Viral Disease Symptoms Research Articles

Induction of anti-viral genes mediated by humoral factors upon stimulation with Lactococcus lactis strain plasma results in repression of dengue virus replication in vitro

Dengue is a mosquito-borne disease caused by dengue virus (DENV) infection. There is currently no effective vaccine or antiviral treatment available against DENV. In previous studies, we showed that Lactococcus lactis strain Plasma (LC-Plasma) could activate plasmacytoid dendritic cells, which play an important role against virus infection. LC-Plasma administration ameliorated symptoms of viral diseases and its effect appeared to be associated with IFN-α induction. However the precise mechanism of LC-Plasma protection remained unclear. In this study, we investigated the effects of LC-Plasma-induced humoral factors on DENV replication using HepG2 cells as an in vitro infection model. When HepG2 cells were preincubated with supernatants of LC-Plasma-stimulated bone marrow-derived dendritic cells, the replication of DENV was significantly inhibited in a dose dependent manner and its activity was evident regardless of the DENV serotype. In addition, the expression of interferon-stimulated genes, including ISG15, IFITM-1, MxA, RSAD2, and RyDEN, was significantly upregulated by humoral factors. We also compared the effects of representative strains of lactic acid bacteria and found that the ability to prevent DENV replication was unique to LC-Plasma. In addition, it was revealed that both anti-DENV replication activity and ISG induction depended on type I IFN rather than type III IFN signaling. Taken together, since LC-Plasma induces, in a more natural form, potent anti-DENV replication activities irrespective of viral serotypes via induction of type I IFN, LC-Plasma could be safely used as a prophylactic anti-DENV option.

Serologic Markers for Ebolavirus Among Healthcare Workers in the Democratic Republic of the Congo.

Healthcare settings have played a major role in propagation of Ebola virus (EBOV) outbreaks. Healthcare workers (HCWs) have elevated risk of contact with EBOV-infected patients, particularly if safety precautions are not rigorously practiced. We conducted a serosurvey to determine seroprevalence against multiple EBOV antigens among HCWs of Boende Health Zone, Democratic Republic of the Congo, the site of a 2014 EBOV outbreak. Interviews and specimens were collected from 565 consenting HCWs. Overall, 234 (41.4%) of enrolled HCWs were reactive to at least 1 EBOV protein: 159 (28.1%) were seroreactive for anti-glycoprotein immunoglobulin G (IgG), 89 (15.8%) were seroreactive for anti-nucleoprotein IgG, and 54 (9.5%) were VP40 positive. Additionally, sera from 16 (2.8%) HCWs demonstrated neutralization capacity. These data demonstrate that a significant proportion of HCWs have the ability to neutralize virus, despite never having developed Ebola virus disease symptoms, highlighting an important and poorly documented aspect of EBOV infection and progression.

Larval Growth of Great Mormon Butterfly (Papilio memnon memnon) Fed with Citrus aurantifolia Leaves

Papilio memnon memnon is one of butterflies that has a specific host plant to lay eggs and for its larval growth, one of the host plants is a Citrus. Citrus leaf plays an important role for the growth of butterflies during the larval phase. The aim of this research is to know nutritional composition of C. aurantifolia leaves, the growth of Papilio memnon memnon larvae which is fed with lime leaf (Citrus aurantiifolia) on Laboratory scale and other factors that influences its growth. The research method used was experiment, design of Completely Random Design with larvae feed as independent variable and larvae growth as dependent variable. The data were analyzed descriptively including body length, larvae body weight, and head capsule width followed by ANOVA and t-test. The results showed that the feeding of C. aurantiifolia leaves had no significant effect on body weight or body length of P. m memnon in all larval phases, from instar 1 to instar 5, but significantly affect the width of larval capsule cap at instar 4 and instar to 5. In the development phase, P. m. memnon larvae found symptoms of Nuclear Polyhedrosis Virus (NPV) disease that causes the death of larvae.

Identificación y caracterización molecular del genoma completo de tres virus en cultivos de lulo (Solanum quitoense) de Antioquia (Colombia)

El lulo es uno de los renglones agrícolas más promisorios para la región andina de Colombia, gracias a sus excelentes características organolépticas y a su potencial para el procesamiento industrial. En Antioquia, se ha observado en los últimos años la presencia de plantas con síntomas de enfermedades virales, que incluyen amarillamientos intervenales, mosaicos y deformación de brotes. En este trabajo, se evaluó dicha situación en un grupo (bulk) de muestras foliares de plantas sintomáticas de lulo obtenidas en municipios del Oriente Antioqueño, utilizando la metodología molecular de secuenciación de nueva generación (NGS), y la confirmación posterior por RT-PCR. Los análisis bioinformáticos de las secuencias obtenidas (10.777.822 de reads) indicaron la presencia de tres virus de RNA en el transcriptoma evaluado; el Cucumber mosaic virus (CMV) se encontró en mayores niveles de infección (40,4% del total de reads), mientras que los otros virus correspondieron al Potato yellow vein virus (PYVV) (0,09%) y Alstroemeria necrotic streak virus (ANSV) (0,06%), siendo posible obtener sus genomas completos. La ocurrencia de los tres virus fue confirmada en plantas individuales de lulo mediante pruebas de RT-PCR/secuenciación Sanger con cebadores específicos diseñados a partir de los datos de NGS (ANSV y CMV), o con cebadores reportados previamente (PYVV). En el futuro será necesario evaluar los efectos de estos virus sobre los rendimientos, longevidad de plantas y calidad de semilla en los cultivos de lulo en el país, así como sus métodos de transmisión, rango de hospedantes y sintomatología específica.

Improved apple latent spherical virus-induced gene silencing in multiple soybean genotypes through direct inoculation of agro-infiltrated Nicotiana benthamiana extract

BackgroundVirus induced gene silencing (VIGS) is a powerful genomics tool for interrogating the function of plant genes. Unfortunately, VIGS vectors often produce disease symptoms that interfere with the silencing phenotypes of target genes, or are frequently ineffective in certain plant genotypes or tissue types. This is especially true in crop plants like soybean [Glycine max (L.) Merr]. To address these shortcomings, we modified the inoculation procedure of a VIGS vector based on Apple latent spherical virus (ALSV). The efficacy of this new procedure was assessed in 19 soybean genotypes using a soybean Phytoene desaturase (GmPDS1) gene as the VIGS target. Silencing of GmPDS1 was easily scored as photo-bleached leaves and/or stems.ResultsIn this report, the ALSV VIGS vector was modified by mobilizing ALSV cDNAs into a binary vector compatible with Agrobacterium tumefaciens-mediated delivery, so that VIGS-triggering ALSV variants could be propagated in agro-infiltrated Nicotiana benthamiana leaves. Homogenate of these N. benthamiana leaves was then applied directly onto the unifoliate of young soybean seedlings to initiate systemic gene silencing. This rapid inoculation method bypassed the need for a particle bombardment apparatus. Among the 19 soybean genotypes evaluated with this new method, photo-bleaching indicative of GmPDS1 silencing was observed in nine, with two exhibiting photo-bleaching in 100% of the inoculated individuals. ALSV RNA was detected in pods, embryos, stems, leaves, and roots in symptomatic plants of four genotypes.ConclusionsThis modified protocol allowed for inoculation of soybean plants via simple mechanical rubbing with the homogenate of N. benthamiana leaves agro-infiltrated with ALSV VIGS constructs. More importantly, inoculated plants showed no apparent virus disease symptoms which could otherwise interfere with VIGS phenotypes. This streamlined procedure expanded this functional genomics tool to nine soybean genotypes.

Seasonal Influenza Split Vaccines Confer Partial Cross-Protection against Heterologous Influenza Virus in Ferrets When Combined with the CAF01 Adjuvant.

Influenza epidemics occur annually, and estimated 5–10% of the adult population and 20–30% of children will become ill from influenza infection. Seasonal vaccines primarily work through the induction of neutralizing antibodies against the principal surface antigen hemagglutinin (HA). This important role of HA-specific antibodies explains why previous pandemics have emerged when new HAs have appeared in circulating human viruses. It has long been recognized that influenza virus-specific CD4(+) T cells are important in protection from infection through direct effector mechanisms or by providing help to B cells and CD8(+) T cells. However, the seasonal influenza vaccine is poor at inducing CD4(+) T-cell responses and needs to be combined with an adjuvant facilitating this response. In this study, we applied the ferret model to investigate the cross-protective efficacy of a heterologous trivalent influenza split-virion (TIV) vaccine adjuvanted with the CAF01 adjuvant, with proven ability to induce CD4(+) T-cell and antibody responses in mice, ferrets, pigs, primates, and humans. Our results indicate that CAF01-adjuvanted vaccine induces HA inhibition (HAI)-independent protection after heterologous challenge, manifested as reduced viral load and fever. On the other hand, we observe increased inflammation in the airways and more neutrophil and mononuclear cell infiltration in these ferrets when compared with optimally protected animals, i.e., ferrets receiving the same vaccine but a homologous challenge. This suggest that HAI-independent immunity induced by TIV + CAF01 can reduce viral shedding and systemic disease symptoms, but does not reduce local inflammation in the nasal cavity.

STUDY OF CUCUMBER MOSAIC VIRUS GENE EXPRESSION IN CAPSICUM ANNUUM

Cucumber mosaic virus (CMV) is a plant pathogenic virus in the genus Cucumovirus, family Bromoviridae. It has the potential and reputation of having the widest host range of any known plant virus including monocotyledons and dicotyledons, herbaceous plants, shrubs and trees. CMV is one of the major diseases in Capsicum annum (chilli). Chilli plant samples exhibiting virus-like disease symptoms were collected from Taman Pertanian Indera Mahkota (location 1) and Greenhouse 12 of Horticulture Research Centre, Serdang (location 2). Viral disease was detected based on symptoms like mosaic-mottling, yellow ringspots and cholorotic that appeared on the leaves. The isolation of total RNA was done by using Vivantis GF-1 total RNA extraction kit. RT-PCR technique was used to detect the presence of virus disease symptoms gene in chillies. Identification of causal agents was based on cDNA amplified product size, using virus-specific oligonucleotides. Actin was used as the internal PCR control. The product size of the DNA fragment was 315 bp. From RT-PCR, the expression of CMV can be detected in chilli plants that exhibited the virus-like disease symptoms. This research revealed that some of the chilli plants at the Taman Pertanian Indera Mahkota and Greenhouse 12 of Horticulture Research Centre have been affected by this viral disease.

First Report of Tomato spotted wilt virus Infecting Soybean in Korea

The soybean (Glycine max (L.) Merr.) is a legume with worldwide popularity which is native to East Asia. Soybeans are grown for their edible beans and used to create soy vegetable oil and fermented soy foods. To date, a large number of viruses that can infect soybeans have been identified (Hill et al. 2014). Tomato spotted wilt virus (TSWV) is a member of the genus Tospovirus in the family Bunyaviridae. TSWV causes serious diseases in many economically important plants including dicots and monocots. TSWV has been identified in soybeans in Iran (Golnaraghi et al. 2001) and Georgia (Nischwitz et al. 2006). In 2016, we collected soybean leaf samples displaying viral disease symptoms such as chlorotic, mosaic, mottling, stunting, and yellowing. 168 samples were collected and categorized by the region that they were collected in. Eight different libraries representing individual provinces were prepared for RNA sequencing using the TruSeq RNA Library Prep Kit v2 in accordance with the manufacturer's instruction...

A tale of survival: Molecular defense mechanisms of soybean to overcome Soybean mosaic virus infection

Plant viruses represent some of the greatest contributors to crop losses worldwide. Viral disease symptoms often include mosaic leaf patterns, crinkled and yellowed leaves, plant stunting and even necrosis. As intracellular pathogens, viruses hijack host cell machinery for their own replication, which can elicit dramatic changes to their hosts at the cellular, molecular and physiological levels. Soybean mosaic virus (SMV) is a widely distributed soybean pathogen, which can cause severe stunting and yield losses to infected plants. A better understanding of the underlying interactions between SMV and soybean will aid in the establishment of disease management plans. In these studies, we implemented high throughput RNA sequencing approaches and targeted metabolite profiling to describe transcriptomic and metabolic changes occurring in soybean leaves ten days post-infection with SMV. A massive defense response was detected by the increased accumulation of transcripts associated with biotic stresses, including those involved in pathogen recognition, autophagy and defense inductors. Moreover, significant decreases in expression were detected for transcripts associated with fundamental growth and development processes, such as nutrient transport and photosynthesis. At the metabolomic level, significant changes were identified in correspondence with viral infection, particularly in amino acid concentrations. Overall, it appears as though SMV inoculated plants reroute their limited resources as a survival strategy, favoring defense over plant development.

RNAi-derived transgenic resistance to Mungbean yellow mosaic India virus in cowpea.

Cowpea is an important grain legume crop of Africa, Latin America, and Southeast Asia. Leaf curl and golden mosaic diseases caused by Mungbean yellow mosaic India virus (MYMIV) have emerged as most devastating viral diseases of cowpea in Southeast Asia. In this study, we employed RNA interference (RNAi) strategy to control cowpea-infecting MYMIV. For this, we generated transgenic cowpea plants harbouring three different intron hairpin RNAi constructs, containing the AC2, AC4 and fusion of AC2 and AC4 (AC2+AC4) of seven cowpea-infecting begomoviruses. The T0 and T1 transgenic cowpea lines of all the three constructs accumulated transgene-specific siRNAs. Transgenic plants were further assayed up to T1 generations, for resistance to MYMIV using agro-infectious clones. Nearly 100% resistance against MYMIV infection was observed in transgenic lines, expressing AC2-hp and AC2+AC4-hp RNA, when compared with untransformed controls and plants transformed with empty vectors, which developed severe viral disease symptoms within 3 weeks. The AC4-hp RNA expressing lines displayed appearance of milder symptoms after 5 weeks of MYMIV-inoculation. Northern blots revealed a positive correlation between the level of transgene-specific siRNAs accumulation and virus resistance. The MYMIV-resistant transgenic lines accumulated nearly zero or very low titres of viral DNA. The transgenic cowpea plants had normal phenotype with no yield penalty in greenhouse conditions. This is the first demonstration of RNAi-derived resistance to MYMIV in cowpea.

Study of viruses co-infecting white clover (Trifolium repens) in China

Globally, white clover (Trifolium repens L.) is commonly infected by plant viruses. It is grown at gardens, roadsides, and public areas as ornamental plants in northern China. Some leaves present disease symptoms that are similar to those of virus infection. However, to our knowledge, no records are available from China regarding white clover (Trifolium repens L.) virus co-infection. To determine the viral species that infect white clover in China, plant samples with virus disease symptoms were collected and virion morphology and ultrastructure morphology of co-infected plants were observed by electron microscopy; viruses were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription PCR (RT-PCR). Virus co-infection was studied by double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) and real-time fluorescence quantitative PCR (RT-qPCR) after rub-inoculation of virus-free white clover planted in a growth chamber (25°C) with a photoperiod of 16 h, using single or several purified virions. Results showed that there were six types of symptoms, including those of shrinking mosaic, shrinking and macular mosaic, severe mottle mosaic, yellow macular mosaic, shrinkage chlorisis, and ring plaque and ring stria. The incidence rates for each symptom were 20.93, 1.48, 16.85, 59.07, 1.30, and 0.37%, respectively, based on the field investigation. Two types of viral pathogens were identified as Alfalfa mosaic virus (AMV) and White clover mosaic virus (WCMV). In mesophyll cells, virus particles with bacilliform virions formed aggregates and linear virions were bundle shaped. The detection rate of AMV was 100% in white clover samples by DAS-ELISA and RT-PCR detection, whereas that of WCMV was 83.33%. The co-infection rate was 83.33%. The relative contents of AMV and WCMV were significantly increased by 5.897- and 3.515-fold upon co-infection, when compared to that with single virus infection. We observed larger starch particles and fewer or collapsed chloroplast grana in co-infected plants; in addition, vacuoles were twisted and smaller, compared to those of healthy plants. To our knowledge, this is the first report of co-infection by AMV and WCMV in white clover, which has caused severe mosaicism and ultrastructure lesions in co-infected plants in China.

First Report of Grapevine fabavirus in Diverse Vitis Species in Korea

HomePlant DiseaseVol. 101, No. 10First Report of Grapevine fabavirus in Diverse Vitis Species in Korea PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Grapevine fabavirus in Diverse Vitis Species in KoreaY. Jo, M. K. Song, H. Choi, J. S. Park, J. W. Lee, and W. K. ChoY. JoSearch for more papers by this author, M. K. SongSearch for more papers by this author, H. ChoiSearch for more papers by this author, J. S. ParkSearch for more papers by this author, J. W. Lee†Corresponding authors: J. W. Lee, E-mail Address: [email protected]; and W. K. Cho, E-mail Address: [email protected]Search for more papers by this author, and W. K. Cho†Corresponding authors: J. W. Lee, E-mail Address: [email protected]; and W. K. Cho, E-mail Address: [email protected]Search for more papers by this authorAffiliationsAuthors and Affiliations Y. Jo , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea M. K. Song , Grape Research Institute, Chungbuk Agricultural Research and Extension Services, Okcheon, 29017, Republic of Korea H. Choi , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea J. S. Park J. W. Lee † , Grape Research Institute, Chungbuk Agricultural Research and Extension Services, Okcheon, 29017, Republic of Korea W. K. Cho † , Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea. Published Online:26 Jul 2017https://doi.org/10.1094/PDIS-04-17-0513-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Grapevine fabavirus (GFabV) is a novel virus that has been recently identified from two Japanese table grapes, Vitis vinifera cvs. Black Beet (BB) and Nagano Purple (NP), derived from South Korea in 2013 (Al Rwahnih et al. 2016). GFabV is a putative member of the genus Fabavirus in the family Secoviridae. The genome of GFabV consists of two RNA fragments named RNA1 and RNA2. To date, GFabV has been identified in North America, India, South Korea, and China (Al Rwahnih et al. 2016; Fan et al. 2017). In 2016, we sampled grapevine leaves from 16 individual grapevine plants representing 12 different grapevine cultivars. Except for a Shine Muscat (V. labruscana Bailey × V. vinifera) plant sampled from a vineyard in Okcheon, all 15 grapevine plants were grown in the Grape Research Institute. Only two grapevine plants of the Shine Muscat cultivar showed viral disease symptoms such as leaf malformations, vein clearing, and yellowing, whereas the other 14 plants did not display any visible disease symptoms. Sixteen libraries were paired-end sequenced using Illumina’s HiSeq 2000 followed by bioinformatics analyses as described previously (Jo et al. 2016). We identified 143 GFabV-associated contigs (75 contigs for RNA1 and 68 contigs for RNA2) ranging from 215 to 5,804 bp from 11 libraries. The GFabV-infected grapevine plants were as follows: Campbell Early (V. labruscana) (two plants), 188-08 (V. monticola × V. riparia) (two plants), Jaok (Vitis hybrid), Shine Muscat (two plants), Chungporang (Vitis hybrid), Okrang (Vitis hybrid), Chungrang (Vitis hybrid), and Jarang (V. vinifera). We assembled two nearly complete genomes for isolate 188-08 (5,675-nt RNA1 and 3,069-nt RNA2) and isolate Shine Muscat (5,804-nt RNA1 and 3,137-nt RNA2). However, four V. vinifera cultivars (i.e., Alicante, Cabernet franc, Cabernet Sauvignon, and Chardonnay) were not infected by GFabV. To confirm the NGS results, we carried out RT-PCR using known GFab-RNA1-specific primers and GFab-RNA2-specific primers (Al Rwahnih et al. 2016). The 642-bp products were amplified from seven cultivars but not from Shine Muscat using GFab-RNA1-specific primers. The 628-bp products were amplified from only two plants of Shine Muscat using GFab-RNA2-specific primers. This result suggests that at least two different primer pairs should be applied to detect GFabV due to their sequence diversity. The 642-bp amplified products from 188-08 and Campbell Early were cloned in the pGEM-T-Easy Vector (Promega, Wisconsin, U.S.A.) followed by Sanger sequencing. The amplified sequences (GenBank KY808370 and KY808371) confirmed that both isolates shared 99% of the nucleotide identity with the known isolate NP. Based on our result, diverse Vitis spp. including V. labruscana and other Vitis hybrids grown in the Grapevine Research Institute except imported grapevine cultivars belonging to V. vinifera have been infected by GFabV. Our results revealed a high prevalence of GFabV in important grapevine cultivars in Korea. Furthermore, a majority of grapevine plants infected by GFabV was asymptomatic; however, the possible role of the isolates of GFabV from Shine Muscat showing disease symptoms should be further studied. Taken together, this is the first report of GFabV infecting diverse Vitis spp. in Korea.

Longitudinal peripheral blood transcriptional analysis of a patient with severe Ebola virus disease.

The 2013-2015 outbreak of Ebola virus disease in Guinea, Liberia, and Sierra Leone was unprecedented in the number of documented cases, but there have been few published reports on immune responses in clinical cases and their relationships with the course of illness and severity of Ebola virus disease. Symptoms of Ebola virus disease can include severe headache, myalgia, asthenia, fever, fatigue, diarrhea, vomiting, abdominal pain, and hemorrhage. Although experimental treatments are in development, there are no current U.S. Food and Drug Administration-approved vaccines or therapies. We report a detailed study of host gene expression as measured by microarray in daily peripheral blood samples collected from a patient with severe Ebola virus disease. This individual was provided with supportive care without experimental therapies at the National Institutes of Health Clinical Center from before onset of critical illness to recovery. Pearson analysis of daily gene expression signatures revealed marked gene expression changes in peripheral blood leukocytes that correlated with changes in serum and peripheral blood leukocytes, viral load, antibody responses, coagulopathy, multiple organ dysfunction, and then recovery. This study revealed marked shifts in immune and antiviral responses that preceded changes in medical condition, indicating that clearance of replicating Ebola virus from peripheral blood leukocytes is likely important for systemic viral clearance.

Establishing a Timeline to Discontinue Routine Testing of Asymptomatic Pregnant Women for Zika Virus Infection - American Samoa, 2016-2017.

The first patients with laboratory-confirmed cases of Zika virus disease in American Samoa had symptom onset in January 2016 (1). In response, the American Samoa Department of Health (ASDoH) implemented mosquito control measures (1), strategies to protect pregnant women (1), syndromic surveillance based on electronic health record (EHR) reports (1), Zika virus testing of persons with one or more signs or symptoms of Zika virus disease (fever, rash, arthralgia, or conjunctivitis) (1-3), and routine testing of all asymptomatic pregnant women in accordance with CDC guidance (2,3). All collected blood and urine specimens were shipped to the Hawaii Department of Health Laboratory for Zika virus testing and to CDC for confirmatory testing. Early in the response, collection and testing of specimens from pregnant women was prioritized over the collection from symptomatic nonpregnant patients because of limited testing and shipping capacity. The weekly numbers of suspected Zika virus disease cases declined from an average of six per week in January-February 2016 to one per week in May 2016. By August, the EHR-based syndromic surveillance (1) indicated a return to pre-outbreak levels. The last Zika virus disease case detected by real-time, reverse transcription-polymerase chain reaction (rRT-PCR) occurred in a patient who had symptom onset on June 19, 2016. In August 2016, ASDoH requested CDC support in assessing whether local transmission had been reduced or interrupted and in proposing a timeline for discontinuation of routine testing of asymptomatic pregnant women. An end date (October 15, 2016) was determined for active mosquito-borne transmission of Zika virus and a timeline was developed for discontinuation of routine screening of asymptomatic pregnant women in American Samoa (conception after December 10, 2016, with permissive testing for asymptomatic women who conceive through April 15, 2017).

RNAi-Mediated Simultaneous Resistance Against Three RNA Viruses in Potato.

RNA interference (RNAi) technology has been successfully applied in stacking resistance against viruses in numerous crop plants. During RNAi, the production of small interfering RNAs (siRNAs) from template double-standard RNA (dsRNA) derived from expression constructs provides an on-switch for triggering homology-based targeting of cognate viral transcripts, hence generating a pre-programmed immunity in transgenic plants prior to virus infection. In the current study, transgenic potato lines (Solanum tuberosum cv. Desiree) were generated, expressing fused viral coat protein coding sequences from Potato virus X (PVX), Potato virus Y (PVY), and Potato virus S (PVS) as a 600-bp inverted repeat expressed from a constitutive 35S promoter. The expression cassette (designated Ec1/p5941) was designed to generate dsRNAs having a hairpin loop configuration. The transgene insertions were confirmed by glufosinate resistance, gene-specific PCR, and Southern blotting. Regenerated lines were further assayed for resistance to virus inoculation for up to two consecutive crop seasons. Nearly 100% resistance against PVX, PVY, and PVS infection was observed in transgenic lines when compared with untransformed controls, which developed severe viral disease symptoms. These results establish the efficacy of RNAi using the coat protein gene as a potential target for the successful induction of stable antiviral immunity in potatoes.

Inducible transgenic tobacco system to study the mechanisms underlying chlorosis mediated by the silencing of chloroplast heat shock protein 90.

Chlorosis is one of the most common symptoms of plant diseases, including those caused by viruses and viroids. Recently, a study has shown that Peach latent mosaic viroid (PLMVd) exploits host RNA silencing machinery to modulate the virus disease symptoms through the silencing of chloroplast-targeted heat shock protein 90 (Hsp90C). To understand the molecular mechanisms of chlorosis in this viroid disease, we established an experimental system suitable for studying the mechanism underlying the chlorosis induced by the RNA silencing of Hsp90C in transgenic tobacco. Hairpin RNA of the Hsp90C-specific region was expressed under the control of a dexamethasone-inducible promoter, resulted in the silencing of Hsp90C gene in 2days and the chlorosis along with growth suppression phenotypes. Time course study suggests that a sign of chlorosis can be monitored as early as 2days, suggesting that this experimental model is suitable for studying the molecular events taken place before and after the onset of chlorosis. During the early phase of chlorosis development, the chloroplast- and photosynthesis-related genes were downregulated. It should be noted that some pathogenesis related genes were upregulated during the early phase of chlorosis in spite of the absence of any pathogen-derived molecules in this system.

Detecting Local Zika Virus Transmission in the Continental United States: A Comparison of Surveillance Strategies

Introduction:The 2015-2017 Zika virus (ZIKV) epidemic in the Americas has driven efforts to strengthen surveillance systems and to develop interventions, testing, and travel recommendations. In the continental U.S. and Hawaii, where limited transmission has been observed, detecting local transmission is a key public health objective. We assessed the effectiveness of three general surveillance strategies for this situation: testing all pregnant women twice during pregnancy, testing blood donations, and testing symptomatic people who seek medical care in an emergency department (ED).Methods:We developed a simulation model for each surveillance strategy and simulated different transmission scenarios with varying population sizes and infection rates. We then calculated the probability of detecting transmission, the number of tests needed, and the number of false positive test results.Results:The probability of detecting ZIKV transmission was highest for testing ED patients with Zika symptoms, followed by pregnant women and blood donors, in that order. The magnitude of the difference in probability of detection between strategies depended on the incidence of infection. Testing ED patients required fewer tests and resulted in fewer false positives than surveillance among pregnant women. The optimal strategy identified was to test ED patients with at least two Zika virus disease symptoms. This case definition resulted in a high probability of detection with relatively few tests and false positives.Discussion:In the continental U.S. and Hawaii, where local ZIKV transmission is rare, optimizing the probability of detecting infections while minimizing resource usage is particularly important. Local surveillance strategies will be influenced by existing public health system infrastructure, but should also consider the effectiveness of different approaches. This analysis demonstrated differences across strategies and indicated that testing symptomatic ED patients is generally a more efficient strategy for detecting transmission than routine testing of pregnant women or blood donors.

Zika Virus: A threat to global public health- WHO Framework Review

Zika virus is an emerging mosquito-borne virus that was first identified in Uganda in 1947 in rhesus monkeys through a monitoring network of sylvatic yellow fever. Background Zika virus is an emerging viral disease that is transmitted through the bite of an infected mosquito, primarily Aedes aegypti, the same vector that transmits chikungunya, dengue and yellow fever. Zika has a similar epidemiology, clinical presentation and transmission cycle in urban environments as chikungunya and dengue, although it generally causes milder illness. Symptoms of Zika virus disease include fever, skin rash, conjunctivitis, muscle and joint pain, malaise and headache, which normally last for 2 to 7 days. National health authorities have reported an observed increase of Guillain-Barré syndrome (GBS) and microcephaly. Today the Brazilian national authorities estimate 500,000 to 1,500,000 cases of Zika virus disease. In October 2015, both Colombia and Cape Verde, off the coast of Africa, reported their first outbreaks of the virus. As of 22 January 2016 Colombia had reported 16,419 cases, El Salvador 3,836 cases and Panama 99 cases of Zika virus disease. As of 12 February, a total of 39 countries in multiple regions have reported autochthonous (local) circulation of Zika virus, and there is evidence of local transmission in six additional countries. As per the health authorities India has not reported any case of Zika Virus. Health Authorities in India is taking adequate precaution to keep Zika Virus outside the India.

English

Cucurbit vegetables play important role as sources of vitamins, micronutrients and income. However, their production is constrained, inter alia, by the virus diseases. Cucumber mosaic virus (CMV; Cucumovirus), Zucchini yellow mosaic virus (ZYMV; Potyvirus) and Watermelon mosaic virus (WMV; Potyvirus) are the major causal agents of devastating virus diseases of the cucurbits. Disease symptoms similar to those caused by these viruses were observed in cucurbits in the coastal lowland of Tanzania. To determine what caused these symptoms, leaf samples were collected from 223 cultivated and wild cucurbit plants and virus infections detected using Double Antibody Sandwich Enzyme-linked immunosorbent Assay (DAS-ELISA). Visual incidence of virus disease symptoms ranged from 0.0 to 90.0% but ELISA test for CMV, ZYMV and WMV revealed the range of 0 to 80%. The highest incidence of the virus infections was that of WMV (33.0%) in Cucumis sativus. The highest incidence of ZYMV and CMV were 10.4 and 13.4% in Citrullus lanatus and Cucurbita pepo, respectively. These viruses were found infecting cucurbits in single, co- and triple infections. Moreover, these viruses were also detected in the wild plants, Cucumis hystrix and Luffa aegyptiaca and in cultivated Vigna unguiculata. ZYMV was the commonest virus in wild plants. Yield losses caused by virus diseases remain undetermined for cucurbits in Tanzania but co- and triple virus infections have implication on disease severity and evolution of these viruses and may pose challenge for breeding for resistance. Key words: Cucurbit virus diseases, DAS-ELISA, virus mixed infections.

Primer reporte de un begomovirus presente en maracuyá amarillo [Passiflora edulis f. flavicarpa (Degener)] en Valle del Cauca, Colombia

El maracuyá amarillo es un cultivo de importancia económica para el Valle del Cauca, pero en los últimos años ha presentado una reducción de hasta un 80% en la producción debido a problemas virales. El objetivo de este estudio fue detectar y caracterizar molecularmente un Begomovirus que está afectando cultivos de maracuyá amarillo localizados en dos zonas del Valle del Cauca, La Unión y Palmira. Se colectaron hojas de maracuyá con síntomas típicos de enfermedad viral, se purificó su DNA genómico y se identificó la presencia de Begomovirus bipartitas mediante PCR empleando cebadores degenerados. Cuatro genomas virales parciales obtenidos de muestras vegetales colectadas en La Unión y Palmira fueron clonados, secuenciados y analizados. El análisis de secuencia del Begomovirus que está afectando maracuyá amarillo en Colombia con otros reportados en la base de datos, indica que éste es un Begomovirus bipartita nuevo que tiene una relación cercana con un Begomovirus aislado de frijol y no tiene ninguna relación con Passionfruit severe leaf distortion virus, un Begomovirus reportado previamente afectando maracuyá amarillo en Brasil. Para nuestro conocimiento, este es el primer reporte de un nuevo Begomovirus bipartita que afecta maracuyá amarillo en Colombia y es diferente de otros Begomovirus previamente reportados a nivel mundial afectando este cultivo.