Mechanistic insights into flow-dependent Virus retention in different nanofilter membranes

The COVID-19 disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has two characteristics that distinguish it from other viral infections. It affects more severely people with pre-existing comorbidities and viral load peaks prior to the onset of the symptoms. Investigating factors that could contribute to these characteristics, we found increased mTOR signaling and suppressed genes related to autophagy, lysosome, and vesicle fusion in Vero E6 cells infected with SARS-CoV-2. Transcriptomic data mining of bronchoalveolar epithelial cells from severe COVID-19 patients revealed that COVID-19 severity is associated with increased expression of genes related to mTOR signaling and decreased expression of genes related to au-tophagy, lysosome function, and vesicle fusion. SARS-CoV-2 infection in Vero E6 cells also re-sulted in virus retention inside the cells and trafficking of virus-bearing vesicles between neighboring cells. Our findings support a scenario where SARS-CoV-2 benefits from compromised autophagic flux and inhibited exocytosis in individuals with chronic hyperactivation of mTOR signaling, which might relate to undetectable proliferation and evasion of the immune system.

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Transmission Efficiency of Papaya ringspot virus by Three Aphid Species

Phytopathology ◽

10.1094/phyto-98-5-0541 ◽

2008 ◽

Vol 98 (5) ◽

pp. 541-546 ◽

Cited By ~ 28

Author(s):

C. M. Kalleshwaraswamy ◽

N. K. Krishna Kumar

Keyword(s):

Aphis Gossypii ◽

Transmission Efficiency ◽

Leaf Disk ◽

Ringspot Virus ◽

Test Plant ◽

Infected Leaf ◽

Papaya Ringspot Virus ◽

Access Period ◽

Virus Retention ◽

Aphid Inoculation

The transmission efficiency of Papaya ringspot virus (PRSV) by three aphid vectors (i.e., Aphis gossypii, A. craccivora, and Myzus persicae) was studied. Efficiency was measured by single-aphid inoculation, group inoculation (using five aphids), duration of virus retention, and the number of plants following a single acquisition access period (AAP) to which the aphids could successfully transmit the virus. Single-aphid inoculation studies indicated that M. persicae (56%) and A. gossypii (53%) were significantly more efficient in transmitting PRSV than A. craccivora (38%). Further, in the former two species, the time required for initiation of the first probe on the inoculation test plant was significantly shorter compared to A. craccivora. PRSV transmission efficiency was 100% in all three species when a group of five aphids were used per plant. There was a perceptible decline in transmission efficiency as the sequestration period increased, although M. persicae successfully transmitted PRSV after 30 min of sequestration. A simple leaf-disk assay technique was employed for evaluating the transmission efficiency of three species of aphids. The results of leaf-disk assays also indicated that A. gossypii (48%) and M. persicae (56%) were more efficient PRSV vectors than A. craccivora. Using leaf-disk assays, the ability of individual aphids to inoculate PRSV serially to a number of plants was studied. Following a single AAP on an infected leaf, M. persicae was more efficient than the other two species with 52.5% transmission after the first inoculation access period (IAP). However, its inoculation efficiency significantly decreased with the second and subsequent IAPs. A. gossypii was able to transmit PRSV sequentially up to four successive leaf disks, but with significantly declining efficiency. Since A. gossypii is reported to be the numerically dominant vector in south India in addition to being a more efficient vector capable of inoculating PRSV to multiple plants, it should be the target vector for control strategies.

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Effects of a pressure release on virus retention with the Ultipor DV20 membrane

Biotechnology and Bioengineering ◽

10.1002/bit.25112 ◽

2013 ◽

Vol 111 (3) ◽

pp. 545-551 ◽

Cited By ~ 22

Author(s):

Melissa A. Woods ◽

Andrew L. Zydney

Keyword(s):

Pressure Release ◽

Virus Retention

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A mass balance approach to the fate of viruses in a municipal wastewater treatment plant during summer and winter seasons

Water Science & Technology ◽

10.2166/wst.2013.722 ◽

2013 ◽

Vol 69 (2) ◽

pp. 364-370 ◽

Cited By ~ 6

Author(s):

Katharina Ulbricht ◽

Hans-Christoph Selinka ◽

Stefanie Wolter ◽

Karl-Heinz Rosenwinkel ◽

Regina Nogueira

Keyword(s):

Wastewater Treatment ◽

Mass Balance ◽

Wastewater Treatment Plant ◽

Municipal Wastewater ◽

Winter Season ◽

Treatment Plant ◽

P Value ◽

Virus Inactivation ◽

Virus Removal ◽

Virus Retention

In contrast to previous discussion on general virus removal efficiency and identifying surrogates for human pathogenic viruses, this study focuses on virus retention within each step of a wastewater treatment plant (WWTP). Additionally, the influence of weather conditions on virus removal was addressed. To account for the virus retention, this study describes a mass balance of somatic coliphages (bacterial viruses) in a municipal WWTP, performed in the winter and summer seasons of 2011. In the winter season, the concentration of coliphages entering the WWTP was about 1 log lower than in summer. The mass balance in winter revealed a virus inactivation of 85.12 ± 13.97%. During the summer season, virus inactivation was significantly higher (95.25 ± 3.69%, p-value <0.05), most likely due to additional virus removal in the secondary clarifier by insolation. Thus, a total removal of coliphages of about 2.78 log units was obtained in summer compared to 1.95 log units in winter. Rainfall events did not statistically correlate with the concentrations of coliphages entering the WWTP in summer.

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Production of ceramic membranes with different pore sizes for virus retention

Journal of Water Process Engineering ◽

10.1016/j.jwpe.2014.10.007 ◽

2014 ◽

Vol 4 ◽

pp. 201-211 ◽

Cited By ~ 28

Author(s):

Julia Werner ◽

Benjamin Besser ◽

Christoph Brandes ◽

Stephen Kroll ◽

Kurosch Rezwan

Keyword(s):

Ceramic Membranes ◽

Pore Sizes ◽

Virus Retention

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Cloth masks as respiratory protections in the COVID-19 pandemic period: evidence gaps

Revista Brasileira de Enfermagem ◽

10.1590/0034-7167-2020-0239 ◽

2020 ◽

Vol 73 (suppl 2) ◽

Author(s):

Ana Cristina de Oliveira e Silva ◽

Ana Maria de Almeida ◽

Maria Eliane Moreira Freire ◽

Jordana de Almeida Nogueira ◽

Elucir Gir ◽

...

Keyword(s):

Hand Hygiene ◽

Infection Control ◽

Infection Prevention ◽

Web Of Science ◽

Preventive Measures ◽

Scientific Evidence ◽

Risk Of Infection ◽

Increased Risk ◽

Surgical Masks ◽

Virus Retention

ABSTRACT Objective: to identify scientific evidence on the effectiveness of using cloth masks as safe protectors against COVID-19. Method: an integrative review of articles available in full obtained at PubMed, CINAHL, and Web of Science. Controlled, non-controlled descriptors and keywords such as “mask”, “home-made” and “cloth” or “cotton” and “infection control” or “infection prevention” were used. Results: thirty-eight articles were selected; of these, seven studies made up the sample. Evidence shows that cloth masks do not have the same protective characteristics as surgical masks, indicating an increased risk of infection due to humidity, diffusion of fluids, virus retention, and improper preparation. Considering the shortage of surgical masks during the pandemic, cloth masks could be proposed as a last resort. Conclusion: cloth masks should be used together with preventive measures, such as home insulation, good respiratory conduct, and regular hand hygiene.

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The Intertwined Life Histories and Transmission Ecologies of Plant, Arthropod, and Vertebrate Viruses

10.20944/preprints202104.0295.v1 ◽

2021 ◽

Author(s):

Jan Slingenbergh

Keyword(s):

Life History ◽

Life Histories ◽

Virus Transmission ◽

Circulatory System ◽

Reproductive Organs ◽

Life History Strategies ◽

Mechanical Transmission ◽

Host Tropism ◽

Host Body ◽

Virus Retention

It remains poorly understood how the life history strategies and transmission ecologies of viruses of plants, arthropods, and vertebrates are interrelated. The present analysis hinges on the virus transmission success. Virus transmission reflects where in the host-body viruses are retained or replicating. Plants, arthropods, and vertebrates share a protective outer-layer, a circulatory system, and reproductive organs. The latter enables vertical virus transmission and associates with virus-host mutualism. Two broadly opposing virus life history strategies are considered. Acute viruses tend to be replicative and are swiftly transmitted to the next host. Instead, persistent viruses keep virus replicating costs and host damage to a minimum. The intertwined life histories and transmission ecologies are accordingly pieced together, based on the virus mono- or instead dual-host tropism, the location of virus retention or replication on or in the host-body, the presence of cyclical or mechanical transmission by arthropods, and of horizontal and vertical host-to-host transmission modes. It is shown that in the arthropod and in the vertebrate animal host, virus circulation in the hemocoel or blood circulation goes hand-in-hand with vertical transmission. Instead, plant phloem viruses do not transmit via seed. The latter is the rule for the plant-only viruses. The risk management implications are discussed in brief.

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Electrospun iron and copper oxide fibers for virus retention applications

Textile Research Journal ◽

10.1177/0040517519834601 ◽

2019 ◽

Vol 89 (21-22) ◽

pp. 4373-4382 ◽

Cited By ~ 2

Author(s):

Mateusz Schabikowski ◽

Alicja Cichoń ◽

Zoltán Németh ◽

Władysław Kubiak ◽

Dariusz Kata ◽

...

Keyword(s):

Drinking Water ◽

Copper Oxide ◽

Contact Time ◽

Ceramic Materials ◽

Organic Salt ◽

Batch Adsorption ◽

Ceramic Fibers ◽

Log Reduction ◽

Polymer Precursors ◽

Virus Retention

This work describes the fabrication of ceramic fibers by electrospinning based on iron(III) oxide or copper(II) oxide. The fibers were produced from organic salt/polymer precursors and transformed into pure ceramic materials by firing. The fibers were designed to remove negatively charged viruses from drinking water. The obtained ceramic fibers were characterized by diameters of 0.23 ± 0.10 μm and 0.17 ± 0.06 μm for iron- and copper-based fibers, respectively. The performance of 0.100 g of fibers in the removal of MS2 bacteriophages in batch adsorption experiments reached log reduction values of 1.70 and 0.44 after 5 min and 10 min of contact time for iron(III) oxide and copper(II) oxide fibers, respectively.

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