Antibacterial and Cytotoxic Effects of Biosynthesized Zinc Oxide and Titanium Dioxide Nanoparticles.

Nanotechnology is a rapidly developing field of research that studies materials having dimensions of less than 100 nanometers. It is applicable in many areas of life sciences and medicine including skin care and personal hygiene, as these materials are the essential components of various cosmetics and sunscreens. The aim of the present study was to synthesize Zinc oxide (ZnO) and Titanium dioxide (TiO2) nanoparticles (NPs) by using Calotropis procera (C. procera) leaf extract. Green synthesized NPs were characterized by UV spectroscopy, Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) to investigate their structure, size, and physical properties. The antibacterial and synergistic effects of ZnO and TiO2 NPs along with antibiotics were also observed against bacterial isolates. The antioxidant activity of synthesized NPs was analyzed by their α-diphenyl-ß-picrylhydrazyl (DPPH) radical scavenging activity. In vivo toxic effects of the synthesized NPs were evaluated in albino mice at different doses (100, 200, and 300 mg/kg body weight) of ZnO and TiO2 NPs administered orally for 7, 14, and 21 days. The antibacterial results showed that the zone of inhibition (ZOI) was increased in a concentration-dependent manner. Among the bacterial strains, Staphylococcus aureus showed the highest ZOI, i.e., 17 and 14 mm against ZnO and TiO2 NPs, respectively, while Escherichia coli showed the lowest ZOI, i.e., 12 and 10 mm, respectively. Therefore, ZnO NPs are potent antibacterial agents compared to TiO2 NPs. Both NPs showed synergistic effects with antibiotics (ciprofloxacin and imipenem). Moreover, the DPPH activity showed that ZnO and TiO2 NPs have significantly (p > 0.05) higher antioxidant activity, i.e., 53% and 58.7%, respectively, which indicated that TiO2 has good antioxidant potential compared to ZnO NPs. However, the histological changes after exposure to different doses of ZnO and TiO2 NPs showed toxicity-related changes in the structure of the kidney compared to the control group. The current study provided valuable information about the antibacterial, antioxidant, and toxicity impacts of green synthesized ZnO and TiO2 NPs, which can be influential in the further study of their eco-toxicological effects.

Challenges related to the cases of lepromatous leprosy: a report of two cases.

Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae with various clinical symptoms. Even though the incidence of leprosy has diminished in Saudi Arabia, it still has not been eliminated. We present two cases of leprosy from India residing in Saudi Arabia that were successfully managed with multidrug therapy. The first patient was a 33-year-old man with a history of enlarging erythematous patch and nose deformity on his face and upper and lower extremities started two years ago. The second patient was a 25-year-old man who presented with multiple hyperpigmented plaques on the upper and lower extremities in the last two years. The patient was firstly misdiagnosed and treated as tinea corporis without improvement. In both patients, the histological study from cutaneous lesions confirmed lepromatous leprosy. This report aimed to introduce the manifestations of leprosy, emphasizing the nose's involvement in the first case and the misdiagnosis of leprosy in the second case.

Ameliorating the Adverse Effects of Tomato mosaic tobamovirus Infecting Tomato Plants in Egypt by Boosting Immunity in Tomato Plants Using Zinc Oxide Nanoparticles.

Tomato mosaic virus (ToMV) is one of the economically damageable Tobamovirus infecting the tomato in Egypt that has caused significant losses. It is therefore of great interest to trigger systemic resistance to ToMV. In this endeavor, we aimed to explore the capacity of ZnO-NPs (zinc oxide nanoparticles) to trigger tomato plant resistance against ToMV. Effects of ZnO-NPs on tomato (Solanum lycopersicum L.) growth indices and antioxidant defense system activity under ToMV stress were investigated. Noticeably that treatment with ZnO-NPs showed remarkably increased growth indices, photosynthetic attributes, and enzymatic and non-enzymatic antioxidants compared to the challenge control. Interestingly, oxidative damage caused by ToMV was reduced by reducing malondialdehyde, H2O2, and O2 levels. Overall, ZnO-NPs offer a safe and economic antiviral agent against ToMV.

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

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.

Molecular Characterization of the Alfalfa mosaic virus Infecting Solanum melongena in Egypt and the Control of Its Deleterious Effects with Melatonin and Salicylic Acid.

During the spring of 2019, distinct virus-like symptoms were observed in the Kafr El-Sheikh Governorate in Egypt in naturally infected eggplants. Leaves of affected plants showed interveinal leaf chlorosis, net yellow, chlorotic sectors, mottling, blisters, vein enation, necrotic intervention, and narrowing symptoms. The Alfalfa mosaic virus (AMV) was suspected of to be involved in this disease. Forty plant samples from symptomatic eggplants and 10 leaf samples with no symptoms were collected. The samples were tested by double antibody sandwich ELISA (DAS-ELISA) using AMV-IgG. Six of the 40 symptomatic leaf samples tested positive for AMV, while, DAS-ELISA found no AMV in the 10 leaf samples without symptoms. The AMV Egyptian isolate (AMV-Eggplant-EG) was biologically isolated from the six positive samples tested by DAS-ELISA and from the similar local lesions induced on Chenopodium amaranticolor and then re-inoculated in healthy Solanum melongena as a source of AMV-Eggplant-EG and confirmed by DAS-ELISA. Reverse transcription polymerase chain reaction (RT-PCR) assay with a pair of primers specific for coat protein (CP) encoding RNA 3 of AMV yielded an amplicon of 666 bp from infected plants of Solanum melongena with AMV-Eggplant-EG. The amplified PCR product was cloned and sequenced. Analysis of the AMV-Eggplant-EG sequence revealed 666 nucleotides (nt) of the complete CP gene (translating 221 amino acid (aa) residues). Analysis of phylogeny for nt and deduced aa sequences of the CP gene using the maximum parsimony method clustered AMV-Eggplant-EG in the lineage of Egyptian isolates (shark-EG, mans-EG, CP2-EG, and FRE-EG) with a high bootstrap value of 88% and 92%, respectively. In addition to molecular studies, melatonin (MTL) and salicylic acid (SA) (100 µM) were used to increase the resistance of eggplant to AMV- infection. Foliar spray with MLT and SA caused a significant increase in the morphological criteria (shoot, root length, number of leaves, leaf area, and leaf biomass), chlorophyll and carotenoid content, antioxidant enzymes, and gene expression of some enzymes compared to the infected plants. On the other hand, treatment with MLT and SA reduced the oxidative damage caused by AMV through the reduction of hydrogen peroxide, superoxide anions, hydroxyl radicals, and malondialdehyde. In conclusion, MLT and SA are eco-friendly compounds and can be used as antiviral compounds.

Mitigating effects of Bean yellow mosaic virus infection in faba bean using new carboxymethyl chitosan-titania nanobiocomposites.

Bean yellow mosaic virus (BYMV) is the main cause of the mosaic and malformation of many plants, worldwide. Thus, the triggering of plant systemic resistance against BYMV is of great interest. In this endeavor, we aimed to explore the capacity of new carboxymethyl chitosan-titania nanobiocomposites (NBCs, NBC1,2) to trigger faba bean plants resistance against BYMV. Effects of NBCs on faba bean (Vicia faba L.) disease severity (DS), growth parameters, and antioxidant defense system activity were investigated under BYMV stress. Noticeably that the DS in NBCs-treated faba bean was significantly reduced compared to untreated plants. Moreover, treatment with NBCs was remarkably increased growth indices, photosynthetic pigments, membrane stability index, and relative water content compared to challenge control. Additionally, enzymatic and non-enzymatic antioxidants and total soluble protein were significantly increased. Contrary, electrolyte leakage, hydrogen peroxide, and lipid peroxidation were reduced. Interestingly that NBC1 has higher efficacy than NBC2 in triggering plant immune-system against BYMV as indicated from DS percentage (DS = 10.66% and 19.33% in case of plants treated with NBC1 and NBC2, respectively). This could be attributed to the higher content of TNPs in NBC1 (21.58%) as compared to NBC2 (14.32%). Overall, NBCs offer safe and economic antiviral agents against BYMV.

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.

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 ß-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.

Biochemical, Serological, Molecular and Natural Host Studies on Tomato Chlorosis Virus in Egypt.

BACKGROUND AND OBJECTIVE: Tomato Chlorosis Virus (ToCV) is a white fly-transmitted and phloem-limited crinivirus reported in this study for the first time in Egypt. ToCV caused drastic reduction in tomato yield since 2013. The aim of this study is to characterize the virus incidence using biological, serological and molecular tools. MATERIAL AND METHODS: The B. tabaci MEAM1 white fly was used for virus isolation and propagation. Identity of ToCV , its natural hosts were confirmed with RT-PCR using a specific primer pair for ToCV-heat shock protein 70 homologue (HSP70h) gene, sequencing and phylogenetic studies. ToCV was purified using the innovative electro-elution technique. The induced antiserum for the Egyptian isolate of the virus (ToCV-Giza) was used for DAS-ELISA and dot blotting immuno-assays to evaluate the virus presence in tomato and other natural hosts. RESULTS: The ToCV-Giza isolate was donated an accession number "MH667315.1" from the GenBank. Blastx sequence analysis of the HSP70h gene indicated 97-99% of amino acid similarities with many tested ToCV isolates. Phylogenetic studies showed the clustering of all ToCV isolates including ToCV-Giza in a separate group from the other tested criniviruses. The virus had a UV spectrum of a nucleoprotein with Amax and Amin at 260 and 240 nm, respectively and A260/280 ratio of 1.33. Out of 52 different tested plant species within 22 families, 44 were positive hosts for ToCV. Thirty seven out of these 44 plant species were considered as new hosts for ToCV in the present study. These included Ammi majus and Coriandrum sativum (Apiaceae), cabbage (Brassicaceae), sweet potato (Convolvulaceae), melon, cucumber, luffa (Cucurbitaceae), soybean, cowpea, faba bean (Fabaceae), Egyptian and American Cotton (Malvaceae). Several ornamentals either herbal type or woody trees belonging to Acanthaceae, Amaranthaceae, Euophorbiaceae, Moraceae and Rubiaceae were also recognized for the first time as hosts for ToCV. CONCLUSION: The obtained results confirmed the wide distribution of ToCV in its natural hosts in Egypt. Hygienic measures including control of the virus vector and removing of natural hosts should be strictly implicated.