Saturday, December 22, 2018

New Microfluidic-Microwave Ring Resonator Biosensor to Detect Pathogenic Bacteria

Canadian researchers utilized the lab-on-a-chip microfluidic technology to develop a new biosensor for real-time detection of pathogenic bacteria.

Bacteria are all around us—in the air, on objects, and both inside and on the surfaces of the human body. They are so small that hundred thousands of them could fit on thetip of a hair. Bacteria are usually harmless, but some of them can causedisease in people who consumed contaminated food and in those with open woundsthat are exposed to dirty water.

Risk of bacterial infection

Bacterial infection is an important public health problem, resulting in a range of diseases and levels of resistance. For example, there are about 1.3 million tuberculosis-related deaths worldwide caused by mycobacterium tuberculosis bacteria every year. At the same time, Salmonella, Escherichia coli, and Listeria are the leading causes of illness and death in the United States due to bacterial pathogens transmitted commonly through food.

While these infectious diseases are highly treatable at an early stage, the current methods of diagnosing infections and performing antibiotic susceptibility are expensive, time-consuming, and labor-intensive. Typically, it takes about two to five days to obtain accurate and reliable diagnosis results. The delays in diagnosis and treatment may result in higher mortality and morbidity due to prolonged disease and the development of complications, as well as increased risk of further transmission of infection.

Real-time detection of pathogenic bacteria

In a recent study published in Nature Scientific Reports, a group of researchers from Canada has utilized the lab-on-a-chip microfluidic technology to develop a biosensor for speedy detection of pathogenic bacteria. The microfluidic chip, made of soft lithography, was injected with bacterial samples and incorporated with a microwave microstrip ring resonator. By sending a microwave signal through the sample, the device is capable of analyzing and then generating a profile of existing bacteria quickly and accurately.

Having tested the device on various situations of Escherichia coli bacteria, the researchers demonstrated that near-immediate responses can be achieved for detecting bacteria concentration at various pH values. The device also enabled direct observation and enumeration of bacteria. This could benefit clinical microbiology laboratories by automating the workflow of antibiotic susceptibility and increasing the capabilities for the diagnosis and handling of bacterial infections.

This study opens new doors to reshape the future diagnosis of pathogenic bacteria. Further experiments are needed to assess the feasibility of rapid diagnosis and management of different infections.


Narang, R. et al.Sensitive, Real-time and Non-Intrusive Detection of Concentration and Growth of Pathogenic Bacteria using Microfluidic-Microwave Ring Resonator Biosensor. Scientific Reports, 8:15807. DOI: 10.1038/s41598-018-34001-w

Mobile Device by UCLA Makes the Detection of Parasitic Infections Faster and More Sensitive

Parasitic infections affect hundreds of millions of people, posing a serious public health threat worldwide. For example, sleeping sickness and Chagas disease are neglected tropical diseases that are caused by the bloodborne Trypanosoma parasite. Historically given little attention, these devastating diseases affect people mainly in sub-Saharan Africa and South America, causing enormous socioeconomic burden.

Optical microscopy of bodily fluid samples by trained medical experts remains one of the most common approaches to diagnose parasitic infections in bodily fluids. However, clinically relevant parasite concentrations in bodily fluids can be extremely low. Because conventional optical microscopy typically has a very small imaging volume, it often struggles to provide the sensitivity needed for early diagnosis. Moreover, the task becomes even more challenging when parasitic infections in the blood needs to be detected. Because there are billions of blood cells in each milliliter of blood, and they cause occlusion, making the task of detecting parasites in blood a needle-in-a-haystack problem.

Researchers at the UCLA Henry Samueli School of Engineering have developed an inexpensive and portable platform that can rapidly detect motile parasites in bodily fluids automatically. Using their platform, more than 3 mL of a bodily fluid sample can be imaged and analyzed within 20 min, providing a throughput that is orders of magnitude better than traditional optical microscopy-based examination.

The research, published in Light: Science & Applications, was led by Aydogan Ozcan, Chancellor's Professor of Electrical and Computer Engineering at UCLA and the associate director of the California NanoSystems Institute at UCLA, along with Kent Hill, a Professor in the Department of Microbiology, Immunology, and Molecular Genetics at UCLA.

Instead of directly capturing a still image of the fluid sample and searching for parasites, this unique platform takes a different approach and detects motion within the sample. It records high-frame-rate videos of the holographic patterns of the sample illuminated with laser light. Then, a motion analysis algorithm analyzes these captured videos at the micro-scale and converts the locomotion of the target parasites within the sample into a signal spot, which is detected and counted using artificial intelligence.

"Although motility is a common feature of various parasites and other disease-causing micro-organisms, its use as a fingerprint for diagnosis is highly underexplored and our work provides landmark results, highlighting this unique opportunity." said Ozcan.

"Our platform can be considered as a motion detector in the microscopic world, which locks onto any moving objects within the sample." said Yibo Zhang, a UCLA doctoral student and the first author of this study, "Locomotion is used as both a biomarker and a contrast mechanism to distinguish parasites from normal cells."

The proof of concept of this device has been demonstrated using Trypanosoma parasites, which have multiple subspecies that cause sleeping sickness and Chagas disease. The detection limit of the device was quantified as 10 parasites per milliliter of whole blood, which is about 5 times better than the state-of-the-art parasitological detection methods. This improved detection limit may lead to a better capability to detect sleeping sickness and Chagas disease at an earlier stage, which is essential to improve the cure rate and reduce prevalence. Beyond trypanosomes, the authors also demonstrated the use of their device to detect Trichomonas vaginalis, highlighting that their technique is applicable to various parasites and motile microorganisms.

The UCLA device is compact and lightweight (1.69 kg) and the cost of the prototype is less than $1850, which can be reduced to less than $800 when manufactured in larger volumes. "Thanks to its high sensitivity, ease-of-use, reduced cost and portability, we believe our technique can improve parasite screening efforts, especially in resource-poor areas and endemic regions." said Hatice Ceylan Koydemir, a UCLA postdoctoral scholar, who is a co-author of this study. Other co-authors of the manuscript are Michelle M. Shimogawa, Sener Yalcin, Alexander Guziak, Tairan Liu, Ilker Oguz, Yujia Huang, Bijie Bai, Yilin Luo, Yi Luo, Zhensong Wei, Hongda Wang, Vittorio Bianco, Bohan Zhang, and Rohan Nadkarni.

This study is supported by the NSF Engineering Research Center (ERC, PATHS-UP), NIH and the Howard Hughes Medical Institute (HHMI).

New Field Test Discerns Between Ebola and Lookalike Fevers

At the close of the 2014-2016 West Africa Ebola crisis, the Paul G. Allen Foundation identified diagnostic gaps as one of the major deficiencies that had contributed to the outbreak’s spread.

“The standard diagnostic tests that exist are very good, but they’re hard to do out in the field in the middle of an outbreak like we saw in West Africa,” said John Connor, a virologist at the Boston University National Emerging Infectious Diseases Laboratory (NEIDL). Instead, samples need to be sent to a facility capable of running the tests, which means it could be several days between taking a sample and getting a diagnosis.

Connor, in collaboration with researchers from Columbia University, the National Institutes of Health Integrated Research Facility, clinical collaborators from Senegal and the Hemorrhagic Fever Lab in Guinea, as well as Becton, Dickinson and Company (BD), came together and proposed an idea for a new kind of diagnostic that would bridge critical gaps in the field.

“We set out to create a rapid, point-of-care diagnostic that could look for malaria, Ebola and other pathogens that are often found in these regions,” said Connor, who is also an associate professor of microbiology at Boston University School of Medicine. The Allen Foundation, based in Seattle, WA, agreed to fund the project.

While there are myriad ways to design rapid, portable diagnostics, the solution pursued by the team was based on a test that could be stored without refrigeration, which is typically hard to maintain along supply routes to rural outbreak areas. That’s why the researchers liked the idea of designing a portable material identification system built on magnetic beads and glass-encased gold nanoparticles.

The system, surface-enhanced Raman scattering (SERS), is based upon the idea that light scatters off of different types of molecules in distinct ways. As such, specific molecules have distinct light-scattering signatures (or unique barcodes) that can be detected. Although the barcodes can be weak on their own, the addition of gold particles amplifies the detectable light signal making the barcode easier to detect.

“Gold amplifies the barcode by about a million times,” Connor said.

Working with BD, which was developing SERS for other applications, Connor and his collaborators helped design a system capable of differentiating between the different barcodes of the malarial parasite and Ebola virus, as well as Marburg and Lassa viruses, two other deadly hemorrhagic fevers found in the same regions of Africa where Ebola outbreaks are common.

At the start of the test, a small sample of blood is mixed with magnetic beads coated in antibodies that attract each of the four infectious agents. If the blood contains malaria-causing parasites or Ebola, Marburg or Lassa viruses, the pathogens glom onto the magnetic beads. At the same time, similar antibodies on glass-encased gold nanoparticles also attach to the pathogens, creating a link between the magnetic and gold beads. Then, inside a small machine, the materials are concentrated into one spot by magnetic force and hit with a small laser beam.

Analyzing the barcode of light that flashes back from a sample, the machine can rapidly provide a readout of the presence of malarial parasites or Ebola, Marburg or Lassa viruses. From sample-taking to final readout, the entire process can be completed in 30 minutes or less. The development of the system, and experimental data showing its efficacy in animal and human blood samples, was published Wednesday in Science Translational Medicine.

Once the sample is added to the tube, there is no need to reopen the tube because all the reagents are already inside, noted Yanis Ben Amor, one of the study's authors. Amor is an associate research scientist and the executive director of the Center for Sustainable Development at Columbia University in New York. For the technicians carrying out the testing, “this was seen as a tremendous advantage in the context of highly infectious samples," he said.

Designed to go anywhere, the system’s components can be battery operated and can fit inside a standard-sized backpack, the researchers said.

“The implications for getting good diagnostics to remote places are huge,” Connor said.

Connor said the value of the diagnostic is not just in identifying who has a contagious illness and who does not, but also in creating better relations with the communities at risk of becoming infected. If patients can rapidly be diagnosed and treated for illness, it can foster trust while immediately helping clinicians identify who should be quarantined and who should be sent home with antimalarial medicines.

Connor said the system could be custom-tailored to detect and differentiate virtually any combination of pathogens, whether they be bacterial, viral, fungal or parasitic.

“The reason I find this system so promising is that it can diagnose more than one thing simultaneously, which is important in the real-world context of infectious diseases,” Connor said. “The disease landscape is complicated and pathogens aren’t operating in isolation from one another.”

Source: MDDI

WPI Researchers Developing a Biosensor That Can Speed Diagnosis of Clostridium difficile

Researchers at Worcester Polytechnic Institute (WPI) are developing a biosensor that doctors and nurses can use to quickly detect Clostridium difficile (C. diff), a dangerous and sometimes fatal gastrointestinal infection. The sensor is designed to be the heart of a handheld device that can be used onsite in doctor’s offices and nursing homes, providing results in minutes instead of days, avoiding the need to send samples out to commercial labs, and making it possible to start treatment earlier, when it is likelier to be more successful.

Highly contagious, C. diff is the most common infectious cause of diarrhea in hospitalized patients The bacteria also causes nausea, dehydration, weight loss, colitis, kidney failure, and an increased white blood cell count. The longer treatment is delayed, the sicker patients become and the harder the infection is to cure. C. diff infects more than 500,000 people each year in the United States, of whom more than 29,000 die within 30 days of diagnosis, according to the Centers for Disease Control and Prevention. It is responsible for as much as $4.8 billion per year in health care costs. A major complication of antibiotic therapy, C. diff generally occurs in older adults who have received antibiotics in hospitals or long-term care facilities.

“C. diff is a very serious disease, especially for the elderly,” said Hong Susan Zhou, associate professor of chemical engineering at WPI and principal investigator for the biosensor research program, which is funded by a $350,000 award from the National Science Foundation. “When people are in the hospital and receiving antibiotics, they are very easily infected and it’s very dangerous. When people start having symptoms of diarrhea, it’s not easy tell if it’s C. diff or not. If they can be diagnosed in the early stages, then it’s more easily treated.”

C. diff is typically detected by culturing a stool sample, a test that has a high rate of false negatives, requires specialized equipment and expertise, and cannot be done at most points-of-care facilities. At present, no single commercially available test offers strong sensitivity and portability, as well as rapid turnaround time and low cost. Inexpensive point-of-care diagnostics for C. diff are needed to improve detection, therapy, and treatment cost, Zhou said “Right now, it takes 24 to 48 hours to receive a C. diff diagnosis,” she noted. “People can get much sicker in just that short period of time.”

Starting in 2012, Zhou began looking for a better and faster way to detect C. diff. That research resulted in a microwave-size biosensor prototype, which she built and demonstrated in her lab in 2015. With the current grant, she is working with Yuxiang (Shawn) Liu, assistant professor of mechanical engineering at WPI and co-PI on the project, to shrink the device to make it portable, and to use nanostructures and new microfluidics techniques to make it more sensitive.

The miniaturized biosensor Zhou and Liu are developing uses electrochemical detection (ECD), an extremely selective and sensitive diagnostic technique, which will enable a C. diff infection to be

The biosensor, left, uses antibodies attached to an electrode to detect the C. diff bacteria. The channels etched into the acrylic microfluidic device will bring even tiny samples to the electrode, located in the chambers at either end.

diagnosed much earlier. The biosensor has an electrode with antibodies attached. When C. diff bacteria bind to the antibodies, they trigger an electrical change that signals the presence of an infection. This process takes just a few minutes, as comparedto the one to two days needed for the traditional lab culture.

The 2015 prototype used gold nanoparticles, laid flat, and a traditional microfluidic platform made of PDMS, a silicon-based organic polymer. That prototype would have been difficult to scale up for mass production, Zhou said. The new device will use 3D gold nanostructures, which have more surface area for the antibodies to adhere to, making the biosensor more sensitive and allowing it to be much smaller than the original prototype.

Liu is developing a new microfluidic platform for the sensor that will enable the stool sample to flow more easily toward the electrode. He is replacing the traditional polymer with an acrylic and will use a laser to cut tiny channels into it. The new platform will be easier to fabricate and to integrate with the new electrode, which Liu also will help fabricate. The goal is to create a reusable handheld biosensor that can make a diagnosis with just a drop of stool, much less than is needed for current lab tests.

It will also be designed to be usable without any special training, making it possible for tests to be conducted on site. “For use in point-of-care facilities, it will be important for it to be easier and less expensive to use,” said Liu.

The technology used in the biosensor can be adapted to test for other types of infectious bacteria, including salmonella, bacterial meningitis, and E. coli. It may even be able to check for cancer biomarkers, Zhou said.

The research team also includes three PhD students: Zanzan Zhu and Zhiru Zhou from Zhou’s lab and Yundong Ren from Liu’s lab. Hanping Feng, a professor at the University of Maryland, will supply the antibodies used in the study.

Source: Worcester Polytechnic Institute 

Handheld Gadget to Provide Rapid Food Quality Testing

A microbiological detection device will help speed up the measurement of contamination in raw meat, thus minimising costs and food waste.

Foodborne diseases are a major public health concern worldwide. Every year an estimated 600 million – about 1 in 10 people – fall ill after eating contaminated food and 420 000 die, according to the World Health Organization. To help address food safety, the EU-funded FRESHDETECT project is developing a portable tool that will determine the microbiological quality of meat products.

A product flyer on the project website notes that the handset determines the "total viable count (TVC) in raw meat without extracting samples and without incubation." It uses a fluorescence spectroscopy process that directs an intense blue light onto the surface of the meat and measures the characteristic fluorescence signatures and the bacterial flora. "The TVC is then calculated using a reliable analysis algorithm to ascertain the microbiological quality of the product. The measurements are non-invasive and last only a few seconds. The results are displayed directly on the device immediately after the measurement."

The device can store up to 2 000 measurements. The results can be transferred to a PC any time via a USB port. As stated in the same product flyer: "Potential fields of application include rapid tests for the in-house control of meat across the entire meat handling and processing chain, as well as delay-free quality monitoring in the receiving and shipping areas."

New dimension

In a news article on the 'FoodNavigator' news website, managing director of project coordinator FreshDetect GmbH Oliver Dietrich said the innovation "creates a new dimension in food safety." According to CORDIS, the "device enables non-invasive microbiological testing without additional operational or maintenance costs." The target users include slaughterhouses, cutting plants, meat processing companies, retailers, wholesalers and butchers. The project aims to bring its "current prototype (TRL7) [technology readiness level 7] to business success with commercialization to these users," CORDIS adds.

In the same news article Dietrich says: "FreshDetect will successively expand its applications to include other food such as fish, dairy products, fruit and vegetables. The focus is not only on bacterial contamination, but also on the detection of pesticides, herbicides, origin, age (degree of ripeness) and other factors."

The ongoing FRESHDETECT (FRESHDETECT – food safety – fast and reliable) project also tackles food waste, which creates about 8 % of all human-caused greenhouse gas emissions. Some 88 million tonnes of food are wasted in the EU every year, with associated costs estimated at EUR 143 billion, according to the European Commission. CORDIS emphasises that "the FreshDetect technology offers a so far unmatched level of food process control allowing an optimization of the food production and minimizing food waste."

The project website notes that although the device has been on the market since the summer of 2017, "it has undergone a series of tests since 2016 that are carried out in conjunction with quality-focused companies in the meat industry." It adds: "We currently offer software datasets for various types of meat. Other datasets for detecting TVC are under development. We are also developing a technology for detecting TVC through transparent packaging (MAP, vacuum)."

3M Earns AOAC® Performance Tested Methods Certification for Rapid Campylobacter Test

3M Food Safety announced today that the 3M™ Molecular Detection Assay 2—Campylobacter, a rapid molecular test method launched earlier this year, has earned Performance Tested MethodsSM (PTM) Certificate number 111803 from the AOAC® Research Institute. The assay utilizes Loop-Mediated Isothermal Amplification (LAMP) technology to overcome the complex instrumentation requirements of traditional, PCR tools, simplifying the testing process and giving technicians greater control and better efficiency.

The AOAC-PTM designation validates the 3M Molecular Detection Assay 2 - Campylobacter with 3M™ Campylobacter Enrichment Broth as an improvement and/or equivalent alternative to USDA FSIS and ISO reference methods for detecting Campylobacter jejuni, Campylobacter coli and Campylobacter lari. An independent lab tested the technology on a variety of matrices including whole raw chicken carcass rinses, raw poultry parts rinses, raw ground poultry rinses, raw turkey carcass sponges and breaded chicken nuggets. Inclusivity/exclusivity and robustness tests were performed as well to assess the assay’s performance.

“We are excited to receive this certification from the AOAC Research Institute,” said Cynthia Zook, 3M Food Safety commercialization manager. “LAMP technology continues to perform exceptionally well compared to conventional tests. We’re proud to be a part of a sea-change in the industry as we continue to innovate and create technologies like this one that are as simple, accurate, fast and reliable as possible.”

Tuesday, December 18, 2018

SpeeDx Receives CE-IVD Mark for ResistancePlus® GC Gonorrhea Test

SpeeDx Pty. Ltd. announced it has received CE-IVD marking for its ResistancePlus® GC assay that detects both the sexually transmitted infection (STI) N. gonorrhoeae, and sequences in the gyrA gene of the bacteria associated with susceptibility to ciprofloxacin (Cipro), a previously used front-line antibiotic treatment. Currently, ceftriaxone ̶ a painful intramuscular injection ̶ combined with azithromycin, is the front-line treatment for gonorrhea in the U.S. However, ceftriaxone represents one of the last remaining antibiotics used for multi-drug-resistant infections and needs to be utilized sparingly so as not to increase resistance to the drug. Already, there are strains of gonorrhea that are resistant to this treatment.

SpeeDx’s new test will allow doctors to confidently and cost-effectively treat up to 70% of gonorrhea infections with a single oral dose of ciprofloxacin because the test establishes disease susceptibility to ciprofloxacin prior to prescribing.

"The ResistancePlus GC test is the first innovation in gonorrhea treatment in decades,” said Dr. Jeffrey Klausner, Professor of Medicine and Public Health at David Geffen School of Medicine and Fielding School of Public Health, University of California, Los Angeles. “With the continued spread of multi-drug gonorrhea, this test can make a real difference.”

Recent surveillance data shows that susceptibility to ciprofloxacin is as high as 70% in some regions and greater than 50% across the majority of countries contributing surveillance data. [1-4]

In response to the clear utility of ciprofloxacin, the British Association of Sexual Health and HIV (BASHH) have recently drafted new gonorrhea management guidelines that include the preferential use of ciprofloxacin over ceftriaxone if antimicrobial susceptibility testing results are available prior to treatment. [5]

“We used a similar test at UCLA in Los Angeles and found that doctors liked the test and were much more likely to prescribe a safer and simpler medicine like oral Cipro tablets instead of using injections like Ceftriaxone,” reports Dr. Klausner.

“ResistancePlus GC is an important next step in our ResistancePlus portfolio and is a welcome addition in managing the extensive antibiotic resistance in N. gonorrhoeae infections,” said Colin Denver, CEO for SpeeDx. “We are already seeing high interest in this test with its clear role in maintaining stewardship of the limited antibiotics still available to treat gonorrhea.”

ResistancePlus GC is the first commercially available molecular test* providing ciprofloxacin susceptibility information and is well placed to support current laboratory molecular testing workflows. “If more doctors use the ResistancePlus GC assay, patients will have a better choice when it comes to treatment and we might make a big difference in controlling antibiotic resistant gonorrhea,” adds Dr. Klausner. “Untreatable gonorrhea is a real threat ̶ use of the ResistancePlus GC assay might stop that.''

*available where CE-mark is accepted, not available in the U.S. or A.U.

About Gonorrhea
N. gonorrhoeae is a bacterium causing gonorrhea, a sexually transmitted infection most frequently causing urethritis in men and cervicitis in women. Gonorrhea can result in infertility or ectopic pregnancy and also increases the risk of acquiring other STIs, including HIV. Transmission from infected mothers to newborns during birth can result in gonococcal conjunctivitis, an infection in the eye (ophthalmia neonatorum).

Prevalence and incidence rates of gonorrhea have been increasing around the world, with corresponding increasing rates of resistance to commonly used antibiotics. [6] Recent studies suggest N. gonorrhoeae is threatening to become untreatable as resistance continues to develop against all known antibiotic treatments. [6] The currently recommended front-line treatment, ceftriaxone, is the last known effective antibiotic, and several extensively drug resistant strains have now been isolated exhibiting resistance to this and many other available treatments. [7,8] Global management strategies for antimicrobial resistance highlight gonorrhea as a priority infection to manage, with more effective use of diagnostic tools listed as a key focus for future development. [9]

About ResistancePlus®
ResistancePlus® kits are multiplex qPCR tests for detection of infectious diseases and antibiotic resistance markers, respectively. Powered by proprietary PlexZyme® and PlexPrime® technologies, the product line offers high multiplexing capability for better, more streamlined infectious disease management. ResistancePlus test offer more than detection, supporting resistance guided therapy by providing actionable information for laboratories and clinicians alike.

1. Harris SR et al. Lancet Infect Dis Published online May 15th 2018.
2. Lahra MM et al. Australian Gonococcal Surveillance Programme annual report, 2015.
3.Heffernan H et al. Antimicrobial resistance and molecular epidemiology of gonococci in NZ, 2014-5.
4.  Kirkcaldy RD et al. MMWR Surveillance Summaries July 15, 2016 / 65(7);1–19.
5. Fifer H. et al. 2018 UK national guideline for the management of infection with Neisseria gonorrhoeae (Draft).
6. Unemo, M. & Jensen, J.S. 2016. Nat. Rev. Urol..268. Published online 10 Jan 2017. doi:10.1038/nrurol
7. PHE Health Protection Report Volume 12, Number 11. 2018.
8. AU DoH Media Statement April17th 2018.
9. Rapid Risk Assessment 7 May 2018. Stockholm: ECDC; 2018.

Rapid Detection of Foodborne Pathogens using Volatile Organic Compounds (VOCs)

A researcher at University of Malaya, Malaysia, has developed a real-time method based on specific volatile organic compounds (VOCs) to detect dangerous bacteria causing foodborne diseases in raw chicken.

The World Health Organisation reported that there were more than 600 million cases of foodborne diseases globally in 2010, causing more than 155,000 deaths worldwide. Several surveillance studies in Malaysia have shown that as high as 9 out of 10 raw chickens in the market are positive for Salmonella and C. jejuni contamination. It was reported that approximately 35—88 percent of raw chicken in Malaysia were contaminated with Salmonella; while C. jejuni was detected in 50—90 percent of farmed chickens and 30—45 percent of raw chicken in the market.

The increased scale of food production and global food trading have raised the risk of failures in our food safety monitoring system to detect foodborne pathogens. Unfortunately, the conventional laboratory-based testing approaches of raw chicken are too slow and can no longer meet the demands of today's large-scale food production. It currently takes two to seven days to complete. A major problem in the current approaches to detect foodborne pathogens is that products must be sacrificed when tested, making the process an expensive affair as it reduces profit margins and raises price. Although new molecular approaches have been adopted to speed up the detection time, the widespread use of this technology is hampered by challenges such as high operational cost and dependency of highly-skilled labour. The technology also suffers from low performance fidelity which is caused by biological interference.

Dr. Chai Lay Ching, food microbiologist from Faculty of Science, University of Malaya (UM), proposed a solution to identify pathogenic bacteria in food based on the detection of specific volatile organic compounds (VOCs) produced by bacteria. Microorganisms are known to emit specific VOCs as gases during the process of breaking down food. The VOCs are a diverse group of carbon-based chemicals that are volatile at ambient temperature and can be detected through smell. Different types of bacteria produce their own VOC signatures. These findings have led the researcher to develop a novel and rapid method to detect bacterial spoilage in food products in a real-time fashion and non-destructive manner, and named her as one of the three winners for the Malaysian L'Oréal-UNESCO for Women in Science Award.

VOCs analysis has been used in clinical diagnosis of various bacterial diseases in humans, such as detection of Clostridium difficile, C. jejuni and Vibrio cholerae in patients' stool. Preliminary laboratory results showed a distinctive VOC-profile associated with C. jejuni in specific laboratory conditions, suggesting the potential of VOC-based biosensors or electric noses that can sniff out these highly pathogenic bacteria in food.

"I accidentally found that Campylobacter produces a very specific scent when we grow them on the agar plate. This allowed me to correctly identify samples with Campylobacter from the negatives ones," Dr. Chai explained.

The findings from this study will generate a database of volatilome of foodborne associated Salmonella and C. jejuni-contamination in raw chicken and different carbon substrates. This work is key for future development of a real-time monitoring system that meet the ideal high-throughput detection criteria. It can be automated, is easy to perform and instantly detects contamination. The application will be key in saving lives and reducing morbidities-associated with these bacteria, as well as helping the food industry to save cost. The successful completion of this project will lead to a better understanding of bacterial metabolism and adaption in different types of substrates, which will help us understand the impact of environment on bacterial growth.

Ultrasensitive Rapid Diagnostic Test Outperformed Regular Rapid Tests in Identifying Asymptomatic Malaria Infections

A recently developed ultrasensitive rapid diagnostic test outperformed regular rapid diagnostic tests in identifying asymptomatic malaria infections, but was still inferior to loop-mediated isothermal amplification, or LAMP, according to study findings.

Writing in Clinical Infectious Diseases, researchers said there is a growing need for accurate tests to identify asymptomatic malaria infections, which may aid in the elimination of the disease.

“The primary objective of the study was to determine the sensitivity and specificity of different diagnostic tests for malaria, including [rapid diagnostic tests (RDTs)], [ultrasensitive RDTs (uRDTs)], LAMP, microscopy and quantitative real-time PCR (qRT-PCR),” Dylan R. Pillai, MD, PhD, a clinician-scientist at the University of Calgary, and colleagues wrote. “The secondary objectives were to determine epidemiological characteristics for malaria and whether asymptomatic individuals harboring malaria were anemic compared to uninfected persons using highly accurate ultrasensitive diagnostics.”

In a cross-sectional study, Pillai and colleagues assessed 562 asymptomatic individuals in the Gambella region of southwest Ethiopia to establish epidemiological characteristics associated with asymptomatic malaria. Participants were tested for malaria by LAMP, ultrasensitive qRT-PCR and three RDTs, including the uRDT Alere Malaria Ag P.f (Abbott), CareStart (Accessbio) and SD Bioline Malaria Ag P.f (Abbott).

According to the findings, compared with qRT-PCR, LAMP had the highest sensitivity (92.6%; 95% CI, 86.4-96.5). The uRDT Alere test was next (33.9%; 95% CI, 25.5-43.1), followed by CareStart (14%; 95% CI, 8.4-21.5); microscopy (7.3%; 95% CI, 2.7-15.3) and SD Bioline (5%; 95% CI, 1.8-10.5).

Additionally, Pillai and colleagues compared the sensitivity of the tests for detecting Plasmodium falciparum specimens only and found the sensitivity for uRDT Alere was 50% (95% CI, 38.8-61.3), whereas SD Bioline was 7.3% (95% CI, 2.7-15.3).

According to the study, every 3.2% increase in the prevalence of asymptomatic malaria caused a decrease in hemoglobin by 1 g/dL when based on a multivariate regression analysis and compared with the gold standard, qRT-PCR. Furthermore, 4.8% deletions were observed in HRP2.

“These data show that uRDT is superior to traditional RDT in detecting asymptomatic individuals, but uRDT is still inferior to molecular techniques, with LAMP having the highest sensitivity to detect malaria compared to qRT-PCR,” Pillai and colleagues wrote. “Further studies are required to identify the optimal diagnostic test for interrupting malaria transmission in elimination studies. Longitudinal studies are also required to investigate the potential clinical benefits of treating asymptomatic malaria.”

Thursday, November 29, 2018

Nanopore Detection of Single Flu Viruses to Control Outbreaks

Influenza is a highly contagious respiratory disease of global importance, which causes millions of infections annually with the ever-present risk of a serious outbreak. Passive vaccination is the only method available for partial control of the virus. Rapid diagnosis of influenza has been explored to prevent outbreaks by enabling medication at very early stages of infection; however, diagnostic sensitivity has not been high enough, until now.

In a new study published in Scientific Reports, a team of researchers led by Osaka University explored the usefulness of combining a single-particle nanopore sensor with artificial intelligence technology, and found that this approach created a new virus typing method that can be used to identify single influenza virions.

Genetic methods can identify many virus species, but require time-intensive processes and specialized staff. Therefore, these methods are unsuitable for point-of-care screening. In a novel approach, the researchers designed a sensor that could assess distinct nanoscale properties of influenza virions within physiological samples.

“We used machine-learning analysis of the electrical signatures of the virions,” says corresponding author Makusu Tsutsui. “Using this artificial intelligence approach to signal analysis, our method can recognize a slight current waveform difference, which cannot be discerned by human eyes. This enables high-precision identification of viruses.”

In testing this sensor, the research team found that electroosmotic flow (liquid motion induced by an electric current across the nanopore) through the pore channel could block the passage of non-virus particles. This ensured that the only particles evaluated by the sensor were virus particles, regardless of the complexity of the sample that contained those viruses.

“Our testing revealed that this new sensor may be suitable for use in a viral test kit that is both quick and simple,” says lead author Akihide Arima, “Importantly, use of this sensor does not require specialized human expertise, so it can readily be applied as a point-of-care screening approach by a wide variety of healthcare personnel.”

In addition to enabling early detection of influenza, this nanosensor method could be modified to enable early detection of other viral particles. This would enable rapid prevention and tracking for a variety of local epidemics and potential pandemics.

The article, "Selective detections of single-viruses using solid-state nanopores," was published in Scientific Reports at DOI:

Source: Osaka University 


Rapid diagnosis of flu before symptom onsets can revolutionize our health through diminishing a risk for serious complication as well as preventing infectious disease outbreak. Sensor sensitivity and selectivity are key to accomplish this goal as the number of virus is quite small at the early stage of infection. Here we report on label-free electrical diagnostics of influenza based on nanopore analytics that distinguishes individual virions by their distinct physical features. We accomplish selective resistive-pulse sensing of single flu virus having negative surface charges in a physiological media by exploiting electroosmotic flow to filter contaminants at the Si3N4 pore orifice. We demonstrate identifications of allotypes with 68% accuracy at the single-virus level via pattern classifications of the ionic current signatures. We also show that this discriminability becomes >95% under a binomial distribution theorem by ensembling the pulse data of >20 virions. This simple mechanism is versatile for point-of-care tests of a wide range of flu types.

New Chlamydia Test Delivers Results in About 30 Minutes

NIBIB-funded researchers recently validated a rapid STD test that delivered accurate results in about 30 minutes for chlamydia, allowing patients to receive treatment immediately, thereby stemming the further spread of disease. Other analyses showed most women preferred the easy self-collection method the test offers.

Point-of-care (POC) testing eliminates the need for follow-up appointments since patients receive treatment at the time of diagnosis. Chlamydia has been identified by the World Health Organization as a sexually transmitted disease (STD) without an available POC test. "POC tests for STDs are making significant progress towards being highly sensitive, specific and easy to read within a short wait time." said Tiffani Bailey Lash, Ph.D., director of the National Institute of Biomedical Imaging and Bioengineering (NIBIB) programs in Point-of-Care Technologies and Connected Health (mHealth and Telehealth).

To help fill this healthcare void, a team at the Johns Hopkins University (JHU) Center for the Development of POC Tests for STDs, led by director Charlotte Gaydos, Dr. P.H., tested the binx health POC system at two clinics, in Maryland and Ohio. The study determined this POC test to accurately give a positive result 93 percent and a negative result 99 percent of the time.

With funding from NIBIB, the JHU Center selected binx health (formerly Atlas Genetics) as one of its first subgrantees to support the development and translation of this promising technology. Dr. Gaydos explained, "It takes time and money for POC technologies to get to the market. The goal of POC technology is to deliver quick results on a mobile platform, giving patients more options. A patient should be able to choose if he/she comes into a clinic, goes to a pharmacy, or takes a test at home for STD diagnosis; the bottom line is to encourage people to get tested."

It is common for STDs to present without visible symptoms, so patients think they are healthy while, in fact, they are spreading STDs. Currently, patients who are tested for STDs typically receive their results anywhere from 2-14 days later, which contributes to the onward transmission and rapid spread of STDs. Studies have shown that even patients who have been tested have a low probability of returning to receive results, counseling, and proper treatment. Many patients don't come back to the clinic for a follow-up appointment due to work or other obligations.

Another concern of doctors is the high number of patients who do not seek treatment for STDs due to privacy issues. In the future, POC tests may allow patients to collect a sample at home and send it in for testing. Dr. Gaydos said she was encouraged to observe that the majority (86%) of women in this study found self-collection in the clinic to be easy, and 70 percent preferred that method.

In this study, the samples were self-collected on a swab in the clinic and then placed into a liquid by a lab technician. The swabs were transported to a clinical lab and loaded into a disposable, hand-held cartridge. The lab technician inserted the cartridge into an instrument which has a user-friendly interface for processing and analysis. Each cartridge contains all the components necessary to complete the screening and deliver a positive negative, or indeterminate result in about 30 minutes.

In addition to the need for accurate and rapid test results, it is also important to consider a patient's attitude toward a POC testing. In the study, researchers received completed questionnaires from 273 women who self-collected their sample for the POC test. If treatment was available before leaving the clinic, only 25 percent of women were willing to wait up to 40 minutes for their test result, but 61 percent were willing to wait 20 minutes or less. Most women (81%) were willing to pay $20 or less for a POC test. Almost all women (96%) would tell their partner the result of their test. "It was promising to see how well-received the test was among patients. I think the world has been waiting for a POC STD test and I am eager to be a part of continuing to develop new POC technology," said Lash.

There is an urgent need to address the record high numbers of STDs reported by the Centers for Disease Control. In the U.S. alone there was a 10% increase in STDs between 2016 and 2017. Comprehensive studies like this one show the importance of understanding a patient's attitude toward POC tests and identifying barriers. The results from this study show the need for a reasonably priced test and results delivered in about half an hour or less so patients get treatment before leaving the clinic. JHU and binx health have recently launched a clinical trial and anticipate the data obtained in the trial will help them achieve FDA-clearance for a Chlamydia and Gonorrhea POC test in the U.S. Gaydos envisions a mobile/digital health approach for patients who do not wish to attend a clinic or doctors' office and are happy to self-collect a sample at home.

More information: Lea E. Widdice et al. Performance of the Atlas Genetics Rapid Test for Chlamydia trachomatis and Womenʼs Attitudes Toward Point-Of-Care Testing, Sexually Transmitted Diseases (2018). DOI: 10.1097/OLQ.0000000000000865 

Researchers Develop Tool for Speedy Diagnosis of Bacterial Infections

Using a small and inexpensive biosensor, researchers at UBC Okanagan, in collaboration with the University of Calgary, have built a diagnostic tool that provides health care practitioners almost instant diagnosis of a bacterial infection.

The tool is able to provide accurate and reliable results in real-time rather than the two-to-five days required for existing processes that test infections and antibiotic susceptibility.

“Advances in lab-on-a-chip microfluidic technology are allowing us to build smaller and more intricate devices that, in the medical research space, can provide more information for health care practitioners while requiring less invasive sampling from patients,” explains Mohammad Zarifi, an assistant professor at UBC Okanagan.

According to health care statistics from 2017, every hour of delay in antibiotic treatment increases mortality rates by nearly eight per cent due to infection complications in the bloodstream.

Zarifi, and his research group in the School of Engineering’s Microelectronics and Advanced Sensors Laboratory, tested their device by tracking the amount of bacteria present in a variety of samples under various scenarios. The scenarios resembled those encountered in clinical microbiological laboratories.

By sending a microwave signal through the sample, the device quickly and accurately analyzes and then generates a profile of existing bacteria.

The diagnostic tool not only provides a rapid, label-free and contactless diagnostic tool for clinical analysis but it also goes further, says Zarifi.

“The device is able to rapidly detect bacteria and in addition, it screens the interaction of that bacteria with antibiotics,” he adds. “The combined results give health care practitioners more information than they currently have available, helping them move forward to determine accurate treatments.”

This biosensor, explains Zarifi is a significant step forward in improving the complex antibiotic susceptibility testing workflow and provides a rapid and automated detection of bacteria as well as screening the bacteria proliferation in response to antibiotics.

The research was published in the journal Nature Scientific Reports with financial support from CMC Microsystems and the Natural Sciences and Engineering Council of Canada.


Sensitive, Real-time and Non-Intrusive Detection of Concentration and Growth of Pathogenic Bacteria using Microfluidic-Microwave Ring Resonator Biosensor

Infection diagnosis and antibiotic susceptibility testing (AST) are time-consuming and often laborious clinical practices. This paper presents a microwave-microfluidic biosensor for rapid, contactless and non-invasive device for testing the concentration and growth of Escherichia Coli (E. Coli) in medium solutions of different pH to increase the efficacy of clinical microbiology practices. The thin layer interface between the microfluidic channel and the microwave resonator significantly enhanced the detection sensitivity. The microfluidic chip, fabricated using standard soft lithography, was injected with bacterial samples and incorporated with a microwave microstrip ring resonator sensor with an operation frequency of 2.5 GHz and initial quality factor of 83 for detecting the concentration and growth of bacteria. The resonator had a coupling gap area on of 1.5 × 1.5 mm2 as of its sensitive region. The presence of different concentrations of bacteria in different pH solutions were detected via screening the changes in resonant amplitude and frequency responses of the microwave system. The sensor device demonstrated near immediate response to changes in the concentration of bacteria and maximum sensitivity of 3.4 MHz compared to a logarithm value of bacteria concentration. The minimum prepared optical transparency of bacteria was tested at an OD600 value of 0.003. The sensor’s resonant frequency and amplitude parameters were utilized to monitor bacteria growth during a 500-minute time frame, which demonstrated a stable response with respect to detecting the bacterial proliferation. A highly linear response was demonstrated for detecting bacteria concentration at various pH values. The growth of bacteria analyzed over the resonator showed an exponential growth curve with respect to time and concurred with the lag-log-stationary-death model of cell growth. This biosensor is one step forward to automate the complex AST workflow of clinical microbiology laboratories for rapid and automated detection of bacteria as well as screening the bacteria proliferation in response to antibiotics.

Tuesday, November 27, 2018

Pregnancy Style Test for E. coli and Romaine Lettuce

With seven deaths, 31 suffering kidney failure, 159 hospitalised and at least 339 Americans and Canadians sickened since 2017 after eating romaine lettuce contaminated with E. coli, news of a faster E. coli test is welcome.

Western University, Ontario, has developed a kit that detects a protein unique to the pathogenic E. coli O157 bacteria and, using flow through technology, is able show results in hours rather than days.

Food samples to be tested are incubated for a few hours then a sample is placed on a pad. After 15 minutes, the pad displays one red line to show it worked properly — and a second if the sample contains E. coli O157; much like how pregnancy tests show their results.

The developers claim their kit also makes the process of testing for E. coli O157 cheaper than existing technology, which could make smaller-scale producers more amenable to testing their products.

Current food testing methods for E. coli typically rely on culture and by the time results are available some days later fresh produce has been shipped to retailers, sold and eaten. With results available in hours, rather than days or weeks, this new test will enable food processors to ensure food is uncontaminated before it is shipped.

Use of a cheaper, rapid test will mean processors can test more frequently.

The romaine lettuce crisis

A common source of E. coli illness is raw fruits and vegetables that have come in contact with faeces from infected animals.

Leafy greens, such as lettuce, can become contaminated in the field by soil, water, animals or improperly composted manure. Lettuce can also be infected by bacteria during and after harvest from handling, storing and transporting the produce.

Contamination in lettuce is also possible at the retail environment, in the refrigerator or from counters and cutting boards through cross-contamination with bacteria from raw meat, poultry or seafood.

Since 1 April 2017, the Canadian Food Inspection Agency has tested more than 2000 samples of imported fresh vegetables and salads, including romaine lettuce and pre-packaged salads containing romaine lettuce, as part of its regular microbiological surveillance program.

None of these samples have proven positive for E. coli O157. This means that contamination levels are low and most romaine lettuces are uncontaminated, but the real need is to identify those lettuces that are contaminated. More tests, with low cost but high accuracy, will help public health officials and produce marketers weed out the affected produce. Western’s new test will be invaluable in this circumstance.

In his blog Publisher’s Platform: How does this “Romaine” acceptable?, Bill Marler asks: “What will growers, processors, shippers, grocery stores, restaurants, consumers, regulators, and politicians do? Good readers – ideas?”. Possibly the best response was from Sue: “This should fix it: Move the growers’ focus from their wallets (greed) to their amygdala (fear.) Host a weekly luncheon for all Western Growers executives - attendance mandatory. Menu: Giant Caesar salad made with romaine lettuce from each grower. Eat it or close down.

The rapid test was developed at Western University’s Schulich School of Medicine & Dentistry and Robarts Research Institute with support from Mitacs, a federal non-profit that encourages academic and industrial collaboration with the food industry.


Mesa Biotech Receives FDA 510(k) Clearance and CLIA Waiver for Its Accula™ RSV Molecular Point of Care Test

Mesa Biotech Inc., is a privately held, molecular diagnostic company that has developed an affordable and easy to operate PCR (polymerase chain reaction) testing platform designed specifically for point-of-care (POC) infectious disease diagnosis. Today, Mesa Biotech announced that it received 510(k) clearance and Clinical Laboratory Improvements Amendments (CLIA) waiver from the US Food and Drug Administration (FDA) for its Accula™ RSV test. The respiratory syncytial virus or RSV test cassette is cleared for diagnosing both children and adult populations.

The Accula RSV test is the second molecular POC diagnostic on the Accula platform to receive FDA clearance and CLIA waiver, following the company's Flu A/Flu B test, cleared earlier this year. The Center for Disease Control (CDC) acknowledges that the specificity and sensitivity of rapid influenza diagnostic tests (RIDT) are lower than for viral culture and RT-PCR and vary by test. The Accula molecular test system provides the superior sensitivity, specificity and information content of laboratory-based PCR testing, while offering the simplicity, convenience and procedural familiarity of traditional POC rapid immunoassays, with its palm-sized, reusable dock and disposable test cassettes. Furthermore, the Accula RSV test is indicated for use with nasal swab collection, which is less invasive than nasopharyngeal swabs and provides a more comfortable specimen collection experience for the patient, especially children.

"The addition of Accula RSV test to our Flu A/Flu B test significantly enhances our upper respiratory rapid, molecular diagnostic offerings," said Dr. Hong Cai, co-founder and CEO of Mesa Biotech. "It is important to have a distinct in-office diagnosis for RSV and flu, especially in young children and the elderly to provide timely, accurate information to clinicians to ensure appropriate treatment and improved patient management."

According to the CDC, young children and older adults are more likely to get serious complications if they get sick with RSV. Each year in the US, an estimated 57,000 children younger than five years old are hospitalized due to RSV infection. Additionally, it is estimated that more than 177,000 older adults are hospitalized and 14,000 of them die in the US due to RSV infection. Adults at the highest risk for severe RSV infection include those 65 years and older, adults with chronic heart or lung disease and/or adults with weakened immune systems.

For rapid distribution of both tests, Mesa Biotech entered into a strategic alliance with Sekisui Diagnostics for exclusive product distribution rights in the U.S. and Canada. The Accula RSV test, along with the company's Flu A/Flu B test, is marketed by Sekisui Diagnostics under the Silaris™ brand.

About Respiratory Syncytial Virus

Respiratory syncytial virus (RSV) is an RNA virus attributable to outbreaks of respiratory tract infections. RSV infections can occur throughout the year, but typically peak during the winter months. RSV most commonly causes a cold-like illness but can also cause lower respiratory infections like bronchiolitis and pneumonia, which often become severe in infants, young children and the elderly with underlying diseases. Diagnosis of RSV is difficult because the initial symptoms can be similar to those caused by other infectious agents. Considering that the RSV virus is highly contagious, accurate diagnosis and prompt treatment of patients can have a positive effect on public health.

About Mesa Biotech Inc.

Mesa Biotech designs, develops, manufactures and commercializes next generation molecular diagnostic tests, bringing the superior diagnostic performance of nucleic acid PCR amplification to the point-of-care (POC). Mesa Biotech's Accula™ System consists of a portable, palm-sized dock and disposable, assay-specific test cassettes. This patented system enables healthcare professionals to access actionable, laboratory-quality results at the POC with greater sensitivity and specificity than current infectious disease rapid immunoassay tests. The Accula Flu A/Flu B and the Accula RSV tests have obtained CE Mark in the EU and 510(k) clearance and Clinical Laboratory Improvements Amendments (CLIA) waiver from the US Food and Drug Administration (FDA). Both products are distributed in the US and Canada by Sekisui Diagnostics under the Silaris™ brand. Mesa Biotech has secured a number of strategic agreements for distribution in Europe and Asia.

Indian Scientists Develop Highly Sensitive and Rapid Tests for Detection of Tuberculosis

Tuberculosis (TB) continues to be one of the leading causes of death worldwide. According to the World Health Organisation (WHO), some 10 million people across the world fell ill with TB in 2017, and 1.6 million died from the disease. India, which saw an estimated 28 lakh cases occurred and 4.8 lakh people died due to the disease in 2015, accounts for one-fourth of the global TB burden. Offering hope of finding tuberculosis early, scientists at the Translational Health Science and Technology Institute (THSTI) and All India Institute of Medical Sciences, New Delhi, have jointly developed highly sensitive and rapid tests for detection of TB infection in lungs and surrounding membranes, says a report in India Science Wire. Early detection and treatment are crucial to prevent the spread, outbreaks, and development of resistance.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It commonly affects the lungs, but can also affect other parts of the body. It spreads from person to person through inhalation of infected air - when people who are infected with TB cough, sneeze they propel the germs into the air. According to the report, when the bacteria attack the lungs, the disease manifests itself as pulmonary form or pulmonary TB - the most common form of TB. But in 2016,  about 15% of new patients were found infected with extrapulmonary TB where organs other than the lungs may be affected.

Till date, the detection of all forms of TB is mostly based on sputum smear microscopy and culture tests. Although smear microscopy is inexpensive and simple, it has low sensitivity. A culture test is highly sensitive but takes 2 to 8 weeks to get results. For detection of bacterial proteins in sputum samples, conventional diagnostic tests use antibodies. And such tests suffer from limitations including batch-to-batch variability, limited shelf-life, and cost said the report.

However, to help address the shortcomings in the present testing protocol, the researchers developed two DNA aptamer-based tests - Aptamer Linked Immobilized Sorbent Assay (ALISA) and Electrochemical Sensor (ECS) for detecting a bacterial protein in the sputum. Aptamers are DNA, RNA or peptide molecules that bind to a specific target molecule. They can be used for both basic research and clinical purposes as macromolecular drugs. Aptamers bind the right target (which defines sensitivity) and at the same time rule out any non-specific binding to other targets.

In the present work, the researchers compared the performance of the newly developed tests with antibody-based tests in 314 sputum samples. The found that ALISA produced 92% sensitivity compared to the antibody-based method that showed 68% sensitive. The team used ALISA to detect a bacterial protein, HspX. But it took five hours for the researchers to yield results as the method requires sputum immobilisation which is a time-consuming step. So the team developed a simplified ECS test. In this technique, the team immobilized the aptamer with an electrode, and upon binding to HspX in the sputum sample, a drop in the electrical signal was recorded.

According to the researchers, the ECS test can be used for screening of samples in the field. It takes as less as 30 minutes to deliver results and is highly sensitive. The ECS test could also detect HspX protein in 91% of the samples tested in the study. In addition, there is no need for sputum sample preparation which is a complex and time-consuming process, said the report.

“We aim to develop aptamers for detection of multiple bacterial proteins simultaneously which is expected to lead a more robust test,” said Tarun Sharma, a member of the research team.

“The aptamer-based screening tests for pulmonary TB, pleural TB, and TB meningitis hold immense promise for a country like India, where the disease burden in high and primary health care is only a dream for many. The ECS platform could be used in a mobile screening van at the point-of-care,” added Jaya Tyagi, who led the research team AIIMS. “We hope that these tests are adopted by the TB programs in the country,” she added.

In the study, the team used the aptamer-based test also for detection of pleural TB, the second most prevalent form of extrapulmonary TB. The researchers note the early diagnosis of pleural TB is limited by the availability of a sensitive and rapid test. The performance of existing DNA-based tests varies widely due to low bacterial load in the pleural fluid sample.

“There is no test for making a confirmed diagnosis of pleural TB. Even WHO-endorsed Gene Xpert has a poor sensitivity of 22%. On the contrary, our aptamer-based test for pleural TB showed 93% sensitivity and is cost-effective,” explained Sagarika Haldar, a member of the research team, was quoted as saying by India Science Wire.

The results were published in the journals ACS Infectious Diseases and Analytical Biochemistry.

LuminUltra Concludes Acquisition Of Aqua-Tools’ Rapid Microbial & Ballast Water Monitoring Solutions

LuminUltra, the Canada-headquartered specialist in microbiological monitoring tools, has completed its acquisition of the Rapid Microbial Solutions (RMS) division of France-based aqua-tools.

The acquisition, announced in October, includes the award-winning B-QUA ballast water test kit and aqua-tools’ European customer base for its 2nd Generation ATP® (Adenosine Triphosphate) measurement products.

Pat Whalen, President and CEO of LuminUltra, said: “The acquisition of aqua-tools’ B-QUA line of ballast water monitoring solutions along with its European customer base is a key development in our strategy to enter the international maritime sector. Our goal is to expand our global footprint through a wider network of partners across the European continent and we look forward to bringing our maritime customers closer to the LuminUltra family.”

aqua-tools employees dedicated to the Rapid Microbial Solutions division have joined the LuminUltra team while remaining in Paris, France. aqua-tools continues to operate as a separate business, focusing solely on its Infection Control Solutions.

Marc Raymond, Managing Director aqua-tools, said: “We are delighted the acquisition has concluded with the successful migration of our rapid microbial solutions and staff to LuminUltra.

“For LuminUltra, the technology transfer is something of a homecoming since the rapid ballast water test kit was initially developed as a collaborative project between aqua-tools, SGS Group (Switzerland) and LuminUltra. The 2nd generation ATP technique used in the B-QUA test kit is proven to be the most reliable and effective indicative monitoring solution on the market.”

The addition of B-QUA compliments LuminUltra’s portfolio of 2nd Generation ATP microbial testing solutions, all of which have significant relevance for the commercial and offshore marine segments.
The company’s Quench-Gone Organic Modified (QGO–M™) test kit, for instance, has been designed specifically to monitor the bacteria content of fuel systems to curtail biofouling and microbial influenced corrosion of pipework. Its water test kit (QGA™) can be used to monitor the microbial quality of drinking water onboard. Both of these analyses can be performed with the same equipment as the one used for ballast water.

“Effective microbiological control is critical for maintaining efficient processes in a number of maritime and offshore applications,” said Whalen.

“LuminUltra’s 2nd Generation ATP testing provides results within minutes to give operators a clear indication of the total microbial activity and health of their water, wastewater and fuel systems. Microbiology is rarely considered a problem until it becomes a problem.”

The acquisition of aqua-tools’ RMS division follows the September purchase of US-based InstantLabs, a developer of DNA-based measurement technologies.

Two Pore Guys Receives Grant to Develop Sensitive, Low-Cost Molecular Diagnostic Tests for Tuberculosis

Two Pore Guys, Inc. (2PG) announced that the company has received a $2.8 million grant from the Bill & Melinda Gates Foundation to develop sensitive, low-cost molecular diagnostic tests for tuberculosis (TB) using its solid-state nanopore technology. The 18-month grant will fund proof-of-concept work to determine if 2PG technology could provide an easy-to-use, sensitive and low-cost point-of-care device that would be compatible with automated, wireless reporting for resource-poor settings.

TB is one of the top 10 causes of death worldwide, and the leading cause from a single infectious agent. Millions of people continue to fall sick with TB each year. WHO estimates 10 million people developed TB last year worldwide.

The WHO 2018 Global TB Report, released in September, calls for an unprecedented mobilization of national and international commitments to meet the global target of ending TB by 2030. Underdiagnosis of TB is a major challenge: only about 6.4 million of the 10 million people who contracted TB in 2017 were officially recorded by national reporting systems, leaving 3.6 million people undiagnosed or detected but not reported. Late detection of Mycobacterium tuberculosis (MTB), the infectious organism that causes TB, increases the risk of transmission, delays treatment, and burdens the healthcare system. Lack of affordable, sensitive and rapid detection of MTB is a major hurdle in low- and middle-income countries. Implementing a low-cost, sensitive and portable molecular diagnostic test is expected to save thousands of dollars per patient.

“Our point-of-care technology platform offers tremendous value to address medical testing needs in resource-limited areas,” said William Dunbar, Co-founder and interim CEO of Two Pore Guys. “We are grateful to the Bill & Melinda Gates Foundation for this support and for their enthusiasm about the promise of our technology. We hope to make a difference in the lives of millions of people around the world who need better access to affordable TB care.”

About the 2PG Technology

Unlike biological nanopores used in some DNA sequencing technologies, 2PG’s devices employ silicon nanopore chips, which are robust sensors that examine a wide range of individual analytes with high sensitivity. Additionally, 2PG workflows can support multiplexed and multi-modal assays, i.e., to test for DNA/RNA and analyte/protein from a single sample source. 2PG’s patented methods also permit genotyping, e.g., for detecting drug resistance.

FluChip-8G Tested in US and China for Rapid Characterization of Influenza Viruses

Scientists at Duke Kunshan University and Duke University are collaborating with InDevR Inc. to evaluate the FluChip-8G Insight system for the rapid identification of the influenza virus subtype from human and animal samples.

The FluChip-8G test promises to be a faster and easier way to determine the subtype of seasonal and non-seasonal influenza viruses. It has the potential to reduce influenza A and B characterization times from two weeks to eight hours.

"Knowing that a patient is infected with a dangerous influenza virus could lead to early antiviral treatment, isolation of the patient, and early identification and mitigation of the virus source, which could save lives," said Professor Gregory Gray, the Principal Investigator for Duke Kunshan and Duke University.

Study teams at Duke Kunshan and Duke are employing the FluChip-8G test alongside standardized WHO/CDC rRT-PCR tests that are currently used for Gray's research in zoonotic influenza virus epidemiology.

The study will use specimens collected by the Duke Kunshan team and collaborators in Vietnam, China, Malaysia and the U.S.

In the United States, specimens will come from Duke University Hospital's Department of Clinical Virology, Wake Forest University's Department of Clinical Virology, and the North Carolina Veterinary Diagnostic Laboratory System, as well as a swine veterinarian from the U.S. Midwest.

"We are excited to participate in the multi-month field validation of this technology," said Haiyan Gao, vice chancellor for academic affairs at Duke Kunshan and Henry Newson Professor of Physics at Duke University.

"This collaboration shows the research strength of Duke Kunshan is widely recognized. It is also a typical example of how joint research projects between China and the United States can make people's lives better," Gao said.

Influenza -- commonly known as the flu -- is a respiratory infection caused by a virus. Influenza A and B viruses are the two types that most commonly infect humans. Influenza A viruses spread between animals and humans and sometimes cause epidemics.

Based in Boulder, Colorado USA InDevR is a leader in progressive new diagnostic and analytical technologies that enable accelerated development and manufacturing of vaccines and other bio-therapeutics.

Advanced development of this new molecular test, which was designed to improve pandemic preparedness, was funded by the Biomedical Advanced Research and Development Authority (HHSO100201400010C, HHSO100201400024C), which is part of the U.S. Department of Health and Human Services.

Wednesday, November 14, 2018

Mesa Biotech Obtains CE Mark for its Accula RSV Molecular Point of Care Test

Mesa Biotech Inc., a privately-held, molecular diagnostic company that has developed an affordable and easy to operate PCR (polymerase chain reaction) testing platform designed specifically for point-of-care (POC), today announced it has obtained CE Mark in the European Union (EU) for its Accula™ RSV Test. The company's RSV test will be marketed by select distributors in the EU at once. Accula RSV Test is pending FDA clearance in the US.

"We are excited to introduce the second test in our PCR-based infectious disease diagnostic portfolio in the EU," said Hong Cai, Co-founder and Chief Executive Officer, Mesa Biotech, Inc. "The Accula RSV brings reference laboratory performance to the point of care, enabling clinicians to quickly and accurately diagnosis and treat their patients."

Respiratory syncytial virus (RSV) is an RNA virus attributable to outbreaks of respiratory tract infections. RSV infections can occur throughout the year, but typically peak during the winter months. Studies indicate that nearly 100 percent of children will suffer from RSV infections by age two. RSV viruses not only cause upper respiratory tract infections but also bronchiolitis of the lower respiratory tract, which often becomes severe in infants and toddlers with underlying diseases. Diagnosis of RSV is difficult because the initial symptoms can be similar to those caused by other infectious agents. Considering that the RSV virus is highly contagious, accurate diagnosis and prompt treatment of patients can have a positive effect on public health.

According to the World Health Organization (WHO), the global burden of RSV-associated acute lower respiratory infection is estimated at 33 million annually, resulting in more than 3 million hospitalizations and almost 60,000 in-hospital deaths in children under five years of age.

The Center for Disease Control (CDC) acknowledges that the specificity and sensitivity of rapid influenza diagnostic tests (RIDT) are lower than for viral culture and RT-PCR and vary by test.  The Accula System, a palm-sized, reusable dock with disposable test cassettes, offers the simplicity, convenience and procedural familiarity of traditional POC rapid immunoassays, while providing the superior sensitivity, specificity and information content of laboratory-based PCR testing. The Accula RSV test is indicated for use with nasal swab collection, which is less invasive than nasopharyngeal swabs and provides a more comfortable specimen collection experience for the patient, especially children.

About Mesa Biotech Inc.

Mesa Biotech designs, develops, manufactures and commercializes next generation molecular diagnostic tests, bringing the superior diagnostic performance of nucleic acid PCR amplification to the point-of-care (POC). Mesa Biotech's Accula™ System consists of a portable, palm-sized dock and disposable, assay-specific test cassettes. This patented system enables healthcare professionals to access actionable, laboratory-quality results at the POC with greater sensitivity and specificity than current infectious disease rapid immunoassay tests. The Accula Flu A/Flu B Test, Mesa Biotech's first product to market, has obtained CE Mark in the EU and 510(k) clearance and Clinical Laboratory Improvements Amendments (CLIA) waiver from the U.S. Food and Drug Administration (FDA).

Bio-Rad Wins USDA Contract for Its Pathogen Detection Testing Products

Bio-Rad Laboratories, Inc., a global leader of life science research and clinical diagnostic products, today announced that the company has been awarded a contract for iQ-Check real-time PCR pathogen detection test kits and the iQ-Check Prep Automation System from the United States Department of Agriculture’s Food Safety and Inspection Service (USDA FSIS).

The contract includes real-time PCR-based tests for pathogens that include Salmonella spp., Listeria monocytogenes, Campylobacter, Escherichia coli O157:H7, and Shiga toxin producing E. coli (STEC) that may be found in raw meat and poultry, ready to eat meat and poultry, processed egg products, and other food products and environmental samples. Bio-Rad’s iQ-Check real-time PCR test kits were selected based on their proven real-time PCR technology that uses highly specific patented DNA probes to detect pathogenic bacteria in a sample. USDA FSIS will also incorporate Bio-Rad’s iQ-Check Prep automation system for high throughput sample processing and elevated traceability.

“We are pleased to partner with the USDA to help protect the food supply,” said Annette Tumolo, Bio-Rad President, Life Science Group. “This is an exciting development for Bio-Rad, reflecting our strong performance in the area of rapid food pathogen testing solutions.”

The iQ-Check kits for pathogen detection are routinely used in food safety programs worldwide, and are recognized by several renowned international validation organizations.

iQ-Check and Bio-Rad are trademarks of Bio-Rad Laboratories, Inc. in certain jurisdictions.

Monday, November 12, 2018

FDA Authorizes Emergency Use of First Ebola Fingerstick Test with Portable Reader

The U.S. Food and Drug Administration announced that an emergency use authorization (EUA) has been issued for a rapid, single-use test for the detection of Ebola virus (Zaire ebolavirus). This is the second Ebola rapid antigen fingerstick test available under EUA, but the first that uses a portable battery-operated reader, which can help provide clear diagnostic results outside of laboratories and in areas where patients are likely to be treated.
The test, called the DPP Ebola Antigen System, is used with blood specimens, including capillary “fingerstick” whole blood, from individuals with signs and symptoms of Ebola virus disease (EVD) in addition to other risk factors, such as living in an area with large numbers of EVD cases and/or having contact with other individuals exhibiting signs and symptoms of EVD.

“The scourge of Ebola tragically demonstrates that we’re a global community when it comes to public health protection. Infectious disease doesn’t recognize nation states. Bacteria and viruses don’t respect territorial boundaries. It takes a sustained, robust and globally coordinated effort to protect our nation and the global community from various infectious disease threats. We’re all in this together. To that end, our FDA team of experts in drugs, vaccines and diagnostics continue to collaborate with our Federal, international and industry partners to employ our collective expertise, experiences from previous incidents, and resources to assist in the global response to the Ebola outbreak in the Democratic Republic of Congo,” said FDA Commissioner Scott Gottlieb, M.D. “This EUA is part of the agency’s ongoing efforts to help mitigate potential, future threats by making medical products that have the potential to prevent, diagnosis or treat available as quickly as possible. We’re committed to helping the people of the DRC effectively confront and end the current Ebola outbreak. By authorizing the first fingerstick test with a portable reader, we hope to better arm health care providers in the field to more quickly detect the virus in patients and improve patient outcomes.”

The FDA’s EUA authority allows the agency to authorize the use of an unapproved medical product, or the unapproved use of an approved medical product when, among other circumstances, there are no adequate, approved and available alternatives. When circumstances exist justifying authorization, the EUA becomes an important mechanism that allows broader access to medical products that have not been FDA cleared or approved and are instead only authorized for use for the duration of an emergency declaration. The FDA’s criteria for issuing an EUA for a diagnostic test includes making an assessment that it is reasonable to believe, based on the totality of evidence available to the agency, that the test may be effective and the known and potential benefits of using the test outweigh its known and potential risks.

In 2014, during the Ebola outbreak in West Africa, an emergency was declared by the Secretary of Health and Human Services. While that outbreak has ended, ongoing, smaller Ebola outbreaks have continued, and the emergency declaration is still in place. Recent outbreaks in remote areas with limited resources can benefit from rapid diagnostic tools, and the issuance of an EUA for the DPP Ebola Antigen System is an important step in addressing these outbreaks.

The DPP Ebola Antigen System provides rapid diagnostic results with tests that can be performed in locations where a healthcare provider does not have access to authorized Ebola virus nucleic acid tests (PCR testing), which are highly sensitive but can only be performed in certain laboratory settings that are adequately equipped. The DPP Ebola Antigen System has been authorized for use with capillary “fingerstick” whole blood, ethylenediaminetetraacetic acid (EDTA, an anticoagulant added to whole blood to prevent coagulation) venous whole blood and EDTA plasma. The DPP Ebola Antigen System should only be run in facilities, including treatment centers and public health clinics where patients are likely to be treated, and laboratories that are adequately equipped, trained and capable of such testing.

While today’s action will increase access to diagnostic tools for healthcare providers who may not have otherwise been equipped to perform tests, it is important to note that a negative result from the DPP Ebola Antigen System, especially in patients with signs and symptoms of EVD, should not be used as the sole basis for patient management decisions. The diagnosis of EVD must be made based on multiple factors such as, history, signs, symptoms, exposure likelihood and other laboratory evidence in addition to the detection of Ebola virus.

The FDA remains committed to using its authorities and resources to advance the development of countermeasures to address emerging threats and recently outlined its efforts to help address Ebola virus outbreaks. The FDA will continue to work with its federal partners and potential commercial product manufacturers in the most expedited manner to increase the availability of authorized diagnostic tests for Ebola virus disease for emergency use during this and any future outbreak.

With the issuance of the EUA for the DPP Ebola Antigen System to Chembio Diagnostic Systems Inc., the FDA has now issued EUAs for nine nucleic acid tests and two rapid diagnostic tests for Ebola virus detection in human specimens.

The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.

Cellphone Technology Developed to Detect HIV

The management of human immunodeficiency virus 1 (HIV), an autoimmune disorder that cripples the immune system by attacking healthy cells, remains a major global health challenge in developing countries that lack infrastructure and trained medical professionals. Investigators from Brigham and Women’s Hospital have designed a portable and affordable mobile diagnostic tool, utilizing a cellphone and nanotechnology, with the ability to detect HIV viruses and monitor its management in resource-limited regions. The novel platform is described in a paper published recently in Nature Communications.

“Early detection of HIV is critical to prevent disease progression and transmission, and it requires long-term monitoring, which can be a burden for families that have to travel to reach a clinic or hospital,” said senior author Hadi ­­Shafiee, PhD, a principal investigator in the Division of Engineering in Medicine and Renal Division of Medicine at the Brigham. “This rapid and low-cost cellphone system represents a new method for detecting acute infection, which would reduce the risk of virus transmission and could also be used to detect early treatment failure.”

Traditional virus monitoring methods for HIV are expensive, requiring the use of polymerase chain reaction (PCR). Shafiee and his colleagues sought to design an affordable, simple tool that makes HIV testing and monitoring possible for individuals in developing countries with less access to medical care.

Utilizing nanotechnology, a microchip, a cellphone and a 3D-printed phone attachment, the researchers created a platform that can detect the RNA nucleic acids of the virus from a single drop of blood. The device detects the amplified HIV nucleic acids through on-phone monitoring of the motion of DNA-engineered beads without using bulky or expensive equipment. The detection precision was evaluated for specificity and sensitivity.

Researchers found that the platform allowed the detection of HIV with 99.1 percent specificity and 94.6 percent sensitivity at a clinically relevant threshold value of 1,000 virus particles/ml, with results within one hour. Notably, the total material cost of the microchip, phone attachment and reagents was less than $5 per test.

“Health workers in developing countries could easily use these devices when they travel to perform HIV testing and monitoring. Because the test is so quick, critical decisions about the next medical step could be made right there,” said Shafiee. “This would eliminate the burden of trips to the medical clinic and provide individuals with a more efficient means for managing their HIV.”

“We could use this same technology as a rapid and low-cost diagnostic tool for other viruses and bacteria as well,” said lead author Mohamed Shehata Draz, ­­PhD, an instructor in the Division of Engineering in Medicine and Renal Division of Medicine at the Brigham.. “This platform could help a lot of people worldwide.”

Funding for this work was provided by the National Institute of Health under award numbers R01AI118502, R21HD092828, and P30ES000002; Harvard T.H. Chan School of Public Health, Harvard Center for Environmental Health through Harvard NIEHS Grant; and American Board of Obstetrics and Gynecology, American College of Obstetricians and Gynecologists, American Society for Reproductive Medicine, Society for Reproductive Endocrinology and Infertility through ASRMAward, and Harvard University Center for AIDS Research (CFAR) under award number 5P30AI060354–14.

Draz, MS et al. “DNA engineered micromotors powered by metal nanoparticles for motion based cellphone diagnostics” Nature Communications DOI: 10.1038/s41467-018-06727-8