnostic tests in LMICs. It was launched by the Bill and Melinda Gates Foundation and World Health Organization’s Special Programme for Research and Training in Tropical Diseases (TDR). Its initial focus was to speed up the development and evaluation of tuberculosis tests. Since then, its work has expanded to include improving diagnosis in other diseases including hepatitis C, HIV, malaria, and neglected tropical diseases.

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PRESS RELEASE: BD MAX™ Molecular Multi-Drug Resistant Tuberculosis Test To Be Included In WHO Updated Consolidated Guidelines On Tuberculosis

BD, a leading global medical technology company, today announced that its BD MAX™ Molecular Multi-Drug Resistant Tuberculosis (MDR-TB) Assay was included in the moderate complexity automated NAAT class of molecular diagnostic technologies that were recognized for high diagnostic accuracy for tuberculosis testing by the World Health Organization (WHO) in advance of an update to its guidelines for TB diagnostic tests.

Laboratorians and clinicians can use the BD MAX™ MDR-TB Assay to simultaneously detect bacteria that cause tuberculosis (TB) and determine if the bacteria contain mutations associated with resistance to two important first-line drugs, isoniazid (INH) and rifampicin (RIF), enhancing the information available to direct the optimal treatment for their patients.

"BD is keenly focused on the fight against antimicrobial resistance and we believe the BD MAX™ MDR-TB Assay will make a real impact on the detection of MDR-TB and better inform which treatment regimen to use for TB patients," said Dave Hickey, president of Life Sciences for BD. "This recognition by WHO is a significant milestone for this product and furthers BD's commitment in the fight to end TB. We look forward to WHO releasing its updated guidelines later this year."

The BD MAX™ MDR-TB Assay is an in vitro diagnostic device with CE mark available in Europe and other countries around the world. The PCR-based molecular diagnostic test is an integrated diagnostic test intended to help in the detection and diagnosis of TB, and INH and RIF resistance in a single assay.

Every year, about 10 million people develop TB and 1.4 million die from the disease. Until the global COVID-19 pandemic, TB was the leading cause of death from a single infectious agent. With proper detection and treatment, TB is curable. Multidrug-resistant TB (MDR-TB), defined as resistance to both isoniazid and rifampicin, remains a critical hurdle in the fight to eradicate tuberculosis as patients with this type of TB will not benefit from those key medicines and could spread the resistant forms of the disease to others.1 Additionally standard testing that only detects RIF resistance can miss cases of TB infection resistant to INH further delaying appropriate treatment and cure for those in need.

BD has a long history in TB diagnostics, having launched the first automated liquid culture system, the BD BACTEC™ MGIT™ Automated Mycobacterial Detection System for comprehensive testing for TB, drug susceptibility and monitoring patients' response to treatment. The BD MAX™ MDR-TB Assay complements this technology enabling clinicians to rapidly test for TB and multidrug resistance as a first-line test and then use the BD BACTEC™ MGIT™ System for broader drug susceptibility testing and patient monitoring.

BD offers a free on-demand webinar featuring Dr. Daniela Maria Cirillo, president of the European Society of Mycobacteriology and head of the Emerging Bacterial Pathogen Research unit at San Raffaele Scientific Institute in Milan. The webinar explores the importance of laboratory diagnostics to stop TB, as well as how the STOP TB Partnership and the ongoing work of the European Society of Mycobacteriology are working to help fight TB. View the on-demand webinar at labroots.com (https://www.labroots.com/webinar/importance-laboratory-diagnostics-fight-tuberculosis).

About BD MAX™ SYSTEM

The BD MAX™ System is a molecular diagnostic platform already in use at thousands of laboratories worldwide. The system is fully automated, reducing the opportunity for human error and increasing the speed to result, and can process 24 samples simultaneously, and up to several hundred samples per 24-hour period. Each unit is capable of performing assays for respiratory infections, enterics, hospital acquired infections, and sexually transmitted infections.

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Scientists Create a DNA Test That Identifies Lyme Disease in Horses

A test under development by a Rutgers professor could have applications for humans and dogs, too

A Rutgers scientist aiming to help heal a sick horse created an ultra-sensitive DNA test that could have applications for difficult-to-detect illnesses in humans such as Lyme disease.

As described in a study published in the Journal of Veterinary Diagnostic Investigation, a special DNA test devised by Steven Schutzer, a professor of medicine at Rutgers New Jersey Medical School, helped a Cornell University School of Veterinary Medicine team identify Neurologic Lyme disease in a sick 11-year-old Swedish Warmblood mare.

Although Lyme disease was suspected, a standard PCR test didn’t detect the disease agent, the corkscrew-shaped bacterium Borrelia burgdorferi.

As with the treatment of most diseases, early detection is essential with Lyme.

“Early diagnosis leads to immediate treatment,” Schutzer said. “And, naturally, that gives the best chance for a cure.”

The Schutzer team’s “genomic hybrid capture assay,” a highly sensitive test the team has been developing, identified the pathogen in a sample of the horse’s spinal fluid, allowing it to be diagnosed and successfully treated. The test works by first selectively isolating DNA from the microorganism causing the disease.

“The method is like having a special, specific ‘fishhook’ that only grabs Borrelia DNA and not the DNA of other microbes, nor the DNA of the host (animal or human),” Schutzer said. “Detecting DNA of the disease is a direct test, meaning we know you have active disease if it’s circulating in the blood or spinal fluid.”

Lyme disease is the most common vector-borne illness in the U.S., according to the Centers for Disease Control and Prevention (CDC). In humans, a characteristic skin rash may or may not occur, along with fever, headache and fatigue. Unchecked, the infection can move to the nervous system, the joints and the heart.

Similar to humans, horses are incidental, dead-end hosts for B. burgdorferi, meaning the hosts carry the infection but do not infect others. Not all infected horses develop clinical signs of Lyme disease. If symptoms occur, they can include chronic weight loss, lameness and low-grade fever. Antibody tests usually are administered when a Lyme disease infection is suspected.

In the case described in the study, an antibody test and a PCR test of the mare didn’t indicate an infection. Only Schutzer’s advanced test detected the disease.

Lyme disease in horses can cause long-term complications that include damage to the nervous system, joints, skin and even vision.

“The diagnosis of Lyme neuroborreliosis (Neurologic Lyme disease) in horses is rarely confirmed antemortem and has frustrated veterinarians for years,” said Thomas Divers, the veterinarian who led the equine team on the paper and who is a professor of medicine and co-chief of the Section of Large Animal Medicine at Cornell University’s College of Veterinary Medicine in New York. “This is a very promising technique. Focused treatment against B. burgdorferi administered in this case resulted in the horse’s complete athletic recovery.”

While many illnesses, such as COVID-19 and strep throat, attack humans with many numbers of pathogens, in other diseases, such as Lyme disease, the bacteria slowly reproduce within a host, producing far fewer numbers and making detection more difficult.

Schutzer, an expert in Lyme and other tick-borne diseases, has been working to devise ways to better detect diseases that possess what he terms “low copy numbers” of a pathogen.

According to the CDC, about 476,000 cases of Lyme disease are reported in humans each year. The black-legged tick, also known as the deer tick, is responsible for most cases of Lyme disease in the U.S. and seems to be increasing in abundance and geographic spread.

Other scientists on the study included Claire Fraser and Emmanuel Mongodin of the Institute of Genome Sciences at the University of Maryland School of Medicine; Christopher Miller of Miller and Associates Equine Practice in Brewster, N.Y.; Rodney Belgrave of Mid-Atlantic Equine Hospital in Ringoes, N.J.; and Rachel Gardner of B.W. Furlong and Associates in Oldwick, N.J.

Source: Rutgers University 

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University Research Advances Food Safety with Faster Listeria Test and Norovirus Vaccine

A new way of detecting deadly Listeria contamination in food and a vaccine for troublesome Norovirus are being reported by major research universities.

University of Georgia College of Engineering researchers report they have a new method for Listeria detection, and the Virginia-Maryland College of Veterinary Medicine at Virginia Tech announced it will evaluate a potential live oral vaccine for norovirus, which is the No. 1 cause of foodborne illness.

Listeriosis, an infection caused by eating food contaminated by the bacterium Listeria monocytogenes, is known for causing severe illness in children, pregnant women, newborns, the elderly, and people with compromised immune systems.

It is the third leading cause of death from foodborne illness, or food poisoning, in the United States. An estimated 1,600 people get sick each year and about 260 die, according to the Centers for Disease Control and Prevention (CDC).

At present, Listeria contamination in food products is identified only through molecular tests conducted in diagnostic laboratories on samples taken at specific control points during the manufacturing and distribution process.

Although very accurate, this method requires significant processing time, transportation of samples, and expensive skilled labor and equipment.

In a new study published in the Journal of The Electrochemical Society, UGA researchers introduce a rapid diagnostic method based on electrochemical biosensing principles.

Electrochemical biosensors are promising alternatives to molecular detection methods because of their ease of use, high specificity, sensitivity, and low cost, according to the researchers.

The UGA researchers use bacteriophages, viruses that infect and replicate within bacteria, as receptors to identify Listeria monocytogenes using an electrochemical sensor.

Meanwhile, Lijuan Yuan, professor of virology and immunology at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, announced the progress being made around a norovirus vaccine. It was developed by Indiana University’s John Patton and colleagues using the Rotarix rotavirus vaccine as a platform.

Using reverse genetics, they will insert a norovirus protein into Gene 7 of the rotavirus. The virus will then express the norovirus protein in the gut, inducing an immune response against norovirus.

Yuan’s Virginia Tech lab will evaluate the replication capacity, immunogenicity, and protective efficacy of the vaccine using gnotobiotic pig models of human rotavirus and norovirus infection and diarrhea. A gnotobiotic animal is one that has been specially raised to contain zero germs or bacteria so researchers can better study the effects of bacteria and viruses such as rotavirus and norovirus.

The CDC says norovirus as the leading cause of vomiting and diarrhea from acute gastroenteritis in the United States, resulting in 19 million to 21 million illnesses every year.

Norovirus tends to affect young children and the elderly the most. It’s responsible for about 24,000 hospitalizations and 925,000 outpatient visits for American children each year, according to the National Center for Biotechnology Information. Rotavirus also causes acute gastroenteritis and hits young children the hardest.

“Together, rotavirus and norovirus cause over 415,000 deaths every year, and norovirus also has a very significant burden even in the countries that don’t have a lot of deaths. The economic cost is huge, with $4.2 billion in direct costs and $60 billion in indirect societal costs. You hear about norovirus outbreaks on the news all the time in hospitals, nursing homes, and cruise ships and how it’s closing down restaurants, so it’s got a lot of economic implications,” said Yuan.

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PRESS RELEASE: Cepheid and BioGX Announce Collaboration to Develop Monkeypox PCR Test for the GeneXpert® System

Cepheid and BioGX announced a collaboration between the two companies to deliver a PCR test for Monkeypox that will run on the GeneXpert system. With a global installed base of over 40,000 GeneXpert systems in 180 countries, this test could be deployed quickly in multiple settings where actionable information is needed.

According to the Centers for Disease Control and Prevention (CDC), monkeypox is rare and does not spread easily between people without close contact. While the threat of monkeypox to the general U.S. population remains low (1), it is important for healthcare providers worldwide to have a preparedness plan. One of the key signs of infection with the virus is fever with development of a maculopapular rash, often appearing as small, raised spots. However, there are many other illnesses, such as chickenpox, measles, bacterial skin infections, syphilis, herpes, and medication-associated allergies that can present with similar symptoms. This underscores the need for a molecular test that can identify monkeypox. The World Health Organization recommends PCR as the preferred laboratory test for monkeypox, using an appropriate skin lesion sample (2).

"Our FleXible Cartridge program gives Cepheid the ability to work with external partners to develop accurate tests quickly when the need arises," said David H. Persing, M.D., Ph.D., Cepheid's EVP and Chief Scientific Officer. Beginning with Bacillus anthracis (Anthrax) and continuing with Mycobacterium tuberculosis, Influenza H1N1, Ebola virus and SARS-CoV-2 among others, Cepheid has a long history of quickly developing and delivering tests that address urgent public health issues as they emerge."

BioGX also has a successful track record of working with government agencies and diagnostic partners to quickly develop and manufacture at-scale molecular tests for detection of emerging pathogens.

"We previously collaborated on a project with the CDC to develop and manufacture a multiplex Monkeypox/Orthopoxvirus test for a GeneXpert-based study (3), and now with Cepheid we are moving to the validation stage utilizing the FleXible cartridge," said Michael Vickery, Ph.D., BioGX's EVP and Chief Scientific Officer. "Regional response teams need a PCR test that is fast and easy to implement when they suspect an outbreak due to a novel pathogen."

Product in development. Not for use in diagnostic procedures. Not reviewed by any regulatory body. Product in development is subject to change and specifications have not yet been established.

References:

1. https://www.cdc.gov/poxvirus/monkeypox/index.html

2. https://www.who.int/news-room/fact-sheets/detail/monkeypox

3. Li D., Wilkins K., McCollum A.M., Osadebe L., Kabamba J., Nquete B., Likafi T., Balilo M.P., Lushima R.S., Malekani J., et al. Evaluation of the GeneXpert for human monkeypox diagnosis. Am. J. Trop. Med. Hyg. 2017;96:405–410. doi: 10.4269/ajtmh.16-0567. - DOI  https://www.ajtmh.org/view/journals/tpmd/96/2/article-p405.xml

About Cepheid

Based in Sunnyvale, Calif., Cepheid is a leading molecular diagnostics company. Cepheid is dedicated to improving healthcare by developing, manufacturing, and marketing accurate yet easy-to-use molecular systems and tests. By automating highly complex and time-consuming manual procedures, the company's solutions deliver a better way for institutions of any size to perform sophisticated molecular diagnostic testing for organisms and genetic-based diseases. Through its strong molecular biology capabilities, the company is focusing on those applications where accurate, rapid, and actionable test results are needed most, such as managing infectious diseases and cancer. 

About BioGX

BioGX is a leading global provider of lyophilized real-time PCR reagents for molecular diagnostics. BioGX, Inc., headquartered in Birmingham, Alabama and Dallas, TX, and its wholly owned subsidiary BioGX B.V., based in Amsterdam, The Netherlands, (collectively "BioGX"), operates in a cGMP compliant environment certified to ISO 13485 medical device development and manufacturing standards. The proprietary Sample-Ready™ technology is at the core of all product offerings for Clinical, Food Safety, Pharma QC and Water Quality molecular testing. BioGX's 60+ multiplex real-time PCR products are marketed and sold worldwide through its Global Distribution Network. 

Image credit: US Centers for Disease Control.

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PRESS RELEASE: New Antibody Detection Method for Coronavirus That Does Not Require a Blood Sample

Despite significant and stunning advances in vaccine technology, the COVID-19 global pandemic is not over. A key challenge in limiting the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is identifying infected individuals. Now, investigators from Japan have developed a new antibody-based method for the rapid and reliable detection of SARS-CoV-2 that does not require a blood sample.

The ineffective identification of SARS-CoV-2-infected individuals has severely limited the global response to the COVID-19 pandemic, and the high rate of asymptomatic infections (16%–38%) has exacerbated this situation. The predominant detection method to date collects samples by swabbing the nose and throat. However, the application of this method is limited by its long detection time (4–6 hours), high cost, and requirement for specialized equipment and medical personnel, particularly in resource-limited countries.

An alternative and complementary method for the confirmation of COVID-19 infection involves the detection of SARS-CoV-2-specific antibodies. Testing strips based on gold nanoparticles are currently in widespread use for point-of-care testing in many countries. They produce sensitive and reliable results within 10–20 minutes, but they require blood samples collected via a finger prick using a lancing device. This is painful and increases the risk of infection or cross-contamination, and the used kit components present a potential biohazard risk. 

Lead author Leilei Bao from the Institute of Industrial Science, The University of Tokyo, explains: “To develop a minimally invasive detection assay that would avoid these drawbacks, we explored the idea of sampling and testing the interstitial fluid (ISF), which is located in the epidermis and dermis layers of human skin. Although the antibody levels in the ISF are approximately15%–25% of those in blood, it was still feasible that anti-SARS-CoV-2 IgM/IgG antibodies could be detected and that ISF could act as a direct substitute for blood sampling.”

After demonstrating that ISF could be suitable for antibody detection, the researchers developed an innovative approach to both sample and test the ISF. “First, we developed biodegradable porous microneedles made of polylactic acid that draws up the ISF from human skin,” explains Beomjoon Kim, senior author. “Then, we constructed a paper-based immunoassay biosensor for the detection of SARS-CoV-2-specific antibodies.” By integrating these two elements, the researchers created a compact patch capable of on-site detection of the antibodies within 3 minutes (result from in vitro tests).

This novel detection device has great potential for the rapid screening of COVID-19 and many other infectious diseases that is safe and acceptable to patients. It holds promise for use in many countries regardless of their wealth, which is a key aim for the global management of infectious disease. 

The article, “Anti SARS CoV 2 IgM/IgG antibodies detection using a patch sensor containing porous microneedles and a paper based immunoassay,” was published in Scientific Reports.

About Institute of Industrial Science, The University of Tokyo

The Institute of Industrial Science, The University of Tokyo (UTokyo-IIS) is one of the largest university-attached research institutes in Japan. Over 120 research laboratories, each headed by a faculty member, comprise UTokyo-IIS, which has more than 1,200 members (approximately 400 staff and 800 students) actively engaged in education and research. Its activities cover almost all areas of engineering. Since its foundation in 1949, UTokyo-IIS has worked to bridge the huge gaps that exist between academic disciplines and real-world applications.

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