Development of a Rapid Fluorescent Diagnostic System to Detect Subtype H9 Influenza A Virus in Chicken Feces

The circulation of the H9N2 virus results in significant economic losses in the poultry industry, and its zoonotic transmission highlights the need for a highly sensitive and rapid diagnostic and detection system for this virus. In this study, the performance of lateral flow test strips for a fluorescent immunochromatographic test (FICT) was optimized for the diagnosis of H9N2 virus-infected animal samples. The novel monoclonal antibodies (McAbs) against influenza A H9 viruses were developed, and two categories of McAbs with linear and conformational epitopes were compared for the performance of rapid diagnostic performance in the presence of feces sample at different time points (2, 4, and 6 days) post-infection (dpi). The limit of detection (LOD) of FICT and Kd values were comparable between linear and conformational epitope McAbs. However, superior performance of linear epitope McAbs pairs were confirmed by two animal studies, showing the better diagnostic performance showing 100% relative sensitivity in fecal samples at 6 dpi although it showed less than 80% sensitivity in early infection. Our results imply that the comparable performance of the linear epitope McAbs can potentially improve the diagnostic performance of FICT for H9N2 detection in feces samples. This highly sensitive rapid diagnostic method can be utilized in field studies of broiler poultry and wild birds.

Download Full-text

SARS-Coronavirus-2 nucleocapsid protein measured in blood using a Simoa ultra-sensitive immunoassay differentiates COVID-19 infection with high clinical sensitivity.

10.1101/2020.08.14.20175356 ◽

2020 ◽

Author(s):

Dandan Shan ◽

Joseph M Johnson ◽

Syrena C Fernandes ◽

Muriel Mendes ◽

Hannah Suib ◽

...

Keyword(s):

Single Molecule ◽

Nucleocapsid Protein ◽

Influenza A ◽

Limit Of Detection ◽

Clinical Sample ◽

Scale Up ◽

Capillary Blood ◽

Influenza B ◽

N Protein ◽

Highly Sensitive

The COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. Despite rapid advances in diagnostic test development and scale-up, there remains an ongoing need for SARS-CoV-2 tests which are highly sensitive, specific, minimally invasive, cost-effective and scalable for broad testing and surveillance. Here we report development of a highly sensitive single molecule array (Simoa) immunoassay on the automated HD-X platform for the detection of SARS-CoV-2 Nucleocapsid protein (N-protein) in venous and capillary blood (fingerstick). In pre-pandemic and clinical sample sets, the assay has 100% specificity and 97.4% sensitivity for serum / plasma samples. The limit of detection (LoD) estimated by titration of inactivated SARS-CoV-2 virus is 0.2 pg/ml, corresponding to 0.05 Median Tissue Culture Infectious Dose (TCID50) per ml, > 2000 times more sensitive than current EUA approved antigen tests. No cross-reactivity to other common respiratory viruses, including hCoV229E, hCoVOC43, hCoVNL63, Influenza A or Influenza B, was observed. We detected elevated N-protein concentrations in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals using capillary blood from a finger-stick collection device. The Simoa SARS-CoV-2 N-protein assay has the potential to detect COVID-19 infection via antigen in blood with similar or better performance characteristics of molecular tests, while also enabling at home and point of care sample collection.

Download Full-text

Detection of Glucose in Human Serum Based on Silicon Dot Probe

Current Analytical Chemistry ◽

10.2174/1573411015666190702152331 ◽

2020 ◽

Vol 16 (6) ◽

pp. 744-752

Author(s):

Kuan Luo ◽

Xinyu Jiang

Keyword(s):

Quantum Dots ◽

Blood Glucose ◽

Human Serum ◽

Organic Dyes ◽

Limit Of Detection ◽

Fasting Blood Glucose ◽

Glucose Biosensor ◽

Metal Nanoclusters ◽

Glucose Levels ◽

Highly Sensitive

Background: Diabetes Mellitus (DM) is a major public metabolic disease that influences 366 million people in the world in 2011, and this number is predicted to rise to 552 million in 2030. DM is clinically diagnosed by a fasting blood glucose that is equal or greater than 7 mM. Therefore, the development of effective glucose biosensor has attracted extensive attention worldwide. Fluorescence- based strategies have sparked tremendous interest due to their rapid response, facile operation, and excellent sensitivity. Many fluorescent compounds have been employed for precise analysis of glucose, including quantum dots, noble metal nanoclusters, up-converting nanoparticles, organic dyes, and composite fluorescent microspheres. Silicon dot as promising quantum dots materials have received extensive attention, owing to their distinct advantages such as biocompatibility, low toxicity and high photostability. Methods: MnO2 nanosheets on the Si nanoparticles (NPs) surface serve as a quencher. Si NPs fluorescence can make a recovery by the addition of H2O2, which can reduce MnO2 to Mn2+, and the glucose can thus be monitored based on the enzymatic conversion of glucose by glucose oxidase to generate H2O2. Therefore, the glucose concentration can be derived by recording the fluorescence recovery spectra of the Si NPs. Results: This probe enabled selective detection of glucose with a linear range of 1-100 μg/mL and a limit of detection of 0.98 μg/mL. Compared with the commercial glucometer, this method showed favorable results and convincing reliability. Conclusion: We have developed a novel method based on MnO2 -nanosheet-modified Si NPs for rapid monitoring of blood glucose levels. By combining the highly sensitive H2O2/MnO2 reaction with the excellent photostability of Si NPs, a highly sensitive, selective, and cost-efficient sensing approach for glucose detection has been designed and applied to monitor glucose levels in human serum with satisfactory results.

Download Full-text

Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Biosensors ◽

10.3390/bios11060192 ◽

2021 ◽

Vol 11 (6) ◽

pp. 192

Author(s):

Bakhtiyar Qader ◽

Issam Hussain ◽

Mark Baron ◽

Rebeca Jiménez-Pérez ◽

Guzmán Gil-Ramírez ◽

...

Keyword(s):

Biological Samples ◽

Limit Of Detection ◽

Computational Design ◽

Signal Change ◽

Highly Sensitive ◽

Limit Of Quantitation ◽

Molecularly Imprinting Polymers ◽

Mip Sensor ◽

Parasitic Mites

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

Download Full-text

A rapid, accurate, scalable, and portable testing system for COVID-19 diagnosis

Nature Communications ◽

10.1038/s41467-021-23185-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Guanhua Xun ◽

Stephan Thomas Lane ◽

Vassily Andrew Petrov ◽

Brandon Elliott Pepa ◽

Huimin Zhao

Keyword(s):

Limit Of Detection ◽

Low Cost ◽

High Volume ◽

N Gene ◽

Testing System ◽

Target Sequence ◽

One Pot ◽

Sequence Detection ◽

Highly Sensitive ◽

Speed Accuracy

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.

Download Full-text

Validation of a Novel Diagnostic Approach Combining the VersaTREK™ System for Recovery and Real-Time PCR for the Identification of Mycobacterium chimaera in Water Samples

Microorganisms ◽

10.3390/microorganisms9051031 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1031

Author(s):

Roberto Zoccola ◽

Alessia Di Blasio ◽

Tiziana Bossotto ◽

Angela Pontei ◽

Maria Angelillo ◽

...

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Limit Of Detection ◽

Detection System ◽

Bacterial Load ◽

Microbial Control ◽

Hospital Setting ◽

Sample Volume ◽

Analytical Sensitivity ◽

Initial Water

Mycobacterium chimaera is an emerging pathogen associated with endocarditis and vasculitis following cardiac surgery. Although it can take up to 6–8 weeks to culture on selective solid media, culture-based detection remains the gold standard for diagnosis, so more rapid methods are urgently needed. For the present study, we processed environmental M. chimaera infected simulates at volumes defined in international guidelines. Each preparation underwent real-time PCR; inoculates were placed in a VersaTREK™ automated microbial detection system and onto selective Middlebrook 7H11 agar plates. The validation tests showed that real-time PCR detected DNA up to a concentration of 10 ng/µL. A comparison of the isolation tests showed that the PCR method detected DNA in a dilution of ×102 CFU/mL in the bacterial suspensions, whereas the limit of detection in the VersaTREK™ was <10 CFU/mL. Within less than 3 days, the VersaTREK™ detected an initial bacterial load of 100 CFU. The detection limit did not seem to be influenced by NaOH decontamination or the initial water sample volume; analytical sensitivity was 1.5 × 102 CFU/mL; positivity was determined in under 15 days. VersaTREK™ can expedite mycobacterial growth in a culture. When combined with PCR, it can increase the overall recovery of mycobacteria in environmental samples, making it potentially applicable for microbial control in the hospital setting and also in environments with low levels of contamination by viable mycobacteria.

Download Full-text

A Compact Detection Platform Based on Gradient Guided-Mode Resonance for Colorimetric and Fluorescence Liquid Assay Detection

Sensors ◽

10.3390/s21082797 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2797

Author(s):

Jing-Jhong Gao ◽

Ching-Wei Chiu ◽

Kuo-Hsing Wen ◽

Cheng-Sheng Huang

Keyword(s):

Limit Of Detection ◽

Detection System ◽

Fluorescence Emission ◽

Assay Sensitivity ◽

Detection Range ◽

Current Form ◽

Guided Mode ◽

Spectral Detection ◽

Guided Mode Resonance ◽

Colorimetric Assays

This paper presents a compact spectral detection system for common fluorescent and colorimetric assays. This system includes a gradient grating period guided-mode resonance (GGP-GMR) filter and charge-coupled device. In its current form, the GGP-GMR filter, which has a size of less than 2.5 mm, can achieve a spectral detection range of 500–700 nm. Through the direct measurement of the fluorescence emission, the proposed system was demonstrated to detect both the peak wavelength and its corresponding intensity. One fluorescent assay (albumin) and two colorimetric assays (albumin and creatinine) were performed to demonstrate the practical application of the proposed system for quantifying common liquid assays. The results of our system exhibited suitable agreement with those of a commercial spectrometer in terms of the assay sensitivity and limit of detection (LOD). With the proposed system, the fluorescent albumin, colorimetric albumin, and colorimetric creatinine assays achieved LODs of 40.99 and 398 and 25.49 mg/L, respectively. For a wide selection of biomolecules in point-of-care applications, the spectral detection range achieved by the GGP-GMR filter can be further extended and the simple and compact optical path configuration can be integrated with a lab-on-a-chip system.

Download Full-text

Performance of BioFire array or QuickVue influenza A + B test versus a validation qPCR assay for detection of influenza A during a volunteer A/California/2009/H1N1 challenge study

Virology Journal ◽

10.1186/s12985-021-01516-0 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

David R. McIlwain ◽

Han Chen ◽

Maria Apkarian ◽

Melton Affrime ◽

Bonnie Bock ◽

...

Keyword(s):

Influenza A ◽

Rapid Test ◽

Influenza Viruses ◽

Qpcr Assay ◽

Superior Performance ◽

Qrt Pcr ◽

Challenge Study ◽

Test Kit ◽

2009 H1n1 ◽

B Test

Abstract Background Influenza places a significant burden on global health and economics. Individual case management and public health efforts to mitigate the spread of influenza are both strongly impacted by our ability to accurately and efficiently detect influenza viruses in clinical samples. Therefore, it is important to understand the performance characteristics of available assays to detect influenza in a variety of settings. We provide the first report of relative performance between two products marketed to streamline detection of influenza virus in the context of a highly controlled volunteer influenza challenge study. Methods Nasopharyngeal swab samples were collected during a controlled A/California/2009/H1N1 influenza challenge study and analyzed for detection of virus shedding using a validated qRT-PCR (qPCR) assay, a sample-to-answer qRT-PCR device (BioMerieux BioFire FilmArray RP), and an immunoassay based rapid test kit (Quidel QuickVue Influenza A + B Test). Results Relative to qPCR, the sensitivity and specificity of the BioFire assay was 72.1% [63.7–79.5%, 95% confidence interval (CI)] and 93.5% (89.3–96.4%, 95% CI) respectively. For the QuickVue rapid test the sensitivity was 8.5% (4.8–13.7%, 95% CI) and specificity was 99.2% (95.6–100%, 95% CI). Conclusion Relative to qPCR, the BioFire assay had superior performance compared to rapid test in the context of a controlled influenza challenge study.

Download Full-text

Highly sensitive and selective colorimetric detection of dual metal ions (Hg2+ and Sn2+) in water: an eco-friendly approach

RSC Advances ◽

10.1039/d0ra09926k ◽

2021 ◽

Vol 11 (24) ◽

pp. 14700-14709

Author(s):

Rintumoni Paw ◽

Moushumi Hazarika ◽

Purna K. Boruah ◽

Amlan Jyoti Kalita ◽

Ankur K. Guha ◽

...

Keyword(s):

Metal Ions ◽

Ag Nanoparticles ◽

Limit Of Detection ◽

Colorimetric Detection ◽

Garlic Extract ◽

Selective Detection ◽

Highly Sensitive ◽

Dual Metal

Synthesis of Ag nanoparticles using Allin based garlic extract for highly sensitive and selective detection of metal ions Hg2+ and Sn2+ in water. The limit of detection (LoD) for Hg2+ and Sn2+ ions were found as 15.7 nM and 11.25 nM respectively.

Download Full-text

Swine influenza vaccines: current status and future perspectives

Animal Health Research Reviews ◽

10.1017/s146625231000006x ◽

2010 ◽

Vol 11 (1) ◽

pp. 81-96 ◽

Cited By ~ 41

Author(s):

Wenjun Ma ◽

Jürgen A. Richt

Keyword(s):

Influenza A ◽

Swine Influenza ◽

Influenza Viruses ◽

Current Status ◽

Economic Losses ◽

Influenza A Viruses ◽

Swine Industry ◽

Effective Strategies ◽

Swine Disease ◽

And Control

AbstractSwine influenza is an important contagious disease in pigs caused by influenza A viruses. Although only three subtypes of influenza A viruses, H1N1, H1N2 and H3N2, predominantly infect pigs worldwide, it is still a big challenge for vaccine manufacturers to produce efficacious vaccines for the prevention and control of swine influenza. Swine influenza viruses not only cause significant economic losses for the swine industry, but are also important zoonotic pathogens. Vaccination is still one of the most important and effective strategies to prevent and control influenza for both the animal and human population. In this review, we will discuss the current status of swine influenza worldwide as well as current and future options to control this economically important swine disease.

Download Full-text

Characterization of H9N2 influenza A viruses isolated from chicken products imported into Japan from China

Epidemiology and Infection ◽

10.1017/s0950268806006728 ◽

2006 ◽

Vol 135 (3) ◽

pp. 386-391 ◽

Cited By ~ 13

Author(s):

M. MASE ◽

M. ETO ◽

K. IMAI ◽

K. TSUKAMOTO ◽

S. YAMAGUCHI

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Influenza A ◽

H9n2 Virus ◽

Amino Acid Substitutions ◽

Influenza A Viruses ◽

Potential Sources

We characterized eleven H9N2 influenza A viruses isolated from chicken products imported from China. Genetically they were classified into six distinct genotypes, including five already known genotypes and one novel genotype. This suggested that such multiple genotypes of the H9N2 virus have possibly already become widespread and endemic in China. Two isolates have amino-acid substitutions that confer resistance to amantadine in the M2 region, and this supported the evidence that this mutation might be a result of the wide application of amantadine for avian influenza treatment in China. These findings emphasize the importance of surveillance for avian influenza virus in this region, and of quarantining imported chicken products as potential sources for the introduction of influenza virus.

Download Full-text