17 research outputs found

    Advanced material against human (Including Covid‐19) and plant viruses: nanoparticles as a feasible strategy

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    The SARS‐CoV‐2 virus outbreak revealed that these nano‐pathogens have the ability to rapidly change lives. Undoubtedly, SARS‐CoV‐2 as well as other viruses can cause important global impacts, affecting public health, as well as, socioeconomic development. But viruses are not only a public health concern, they are also a problem in agriculture. The current treatments are often ineffective, are prone to develop resistance, or cause considerable adverse side effects. The use of nanotechnology has played an important role to combat viral diseases. In this review three main aspects are in focus: first, the potential use of nanoparticles as carriers for drug delivery. Second, its use for treatments of some human viral diseases, and third, its application as antivirals in plants. With these three themes, the aim is to give to readers an overview of the progress in this promising area of biotechnology during the 2017–2020 period, and to provide a glance at how tangible is the effectiveness of nanotechnology against viruses. Future prospects are also discussed. It is hoped that this review can be a contribution to general knowledge for both specialized and non‐specialized readers, allowing a better knowledge of this interesting topic.REDES‐ANID. Grant Number: 180003 Universidad de La Frontera. Grant Number: DI20‐1003 FAPESP. Grant Numbers: 2018/08194‐2, 2018/02832‐7 CNPq. Grant Numbers: 404815/2018‐9, 313117/2019‐5 CONICYT/FAPESP. Grant Number: 2018/08194‐2 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Grant Numbers: 001, ANID/FONDAP/15130015 FCT. Grant Number: PTDC/CTM‐TEX/28295/2017 FEDER POCI Portugal 2020 program COMPETE. Grant Number: UID/CTM/00264/2019 FCT/MCTE

    Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel

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    Preparación y propiedades de tensión superficial de derivados del åcido a-aciloxisuccínico a partir de derivados del åcido målico y åcidos grasos del aceite de gérmen de arroz

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    Surface active compounds were prepared from malic acid by esterification with acyl chloride (II)a-d, of [palmitic, stearic, oleic, linoleic and mixed fatty acids of rice bran oil (RBO) (II)e], in the presence of pyridine as catalyst, forming (III)a-e ,  which are  converted to anionic disodium salt (IV)a-e . The prepared a-acyl-oxysuccinic acid derivatives (III)a-e was oxypropenoxylated with various moles of propylene oxide (n= 2, 4, 6 and 8) to give (V-IX)a-d . These compounds were converted to nonionic surfactants with two terminal amide oxime groups  (XV-XIX)a-d as molecular aggregations and surface active agents in aqueous media. The structures were confirmed by micro analysis, IR and 1H NMR spectra. The surface active properties of the prepared compounds revealed excellent results.Se han preparado compuestos de tensión superficial a partir de ácido málico por esterificación con cloruro de acilo (II)a-d de [palmítico, esteárico, oleico, linoleico y ácidos grasos mezclados de aceite de gérmen de arroz (RBO) (II)e], en presencia de piridina como catalizador, formando (III)a-e, los cuales son convertidos a sales disódicas aniónicas (IV)a-e. El derivado del ácido a-acil-oxisuccínico preparado (III)a-e fue oxipropenoxilado con varios moles de óxido de propileno (n=2, 4, 6 y 8) para dar (V-IX)a-d. Estos compuestos fueron convertidos en tensioactivos no iónicos con dos grupos amida oxima terminal (XV-XIX)a-d como agregaciones moleculares y agentes tensioactivos en medio acuoso. Las estructuras se confirmaron por microanálisis, IR y espectros de 1H NMR. Las propiedades tensioactivas de los compuestos preparados revelaron excelentes resultados

    Isolation and Characterization of Two Virulent Phages to Combat Staphylococcus aureus and Enterococcus faecalis causing Dental Caries

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    This study aimed to isolate and characterize bacteriophages, as a biocontrol agent, against certain antibiotic-resistant bacteria causing dental caries. Here, two dental caries-causing bacteria S. aureus and E. faecalis were isolated and characterized biochemically using the automated VITEKŸ 2 system. Antibiotic sensitivity pattern of the isolated dental caries bacteria was assessed against selection of antibiotics. The two isolates showed resistance against most of the tested antibiotics. To overcome this problem, two lytic phages vB_SauM-EG-AE3 and vB_EfaP-EF01 were isolated, identified, and applied to control the growth of S. aureus and E. faecalis, respectively. Phages were identified morphologically using TEM and showed that vB_SauM-EG-AE3 phage is related to Myoviridae and vB_EfaP-EF01 phage belongs to Podoviridae. The two phages exhibited high lytic activity, high stability, and a narrow host range. The one-step growth curve of phages showed burst sizes of 78.87 and 113.55 PFU/cell with latent periods of 25 and 30 minutes for S. aureus phage and E. faecalis phage respectively. In addition, the two phages showed different structural protein profiles and exhibited different patterns using different restriction enzymes. The genome sizes were estimated to be 13.30 Kb and 15.60 Kb for phages vB_SauM-EGAE3, vB_EfaP-EGAE1, respectively. Complete inhibition of bacterial growth was achieved using phages with MOIs of 103, 102 and 10 after 1, 3, 5, and 24 h of incubation at 37°C. Hence, this study indicates that the isolated bacteriophages are promising biocontrol agents that could challenge antibiotic-resistant dental caries bacteria to announce new successful alternatives to antibiotics

    First record of Citrus viroid II (CVd-II) associated with

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    Citrus fruit is one of the major traditional agricultural products of Egypt. Constraints to fruit production are mainly related to tree decline caused by infection with viroids (Hadidi et al., 2003). The group II viroids, including Hop stunt viroid (HSVd) the causal agent of cachexia, have not been reported previously associated with gummy bark disease affecting sweet orange in Egypt. Gummy bark disease is a phloem discoloration affecting only sweet orange (Fig. 1), which was the first described by Nour-Eldin (1956). Affected trees are usually stunted to varying degrees and sometimes severely reduced in size. In 2008, a total of 65 samples of sweet orange (cvs. Navel, Balady and Valencia) were collected; these samples were both from trees with gummy bark symptoms (a reddish-brown line under the bark and gum-impregnated tissue, around the circumference and especially near the bud union) and from trees of the same cultivars with no symptoms, growing in close proximity. The samples were indexed for viroids by inoculation of Etro

    Characterization and Full Genome Sequence of Novel KPP-5 Lytic Phage against Klebsiella pneumoniae Responsible for Recalcitrant Infection

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    Klebsiella pneumoniae is a hazardous opportunistic pathogen that is involved in many serious human diseases and is considered to be an important foodborne pathogen found in many food types. Multidrug resistance (MDR) K. pneumoniae strains have recently spread and increased, making bacteriophage therapy an effective alternative to multiple drug-resistant pathogens. As a consequence, this research was conducted to describe the genome and basic biological characteristics of a novel phage capable of lysing MDR K. pneumoniae isolated from food samples in Egypt. The host range revealed that KPP-5 phage had potent lytic activity and was able to infect all selected MDR K. pneumoniae strains from different sources. Electron microscopy images showed that KPP-5 lytic phage was a podovirus morphology. The one-step growth curve exhibited that KPP-5 phage had a relatively short latent period of 25 min, and the burst size was about 236 PFU/infected cells. In addition, KPP-5 phage showed high stability at different temperatures and pH levels. KPP-5 phage has a linear dsDNA genome with a length of 38,245 bp with a GC content of 50.8% and 40 predicted open reading frames (ORFs). Comparative genomics and phylogenetic analyses showed that KPP-5 is most closely associated with the Teetrevirus genus in the Autographviridae family. No tRNA genes have been identified in the KPP-5 phage genome. In addition, phage-borne virulence genes or drug resistance genes were not present, suggesting that KPP-5 could be used safely as a phage biocontrol agent

    Changes in tryptophan and phenylalanine in chronic HCV patients treated with direct acting antiviral (sofosbuvir)

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    Abstract Background Chronic hepatitis C virus (HCV) infection represents a global public health challenge, and new drugs have been authorized for its treatment. The current study aimed to detect the change in blood levels of tryptophan and phenylalanine with the recent therapy direct-acting antiviral (sofosbuvir). Methods This case-controlled study was conducted on HCV patients including 40 treated with direct-acting antiviral (sofosbuvir), 40 untreated underestimations of full medical history, and laboratory tests involved ELISA assay and real-time (RT) PCR technique as well as measuring tryptophan and phenylalanine by HPLC-UV, in addition to 20 apparently healthy subjects served as a control group. Results There is a high statistical significant decrease in tryptophan and increase in phenylalanine in treated cases than untreated cases and control groups. This study showed that phenylalanine at the cutoff of 2.13 Όg/ml had 96.9% sensitivity and 62.5% specificity among treated cases; also, tryptophan at the cutoff of 8.53 ng/ml had 81.2% sensitivity and 75% specificity to predict severe depression. There is a statistically significant increase in tryptophan and decrease in phenylalanine in mild/moderate than very severe depression. Conclusion Direct-acting antiviral (sofosbuvir) causes a decrease in tryptophan levels and increase in phenylalanine levels that as a result leading to depressive symptoms as adverse effects, so advising by dietary supplements of tryptophan for patients treated from chronic HCV by direct-acting antiviral (sofosbuvir)

    Improving Regulation of Enzymatic and Non-Enzymatic Antioxidants and Stress-Related Gene Stimulation in Cucumber mosaic cucumovirus-Infected Cucumber Plants Treated with Glycine Betaine, Chitosan and Combination

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    Cucumber mosaic cucumovirus (CMV) is a deadly plant virus that results in crop-yield losses with serious economic consequences. In recent years, environmentally friendly components have been developed to manage crop diseases as alternatives to chemical pesticides, including the use of natural compounds such as glycine betaine (GB) and chitosan (CHT), either alone or in combination. In the present study, the leaves of the cucumber plants were foliar-sprayed with GB and CHT—either alone or in combination—to evaluate their ability to induce resistance against CMV. The results showed a significant reduction in disease severity and CMV accumulation in plants treated with GB and CHT, either alone or in combination, compared to untreated plants (challenge control). In every treatment, growth indices, leaf chlorophylls content, phytohormones (i.e., indole acetic acid, gibberellic acid, salicylic acid and jasmonic acid), endogenous osmoprotectants (i.e., proline, soluble sugars and glycine betaine), non-enzymatic antioxidants (i.e., ascorbic acid, glutathione and phenols) and enzymatic antioxidants (i.e., superoxide dismutase, peroxidase, polyphenol oxidase, catalase, lipoxygenase, ascorbate peroxidase, glutathione reductase, chitinase and β-1,3 glucanase) of virus-infected plants were significantly increased. On the other hand, malondialdehyde and abscisic acid contents have been significantly reduced. Based on a gene expression study, all treated plants exhibited increased expression levels of some regulatory defense genes such as PR1 and PAL1. In conclusion, the combination of GB and CHT is the most effective treatment in alleviated virus infection. To our knowledge, this is the first report to demonstrate the induction of systemic resistance against CMV by using GB
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