scholarly journals Broad-range and Effective Detection of Human Noroviruses by Colloidal Gold Immunochromatographic Assay Based on the Shell Domain of the Major Capsid Protei

2020 ◽  
Author(s):  
Meng Xu ◽  
Feifeng Lu ◽  
Qingping Wu ◽  
Jumei Zhang ◽  
Peng Tian ◽  
...  
Keyword(s):  
Colloidal Gold ◽  
High Sensitivity ◽  
Relative Sensitivity ◽  
Immunochromatographic Assay ◽  
Clinical Samples ◽  
Special Equipment ◽  
Human Noroviruses ◽  
Infected People ◽  
Sensitivity Specificity

Abstract Background: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all ages worldwide. As the replication of HuNoVs in vitro is immature, the detection of HuNoVs is depended on molecular assays such as RT-PCR and RT-qPCR. However, these molecular-based techniques require special equipment, unique reagents, experienced operators to perform, and extended time to get results. In addition, the genotypes of HuNoVs are broad. Therefore, a method for rapidly, broad-range, and effective approach for HuNoVs would be more applicable for screening infected people when outbreaks occur.Results: In this study, a colloidal-gold-based immunochromatographic assay (ICA) was developed for highly effective detection of HuNoVs in clinical samples. Monoclonal antibodies (McAbs) against the shell (S) domain in the major capsid protein of HuNoV were used in the ICA. The limitations of detection for HuNoVs in clinical samples were 1.2×106 genomic copies per gram (gc/g) and 4.4×105 gc/g for genogroup I and II (GI and GII) HuNoVs, respectively. A total of 122 samples were tested for HuNoVs by ICA and compared against that by RT-qPCR. The relative sensitivity, specificity and agreement of the ICA was 84.2 % (95% CI: 83.6-84.8 %), 100.0 % (95 % CI: 98.5-100.0 %) and 87.7 % (95% CI: 85.6-89.8 %), respectively. No cross-reaction with other common enteric viruses or bacteria was observed. The ICA could detect a broad range of genotypes, including GI.1, GI.3, GI.4, GI.6, GI.14, GII.2, GII.3, GII.4, GII.6, GII.13, and GII.17 HuNoVs.Conclusions: Our results demonstrated that ICA targeting the S domain protein is a promising candidate for effectively improve identifying different genotypes of HuNoVs in clinical samples with high sensitivity and specificity.

scholarly journals Broad-range and Effective Detection of Human Noroviruses by Colloidal Gold Immunochromatographic Assay Based on the Shell Domain of the Major Capsid Protein

2020 ◽  
Author(s):  
Meng Xu ◽  
Feifeng Lu ◽  
Qingping Wu ◽  
Jumei Zhang ◽  
Peng Tian ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Colloidal Gold ◽  
Major Capsid Protein ◽  
Relative Sensitivity ◽  
Immunochromatographic Assay ◽  
Clinical Samples ◽  
Special Equipment ◽  
Human Noroviruses ◽  
Infected People

Abstract Background: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all ages worldwide. As the replication of HuNoVs in vitro is immature, the detection of HuNoVs is depended on molecular assays such as RT-PCR and RT-qPCR. However, these molecular-based techniques require special equipment, unique reagents, experienced operators to perform, and extended time to get results. In addition, the diversity of viral genotypes is high. Therefore, a method for rapidly, broad-range, and effective detectionf of HuNoVs was desiderated for screening the excrement or vomit from infected people when outbreaks occur.Results: In this study, a colloidal-gold-based immunochromatographic assay (ICA) was developed for highly effective detection of HuNoVs in clinical samples. Monoclonal antibodies (MAbs) against the shell (S) domain in the major capsid protein of HuNoVs were used in the ICA. The limitations of detection for HuNoVs in clinical samples were 1.2×106 genomic copies per gram of stool sample (gc/g) and 4.4×105 gc/g for genogroup I and II (GI and GII) HuNoVs, respectively. A total of 122 clinical samples were tested for HuNoVs by ICA and compared against that by RT-qPCR. The relative sensitivity, specificity and agreement of the ICA was 84.2 % (95% CI: 83.6-84.8 %), 100.0 % (95 % CI: 98.5-100.0 %) and 87.7 % (95% CI: 85.6-89.8 %), respectively. No cross-reaction with other common enteric viruses or bacteria was observed. The ICA could detect a broad range of genotypes, including GI.1, GI.3, GI.4, GI.6, GI.14, GII.2, GII.3, GII.4, GII.6, GII.13, and GII.17 HuNoVs.Conclusions: Our results demonstrated that ICA targeting the S domain of VP1 is a promising candidate for effectively improve identifying different genotypes of HuNoVs in clinical samples with high sensitivity and specificity.

scholarly journals Broad-range and Effective Detection of Human Noroviruses by Colloidal Gold Immunochromatographic Assay Based on the Shell Domain of the Major Capsid Protein

2021 ◽  
Author(s):  
Meng Xu ◽  
Feifeng Lu ◽  
Chenang Lyu ◽  
Qingping Wu ◽  
Jumei Zhang ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Colloidal Gold ◽  
Major Capsid Protein ◽  
Age Groups ◽  
Immunochromatographic Assay ◽  
Clinical Samples ◽  
Special Equipment ◽  
Human Noroviruses ◽  
Infected People

Abstract Background: Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all age groups worldwide. HuNoVs can be detected in vitro using molecular assays such as RT-PCR and RT-qPCR. However, these molecular-based techniques require special equipment, unique reagents, experienced personnel, and extended time to obtain results. Besides, the diversity of viral genotypes is high. Therefore, methods that are rapid, broad-range and effective in the detection of HuNoVs are desiderated for screening the feces or vomit of infected people during outbreaks.Results: In this study, a colloidal-gold-based immunochromatographic assay (ICA) was developed for effective detection of HuNoVs in clinical samples. Monoclonal antibodies (MAbs) against the shell (S) domain in the major capsid protein of HuNoVs were used in the ICA. The limitations of detection for HuNoVs in clinical samples were 1.2×106 genomic copies per gram of stool sample (gc/g) and 4.4×105 gc/g for genogroup I and II (GI and GII) HuNoVs, respectively. A total of 122 clinical samples were tested for HuNoVs by ICA and compared against RT-qPCR. The relative sensitivity, specificity and agreement of ICA was 84.2 % (95% CI: 83.6-84.8 %), 100.0 % (95 % CI: 98.5-100.0 %) and 87.7 % (95% CI: 85.6-89.8 %), respectively. No cross-reaction with other common enteric viruses or bacteria was observed. The ICA detected a broad range of genotypes, including GI.1, GI.3, GI.4, GI.6, GI.14, GII.2, GII.3, GII.4, GII.6, GII.13, and GII.17 HuNoVs.Conclusions: This study demonstrates that ICA targeting the S domain of VP1 is a promising candidate for effectively identifying the different genotypes of HuNoVs in clinical samples with high sensitivity and specificity.

scholarly journals Developments in the HCV Screening Technologies Based on the Detection of Antigens and Antibodies

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4257 ◽  
Author(s):  
Warkad ◽  
Song ◽  
Pal ◽  
Nimse
Keyword(s):  
Acute Infection ◽  
Health Sector ◽  
High Sensitivity ◽  
Global Scale ◽  
Hcv Infection ◽  
Infected People ◽  
Chronic Hcv Infection ◽  
Hcv Screening ◽  
Chronic Hcv ◽  
Sensitivity Specificity

Hepatitis C virus (HCV) accounts for 15%–20% of cases of acute infection, and chronic HCV infection is developed in about 50%–80% of HCV patients. Unfortunately, due to the lack of proper medical care, difficulty in screening for HCV infection, and lack of awareness resulted in chronic HCV infection in 71 million people on a global scale, and about 399,000 deaths in 2016. It is crucial to recognize that the effective use of antiviral medicines can cure more than 95% of HCV infected people. The Global Health Sector Strategy (GHSS) aim is to reduce the new HCV infections and the HCV associated mortality by 90% and 65%, respectively. Therefore, the methods that are simple, yet powerful enough to detect HCV infections with high sensitivity, specificity, and a shorter window period are crucial to restrain the global burden of HCV healthcare. This article focuses on the technologies used for the detection of HCV in clinical specimens.

scholarly journals Validation of an NGS Panel Designed for Detection of Actionable Mutations in Tumors Common in Latin America

2021 ◽  
Vol 11 (9) ◽  
pp. 899
Author(s):  
Mauricio Salvo ◽  
Evelin González-Feliú ◽  
Jessica Toro ◽  
Iván Gallegos ◽  
Ignacio Maureira ◽  
...  
Keyword(s):  
Latin America ◽  
Latin American ◽  
Hedgehog Signaling ◽  
Predictive Biomarkers ◽  
High Sensitivity ◽  
Clinical Samples ◽  
Dna Integrity ◽  
Precision Oncology ◽  
Single Nucleotide Variants ◽  
Sensitivity Specificity

Next-generation sequencing (NGS) is progressively being used in clinical practice. However, several barriers preclude using this technology for precision oncology in most Latin American countries. To overcome some of these barriers, we have designed a 25-gene panel that contains predictive biomarkers for most current and near-future available therapies in Chile and Latin America. Library preparation was optimized to account for low DNA integrity observed in formalin-fixed paraffin-embedded tissue. The workflow includes an automated bioinformatic pipeline that accounts for the underrepresentation of Latin Americans in genome databases. The panel detected small insertions, deletions, and single nucleotide variants down to allelic frequencies of 0.05 with high sensitivity, specificity, and reproducibility. The workflow was validated in 272 clinical samples from several solid tumor types, including gallbladder (GBC). More than 50 biomarkers were detected in these samples, mainly in BRCA1/2, KRAS, and PIK3CA genes. In GBC, biomarkers for PARP, EGFR, PIK3CA, mTOR, and Hedgehog signaling inhibitors were found. Thus, this small NGS panel is an accurate and sensitive method that may constitute a more cost-efficient alternative to multiple non-NGS assays and costly, large NGS panels. This kind of streamlined assay with automated bioinformatics analysis may facilitate the implementation of precision medicine in Latin America.

scholarly journals Dog Savior: Immediate Scent-Detection of SARS-COV-2 by Trained Dogs

2020 ◽  
Author(s):  
Omar Vesga ◽  
Andres F. Valencia ◽  
Alejandro Mira ◽  
Felipe Ossa ◽  
Esteban Ocampo ◽  
...  
Keyword(s):  
Infected Individual ◽  
High Sensitivity ◽  
The Body ◽  
High Rate ◽  
Diagnostic Tools ◽  
Predictive Values ◽  
Infected People ◽  
Molecular Tests ◽  
Production And Distribution ◽  
Sensitivity Specificity

AbstractMolecular tests for viral diagnostics are essential to confront the COVID-19 pandemic, but their production and distribution cannot satisfy the current high demand. Early identification of infected people and their contacts is the key to being able to isolate them and prevent the dissemination of the pathogen; unfortunately, most countries are unable to do this due to the lack of diagnostic tools. Dogs can identify, with a high rate of precision, unique odors of volatile organic compounds generated during an infection; as a result, dogs can diagnose infectious agents by smelling specimens and, sometimes, the body of an infected individual. We trained six dogs of three different breeds to detect SARS-CoV-2 in respiratory secretions of infected patients and evaluated their performance experimentally, comparing it against the gold standard (rRT-PCR). Here we show that viral detection takes one second per specimen. After scent-interrogating 9,200 samples, our six dogs achieved independently and as a group very high sensitivity, specificity, predictive values, accuracy, and likelihood ratio, with very narrow confidence intervals. The highest metric was the negative predictive value, indicating that with a disease prevalence of 7.6%, 99.9% of the specimens indicated as negative by the dogs did not carry the virus. These findings demonstrate that dogs could be useful to track viral infection in humans, allowing COVID-19 free people to return to work safely.

scholarly journals mRNA technology as one of the promising platforms for the SARS-CoV-2 vaccine development

2020 ◽  
Vol 24 (7) ◽  
pp. 802-807
Author(s):  
A. A. Ilyichev ◽  
L. A. Orlova ◽  
S. V. Sharabrin ◽  
L. I. Karpenko
Keyword(s):  
Recombinant Proteins ◽  
Messenger Rna ◽  
Viral Vectors ◽  
Vaccine Development ◽  
Dna Vaccines ◽  
High Sensitivity ◽  
Practical Implementation ◽  
Process Technology ◽  
Infected People

After the genome sequence of SARS-CoV-2 (Severe acute respiratory syndrome-related coronavirus 2) was published and the number of infected people began to increase rapidly, many global companies began to develop a vaccine. Almost all known approaches to vaccine design were applied for this purpose, including inactivated viruses, mRNA and DNA-vaccines, vaccines based on various viral vectors, synthetically generated peptides and recombinant proteins produced in cells of insects and mammals. This review considers one of the promising vaccine platforms based on messenger RNA. Until recent years, mRNA-vaccination was out of practical implementation due to high sensitivity to nuclease degradation and consequent instability of drugs based on mRNA. Latest technological advances significantly mitigated the problems of low immunogenicity, instability, and difficulties in RNA-vaccine delivery. It is worth noting that mRNA-vaccines can efficiently activate both components of the immune system, i. e. T-cell and humoral responses. The essential advantage of mRNA-vaccines includes fast, inexpensive, scalable and uniform production providing a large output of desirable products in vitro. Synthesis and purification processes significantly simplify the process technology of mRNA drugs with injectable purity. Thus, mRNA production via in vitro transcription is more advantageous as compared with DNA-vaccines since it is a chemical process without the use of cells. mRNA techniques make it possible to pass all the phases of vaccine development much faster in comparison with the production of vaccines based on inactivated viruses or recombinant proteins. This property is critically important when designing vaccines against viral pathogens as the main problem of disease control includes a time gap between an epidemic and vaccine development. This paper discusses studies on the development of vaccines against coronaviruses including SARS-CoV-2 with special attention to the mRNA technique.

scholarly journals Contamination of Zearalenone from China in 2019 by a Visual and Digitized Immunochromatographic Assay

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 521
Author(s):  
Xia Hong ◽  
Yuhao Mao ◽  
Chuqin Yang ◽  
Zhenjiang Liu ◽  
Ming Li ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Site Investigation ◽  
Immunochromatographic Assay ◽  
Quantitative Detection ◽  
Significant Information ◽  
Detection Model ◽  
Positive Rate ◽  
Highly Correlated ◽  
Sensitivity Specificity

Zearalenone (ZEN) is a prevalent mycotoxin that needs intensive monitoring. A semi-quantitative and quantitative immunochromatographic assay (ICA) was assembled for investigating ZEN contamination in 187 samples of cereal and their products from China in 2019. The semi-quantitative detection model had a limit of detection (LOD) of 0.50 ng/mL with visual judgment and could be completely inhibited within 5 min at 3.0 ng/mL ZEN. The quantitative detection model had a lower LOD of 0.25 ng/mL, and ZEN could be accurately and digitally detected from 0.25–4.0 ng/mL. The ICA method had a high sensitivity, specificity, and accuracy for on-site ZEN detection. For investigation of the authentic samples, the ZEN-positive rate was 62.6%, and the ZEN-positive levels ranged from 2.7 to 867.0 ng/g, with an average ZEN-positive level being 85.0 ng/g. Of the ZEN-positive samples, 6.0% exceeded the values of the limit levels. The ZEN-positive samples were confirmed to be highly correlated using LC-MS/MS (R2 = 0.9794). This study could provide an efficiency and accuracy approach for ZEN in order to achieve visual and digitized on-site investigation. This significant information about the ZEN contamination levels might contribute to monitoring mycotoxin occurrence and for ensuring food safety.

scholarly journals Synthesis, Cytotoxicity Assessment and Optical Properties Characterization of Colloidal GdPO4:Mn2+, Eu3+ for High Sensitivity Luminescent Nanothermometers Operating in the Physiological Temperature Range

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 421 ◽  
Author(s):  
Kamila Maciejewska ◽  
Blazej Poźniak ◽  
Marta Tikhomirov ◽  
Adrianna Kobylińska ◽  
Łukasz Marciniak
Keyword(s):  
Synthesis Method ◽  
High Sensitivity ◽  
Relative Sensitivity ◽  
Spectroscopic Properties ◽  
Physiological Temperature ◽  
Temperature Range ◽  
Cytotoxicity Studies ◽  
Cytotoxicity Assessment

Herein, a novel synthesis method of colloidal GdPO4:Mn2+,Eu3+ nanoparticles for luminescent nanothermometry is proposed. XRD, TEM, DLS, and zeta potential measurements confirmed the crystallographic purity and reproducible morphology of the obtained nanoparticles. The spectroscopic properties of GdPO4:Mn2+,Eu3+ with different amounts of Mn2+ and Eu3+ were analyzed in a physiological temperature range. It was found that GdPO4:1%Eu3+,10%Mn2+ nanoparticles revealed extraordinary performance for noncontact temperature sensing with relative sensitivity SR = 8.88%/°C at 32 °C. Furthermore, the biocompatibility and safety of GdPO4:15%Mn2+,1%Eu3+ was confirmed by cytotoxicity studies. These results indicated that colloidal GdPO4 doped with Mn2+ and Eu3+ is a very promising candidate as a luminescent nanothermometer for in vitro applications.

scholarly journals Molecular Diagnosis of Leishmaniasis: Quantification of Parasite Load by a Real-Time PCR Assay with High Sensitivity

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 865
Author(s):  
Germano Castelli ◽  
Federica Bruno ◽  
Stefano Reale ◽  
Simone Catanzaro ◽  
Viviana Valenza ◽  
...  
Keyword(s):  
Real Time ◽  
Quantitative Pcr ◽  
Real Time Pcr ◽  
High Sensitivity ◽  
Parasite Load ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Predictive Values ◽  
Low Sensitivity

Real-time PCR was developed to quantify Leishmania infantum kinetoplast DNA and optimized to achieve a sensitivity of 1 parasite/mL. For this purpose, we cloned the conserved kDNA fragment of 120 bp into competent cells and correlated them with serial dilutions of DNA extracted from reference parasite cultures calculating that a parasite cell contains approximately 36 molecules of kDNA. This assay was applied to estimate parasite load in clinical samples from visceral, cutaneous leishmaniasis patients and infected dogs and cats comparing with conventional diagnosis. The study aimed to propose a real-time PCR for the detection of Leishmania DNA from clinical samples trying to solve the diagnostic problems due to the low sensitivity of microscopic examination or the low predictive values of serology and resolve problems related to in vitro culture. The quantitative PCR assay in this study allowed detection of Leishmania DNA and quantification of considerably low parasite loads in samples that had been diagnosed negative by conventional techniques. In conclusion, this quantitative PCR can be used for the diagnosis of both human, canine and feline Leishmaniasis with high sensitivity and specificity, but also for evaluating treatment and the endpoint determination of leishmaniasis.

scholarly journals Comparison of Different Phenotypic Tests versus PCR in the Detection of Carbapenemase-Producing Pseudomonas aeruginosa Isolates in Hamadan, Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Masoumeh Beig ◽  
Mohammad Taheri ◽  
Mohammad Reza Arabestani
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Sensitivity ◽  
Test Method ◽  
Clinical Samples ◽  
Predictive Values ◽  
Carbapenem Resistant ◽  
Accurate Detection ◽  
Phenotypic Methods ◽  
Sensitivity Specificity ◽  
Phenotypic Tests

In recent years, the prevalence of carbapenem-resistant Pseudomonas aeruginosa isolates has become a worldwide concern. Rapid and accurate detection of carbapenemase-producing P. aeruginosa isolates is so important. The aim of this study was to evaluate the performance of the phenotypic methods such as Modified Hodge test (MHT), CarbaNP (CNPt), combined double-disk synergy test (CDDT), and carbapenem inactivation method (CIM) for rapid and accurate detection of clinical carbapenemase production of P. aeruginosa isolates. This study was performed on 97 P. aeruginosa strains, which were isolated from clinical samples in Hamadan hospitals, western Iran in 2017-2018. Antibiotic susceptibility testing was performed using disk diffusion and minimum inhibitory concentration (MIC) by E-test method. We evaluated the performance of MHT, CarbaNP, CDDT, and CIM tests in comparison to polymerase chain reaction (PCR) for the detection of carbapenemase-producing isolates. Additionally, the presence of carbapenem-resistant genes was investigated using the PCR method. Our findings showed that the highest resistance was to cefoxitin (94.8%). Moreover, among the carbapenem antibiotics, the highest resistance was to imipenem (49.4%). Among the 49 carbapenem-resistant isolates, 42 (85.7%) isolates were MIC positive. The results of phenotypic tests showed that CarbaNP, CIM, CDDT, and MHT tests were positive in (48/49, 97.95%), (46/49, 93.87%), (27/49, 57.44%), and (25/49, 53.19%) of isolates, respectively. CarbaNP and CIM tests showed high sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) compared to PCR in P. aeruginosa isolates. CarbaNP and CIM tests are highly sensitive and specific tests for identifying carbapenemase-producing P. aeruginosa isolates.

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