97 research outputs found
In-Field LAMP Detection of Flavescence Dorée Phytoplasma in Crude Extracts of the Scaphoideus titanus Vector
One of the most destructive diseases affecting grapevine in Europe is caused by Flavescence Dorée phytoplasma (FDp), which belongs to the 16Sr-V group and is a European Union quarantine pathogen. Although many molecular techniques such as loop-mediated isothermal amplification (LAMP) are widely used for the rapid detection of FDp in infected grapevine plants, there is no developed isothermal amplification assay for FDp detection in the insect vectors that are fundamental for the spread of the disease. For this reason, a simple in-field real-time LAMP protocol was optimized and developed for the specific detection of FDp in the insect vector Scaphoideus titanus. The LAMP assay was optimized to work with crude insect extracts obtained by manually shaking a single insect in a buffer for 5 min. Such a simple, sensitive, specific, economic, and user-friendly LAMP assay allowed the detection of FDp in S. titanus in less than half an hour, directly in the field. The developed insect tissue preparation procedure, combined with the LAMP protocol, promptly revealed the presence of FDp in infected S. titanus directly in the vineyards, allowing for monitoring of the spread of the pathogen in the field and to apply timely strategies required for the mandatory control of this pathogen
First report of Tomato leaf curl Sinaloa virus infecting tomato crops in Panama
In April 2011 and September 2012, virus-like symptoms were observed in open field- and greenhouse-grown tomato crops (Solanum lycopersicum) in Chiriqu\ued, the westernmost province of Panama. Samples from symptom-bearing plants (127 in all) were collected and tested for the presence of begomoviruses by polymerase chain reaction (PCR) assays with sets of degenerated primers designed to amplify parts of the DNA-A and DNA-B components (Rojas et al., 1993; Table 1). Products of the expected sizes, obtained with both DNA-A- and DNA-B-specific primers for 49 samples, suggested infection with New World bipartite begomoviruses. This corresponds to an incidence of 26% (8 plants) in open field, and 43% (41 plants) in greenhouse crops. Primers specific for ten tomato-infecting begomoviruses found in Central America (Engel et al., 1998; Nakhla et al., 2005; Table 1) were used to typify the PCR-positive samples
First outbreak of Pepper vein yellows virus infecting sweet pepper in Italy
Sweet pepper (Capsicum annum) is an economically important crop worldwide, including Sicily where about 4,000 hectares are grown each year. In October 2015, severe symptoms not previously reported by growers in the horticultural area of the province of Trapani (Sicily, Italy) were observed on sweet pepper plants in eight different greenhouses. Symptoms included upward leaf curling, internodal shortening and interveinal yellowing. Symptoms were more evident in the upper part of the plants. These symptoms were reminiscent of those caused by poleroviruses. In the greenhouse, symptoms were evident in about 35% of the plants. Three samples per greenhouse (24 in total) were collected for analysis
First report of Tomato leaf curl New Delhi virus affecting zucchini squash in an important horticultural area of southern Italy
omato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus (family Geminiviridae) which infects species in the families Cucurbitaceae and Solanaceae (Padidam et al., 1995; Mizutani et al., 2011). Begomoviruses are transmitted by the whitefly Bemisia tabaci in a persistent manner (Rosen et al., 2015). In October 2015, severe symptoms not previously reported by growers in the horticultural area of the Province of Trapani (Sicily, Italy) were observed on zucchini squash (Cucurbita pepo) in open fields. The symptoms included yellow mosaic, severe leaf curling, swelling of veins of young leaves, shortening of internodes, roughness of the skin of fruit and reduced fruit size; the symptoms were reminiscent of those caused by begomoviruses. Total DNA was extracted from young leaves of 22 plants by phenol/chloroform extraction and ethanol precipitation. PCR was performed with the A1F/A1R primer pair (Mizutani et al., 2011) for the DNA-A component and the pair described by Ruiz et al. (2015) for the DNA-B component to amplify a ~1200-bp fragment of DNA-A and a ~890 bp fragment of DNA-B, respectively. All 10 samples were positive by PCR with both primer pairs. No amplification products were obtained using primers specific for the monopartite begomoviruses Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus (Davino et al., 2008). DAS-ELISA analysis for Cucumber mosaic virus, Papaya ring spot virus and Zucchini yellow mosaic virus (Loewe Phytodiagnostica, Germany) yielded negative results
Radiographers and COVID-19 pneumonia: diagnostic performance using CO-RADS
Introduction: A more structured role of radiographers is advisable to speed up the management of patients with suspected COVID-19. The purpose of our study was to evaluate the diagnostic performance of radiographers in the detection of COVID-19 pneumonia on chest CT using CO-RADS descriptors. Methods: CT images of patients who underwent RT-PCR and chest CT due to COVID-19 suspicion between March and July 2020 were analysed retrospectively. Six readers, including two radiologists, two highly experienced radiographers and two less experienced radiographers, independently scored each CT using the CO-RADS lexicon. ROC curves were used to investigate diagnostic accuracy, and Fleiss’κ statistics to evaluate inter-rater agreement. Results: 714 patients (419 men; 295 women; mean age: 64 years ±19SD) were evaluated. CO-RADS> 3 was identified as optimal diagnostic threshold. Highly experienced radiographers achieved an average sensitivity of 58.7% (95%CI: 52.5–64.7), an average specificity of 81.8% (95%CI: 77.9–85.2), and a mean AUC of 0.72 (95%CI: 0.68–0.75). Among less experienced radiographers, an average sensitivity of 56.3% (95%CI: 50.1–62.2) and an average specificity of 81.5% (95%CI: 77.6–84.9) were observed, with a mean AUC of 0.71 (95%CI: 0.68–0.74). Consultant radiologists achieved an average sensitivity of 60.0% (95%CI: 53.7–65.8), an average specificity of 81.7% (95%CI: 77.8–85.1), and a mean AUC of 0.73 (95%CI: 0.70–0.77). Conclusion: Radiographers can adequately recognise the classic appearances of COVID-19 on CT, as described by the CO-RADS assessment scheme, in a way comparable to expert radiologists. Implications for practice: Radiographers, as the first healthcare professionals to evaluate CT images in patients with suspected SARS-CoV-2 infection, could diagnose COVID-19 pneumonia by means of a categorical reporting scheme at CT in a reliable way, hence playing a primary role in the early management of these patients
Guide to the Illinois Caverns State Natural Area
LimitedCaves are fragile environments and are protected under the Federal Cave Protection Act of 1988. Over the years, a number of caves have had irreversible damage from vandals. Visitors also exacerbate the problem of white nose syndrome, which is severely reducing Illinois bat populations. This report should not be made easily available in digital format to individuals who may access caves without knowledge of or respect for the extremely fragile nature of the cave environment. Additionally, Illinois Caverns is closed indefinitely, in part, due to concerns about White Nose Syndrome
Diagnostic accuracy and interobserver variability of CO-RADS in patients with suspected coronavirus disease-2019: a multireader validation study
Objective: To conduct a multireader validation study to evaluate the interobserver variability and the diagnostic accuracy for the lung involvement by COVID-19 of COVID-19 Reporting and Data System (CO-RADS) score. Methods: This retrospective study included consecutive symptomatic patients who underwent chest CT and reverse transcriptase-polymerase chain reaction (RT-PCR) from March 2020 to May 2020 for suspected COVID-19. Twelve readers with different levels of expertise independently scored each CT using the CO-RADS scheme for detecting pulmonary involvement by COVID-19. Receiver operating characteristic (ROC) curves were computed to investigate diagnostic yield. Fleiss’ kappa statistics was used to evaluate interreader agreement. Results: A total of 572 patients (mean age, 63 ± 20 [standard deviation]; 329 men; 142 patients with COVID-19 and 430 patients without COVID-19) were evaluated. There was a moderate agreement for CO-RADS rating among all readers (Fleiss’ K = 0.43 [95% CI 0.42–0.44]) with a substantial agreement for CO-RADS 1 category (Fleiss’ K = 0.61 [95% CI 0.60–0.62]) and moderate agreement for CO-RADS 5 category (Fleiss’ K = 0.60 [95% CI 0.58–0.61]). ROC analysis showed the CO-RADS score ≥ 4 as the optimal threshold, with a cumulative area under the curve of 0.72 (95% CI 66–78%), sensitivity 61% (95% CI 52–69%), and specificity 81% (95% CI 77–84%). Conclusion: CO-RADS showed high diagnostic accuracy and moderate interrater agreement across readers with different levels of expertise. Specificity is higher than previously thought and that could lead to reconsider the role of CT in this clinical setting. Key Points: • COVID-19 Reporting and Data System (CO-RADS) demonstrated a good diagnostic accuracy for lung involvement by COVID-19 with an average AUC of 0.72 (95% CI 67–75%). • When a threshold of ≥ 4 was used, sensitivity and specificity were 61% (95% CI 52–69%) and 81% (95% CI 76–84%), respectively. • There was an overall moderate agreement for CO-RADS rating across readers with different levels of expertise (Fleiss’ K = 0.43 [95% CI 0.42–0.44])
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