VirusDisease最新文献

Marek's disease is an oncogenic virus that produces malignant lymphomas in chickens. Rapid easy detection of Marek's disease is of great importance for early diagnosis and control of the disease. In this study, identification of Marek's disease virus serotype 1 was done by using a colorimetric integrated polymerase chain reaction with Meq gene. The forward primer of the Meq gene which is specific to MDV serotype 1 was integrated with HRPzyme sequence (916 bp) and amplified during the PCR. The PCR product including HRPzyme produced the distinguished blue colour with chromogenic substrates which was visualized by the naked eye. From these observations, simple, rapid colorimetric PCR assay of Marek's disease virus was performed without using agarose gel electrophoresis.

The global coronavirus disease 2019 (COVID-19) outbreak, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has substantially impacted both health and the economy. It is essential to comprehend the effects of COVID-19 on children with compromised immune systems to develop effective strategies for management and mitigation. This review aims to provide comprehensive insights into various aspects related to pediatric COVID-19 infection and the effects of COVID-19 on the pediatric immunocompromised population. It covers epidemiology, pathogenesis, diagnosis, management, complications, long-term effects, and special considerations and challenges in diagnosis and management. A comprehensive examination of existing literature was undertaken to gather and integrate current understanding of COVID-19 in pediatric immunocompromised demographics. Key aspects such as viral pathogenesis, immune responses, diagnosis methods, management strategies, and nonpharmacological interventions were analyzed and discussed. Pediatric patients generally exhibit milder symptoms and better outcomes than adults, with differences in immune responses contributing to reduced severity. Immunocompromised individuals face a heightened risk of severe COVID-19 and complications due to impaired immune function. Diagnosis methods and management strategies must consider each population's unique characteristics and challenges. A deeper scientific inquiry is needed to explicate immune responses, potential long-term effects, and the best management strategies for pediatric immunocompromised COVID-19 patients. Multidisciplinary collaboration and advancements in diagnostics and therapeutics will enhance our understanding and improve outcomes for these vulnerable populations, ultimately contributing to effective pandemic control efforts.

Introduction: MicroRNAs (miRNAs) play many roles in basic biological processes such as virus proliferation and growth. In this research, we sought to investigate the prognostic and diagnostic potential of miR-155 and miR-1275 in the induction and severity of Graft-Versus-Host Disease (aGVHD) following hematopoietic stem cell transplantation (HSCT). Additionally, we evaluated the association between these miRNAs' expression and HBV infection in patients with HSCT.

Method: In the present research, 135 consecutive patients receiving allogeneic HSCT were enrolled. We assessed the expression levels of miR-155 and miR-1275 in the peripheral blood of patients before and after HSCT by SYBR Green Real-Time PCR. In these patients Hepatitis B virus (HBV) load was also determined by HBV antibody assay.

Results: MiR-1275 and miR-155 expression levels were significantly lower in patients after HSCT. A significant association was found between miR-155 and miR-1275 expression levels in patients who developed aGvHD compared with those without aGvHD. We also found that only MiR-155 expression level was significantly increased in HBV + patients compared with HBV- patients.

Conclusion: Both MiR-1275 and miR-155 genes have the potential to be used as therapeutic targets in HSCT patients in the future. The expression level of both could be employed as biomarkers for aGvHD induction. Moreover, MiR-155 expression level was connected to the pathogenesis of HBV infection.

Bean common mosaic virus (BCMV) is one of the most serious and devastating Potyvirus of leguminous crops. In mung bean (Vigna radiata), BCMV is an emerging virus causing enormous losses to the crop, thereby reducing the production and profitability of the crop. Being seed borne and aphid transmitted virus, it important to reduce the spread and prevent its transfer to new geographical locations using rapid, specific and sensitive detection techniques. In this study, reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was devised to rapidly and specifically detect BCMV. Three pairs of specific primers were designed targeting the BCMV genome. To determine the ideal temperature, reactions were carried out across a temperature range of 45 °C to 70 °C, with intervals of 5 °C. The optimal temperature for the assay was determined to be 60 °C with a 30-min incubation period. Comparison between the RT-LAMP and conventional reverse transcription polymerase chain reaction (RT-PCR) revealed that former can detect the BCMV upto 10^- 9 and was one hundred times more sensitive than later. It was also determined that RT-LAMP was specific only in detecting BCMV, with no cross-reactivity with other closely related non-target viruses [potato virus Y (PVY), bean common mosaic necrosis virus (BCMNV), clover yellow vein virus (ClYVV) and soybean mosaic virus (SMV)]. After incubating the reactions at constant temperature of (60 °C/30 min), a characteristic ladder like banding pattern was observed on agarose gel for positive samples. Colorimetric tests (SYBR Green I) were also performed to reduce the requirement of laboratory equipment for visualizing RT-LAMP results. The results developed by SYBR Green I were comparable to that of agarose gel and can be visualized with naked eye. The developed RT-LAMP assay enables rapid detection of BCMV at 60 °C within a time period of 30-min.

Soybean yellow mottle mosaic virus is an emerging viral pathogen in leguminous crops including soybean. The present study was carried with 18 soybean cultivars to screen and identify the resistant cultivars to SYMMV infection under controlled environment glasshouse. Agro-inoculation of French bean cv. Arka Sharat with SYMMV produced systemic symptoms of mosaic and chlorotic blotches. Mechanical sap inoculation of 18 soybean cultivars with SYMMV infected French bean leaves produced systemic symptoms like chlorotic spots, chlorotic blotches, mosaic, mottle and veinal mild mottling by 15-20 dpi. The PDI on a scale of 0-5 showed that out of 18 cultivars, only SL-979 cultivar was moderately resistant, seven cultivars were moderately susceptible, and eight cultivars were susceptible, while two cultivars displayed highly susceptible reaction (SL-958 & JS-335). Detection of SYMMV through DAC-ELISA showed the absorbance values of 0.84 to 2.05 at 405 nm. RT-PCR analysis of these cultivars showed amplification of 1065 bp fragment with CP primers. The present study clearly showed that none of the screened soybean cultivar is resistant against SYMMV, suggesting a need for further research into breeding programs that may enhance resistance to SYMMV.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-024-00905-7.

Bovine ephemeral fever (BEF) is caused by BEF virus (BEFV) belonging to the Genus Ephemerovirus under the Family Rhabdoviridae. The BEFV carries a single-stranded, negative-sense RNA genome. Not much is known about the various aspects of BEFV replication, its interaction with cellular proteins or the cellular response to BEFV infection. Here, we report the rescue of BEFV through reverse genetics. A full-length cDNA copy of BEFV was assembled to be driven by the RNA polymerase I (PolI) promoter. Parallely, eukaryotic expression plasmids containing BEFV sequences encoding the helper proteins N, P and L, which form the replicase complex, were generated. The expression of N and P proteins were verified by using the in-house generated and purified polyclonal sera. Transfection of the full-length cDNA copy along with the helper plasmids rescued BEFV, as evaluated by transmission electron microscopy, reverse-transcription polymerase reaction, immunofluorescence and Western blotting. However, the virus did not produce a cytopathic effect and failed to be propagated beyond a certain number of passages. The results lay the foundation for establishment of reverse genetics for BEFV but also highlight the difficulties in studying this virus.

Dengue virus (DENV) and West Nile (WNV) viruses are important re-emerging mosquito-borne members of the genus Flavivirus that are under-recognized in many parts of Africa. This review aims to evaluate the existing literature on the transmission, epidemiology, diagnostic techniques, clinical presentation and prevention of infection with DENV and WNV in Southern Africa. Literature shows that both DENV and WNV are transmitted by mosquitoes of Aedes spp. and Culex species., respectively, and both viruses are widespread in the Southern African region. Epidemiologically, sporadic outbreaks have been reported of both DENV and WNV in various Southern African countries, indicating the ongoing threat of these viruses. However, the lack of comprehensive surveillance and diagnostic capacity challenges accurate estimation of their true prevalence. Diagnostic techniques for DENV and WNV involve serological tests, molecular tests and viral isolation, enabling prompt diagnosis and differentiation from other febrile illnesses. In Southern Africa, infection with DENV and WNV presents significant public health concerns, with the clinical presentation of both infections ranging from asymptomatic cases to severe manifestations. Symptoms of infection include high fever, myalgia, rash, and, in severe cases, haemorrhagic fever for DENV and neurological complications for WNV. No specific antiviral treatment exists for either virus, underscoring the importance of supportive care and symptom management. To prevent the spread of DENV and WNV in Southern African countries, a combination of prevention and treatment strategies should be employed, including effective mosquito control, continuous monitoring of vector population dynamics, public health education, and surveillance and reporting systems for averting future outbreaks.

Porcine parvovirus 2 (PPV2) is one the viruses that has been reported to be associated with respiratory ailments in pigs. In North Kerala, there has been an increase in the cases of respiratory diseases in pigs. The prevalence of porcine circovirus 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) that are associated with respiratory disease in pigs has been established in Kerala. However, no study has been carried out on PPV2 in the state. This paper reports the results of a pioneer study carried out to detect and characterize PPV2 associated with cases of respiratory ailments in pigs in North Kerala. A total of 54 samples were tested for the presence of PPV2 by NS1 and VP1 gene-based polymerase chain reaction (PCR). Of the samples tested, 3 (5.56%) were found to be positive for the virus. In two samples, coinfection of PPV2 and PCV2 was observed. On phylogenetic analysis of the VP1 gene of the virus, it was revealed that the virus was similar to PPV2 viruses detected in Croatia, Hungary and Romania. The results of the study indicate that PPV2 is present in pigs of North Kerala and that its prevalence is low. Since the virus is capable of inducing significant pathological changes in the lungs, and due to the possibility of coinfection with other viruses inducing respiratory ailments, measures are to be taken to control the spread of the virus in pigs in Kerala.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-025-00909-x.

Cucurbit yellow stunting disorder virus (CYSDV), has recently been detected in different crops in India, including cucumber, bitter gourd, and watermelon. To investigate the distribution of emerging criniviruses, symptomatic round melon and wild melon plants were analyzed through transmission electron microscopy and RT-PCR. Long filamentous virions (~ 850 nm in length) resembling criniviruses and ~ 550 bp amplicons of RdRp gene specific to the genus Crinivirus were observed. The phylogeny using coat protein gene amino acid sequences of different criniviruses revealed grouping of round melon and wild melon isolates of this study with CYSDV isolates originating from Mexico. These isolates exhibited up to 100% amino acid sequence homology with other previously reported CYSDV isolates worldwide. Further, the associated virus was transmitted successfully to the healthy cucumber test plants in the whitefly-based bio-assay. Results of this study confirm the association of CYSDV in round melon and wild melon plants for the first time in India, highlighting the virus's rapid geographic and host range expansion. The findings emphasize the urgent need for strategies to manage and mitigate the spread of this devastating virus.

Viruses cause significant economic losses to fruit-tree orchards by reducing fruit yield and quality. Among viruses that infect grapevines (Vitis spp.) and prunuses (Prunus spp.), carnation ringspot virus, peach rosette mosaic virus, raspberry ringspot virus, strawberry latent ringspot virus, sowbane mosaic virus, and grapevine vein yellow virus (tomato ringspot virus) have all been designated as plant quarantine pathogens in Japan. Although these viruses can be screened using sap inoculation on quinoa (Chenopodium quinoa), it is difficult to identify the species based solely on symptoms. Several diagnostic tests can be applied to diagnose viral infections in plants; however, by and large, polymerase chain reaction (PCR) is the most commonly used method. In particular, multiplex PCR allows simultaneous detection of multiple targets in a single assay, thereby reducing costs, labor, and time. Therefore, reliable diagnostic methods using PCR based on the genetic diversity of viruses are critical for detecting viral infections in fruit-tree orchards. In this study, we developed a two-step reverse transcription (RT)-multiplex PCR for quick and cost-effective detection of the six viruses listed above in infected quinoa, using newly designed primer sets. Primers were designed for each viral variant based on all sequence data obtained from the NCBI database. The detection sensitivities of our assay were equivalent to or even 1-10,000 times greater than those of previously reported singleplex RT-PCR assays, with the added advantage of zero non-specific reactions occurring. The proposed assay will be useful for identifying and selecting healthy nurseries and for plant quarantine inspections.

Supplementary information: The online version contains supplementary material available at 10.1007/s13337-025-00911-3.