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Variation in seed transmission of cowpea viruses between single and multiple infections Texte intégral
2024
Ogunsola, K.E. | Kumar, P.L.
Seed transmission (ST) plays an important role in virus dispersion and disease epidemiology. Many viruses infecting cowpea are known to be seed-transmitted. This study evaluated the rate of virus ST in cowpea varieties inoculated under screenhouse conditions (SC) with bean common mosaic virus-blackeye cowpea mosaic strain (BCMV-BlCM), Southern bean mosaic virus (SBMV) and cucumber mosaic virus (CMV) under single and multiple-infections. Up to 50 seeds harvested from the virus-infected plants of each variety per treatment were used for the grow-out test under insect-proof SC. Data were recorded on seed germination (SG), symptoms in seedlings, and virus ST. The leaf samples were tested for viruses by enzyme-linked immunosorbent assay (ELISA) and reverse-transcription polymerase chain reaction (RT-PCR). The SG rate was 78 ± 2.8–100 ± 0% in all treatments. A total of 1.5% of 1,604 seedlings infected singly showed symptoms, whereas in diagnostics testing, viruses were detected in 2.6% of plants, indicating occurrence of asymptomatic ST. The highest rate of transmission observed for single infections was 17% CMV in IT98K-133–1-1, 17.1% BCMV-BlCM in IT98K-503–1, and 2.3% SBMV in IT99K-1060. The highest CMV frequency under coinfection was 22.2% in plants inoculated (PI) with SBMV + CMV, 4.2% for BCMV-BlCM in PI with BCMV-BlCM + CMV and 2.3% for SBMV in PI with BCMV-BlCM + SBMV + CMV. This study indicated high variation in the rates of ST based on cultivar and virus type, and for each virus under mixed-infection conditions. Diagnostic confirmation detected a higher percentage of seed-transmitted viruses compared to visual assessment, warranting the need for diagnostics for the reliable detection of seed-transmitted viruses.
Afficher plus [+] Moins [-]Detection and diversity of maize yellow mosaic virus infecting maize in Nigeria Texte intégral
2019
Yahaya, A. | Dangora, D.B. | Alabi, O.J. | Zongoma, A.M. | Kumar, P. Lava
Detection and diversity of maize yellow mosaic virus infecting maize in Nigeria Texte intégral
2019
Yahaya, A. | Dangora, D.B. | Alabi, O.J. | Zongoma, A.M. | Kumar, P. Lava
Maize yellow mosaic virus (MaYMV; genus Polerovirus; family Luteoviridae) was recently characterized from maize in China and subsequently detected in mixed infection with sugarcane mosaic virus (genus Potyvirus; family Potyviridae) in sugarcane and itch grass in Nigeria. This study was conducted to understand the status and genetic diversity of MaYMV in maize fields in the northern guinea savannah region of Nigeria. A survey was conducted in 2017 and maize (n = 90) and itch grass (n = 10) plants suspected of virus infection based on appearance of mosaic and/or yellowing symptoms were sampled in Kaduna (n = 65) and Katsina (n = 35) states. The samples were screened individually by reverse transcription polymerase chain reaction using the genus-specific primers targeting poleroviruses and potyviruses Pol-G-F and Pol-G-R primers encompassing the partial P1–P2 fusion protein and coat protein genes of poleroviruses and primer pair CI-For & CI-Rev encompassing the partial cylindrical inclusion proteins of most potyviruses. A subset of amplified DNA fragments was cloned, Sanger-sequenced, and the obtained sequences were bioinformatically analyzed along with corresponding sequences from GenBank. The ~ 1.1 Kb polerovirus fragment was detected in 32.2% (29/90) of the maize samples while all 10 itch grass samples tested negative. BLASTN analysis of sequences derived from six polerovirus samples confirmed the virus identity as MaYMV. In pairwise comparisons, the MaYMV sequences derived in this study shared 97–99% nucleotide identity with sequences of other MaYMV isolates available in the NCBI GenBank. Phylogenetic analysis revealed the segregation of global MaYMV sequences into three host-independent clusters with pattern of geographic structuring.
Afficher plus [+] Moins [-]Detection and diversity of maize yellow mosaic virus infecting maize in Nigeria [Erratum: September 2020, Vol.31(3), pp.396-397] Texte intégral
2019
Yahaya, Adama | Dangora, Danladi B. | Alabi, Olufemi J. | Zongoma, Aisha M. | Kumar, P Lava
Maize yellow mosaic virus (MaYMV; genus Polerovirus; family Luteoviridae) was recently characterized from maize in China and subsequently detected in mixed infection with sugarcane mosaic virus (genus Potyvirus; family Potyviridae) in sugarcane and itch grass in Nigeria. This study was conducted to understand the status and genetic diversity of MaYMV in maize fields in the northern guinea savannah region of Nigeria. A survey was conducted in 2017 and maize (n = 90) and itch grass (n = 10) plants suspected of virus infection based on appearance of mosaic and/or yellowing symptoms were sampled in Kaduna (n = 65) and Katsina (n = 35) states. The samples were screened individually by reverse transcription polymerase chain reaction using the genus-specific primers targeting poleroviruses and potyviruses Pol-G-F and Pol-G-R primers encompassing the partial P1–P2 fusion protein and coat protein genes of poleroviruses and primer pair CI-For & CI-Rev encompassing the partial cylindrical inclusion proteins of most potyviruses. A subset of amplified DNA fragments was cloned, Sanger-sequenced, and the obtained sequences were bioinformatically analyzed along with corresponding sequences from GenBank. The ~ 1.1 Kb polerovirus fragment was detected in 32.2% (29/90) of the maize samples while all 10 itch grass samples tested negative. BLASTN analysis of sequences derived from six polerovirus samples confirmed the virus identity as MaYMV. In pairwise comparisons, the MaYMV sequences derived in this study shared 97–99% nucleotide identity with sequences of other MaYMV isolates available in the NCBI GenBank. Phylogenetic analysis revealed the segregation of global MaYMV sequences into three host-independent clusters with pattern of geographic structuring.
Afficher plus [+] Moins [-]Distribution and diversity of viruses infecting yams (Dioscorea spp.) in Cameroon Texte intégral
2019
Azeteh, I.N. | Hanna, R. | Njukeng, A.P. | Oresanya, A.O. | Sakwe, P.N. | Kumar, P. Lava
Yam (Dioscorea spp.) is an important food crop cultivated for its edible tubers in Cameroon. Surveys were conducted in Cameroon to determine the incidence and severity of yam mosaic disease and associated viruses in 124 yam farms in four agro-ecological zones in 2014 and 2016. Dioscorea rotundata, D. cayenensis, D. alata, D. Dumetorum and D. bulbifera were most frequently detected yam species in the fields. Symptoms of virus disease were observed on 81.5% of the farms surveyed and the disease incidence ranged from 0 to 96.7%, with an overall mean of 26.5%. Mean symptom severity estimated using a numerical rating scale of 1–5, ranged from 2 to 4.1, with an overall mean of 2.6. Representative set of leaf samples collected from farmers’ fields were tested for three viruses known to cause yam mosaic disease in West Africa, viz., Yam mosaic virus (YMV), Yam mild mosaic virus (YMMV) and Cucumber mosaic virus (CMV), using multiplex RT-PCR. YMV and YMMV were detected in 220 (37.2%) of the 591 samples tested and 75% of the farms surveyed. None of the samples tested positive to CMV. Phylogenetic analysis based on the coat protein sequencing of 27 YMV isolates clustered these isolates into three phylogenetic groups. This study demonstrated high prevalence of mosaic disease in yam fields and YMV as main causal agent. Knowledge generated in this study will be useful to augment diagnostic tools and yam mosaic disease control with a view to improve on yam production in Cameroon.
Afficher plus [+] Moins [-]Susceptibility to foot and mouth disease virus infection in vaccinated cattle, and host BoLA A and BoLA DRB3 genes polymorphism Texte intégral
2022
Chaudhary, Yash | Khuntia, Purnati | Kaul, Rajiv
The vaccination of the susceptible animal population against FMDV remains the most important measure to control the virus and prevent economic loss. Occurrence of infection in vaccinated animals is well-known in some diseases and is termed as breakthrough infection. The reasons include host genetic factors which can play an important role resulting in differences in susceptibility of animals to virus infection even with vaccine induced protective immune response. The Major Histocompatibility Complex (MHC) of bovines i.e. Bovine Leukocyte Antigen (BoLA) is important for antigen presentation. The BoLA DRB3 allele, which codes for the beta chain in Class II antigen, has been extensively studied and numerous reports have previously shown association of polymorphism in the gene with resistance/ susceptibility to several bacterial and viral diseases. In addition, previous studies have shown relationship between BoLA Class I and resistance or susceptibility to different diseases in cattle. The present study investigated the polymorphism in BoLA DRB3 and BoLA gene sequences of host and their relation with breakthrough FMDV infection in vaccinated animals. The study has identified three polymorphic sites each in both the genes which correlate with evidence of recent infection indicating their role in determining susceptibility of vaccinated animals to FMDV infection. Our limited study was performed on a relatively small samples size collected from one region of country. Further validation would require more detailed investigations on larger sample size.
Afficher plus [+] Moins [-]Detection of porcine enteric picornaviruses from faecal samples of Indian pigs Texte intégral
2022
Patel, Shailesh Kumar | Agrawal, Aditya | Pāṭhaka, Mamatā | Singh, Alok | Varshney, Rajat | Rana, Jigyasa | Saikumar, G.
Porcine enteric picornaviruses often consequence diarrhoea and nervous complications in pig and pose enormous loss to pig farming. The present study expands the limited Indian data of porcine enteric picornaviruses which is needed for the early implementation of control measures and to check further outbreaks. A total of 398 porcine faecal samples from Uttar Pradesh, Madhya Pradesh, Chhattisgarh and Jharkhand state of India were screened for porcine teschovirus (PTV), porcine sapelovirus (PSV) and enterovirus G (EV-G) by reverse transcriptase-polymerase chain reaction (RT-PCR) using 5′UTR-specific primers. The prevalence of PTV, PSV and EV-G was found to be 12.81% (51/398), 5.77% (23/398) and 24.37% (97/398), respectively. EV-G was relatively higher in circulation in Indian pigs among all the included enteric picornaviruses. Conversely, the concurrent infection of more than one enteric picornavirus was also frequent.
Afficher plus [+] Moins [-]Growth kinetics of an Indian isolate of highly pathogenic porcine reproductive and respiratory syndrome virus in MARC-145 cells Texte intégral
2022
Kombiah, Subbiah | Senthilkumar, Dhanapal | Kumar, Manoj | Sivasankar, Panickan | Singh, Vijendra P. | Rajukumar, Katherukamem
The aim of the present study was to understand the replication kinetics of an Indian isolate of highly pathogenic porcine reproductive and respiratory syndrome (PRRS) virus (Ind-297221) in MARC-145 cells infected at different multiplicity of infection (MOI) of 1.0, 0.1, 0.01 and 0.001. PRRSV titre in the infected cell fraction and the culture supernatant harvested at different intervals (12, 36, 48, 72, 96 and 120 h) post infection (hpi) was estimated by immunoperoxidase monolayer assay. Viral RNA copy numbers were quantified by TaqMan RT-PCR. PRRS virus could be detected first in intracellular fraction at 12 hpi in cells infected at 1.0 MOI, whereas in the extracellular fraction, earliest detection was at 36 hpi. Highest PRRSV titre of 1.3 × 10⁵.⁰ TCID₅₀/mL was achieved in 0.01 and 0.001 MOI groups at 96 hpi. Infection with 0.01 MOI resulted in the maintenance of maximum titre up to 120 hpi. The maximum viral copy numbers observed was 3.15 × 10⁷.⁰ in 0.1 MOI group at 120 hpi in culture medium. The results of the study showed that MARC-145 cells infected with Indian PRRSV at 0.01 MOI and harvested in 96–120 hpi was found to be optimum for obtaining maximum virus yield and hence can be used for bulk propagation of the virus.
Afficher plus [+] Moins [-]Refractory atypical trigeminal neuralgia associated with reactivated herpesvirus infection: pathogenetic link and efficacy of combination antiviral therapy Texte intégral
2022
Maltsev, Dmitry | Fedirko, Volodymyr
The purpose of this study is to diagnose herpesvirus infections in refractory atypical trigeminal neuralgia, to assess pathogenetic links, and to explore the efficacy of antiviral treatment. In a prospective controlled study, 95 patients with trigeminal neuralgia received antiviral therapy (valacyclovir + alpha2b-interferon) (experimental group, EG). Other patients refused to receive treatment (control group 1 (CG1), n = 31). Control group 2 (CG2) included 32 healthy individuals of the same age and sex. Herpesvirus infection was diagnosed in blood leukocytes by PCR (Biocom, Russian Federation). Serum concentrations of IgM, IgA and IgG to HSV-1/2, VZV (ELISA, Vector-Best, Russian Federation) were determined. Reactivation of herpesvirus infections was observed in the EG in 87% of cases. The heterogeneity of herpesvirus-associated damage of trigeminal nerves and anatomically related areas of the central nervous system (CNS) has been demonstrated. The treatment applied was effective for herpesvirus infection (77%) and pain (61%) and ineffective for immunity correction (26% of cases). Atypical refractory trigeminal neuralgia is associated with herpesvirus infections that reactivate due to minor immunodeficiencies. Antiviral treatment suppresses herpesviruses and reduces the intensity of pain.
Afficher plus [+] Moins [-]Molecular characterization of novel bipartite begomovirus associated with enation leaf disease of Garden croton (Codiaeum variegatum L.) Texte intégral
2022
Venkataravanappa, V. | Vinaykumar, H. D. | Hiremath, Shridhar | Mantesh, M. | Shankarappa, K. S. | Basha, C. R Jahir | Reddy, M Krishna | Reddy, C. N Lakshminarayana
Garden croton (Codiaeum variegatum L.) plants showing typical begomovirus symptoms of vein twisting, enation and curling were collected from different gardens at Varanasi, Uttar Pradesh state of India ranged from 20 to 30%. All the 10 ten (CR1-CR10) infected samples of garden croton resulted in expected amplicon of 1.2 Kb in PCR specific to begomoviruses. No amplification was obtained for betasatellite and alphasatellite specific primers. The complete genome sequence of DNA-A and DNA-B for two isolates (CR1 and CR2) was obtained through rolling cycle amplification (RCA) and comparisons were made with other begomoviruses using Sequence Demarcation Tool (SDT) which revealed that, DNA-A of two isolates, CR1 (Acc.No.: MW816855) and CR2 (Acc.No.: MW816856) showed maximum nucleotide (nt) identity of 85.7–85.9% with Tomato leaf curl Karnataka virus, which is below the threshold percentage of begomovirus species demarcation, hence considered as novel begomovirus and proposed the name Garden croton enation leaf curl virus (CroELCuV) [IN: Varanasi: Croton: 18]. Further, DNA-B these isolates shared maximum nt identity of 91.0–92.2% (DNA-B) with Tomato leaf curl New Delhi virus. Recombination and GC plot analysis showed that the recombination occured at in low GC content regions of DNA-A and DNA-B of the CroELCuV and are derived from the previously reported several begomoviruses. This is the first record of novel bipartite begomovirus associated with vein twisting, enation and leaf curling of disease of garden garden croton in India and world.
Afficher plus [+] Moins [-]Identification of novel lncRNA by reanalysis of RNA-seq data in Zika Virus Infected hiNPCs Texte intégral
2022
Venkatesan, Amouda | Barik, Aishwarya | Paul, Dahrii | Muthaiyan, Mathavan | Das, Rajesh
The Zika Virus (ZIKV) infection is a serious, public health concern with no vaccines or antiviral treatments. This study aims to identify the differentially expressed long non-coding RNAs (lncRNAs) in ZIKV infected human-induced neuroprogenitor cells (hiNPCs). Though lncRNA is well-known for its role in gene regulation, its role in ZIKV infection remains unclear. Thus, taking advantage of publicly available transcriptome data, BioProject PRJNA551246 was analysed. Performed the gene ontology and pathway analysis of differentially expressed lncRNAs were functionally interpreted based on the neighbouring protein-coding genes (100 kb upstream and downstream of each lncRNAs). The study revealed 19 novels and 237 differentially expressed lncRNAs in ZIKV infected hiNPCs. They are found to be significantly enriched in type I interferon signalling pathway, negative regulation of viral genome replication, defense response to the virus, pathways involved in Influenza A and Herpes simplex infection, tumor necrosis factor signalling pathway, and apoptosis. In ZIKV, associated microcephaly type I interferon act as potential modulating factors. Type-I interferon inhibits ZIKV replication in many human cell types. The results support future studies on understanding the structure and function of the novel lncRNAs and experimental approaches to determine the role of the lncRNAs in ZIKV induced infection.
Afficher plus [+] Moins [-]Surface contamination by SARS-CoV2 RNA in dedicated COVID care area of a tertiary care hospital in North India Texte intégral
2022
Sarkar, Subhabrata | Ghosh, Arnab | Mohindra, Ritin | Thomas, Linta | Yadav, Devender | Kandpal, Harish Chand | Biswal, Manisha | Lakshmi, P. V. M. | Suri, Vikas | Koushal, Vipin | Malhotra, Pankaj | Ratho, R. K. | Puri, G. D. | Singh, Mini P.
Environmental surfaces are potential source of SARS-CoV2 transmission. The study assessed the efficacy of hospital disinfection policy and contamination of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) RNA in COVID management Hospital. Inanimate surfaces from both patient areas (n = 70) and non-patient areas (n = 39) were sampled through surface swabbing and subjected to Reverse transcriptase PCR. Out of the 70 samples collected from the COVID hospital, SARS-CoV2 RNA positivity of 17.5% (7/40) and 6.7% (2/30) was seen in high risk and moderate risk area respectively. Samples from Non COVID related patient area such as CD ward and administrative block were assessed and the SARS CoV-2 RNA positivity was 0% and 10% respectively. Among the total 8 environmental surface samples positive for SARS-CoV2 RNA detected from the area surrounding the SARS-CoV2 infected patients, maximum positivity of 31.8% (7/22) was found among the environmental samples collected around the patients with < 20 Ct value in nasopharyngeal swab samples followed by 3.3% positivity (1/30) around patients with Ct value ranging from 20 to 25 whereas no SARS-CoV2 RNA (0/5) was detected around the patient with > 25 Ct value. Nearly 50% (2/4) of the surface samples came positive from the resident PPE and mobile of the treating doctors which largely elaborates the need for stringent doffing measurement and hand hygiene policy post doffing. The study emphasizes the necessity of frequent and aggressive disinfection policy to prevent nosocomial infection in such high risk areas within close vicinity of the patients.
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