scholarly journals Simple and Portable Magnetic Immunoassay for Rapid Detection and Sensitive Quantification of Plant Viruses

2015 ◽  
Vol 81 (9) ◽  
pp. 3039-3048 ◽  
Author(s):  
Stefanie Rettcher ◽  
Felicitas Jungk ◽  
Christoph Kühn ◽  
Hans-Joachim Krause ◽  
Greta Nölke ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Plant Pathogens ◽  
High Sensitivity ◽  
Potato Virus X ◽  
Plant Viruses ◽  
Economic Losses ◽  
Virus Concentration ◽  
Content Type ◽  
Agricultural Industry ◽  
Sum Frequency

ABSTRACTPlant pathogens cause major economic losses in the agricultural industry because late detection delays the implementation of measures that can prevent their dissemination. Sensitive and robust procedures for the rapid detection of plant pathogens are therefore required to reduce yield losses and the use of expensive, environmentally damaging chemicals. Here we describe a simple and portable system for the rapid detection of viral pathogens in infected plants based on immunofiltration, subsequent magnetic detection, and the quantification of magnetically labeled virus particles.Grapevine fanleaf virus(GFLV) was chosen as a model pathogen. Monoclonal antibodies recognizing the GFLV capsid protein were immobilized onto immunofiltration columns, and the same antibodies were linked to magnetic nanoparticles. GFLV was quantified by immunofiltration with magnetic labeling in a double-antibody sandwich configuration. A magnetic frequency mixing technique, in which a two-frequency magnetic excitation field was used to induce a sum frequency signal in the resonant detection coil, corresponding to the virus concentration within the immunofiltration column, was used for high-sensitivity quantification. We were able to measure GFLV concentrations in the range of 6 ng/ml to 20 μg/ml in less than 30 min. The magnetic immunoassay could also be adapted to detect other plant viruses, includingPotato virus XandTobacco mosaic virus, with detection limits of 2 to 60 ng/ml.

ANALYTICAL SYSTEMS BASED ON RECOMBINASE POLYMERASE AMPLIFICATION FOR RAPID DETECTION OF VIRAL, VIROID AND BACTERIAL PLANT PATHOGENS

2021 ◽  
Vol 1 (19) ◽  
pp. 242-244
Author(s):  
A.V. Ivanov ◽  
A.V. Zherdev ◽  
B.B. Dzantiev
Keyword(s):  
Potato Virus ◽  
Rapid Detection ◽  
Plant Pathogens ◽  
Potato Virus X ◽  
Potato Spindle Tuber Viroid ◽  
Recombinase Polymerase Amplification ◽  
Analysis Time ◽  
Potato Blackleg ◽  
Test Systems ◽  
Dickeya Solani

Test systems have been developed for the detection of phytopathogens, combining recombinase polymerase amplification and membrane test strips. Test systems provide detection of potato virus X, potato spindle tuber viroid, potato blackleg pathogen (Dickeya solani), as well as multi-analysis of three viruses. Amplification is carried out at 37 °C. The analysis time does n ot exceed 30 min.

scholarly journals Multiplex Detection of Three Select Agents Directly from Blood by Use of the GeneXpert System

2019 ◽  
Vol 57 (5) ◽  
Author(s):  
Padmapriya P. Banada ◽  
Srinidhi Deshpande ◽  
Sukalyani Banik ◽  
Darshini Shah ◽  
Ranie Koshy ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Severe Disease ◽  
High Sensitivity ◽  
Negative Control ◽  
Blood Samples ◽  
Content Type ◽  
Clinical Patient

ABSTRACT Francisella tularensis, Bacillus anthracis, and Yersinia pestis are tier 1 select agents with the potential to rapidly cause severe disease. Rapid detection of these bacteria from patient samples at the point of care could contribute to improved clinical outcomes in the event of a bioterrorism attack. A multiplex nested PCR assay for detection of F. tularensis, B. anthracis, and Y. pestis directly from patient blood samples was developed using the GeneXpert system. The multiplex GeneXpert cartridge-based assay includes all necessary sample processing and amplification reagents. Blood samples spiked with different numbers of CFU were used to measure the analytical limit of detection (LOD) and dynamic range. Sensitivity was determined by testing spiked blood samples and negative-control blood in a blind manner. Specificity was determined by testing against nontarget pathogens and blood samples from clinical patients. The assay LOD was 8.5 CFU/ml for F. tularensis, 10 CFU/ml for B. anthracis, and 4.5 CFU/ml for Y. pestis. The sensitivity was 100% at the LOD for all three select agent bacteria in spiked patient blood samples. The assay specificity was 100% when it was tested against both nontarget pathogens and clinical patient blood samples. The total assay time was approximately 100 min. This automated assay, which is suitable for use at the point of care, identifies three select agents directly in blood without the need for enrichment with a high sensitivity within 100 min. This assay may enable rapid detection and treatment of patients infected with the target organisms in the event of a bioterrorism attack.

scholarly journals The P25 Protein of Potato Virus X (PVX) Is the Main Pathogenicity Determinant Responsible for Systemic Necrosis in PVX-Associated Synergisms

2014 ◽  
Vol 89 (4) ◽  
pp. 2090-2103 ◽  
Author(s):  
Emmanuel Aguilar ◽  
David Almendral ◽  
Lucía Allende ◽  
Remedios Pacheco ◽  
Bong Nam Chung ◽  
...  
Keyword(s):  
Potato Virus ◽  
Rna Silencing ◽  
Potato Virus X ◽  
Threshold Level ◽  
Plant Viruses ◽  
Plum Pox Virus ◽  
Systemic Necrosis ◽  
Suppressor Activity ◽  
Content Type ◽  
Reading Frame

ABSTRACTMost plant viruses counter the RNA silencing-based antiviral defense by expressing viral suppressors of RNA silencing (VSRs). In this sense, VSRs may be regarded as virulence effectors that can be recognized by the host as avirulence (avr) factors to induceR-mediated resistance. We made use ofAgrobacterium-mediated transient coexpression of VSRs in combination withPotato virus X(PVX) to recapitulate in local tissues the systemic necrosis (SN) caused by PVX-potyvirus synergistic infections inNicotiana benthamiana. The hypersensitive response (HR)-like response was associated with an enhanced accumulation of PVX subgenomic RNAs. We further show that expression of P25, the VSR of PVX, in the presence of VSR from different viruses elicited an HR-like response inNicotianaspp. Furthermore, the expression of P25 by aPlum pox virus(PPV) vector was sufficient to induce an increase of PPV pathogenicity that led to necrotic mottling. A frameshift mutation in the P25 open reading frame (ORF) of PVX did not lead to necrosis when coexpressed with VSRs. These findings indicate that P25 is the main PVX determinant involved in eliciting a systemic HR-like response in PVX-associated synergisms. Moreover, we show that silencing ofSGT1andRAR1attenuated cell death in both PVX-potyvirus synergistic infection and the HR-like response elicited by P25. Our study underscores that P25 variants that have impaired ability to suppress RNA silencing cannot act as elicitors when synergized by the presence of other VSRs. These findings highlight the importance of RNA silencing suppression activity in the HR-like response elicited by VSRs in certain hosts.IMPORTANCEThe work presented here describes how the activity of the PVX suppressor P25 elicits an HR-like response inNicotianaspp. when overexpressed with other VSR proteins. This finding suggests that the SN response caused by PVX-associated synergisms is a delayed immune response triggered by P25, once it reaches a threshold level by the action of other VSRs. Moreover, this work supports the contention that the silencing suppressor activity of PVX P25 protein is a prerequisite for HR elicitation. We propose that unidentified avr determinants could be involved in other cases of viral synergisms in which heterologous “helper” viruses encoding strong VSRs exacerbate the accumulation of the avr-encoding virus.

scholarly journals LAMP-Coupled CRISPR–Cas12a Module for Rapid and Sensitive Detection of Plant DNA Viruses

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 466
Author(s):  
Ahmed Mahas ◽  
Norhan Hassan ◽  
Rashid Aman ◽  
Tin Marsic ◽  
Qiaochu Wang ◽  
...  
Keyword(s):  
Low Cost ◽  
Virus Detection ◽  
High Sensitivity ◽  
Plant Viruses ◽  
Economic Losses ◽  
New Delhi ◽  
Dna Viruses ◽  
Point Of Use ◽  
Tomato Leaf Curl ◽  
Leaf Curl

One important factor for successful disease management is the ability to rapidly and accurately identify the causal agent. Plant viruses cause severe economic losses and pose a serious threat to sustainable agriculture. Therefore, optimization of the speed, sensitivity, feasibility, portability, and accuracy of virus detection is urgently needed. Here, we developed a clustered regularly interspaced short palindromic repeats (CRISPR)-based nucleic acid diagnostic method utilizing the CRISPR–Cas12a system for detecting two geminiviruses, tomato yellow leaf curl virus (TYLCV) and tomato leaf curl New Delhi virus (ToLCNDV), which have single-stranded DNA genomes. Our assay detected TYLCV and ToLCNDV in infected plants with high sensitivity and specificity. Our newly developed assay can be performed in ~1 h and provides easy-to-interpret visual readouts using a simple, low-cost fluorescence visualizer, making it suitable for point-of-use applications.

scholarly journals Softening of Processed Plant Virus Infected Cucumis sativus Fruits

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1451
Author(s):  
Anne-Katrin Kersten ◽  
Sabrina Scharf ◽  
Martina Bandte ◽  
Peer Martin ◽  
Peter Meurer ◽  
...  
Keyword(s):  
Cucumis Sativus ◽  
Plant Virus ◽  
Plant Viruses ◽  
Economic Losses ◽  
Symptom Expression ◽  
Considerable Influence ◽  
Mechanical Inoculation ◽  
Morphological Alterations ◽  
Texture Properties ◽  
Textural Changes

Texture softening of pickled cucumbers does not meet consumers’ quality expectations and leads to economic losses. The factor(s) triggering this phenomenon is still unknown. We investigated the importance of plant viruses such as Cucumber green mottle mosaic tobamovirus (CGMMV) and Zucchini yellow mosaic potyvirus (ZYMV) in the context of softening of pickles. Cucumber plants (Cucumis sativus) were infected by mechanical inoculation, grown under greenhouse conditions and tested positive for the viral infection by ELISA. The severity of virus infection was reflected in yield and symptom expression. Histological and morphological alterations were observed. All fruits were pasteurized, separately stored in jars and subjected to texture measurements after four, six and 12 months. CGMMV-infections were asymptomatic or caused mild symptoms on leaves and fruit, and texture quality was comparable to control. At the same time, fruits of ZYMV-infected plants showed severe symptoms like deformations and discoloration, as well as a reduction in firmness and crunchiness after pasteurization. In addition, histological alterations were detected in such fruits, possibly causing textural changes. We conclude that plant viruses could have a considerable influence on the firmness and crunchiness of pickled cucumbers after pasteurization. It is possible that the severity of symptom expression has an influence on texture properties.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

scholarly journals Low-Molecular-Weight Metabolites Secreted by Paenibacillus larvae as Potential Virulence Factors of American Foulbrood

2014 ◽  
Vol 80 (8) ◽  
pp. 2484-2492 ◽  
Author(s):  
Hedwig-Annabell Schild ◽  
Sebastian W. Fuchs ◽  
Helge B. Bode ◽  
Bernd Grünewald
Keyword(s):  
Molecular Weight ◽  
Virulence Factors ◽  
Gene Clusters ◽  
Paenibacillus Larvae ◽  
Economic Losses ◽  
Low Molecular Weight ◽  
American Foulbrood ◽  
Toxic Activity ◽  
Content Type

ABSTRACTThe spore-forming bacteriumPaenibacillus larvaecauses a severe and highly infective bee disease, American foulbrood (AFB). Despite the large economic losses induced by AFB, the virulence factors produced byP. larvaeare as yet unknown. To identify such virulence factors, we experimentally infected young, susceptible larvae of the honeybee,Apis mellifera carnica, with differentP. larvaeisolates. Honeybee larvae were rearedin vitroin 24-well plates in the laboratory after isolation from the brood comb. We identified genotype-specific differences in the etiopathology of AFB between the tested isolates ofP. larvae, which were revealed by differences in the median lethal times. Furthermore, we confirmed that extracts ofP. larvaecultures contain low-molecular-weight compounds, which are toxic to honeybee larvae. Our data indicate thatP. larvaesecretes metabolites into the medium with a potent honeybee toxic activity pointing to a novel pathogenic factor(s) ofP. larvae. Genome mining ofP. larvaesubsp.larvaeBRL-230010 led to the identification of several biosynthesis gene clusters putatively involved in natural product biosynthesis, highlighting the potential ofP. larvaeto produce such compounds.

Project, programme and portfolio maturity: a case study of Australian Federal Government

2014 ◽  
Vol 7 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Michael Young ◽  
Raymond Young ◽  
Julio Romero Zapata
Keyword(s):  
Federal Government ◽  
Management Practices ◽  
Stakeholder Management ◽  
High Sensitivity ◽  
Development Planning ◽  
Government Agencies ◽  
Maturity Model ◽  
Australian Government ◽  
Content Type ◽  
Management Processes

Purpose – This paper aims to examine the notion of maturity assessment and maturity models more broadly and goes on to examine the findings from the assessments of project, programme and portfolio maturity undertaken across Australian Government agencies. Design/methodology/approach – A statistical analysis was performed to determine the level of maturity that best represents the Australian Federal Government agencies as a whole. The unit of analysis in this study is the agencies overall scores in each sub-model across the seven perspectives of the portfolio, programme and project management maturity model (P3M3) maturity model. Findings – This study has identified a number of interesting findings. First, the practices of project, programme and portfolio across the dataset practiced independently of each other. Second, benefits management and strategy alignment practices are generally poor across Australian Government agencies. Third, programme management practices are the most immature. Finally, the results showed a high sensitivity to the “generic attributes” of roles and responsibilities, experience, capability development, planning and estimating and scrutiny and review. Research limitations/implications – All data used in this analysis are secondary data collected from individual Australian Government agencies. The data were collected by accredited consultants following a common data collection method and using a standard template to ensure a consistent approach. Practical implications – The study poses some implications for practice, particularly given the context of Australian Federal Government agencies current plans and action to improve organisational maturity. The study suggests that benefits management processes at the project level and benefits management, governance and stakeholder management processes at the programme level should be an area of focus for improvement. Originality/value – This study is the first attempt to systematically review the data collected through such an assessment and in particular identify the findings and the implications at a whole of government level.

Gold Immunochromatography Assay - A Newly Rapid Detection Technique for Aquatic Products

2013 ◽  
Vol 690-693 ◽  
pp. 1449-1454
Author(s):  
Yuan Wang ◽  
Hui Juan Yu ◽  
Bei Lei Qian ◽  
You Qiong Cai ◽  
Dong Mei Huang ◽  
...  
Keyword(s):  
Rapid Detection ◽  
High Sensitivity ◽  
Detection Technique ◽  
Detection Methods ◽  
Future Perspectives ◽  
Auxiliary Equipment ◽  
Basic Principles ◽  
Aquatic Products ◽  
Immunological Detection

Gold immunochromatography assay (GICA) technique has the following characteristics: rapid and simple, high sensitivity, good specificity, no auxiliary equipment, ease of interpreting results, and satisfactory stability. The technique has become one of the most rapid and sensitive immunological detection methods, which is widely used in medical, biological and other fields. The article focuses on the basic principles and technical characteristics of GICA, and briefly describes the applications and future perspectives in the rapid detection of aquatic products.

Influence of occupational heat stress on labour productivity – a case study from Chennai, India

2016 ◽  
Vol 65 (2) ◽  
pp. 245-255 ◽  
Author(s):  
Jeremiah Chinnadurai ◽  
Vidhya Venugopal ◽  
Kumaravel P ◽  
Paramesh R
Keyword(s):  
Climate Change ◽  
Heart Rate ◽  
Heat Stress ◽  
Pearson Correlation ◽  
Labour Productivity ◽  
Productivity Loss ◽  
Threshold Limit Value ◽  
Control Measures ◽  
Economic Losses ◽  
Content Type

Purpose – Raise in temperatures due to climate change is likely to increase the heat stress in occupations that are physically exerting and performed outdoors which might potentially have adverse health and productivity consequences. The purpose of this paper is to estimate the productivities in construction work under the influence of heat stress using the predicted mean vote (PMV) index. Design/methodology/approach – Field studies were conducted during May 2014 which is summer time in Chennai. Continuous heart rate of workers and wet bulb globe temperature measurements are conducted for workers engaged in different jobs in construction. Metabolic rates and the workload of the workers from heart rate were calculated using the ISO method 8996 and the PMV values are calculated using the tool developed by Malchaire based on the method ISO 7730. Direct observations and personal interviews were conducted to substantiate the productivity estimations. Findings – The results showed that workers working outdoors with moderate and heavy workload exceeded the threshold limit value of 28°C and had adverse productivity impacts (18-35 per cent productivity loss), whereas the workers engaged in light indoor work was not affected by heat stress and consequent productivity losses. The productivity estimations using the PMV index is found to be statistically significant for three types of construction works (Pearson correlation coefficient value of −0.78) and also correlated well with the observations and self-reported productivities of the workers. Originality/value – The method used in this paper provides a scientific and reliable estimation of the productivities which may benefit the industry to set realistic project completion goals in hot weather and also implement interventions and policies to protect workers’ health. Developing adaptive strategies and implementing control measures are the need of the hour to protect worker’s health and economic losses in the face of climate change.

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