scholarly journals Persistence of SARS-CoV-2 virus and viral RNA on hydrophobic and hydrophilic surfaces and investigating contamination concentration

2021 ◽  
Author(s):  
Susan Elizabeth Paton ◽  
Antony Spencer ◽  
Isobel Garratt ◽  
Katy-Anne Thompson ◽  
Ikshitaa Dinesh ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Genome Copy ◽  
Log Reduction ◽  
Hydrophilic Surfaces ◽  
Mask Material ◽  
Environmental Surface ◽  
Contamination Concentration ◽  
Over Time

The transmission of SARS-CoV-2 is likely to occur through a number of routes, including contact with contaminated surfaces. Many studies have used RT-PCR analysis to detect SARS-CoV-2 RNA on surfaces but seldom has viable virus been detected. This paper investigates the viability over time of SARS-CoV-2 dried onto a range of materials and compares viability of the virus to RNA copies recovered, and whether virus viability is concentration dependant. Viable virus persisted for the longest time on surgical mask material and stainless steel with a 99.9% reduction in viability by 124 and 113 hours respectively. Viability of SARS-CoV-2 reduced the fastest on a polyester shirt, with a 99.9% reduction within 2.5 hours. Viability on cotton was reduced second fastest, with 99.9% reduction in 72 hours. RNA on all the surfaces exhibited a one log reduction in genome copy recovery over 21 days. The findings show that SARS-CoV-2 is most stable on non-porous hydrophobic surfaces. RNA is highly stable when dried on surfaces with only one log reduction in recovery over three weeks. In comparison, SARS-CoV-2 viability reduced more rapidly, but this loss in viability was found to be independent of starting concentration. Expected levels of SARS-CoV-2 viable environmental surface contamination would lead to undetectable levels within two days. Therefore, when RNA is detected on surfaces it does not directly indicate presence of viable virus even at high CT values.

scholarly journals Persistence of SARS-CoV-2 virus and viral RNA in relation to surface type and contamination concentration

2021 ◽  
Author(s):  
Susan Paton ◽  
Antony Spencer ◽  
Isobel Garratt ◽  
Katy-Anne Thompson ◽  
Ikshitaa Dinesh ◽  
...  
Keyword(s):  
Pcr Analysis ◽  
Surface Sampling ◽  
Rt Pcr ◽  
Bank Note ◽  
Log Reduction ◽  
Copy Numbers ◽  
Mask Material ◽  
Environmental Surface ◽  
Contamination Concentration ◽  
The Impact

The transmission of SARS-CoV-2 is likely to occur through a number of routes, including contact with contaminated surfaces. Many studies have used RT-PCR analysis to detect SARS-CoV-2 RNA on surfaces but seldom has viable virus been detected. This paper investigates the viability over time of SARS-CoV-2 dried onto a range of materials and compares viability of the virus to RNA copies recovered, and whether virus viability is concentration dependant. Viable virus persisted for the longest time on surgical mask material and stainless steel with a 99.9% reduction in viability by 122 and 114 hours respectively. Viability of SARS-CoV-2 reduced the fastest on a polyester shirt, with a 99.9% reduction within 2.5 hours. Viability on the bank note was reduced second fastest, with 99.9% reduction in 75 hours. RNA on all the surfaces exhibited a one log reduction in genome copy recovery over 21 days. The findings show that SARS-CoV-2 is most stable on non-porous hydrophobic surfaces. RNA is highly stable when dried on surfaces with only one log reduction in recovery over three weeks. In comparison, SARS-CoV-2 viability reduced more rapidly, but this loss in viability was found to be independent of starting concentration. Expected levels of SARS-CoV-2 viable environmental surface contamination would lead to undetectable levels within two days. Therefore, when RNA is detected on surfaces it does not directly indicate presence of viable virus even at high CT values. Importance This study shows the impact of material type on the viability of SARS-CoV-2 on surfaces. It demonstrates that the decay rate of viable SARS-CoV-2 is independent of starting concentration. However, RNA shows high stability on surfaces over extended periods. This has implications for interpretation of surface sampling results using RT-PCR to determine the possibility of viable virus from a surface, where RT-PCR is not an appropriate technique to determine viable virus. Unless sampled immediately after contamination it is difficult to align RNA copy numbers to quantity of viable virus on a surface.

scholarly journals Validation Study for VERIPRO® SARS-CoV-2 Env Assay for the Detection of SARS-CoV-2 from Stainless Steel Environmental Surface Swabs: Emergency Response Validation-AOAC—AOAC Performance Tested MethodSM 122001

2021 ◽  
Author(s):  
Adam Joelsson ◽  
Shannon Green ◽  
Nicholas Siciliano ◽  
Vikrant Dutta ◽  
Ron Johnson
Keyword(s):  
Stainless Steel ◽  
Emergency Response ◽  
Causative Agent ◽  
In Silico ◽  
Reference Method ◽  
In Silico Analysis ◽  
Accurate Method ◽  
Rt Pcr ◽  
Environmental Surface ◽  
Silico Analysis

Abstract Background The VERIPRO SARS-CoV-2 Env assay uses reverse transcriptase PCR (RT-PCR) to detect SARS-CoV-2, the causative agent of COVID-19, from stainless steel environmental sample swabs. Objective To validate the VERIPRO SARS-CoV-2 Env assay as part of the AOAC Research Institute’s Emergency Response Validation Performance Tested MethodSM program. Methods The VERIPRO SARS-CoV-2 Env assay was evaluated for specificity using in silico analysis of 15 764 SARS-CoV-2 sequences and 65 exclusivity organisms (both near neighbors and background organisms). The candidate method was evaluated in an unpaired study design for one environmental surface (stainless steel) and compared to the U.S. Centers for Disease Control and Prevention 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel, Instructions for Use (Revision 4, Effective 6/12/2020). Results Results of the in silico analysis demonstrated the specificity of the method in being able to detect target sequences and discriminate them from near neighbors. In the matrix study, the candidate method demonstrated statistically significant better recovery of the target analyte than the reference method. Conclusions The VERIPRO SARS-CoV-2 Env assay is a rapid and accurate method that can be utilized by food producers to detect the causative agent of COVID-19 on food contact surfaces. Highlights The VERIPRO SARS-CoV-2 Env assay can be performed without the need for an optional RNA purification step to detect SARS-CoV-2 from environmental surfaces.

scholarly journals Phenotypical and Functional Characteristics of Human Regulatory T Cells during Ex Vivo Maturation from CD4+ T Lymphocytes

2021 ◽  
Vol 11 (13) ◽  
pp. 5776
Author(s):  
Varvara G. Blinova ◽  
Natalia S. Novachly ◽  
Sofya N. Gippius ◽  
Abdullah Hilal ◽  
Yulia A. Gladilina ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Ex Vivo ◽  
Pcr Analysis ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Inflammatory Reactions ◽  
Effector Cells ◽  
Cycle Regulation ◽  
Further Development

Regulatory T cells (Tregs) participate in the negative regulation of inflammatory reactions by suppressing effector cells. In a number of autoimmune disorders, the suppressive function and/or the number of Tregs is compromised. The lack of active functioning Tregs can be restored with adoptive transfer of expanded ex vivo autologous Tregs. In our study, we traced the differentiation and maturation of Tregs CD4+CD25+FoxP3+CD127low over 7 days of cultivation from initial CD4+ T cells under ex vivo conditions. The resulting ex vivo expanded cell population (eTregs) demonstrated the immune profile of Tregs with an increased capacity to suppress the proliferation of target effector cells. The expression of the FoxP3 gene was upregulated within the time of expansion and was associated with gradual demethylation in the promotor region of the T cell-specific demethylation region. Real-time RT-PCR analysis revealed changes in the expression profile of genes involved in cell cycle regulation. In addition to FOXP3, the cells displayed elevated mRNA levels of Ikaros zinc finger transcription factors and the main telomerase catalytic subunit hTERT. Alternative splicing of FoxP3, hTERT and IKZF family members was demonstrated to be involved in eTreg maturation. Our data indicate that expanded ex vivo eTregs develop a Treg-specific phenotype and functional suppressive activity. We suggest that eTregs are not just expanded but transformed cells with enhanced capacities of immune suppression. Our findings may influence further development of cell immunosuppressive therapy based on regulatory T cells.

scholarly journals A New Multiplatform Model for Outpatient Prenatal and Postpartum Care in a Cohort of COVID-19-Affected Obstetric Patients

2021 ◽  
Vol 18 (10) ◽  
pp. 5144
Author(s):  
Mar Muñoz-Chápuli Gutiérrez ◽  
Ana Durán-Vila ◽  
Javier Ruiz-Labarta ◽  
Pilar Payá-Martínez ◽  
Pilar Pintado Recarte ◽  
...  
Keyword(s):  
Clinical Manifestations ◽  
Specific Treatment ◽  
Rt Pcr ◽  
Good Adherence ◽  
Major Morbidity ◽  
Reference Hospital ◽  
The Mean ◽  
Discharge From Hospital ◽  
Over Time

Spain was one of the epicenters of the first wave of the COVID-19 pandemic. We describe in this article the design and results of a new telephone-and-telematic multiplatform model of systematic prenatal and postpartum follow-up for COVID-19-affected women implemented in a tertiary reference hospital in Madrid. We included patients with RT-PCR-confirmed COVID-19 during pregnancy or delivery from 10 March 2020 to 15 December 2020. We had a total of 211 obstetric patients: 148 (70.1%) were tested at the onset of suspicious clinical manifestations and 62 (29.4%) were tested in the context of routine screening. Of all the patients, 60 women (28.4%) were asymptomatic and 97 (46%) presented mild symptoms. Fifty-one women (24.2%) were admitted to our hospital for specific treatment because of moderate or severe symptoms. We had no missed cases and a good adherence. The mean number of calls per patient was 2.3. We performed 55 in-person visits. We analyzed the complexity of our program over time, showing a two-wave-like pattern. One patient was identified as needing hospitalization and we did not record major morbidity. Telemedicine programs are a strong and reproducible tool to reach to pregnant population affected by COVID-19, to assess its symptoms and severity, and to record for pregnancy-related symptoms both in an outpatient regime and after discharge from hospital.

scholarly journals Role of Innate Inflammation in the Regulation of Tissue Remodeling during Tooth Eruption

2021 ◽  
Vol 9 (1) ◽  
pp. 7
Author(s):  
Yusuke Makino ◽  
Kaoru Fujikawa ◽  
Miwako Matsuki-Fukushima ◽  
Satoshi Inoue ◽  
Masanori Nakamura
Keyword(s):  
Bacterial Infections ◽  
Tooth Movement ◽  
Tooth Eruption ◽  
Intercellular Adhesion Molecule ◽  
Enamel Organ ◽  
Pcr Analysis ◽  
Maturation Stage ◽  
Oral Epithelium ◽  
Rt Pcr ◽  
Inflammatory Reactions

Tooth eruption is characterized by a coordinated complex cascade of cellular and molecular events that promote tooth movement through the eruptive pathway. During tooth eruption, the stratum intermedium structurally changes to the papillary layer with tooth organ development. We previously reported intercellular adhesion molecule-1 (ICAM-1) expression on the papillary layer, which is the origin of the ICAM-1-positive junctional epithelium. ICAM-1 expression is induced by proinflammatory cytokines, including interleukin-1 and tumor necrosis factor. Inflammatory reactions induce tissue degradation. Therefore, this study aimed to examine whether inflammatory reactions are involved in tooth eruption. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed sequential expression of hypoxia-induced factor-1α, interleukin-1β, and chemotactic factors, including keratinocyte-derived chemokine (KC) and macrophage inflammatory protein-2 (MIP-2), during tooth eruption. Consistent with the RT-PCR results, immunohistochemical analysis revealed KC and MIP-2 expression in the papillary layer cells of the enamel organ from the ameloblast maturation stage. Moreover, there was massive macrophage and neutrophil infiltration in the connective tissue between the tooth organ and oral epithelium during tooth eruption. These findings suggest that inflammatory reactions might be involved in the degradation of tissue overlying the tooth organ. Further, these reactions might be induced by hypoxia in the tissue overlying the tooth organ, which results from decreased capillaries in the tissue. Our findings indicate that bacterial infections are not associated with the eruption process. Therefore, tooth eruption might be regulated by innate inflammatory mechanisms.

scholarly journals RT-PCR analysis of Deformed wing virus in honeybees (Apis mellifera) and mites (Varroa destructor)

2005 ◽  
Vol 86 (12) ◽  
pp. 3419-3424 ◽  
Author(s):  
Constanze Yue ◽  
Elke Genersch
Keyword(s):  
Varroa Destructor ◽  
Pcr Analysis ◽  
Body Parts ◽  
Rt Pcr ◽  
Larval Food ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Significant Difference ◽  
Almost All ◽  
Viral Sequences

Deformed wing virus (DWV) is a honeybee viral pathogen either persisting as an inapparent infection or resulting in wing deformity. The occurrence of deformity is associated with the transmission of DWV through Varroa destructor during pupal stages. Such infections with DWV add to the pathology of V. destructor and play a major role in colony collapse in the course of varroosis. Using a recently developed RT-PCR protocol for the detection of DWV, individual bees and mites originating from hives differing in Varroa infestation levels and the occurrence of crippled bees were analysed. It was found that 100 % of both crippled and asymptomatic bees were positive for DWV. However, a significant difference in the spatial distribution of DWV between asymptomatic and crippled bees could be demonstrated: when analysing head, thorax and abdomen of crippled bees, all body parts were always strongly positive for viral sequences. In contrast, for asymptomatic bees viral sequences could be detected in RNA extracted from the thorax and/or abdomen but never in RNA extracted from the head. DWV replication was demonstrated in almost all DWV-positive body parts of infected bees. Analysing individual mites for the presence of DWV revealed that the percentage of DWV-positive mites differed between mite populations. In addition, it was demonstrated that DWV was able to replicate in some but not all mites. Interestingly, virus replication in mites was correlated with wing deformity. DWV was also detected in the larval food, implicating that in addition to transmission by V. destructor DWV is also transmitted by feeding.

scholarly journals Reproductive failure in mice lacking inter-alpha-trypsin inhibitor (ITI) – ITI target genes in mouse ovary identified by microarray analysis

2004 ◽  
Vol 183 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Mika Suzuki ◽  
Hiroshi Kobayashi ◽  
Yoshiko Tanaka ◽  
Naohiro Kanayama ◽  
Toshihiko Terao
Keyword(s):  
Real Time ◽  
Trypsin Inhibitor ◽  
Target Genes ◽  
Reproductive Function ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Reproductive Process ◽  
Female Mice ◽  
Retinoid Metabolism ◽  
Regulatory Effects

Bikunin, a Kunitz-type protease inhibitor, is found in blood and urine. It has been established by two laboratories independently that the bikunin knockout female mice display a severe reduction in fertility: the cumulus oophorus has a defect in forming the extracellular hyaluronan-rich matrix during expansion. Proteins of the inter-alpha-trypsin inhibitor (ITI) family are eliminated in mice in which the bikunin gene has been inactivated, since bikunin is essential for their biosynthesis. Proteins of the ITI family may contribute to the microenvironment in which ovulation takes place. It is not clear, however, whether a single mechanism affects the reproductive function including ovulation. For identifying the full repertoire of the ITI deficiency-related genes, a cDNA microarray hybridization screening was conducted using mRNA from ovaries of wild-type or bik−/− female mice. A number of genes were identified and their regulation was confirmed by real-time RT-PCR analysis. Our screen identified that 29 (0.7%) and 5 genes (0.1%) of the genes assayed were, respectively, up- and down-regulated twofold or more. The identified genes can be classified into distinct subsets. These include stress-related, apoptosis-related, proteases, signaling molecules, aging-related, cytokines, hyaluronan metabolism and signaling, reactive oxygen species-related, and retinoid metabolism, which have previously been implicated in enhancing follicle development and/or ovulation. Real-time RT-PCR analysis confirmed that these genes were up- and down-regulated two- to tenfold by bikunin knockout. These studies demonstrate that proteins of the ITI family may exert potent regulatory effects on a major physiological reproductive process, ovulation.

Quantitative RT-PCR analysis of MMP and TIMP MRNA expression in correlation to liver histology in patients with chronic hepatitis C

2000 ◽  
Vol 118 (4) ◽  
pp. A1469
Author(s):  
Dirk Michels ◽  
Christian I. Haberkorn ◽  
Burkhard Arndt ◽  
Michael P. Manns
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C ◽  
Mrna Expression ◽  
Chronic Hepatitis C ◽  
Liver Histology ◽  
Pcr Analysis ◽  
Rt Pcr

Improved Methods for Extracting RNA from Exfoliated Human Colonocytes in Stool and RT-PCR Analysis

2004 ◽  
Vol 49 (11-12) ◽  
pp. 1889-1898 ◽  
Author(s):  
Farid E. Ahmed ◽  
Stephanie I. James ◽  
Donald T. Lysle ◽  
Larry J. Dobbs ◽  
Roberta M. Johnke ◽  
...  
Keyword(s):  
Pcr Analysis ◽  
Rt Pcr ◽  
Improved Methods

scholarly journals Biological and Molecular Characteristics of a Novel Partitivirus Infecting the Edible Fungus Lentinula edodes

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 726-733 ◽  
Author(s):  
Mengpei Guo ◽  
Yinbing Bian ◽  
Jinjie Wang ◽  
Gangzheng Wang ◽  
Xiaolong Ma ◽  
...  
Keyword(s):  
Lentinula Edodes ◽  
Control Strategies ◽  
Phylogenetic Analyses ◽  
Pcr Analysis ◽  
Molecular Characteristics ◽  
Rt Pcr ◽  
Edible Fungus ◽  
Qpcr Analysis ◽  
Disease Diagnostics ◽  
Wild Strains

A new partitivirus named Lentinula edodes partitivirus 1 (LePV1) was isolated from a diseased L. edodes strain with severe degeneration of the mycelium and imperfect browning in bag cultures. The nucleotide sequences of LePV1 dsRNA-1 and dsRNA-2 were determined; they were 2,382 bp and 2,245 bp in length, and each contained a single ORF encoding RNA-dependent RNA polymerase (RdRp) and coat protein (CP), respectively. The purified virus preparation contained isometric particles 34 nm in diameter encapsidating these dsRNAs. Phylogenetic analyses showed LePV1 to be a new member of Betapartitivirus, with the RdRp sequence most closely related to Grapevine partitivirus. RT-PCR analysis showed that 27 of the 56 Chinese L. edodes core collection strains carry LePV1, with the virus being more common in wild strains than cultivated strains. In addition, qPCR analysis suggested that coinfection with L. edodes mycovirus HKB (LeV-HKB) could increase replication of the RdRp gene of LePV1. This study may be essential for the development of more accurate disease diagnostics and the formulation of control strategies for viral diseases in L. edodes.

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