scholarly journals Characterization of Pepper leafroll chlorosis virus, a New Polerovirus Causing Yellowing Disease of Bell Pepper in Saudi Arabia

Plant Disease ◽  
2018 ◽  
Vol 102 (2) ◽  
pp. 318-326 ◽  
Author(s):  
A. Kamran ◽  
L. Lotos ◽  
M. A. Amer ◽  
M. A. Al-Saleh ◽  
I. M. Alshahwan ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Sequence Similarity ◽  
Aphis Gossypii ◽  
Aphid Transmission ◽  
Bell Pepper ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Growing Seasons ◽  
Arable Weeds ◽  
Sequence Similarity Analysis

During the growing seasons of 2014 through 2016, a total of 336 leaf samples from bell pepper (showing leafroll and interveinal yellowing) and arable weeds were collected from Riyadh region, Saudi Arabia. The use of a polerovirus generic reverse transcription (RT)-PCR assay confirmed their presence in the bell pepper samples. Sequencing of the generic amplicon revealed high similarity (87.6 to 98.1% in nt) with four poleroviruses; Tobacco vein distorting virus, Pepper vein yellows virus, Pepper yellows virus, and Pepper yellow leaf curl virus. To further characterize one of these isolates (105D), a larger part of the genome (∼1,300 nt) spanning approximately from the 3′ end of ORF2 to the middle of ORF3, was amplified and sequenced. Blasting the resulting sequence revealed the low amino acid and nucleotide identity percentages in the coat protein and movement protein partial genes with viruses deposited in GenBank. Next-generation sequence was used to acquire a larger part of the genome, which resulted in the reconstruction of isolate 105D’s partial genome (5,496 nt). Sequence similarity analysis revealed the presence of a divergent polerovirus isolate belonging to a new species that was tentatively named Pepper leafroll chlorosis virus (PeLRCV). Using a specific RT-PCR assay for this isolate confirmed the presence of this new viral species in the symptomatic peppers. Aphid transmission experiments showed that PeLRCV is vectored by Aphis gossypii and that it can infect at least five out of the 15 different plants species tested. Based on our findings, PeLRCV is a new member of genus Polerovirus in the family Luteoviridae.

scholarly journals Identification and functional analysis of a testis‑biased gene encoding serine/arginine‑rich protein in silkworm, Bombyx mori

2019 ◽  
Vol 71 (4) ◽  
pp. 639-645
Author(s):  
Li-Ying Zhang ◽  
Juan Li ◽  
Xing-Fu Zha
Keyword(s):  
Amino Acids ◽  
Bombyx Mori ◽  
Sequence Similarity ◽  
Similarity Analysis ◽  
Specific Gene ◽  
Rt Pcr ◽  
Gene Encoding ◽  
Fundamental Process ◽  
Sequence Similarity Analysis ◽  
Silkworm Bombyx Mori

Spermatogenesis is a fundamental process in sexual reproduction. In this study, we cloned a 716-bp cDNA of a testis-biased gene in Bombyx mori, named as BmRS-TS, which encodes a polypeptide of 164 amino acids, containing 26.7% arginine and serine residues. Sequence similarity analysis showed that BmRS-TS is a lepidopteran-specific gene. Results of RT-PCR and Western analysis revealed that BmRS-TS was expressed predominantly in the testis. Immunohistochemistry assay showed that the BmRS-TS protein was mostly located in primary spermatocytes. Moreover, knockdown of BmRS-TS by RNA interference (RNAi) showed that the morphology of the mature sperm was abnormal and that sperm bundles were broken up. Our results suggest that BmRS-TS plays an important role in silkworm spermatogenesis and provide some clues for understanding the mechanism that underlies spermatogenesis, which can be used as a reference for other lepidopterans.

1089: Prognostic Value of Molecular Staging of Bladder Cancer with RT -PCR Assay for KRT20: Results at 5 Year-Follow-up

2007 ◽  
Vol 177 (4S) ◽  
pp. 360-360
Author(s):  
Ana Agud ◽  
Maria J. Ribal ◽  
Lourdes Mengual ◽  
Mercedes Marin-Aguilera ◽  
Laura Izquierdo ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Prognostic Value ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Molecular Staging

Polymerase chain reaction amplification and typing of rotavirus in environmental samples

1995 ◽  
Vol 31 (5-6) ◽  
pp. 371-374 ◽  
Author(s):  
R. Gajardo ◽  
R. M. Pintó ◽  
A. Bosch
Keyword(s):  
Polymerase Chain Reaction ◽  
Environmental Samples ◽  
Polymerase Chain Reaction Amplification ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Group A ◽  
Reaction Amplification ◽  
Stool Specimens ◽  
Polymerase Chain

A reverse transcription polymerase chain reaction (RT-PCR) assay is described that has been developed for the detection and serotyping of group A rotavirus in stool specimens and concentrated and non-concentrated sewage specimens.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

Effective optimization of SARS-CoV-2 laboratory testing variables in an era of supply chain constraints

2020 ◽  
Vol 15 (15) ◽  
pp. 1483-1487
Author(s):  
Nikhil S Sahajpal ◽  
Ashis K Mondal ◽  
Allan Njau ◽  
Sudha Ananth ◽  
Kimya Jones ◽  
...  
Keyword(s):  
Supply Chain ◽  
Rna Extraction ◽  
Nasopharyngeal Swab ◽  
Sample Collection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Short Supply ◽  
Viral Transport ◽  
3D Printed ◽  
Bridging Studies

RT-PCR-based assays for the detection of SARS-CoV-2 have played an essential role in the current COVID-19 pandemic. However, the sample collection and test reagents are in short supply, primarily due to supply chain issues. Thus, to eliminate testing constraints, we have optimized three key process variables: RNA extraction and RT-PCR reactions, different sample types and media to facilitate SARS-CoV-2 testing. By performing various validation and bridging studies, we have shown that various sample types such as nasopharyngeal swab, bronchioalveolar lavage and saliva, collected using conventional nasopharyngeal swabs, ESwab or 3D-printed swabs and, preserved in viral transport media, universal transport media, 0.9% sodium chloride or Amies media are compatible with RT-PCR assay for COVID-19. Besides, the reduction of PCR reagents by up to fourfold also produces reliable results.

scholarly journals Is it enough for COVID-19 screening test? Limitation of swab test and general characteristics of mild symptom patients

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Sungwoo Choi ◽  
Hyo Jeong Choi ◽  
Ho Jung Kim
Keyword(s):  
Screening Test ◽  
Community Treatment ◽  
Upper Respiratory Tract ◽  
Test Results ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Positive Rate ◽  
Upper Respiratory ◽  
Polymerase Chain ◽  
Discharge Criteria

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.

Comparative Evaluation of In Vitro and In Vivo Assays for the Detection of Avian Infectious Bronchitis Virus as a Contaminant of Live Poultry Vaccines

1998 ◽  
Vol 26 (5) ◽  
pp. 629-634
Author(s):  
Emiliana Falcone ◽  
Edoardo Vignolo ◽  
Livia Di Trani ◽  
Simona Puzelli ◽  
Maria Tollis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Serological Response ◽  
Avian Infectious Bronchitis Virus ◽  
Animal Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
In Vivo Test ◽  
Infectious Bronchitis

A reverse transcriptase polymerase chain reaction (RT-PCR) assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

scholarly journals Identification of Epidemiological Traits by Analysis of SARS−CoV−2 Sequences

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 764
Author(s):  
Bohu Pan ◽  
Zuowei Ji ◽  
Sugunadevi Sakkiah ◽  
Wenjing Guo ◽  
Jie Liu ◽  
...  
Keyword(s):  
Clustering Analysis ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Host Age ◽  
Hierarchical Clustering Analysis ◽  
Genome Sequences ◽  
Geographic Patterns ◽  
Rapid Spread ◽  
Pairwise Sequence Similarity ◽  
Sequence Similarity Analysis

Severe acute respiratory syndrome coronavirus 2 (SARS−CoV−2) has caused the ongoing global COVID-19 pandemic that began in late December 2019. The rapid spread of SARS−CoV−2 is primarily due to person-to-person transmission. To understand the epidemiological traits of SARS−CoV−2 transmission, we conducted phylogenetic analysis on genome sequences from >54K SARS−CoV−2 cases obtained from two public databases. Hierarchical clustering analysis on geographic patterns in the resulting phylogenetic trees revealed a co-expansion tendency of the virus among neighboring countries with diverse sources and transmission routes for SARS−CoV−2. Pairwise sequence similarity analysis demonstrated that SARS−CoV−2 is transmitted locally and evolves during transmission. However, no significant differences were seen among SARS−CoV−2 genomes grouped by host age or sex. Here, our identified epidemiological traits provide information to better prevent transmission of SARS−CoV−2 and to facilitate the development of effective vaccines and therapeutics against the virus.

scholarly journals Development and application of a real-time RT-PCR assay to rapidly detect H2 subtype avian influenza A viruses

2021 ◽  
pp. 104063872199481
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Hangping Yao ◽  
Nanping Wu ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Real Time ◽  
Influenza A ◽  
Minor Groove Binder ◽  
Rt Pcr ◽  
Influenza A Viruses ◽  
Pcr Assay ◽  
Infectious Dose ◽  
The Matrix ◽  
Taqman Minor Groove Binder

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID50)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.

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