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Type III protein secretion systems of nitrogen-fixing rhizobia deliver effector proteins into leguminous host cells to promote or inhibit the nodule symbiosis. However, mechanisms underlying effector-triggered inhibition of nodulation remain largely unknown. Nodulation outer protein T (NopT) of Sinorhizobium sp. NGR234 is an effector protease related to the Pseudomonas effector Avirulence protein Pseudomonas phaseolicola B (AvrPphB). Here, we constructed NGR234 mutants producing different NopT variants and found that protease activity of NopT negatively affects nodulation of smooth crotalaria (Crotalaria pallida). NopT variants lacking residues required for autocleavage and subsequent lipidation showed reduced symbiotic effects and were not targeted to the plasma membrane. We further noticed that Sinorhizobium fredii strains possess a mutated nopT gene. Sinorhizobium fredii USDA257 expressing nopT of NGR234 induced considerably fewer nodules in soybean (Glycine max) cv. Nenfeng 15 but not in other cultivars. Effector perception was further examined in NopT-expressing leaves of Arabidopsis (Arabidopsis thaliana) and found to be dependent on the protein kinase Arabidopsis AvrPphB Susceptible 1 (AtPBS1) and the associated resistance protein Arabidopsis Resistance to Pseudomonas syringae 5 (AtRPS5). Experiments with Nicotiana benthamiana plants indicated that the soybean homolog GmPBS1-1 associated with AtRPS5 can perceive NopT. Further analysis showed that NopT cleaves AtPBS1 and GmPBS1-1 and thus can activate these target proteins. Insertion of a DKM motif at the cleavage site of GmPBS1-1 resulted in increased proteolysis. Nodulation tests with soybeans expressing an autoactive GmPBS1-1 variant indicated that activation of a GmPBS1-1-mediated resistance pathway impairs nodule formation in cv. Nenfeng 15. Our findings suggest that legumes face an evolutionary dilemma of either developing effector-triggered immunity against pathogenic bacteria or establishing symbiosis with suboptimally adapted rhizobia producing pathogen-like effectors.
Assuntos
Arabidopsis , Fabaceae , Rhizobium , Arabidopsis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Endopeptidases/metabolismo , Fabaceae/metabolismo , Peptídeo Hidrolases/metabolismo , Rhizobium/fisiologia , Glycine max/metabolismo , Simbiose/genéticaRESUMO
Downy mildew caused by oomycete pathogen Plasmopara viticola is a devastating disease of grapevine. P. viticola secretes an array of RXLR effectors to enhance virulence. One of these effectors, PvRXLR131, has been reported to interact with grape (Vitis vinifera) BRI1 kinase inhibitor (VvBKI1). BKI1 is conserved in Nicotiana benthamiana and Arabidopsis thaliana. However, the role of VvBKI1 in plant immunity is unknown. Here, we found transient expression of VvBKI1 in grapevine and N. benthamiana increased its resistance to P. viticola and Phytophthora capsici, respectively. Furthermore, ectopic expression of VvBKI1 in Arabidopsis can increase its resistance to downy mildew caused by Hyaloperonospora arabidopsidis. Further experiments revealed that VvBKI1 interacts with a cytoplasmic ascorbate peroxidase, VvAPX1, an ROS-scavenging protein. Transient expression of VvAPX1 in grape and N. benthamiana promoted its resistance against P. viticola, and P. capsici. Moreover, VvAPX1 transgenic Arabidopsis is more resistant to H. arabidopsidis. Furthermore, both VvBKI1 and VvAPX1 transgenic Arabidopsis showed an elevated ascorbate peroxidase activity and enhanced disease resistance. In summary, our findings suggest a positive correlation between APX activity and resistance to oomycetes and that this regulatory network is conserved in V. vinifera, N. benthamiana, and A. thaliana.
Assuntos
Arabidopsis , Oomicetos , Phytophthora , Vitis , Ascorbato Peroxidases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Phytophthora/metabolismo , Proteínas/metabolismo , Resistência à Doença/genética , Vitis/genética , Vitis/metabolismo , Doenças das Plantas/genética , Regulação da Expressão Gênica de PlantasRESUMO
A rich diversity of radiation-resistant (Rr) and desiccation-resistant (Dr) bacteria has been found in arid habitats of the world. Evidence from scientific research has linked their origin to reactive oxygen species (ROS) intermediates. Rr and Dr. bacteria of arid regions have the potential to regulate imbalance radicals and evade a higher dose of radiation and oxidation than bacterial species of non-arid regions. Photochemical-activated ROS in Rr bacteria is run through photo-induction of electron transfer. A hypothetical model of the biogeochemical cycle based on solar radiation and desiccation. These selective stresses generate oxidative radicals for a short span with strong reactivity and toxic effects. Desert-inhibiting Rr bacteria efficiently evade ROS toxicity with an evolved antioxidant system and other defensive pathways. The imbalanced radicals in physiological disorders, cancer, and lung diseases could be neutralized by a self-sustaining evolved Rr bacteria antioxidant system. The direct link of evolved antioxidant system with intermediate ROS and indirect influence of radiation and desiccation provide useful insight into richness, ecological diversity, and origin of Rr bacteria capabilities. The distinguishing features of Rr bacteria in deserts present a fertile research area with promising applications in the pharmaceutical industry, genetic engineering, biological therapy, biological transformation, bioremediation, industrial biotechnology, and astrobiology.
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Fluorescent carbon dots have been highly reported nanomaterials in recent times because of their excellent physio-chemical properties and various field of applications. Herein, a one-step hydrothermal approach was used to synthesize high biocompatible nitrogen and sulfur co-doped carbon dots, and examined their chemical sensing (Hg2+) and biological imaging properties. The N,S-CDs exhibited blue light, demonstrating a high quantum yield of up to 44.5% and excitation-independent fluorescent characteristics. Cytotoxicity was observed by CCK-8 assay using T-ca cells as a target source. Cell viability was recorded over 80% even after 7 days of treatment with a concentration up to 400 µg/mL, indicating low-toxicity of N,S-CDs. Notably, the bright blue fluorescence of N,S-CDs was quenched by introducing toxic Hg2+ ions into the solution. The detection limit was calculated to be about â¼3.5 nM, which is quite impressive compared to previous reports. Because of their low-toxicity, nano-size, and environment friendly properties, N,S-CDs could be excellent fluorescent agents for bio-imaging applications. The biological stability of fluorescent N,S-CDs was tested over time, and the findings were significant even after 8 days of incubation with T-ca cells. Because of good biocompatibility and bright fluorescence, N,S-CDs were suitable for in vivo imaging.
Assuntos
Mercúrio , Pontos Quânticos , Carbono/toxicidade , Carbono/química , Pontos Quânticos/toxicidade , Pontos Quânticos/química , Nitrogênio/química , Enxofre/química , Corantes Fluorescentes/toxicidade , Corantes Fluorescentes/química , Mercúrio/toxicidadeRESUMO
SARS-CoV-2 causes Coronavirus Disease 2019 (COVID-19), an infectious condition that can present none or one or more of these symptoms: fever, cough, headache, sore throat, loss of taste and smell, aches, fatigue and musculoskeletal pain. For the prevention of COVID-19, there are vaccines available including those developed by Pfizer, Moderna, Sinovac, Janssen, and AstraZeneca. Recent evidence has shown that some COVID-19-vaccinated individuals can occasionally develop as a potential side effect Guillain-Barre syndrome (GBS), a severe neurological autoimmune condition in which the immune response against the peripheral nerve system (PNS) can result in significant morbidity. GBS had been linked previously to several viral or bacterial infections, and the finding of GBS after vaccination with certain COVID-19, while rare, should alert medical practitioners for an early diagnosis and targeted treatment. Here we review five cases of GBS that developed in different countries after COVID-19 vaccination.
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan city of China in late December 2019 and identified as a novel coronavirus disease 2019 (COVID-19). On January 30, the World Health Organization (WHO) declared the coronavirus outbreak a global public health emergency. The rapid spread of the pathogen across the communities shock the entire population. As no existing therapy were available during the pandemic. Health professionals recommended frequent washing of hands with soap and alcohol-based sanitizers. Disinfectants were extensively sprayed to minimize the possibility of getting COVID-19. Despite the potential benefits of these germicidal agents against COVID-19. Alcohol-based hand sanitizers lead to dry skin, infection, and alcohol poisoning. Children are considered more prone to alcohol poisoning and other major health concern. Precautionary measures should be ensured to protect the community from the possible risk associated with disinfectants.
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BACKGROUND: Protocols for Agrobacterium rhizogenes-mediated hairy root transformation of the model legume Lotus japonicus have been established previously. However, little efforts were made in the past to quantify and improve the transformation efficiency. Here, we asked whether effectors (nodulation outer proteins) of the nodule bacterium Sinorhizobium sp. NGR234 can promote hairy root transformation of L. japonicus. The co-expressed red fluorescent protein DsRed1 was used for visualization of transformed roots and for estimation of the transformation efficiency. RESULTS: Strong induction of hairy root formation was observed when A. rhizogenes strain LBA9402 was used for L. japonicus transformation. Expression of the effector gene nopP in L. japonicus roots resulted in a significantly increased transformation efficiency while nopL, nopM, and nopT did not show such an effect. In nopP expressing plants, more than 65% of the formed hairy roots were transgenic as analyzed by red fluorescence emitted by co-transformed DsRed1. A nodulation experiment indicated that nopP expression did not obviously affect the symbiosis between L. japonicus and Mesorhizobium loti. CONCLUSION: We have established a novel protocol for hairy root transformation of L. japonicus. The use of A. rhizogenes LBA9402 carrying a binary vector containing DsRed1 and nopP allowed efficient formation and identification of transgenic roots.
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Air pollution (AP) is one of the leading causes of health risks because it causes widespread morbidity and mortality every year. Its impact on the environment includes acid rain and decreased visibility, but more importantly, it also has an impact on human health. The rise of COVID-19 demonstrates the cost of failing to manage AP. COVID-19 can be spread through the air, and atmospheric particulate matters (PMs) can create a good atmosphere for the long-distance spread of the virus. Moreover, these PMs can cause lung cell inflammation, thereby increasing sensitivity and the severity of symptoms in COVID-19 patients. In this study, we emphasized the potential role of PMs in the spread of COVID-19. The relationship among COVID-19, PMs, and angiotensin-converting enzyme 2 (ACE2) (receptor involved in virus entry into lung cells and inflammation) was also summarized.
Assuntos
Poluentes Atmosféricos/análise , Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/transmissão , Material Particulado/análise , Poluentes Atmosféricos/toxicidade , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/patologia , Humanos , Inflamação , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Material Particulado/toxicidade , SARS-CoV-2/fisiologiaRESUMO
BACKGROUND: It is essential to follow World Health Organization drug prescribing indicators to ensure rational prescribing in every health care setting. OBJECTIVE: To evaluate the prescriptions in the endocrinology department, according to the World Health Organization (WHO), recommended Ghana guidelines for diabetes management and rational therapy. METHODS: Concurrent and retrospective study design was used. The prescriptions of 100 diabetes patients were assessed for the type of medicine, dosage form, number of drugs, diabetes type, and deviation from standard guidelines. RESULTS: In a total of 100 prescriptions, the pattern was reported as injections (31%), antibiotics (18%), and metformin (31.1%). Half of the prescriptions were according to WHO guidelines. The number of drugs per prescription was reported at 5.2. A 70% rational approach was followed in prescribing. 81% of drugs were prescribed from the Essential Drug List (EDL) of the WHO. However, the National Essential Drug List (NEDL) was followed by 27%. The percentage of drugs on generic names was 0.7%. Eighty-four patients showed net improvement in health; 16 patients showed higher glycemic range at the time of discharge. CONCLUSION: The conclusion of the present study indicates that WHO Ghana guidelines were not followed up to the mark to improve the overall health status of diabetic patients and rational prescribing.
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Hospitals are the most prominent places for the growth and spread of bacteria which are resistant to the available antibiotics. This antibiotic resistance is due to the over and misuse of antibiotic dosages of a high-density of patient population which are in frequent interaction with inanimate items of the hospitals and the consequent risk of cross infection. Out of 1010 samples of the current study, 510 (50.49%) were culture positive of which 329 (64.5%) were Gram-positive while 181 (35.49%) Gram negative. The Gram positive bacterial isolates in the current study were; S. aureus and S. epidermidis while Gram negative were; Citrobacter, P. aeruginosa, Provedencia, E. coli, Proteus, Klebsiella, Shigella and Serratia. In the current study, 50 ESBL and 10 MBL producing isolates were obtained from inanimate objects. The ESBL positive isolates were highly resistant to MEM. Out of 50 ESBL, 2 isolates were resistant to DO, SXT and FEP while 1 was resistant to TZP and CN. The BlaTEM gene was detected in 22 and BlaCTX was detected in 19 ESBL producing isolates. Six of the MBL producing isolates were NDM positive while all of the isolates were AmpC negative. Most of the isolates had more than two resistant genes. Several classes of inhibitors have been reported for ß-lactamase TEM, Metallo-ß-lactamase and ß-lactamase proteins. Complex-base pharmacophore models were generated on the bases of co-crystalline ligands attached in the 3-D structures of the proteins. The validated pharmacophore models were used for the screening of ZINC drug like database. As a screening results 571 structurally diverse hits of Ethyl Boronic Acid, 866 on L-Captopril and 1020 of Nacubactam were mapped and filtered via Lipinski's rule of five. In conclusion, 30 hits (10 to each protein) having diverse structure and binding modes with all the three proteins active sites were selected as leading novel inhibitors. These selected novel inhibitors have different scaffolds and a strong possibility to act as an additional starting opinion in the development of new and potential inhibitors.
Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/microbiologia , Desenho de Fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/genética , Antibacterianos/síntese química , Antibacterianos/química , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento MolecularRESUMO
Current study was focused to examine the total bacterial count in packed and unpacked ice cream and kulfa collected from 12 different localities of Lahore. The bacterial colonies were isolated and grown on agar-broth media under sterilized conditions. Serial dilution technique was used to compose the replicates to get total viable count of bacteria. Results in case of packed ice cream samples indicated maximum (618 × 10-6 CFU/g) and minimum (79 × 10-6 CFU/g) bacterial count while in case of unpacked ice cream samples maximum and minimum bacterial count was 163 × 10-6 CFU/g and 71 × 10-6 CFU/g, respectively. Whereas in case of packed kulfa samples, maximum and minimum recorded bacterial count was 163 × 10-6 CFU/g and 72 × 10-6 CFU/g, respectively. The LM and SEM of the isolated bacteria were also performed for correct identification. Results indicated that the total bacterial count recorded in the samples exceeded the standard tolerable range which can lead to serious health damage of consumers.