Virus research最新文献

Avian Influenza Viruses (AIVs) pose today a very significant risk to global health given the widespread circulation of H5N1 highly pathogenic avian influenza viruses (HPAIV). After decimating the avian population all over the world, these viruses spill over to many different mammal species, causing also fatal outbreaks. As the virus continues to evolve increasing human cases of H5N1 HPAIV have been reported, causing concern that these viruses may adapt to the human host and became a pandemic new virus. In order to gain insight into this matter, a detailed phylogenetic analysis of H5N1 HPAIV isolated from humans was performed. A significant number of substitutions have been found in the hemagglutinins (HA) and neuraminidases (NA) among the three H5N1 clades already detected in human cases. Some of these substitutions were found to produce changes in the 3D structure of these proteins. Substitutions providing an evolutionary advantage to replicate or evade the immune response in mammals have been found in several non-structural proteins of strains infecting humans, including regulatory proteins, like PA-X or PB1-F2. A significant degree of polymorphic sites was observed in the proteins of the polymerase complex. The results of these studies are discussed in terms of the evolution of H5N1 HPAIV infecting humans and future work to be done to address the pandemic potential of these viruses.

Background: Leucocytes cell population data (CPD) parameters have been applied in diagnosis and prognosis of viral infections. We aim to explore pattern of leucocytes CPD in people living with HIV (PLWH) and its role in clinical stratification.

Methods: This study included treatment-naïve PLWH and healthy control. Clinical HIV stages were determined. Laboratory assessment was conducted using complete blood picture, CPD, CD4+ T cells count, and HIV RNA testing. Correlation between CPD with CD4+ and HIV RNA was evaluated.

Results: A total of 125 were recruited; 70 cases and 55 control. Age and gender were not significantly different. WHO stage 3 was predominant at 34.29% and half of PLWH had advanced HIV. CPD parameters of neutrophils, lymphocytes and monocytes composition were significantly higher in PLWH. Parameters of neutrophils nucleic acid contents, lymphocytes dispersion of nucleic acid contents, and both neutrophils and lymphocytes size were significantly higher in PLWH. CD4+ T cells count positively correlated with WBCs, lymphocytes and monocytes count and size, but negatively correlated with lymphocytes composition, nucleic acid contents, and size, and both monocytes and neutrophils composition and nucleic acid contents. Viral load negatively correlated with neutrophils size.

Conclusion: CPD can be a cost-effective quantitative tool reflecting immune depletion in HIV. By decoding these parameters, clinicians can stratify PLWH risk of disease progression beyond CD4+ T cells count and viral load.

The Varroa mite (Varroa destructor) has reshaped the viral landscape of honey bee colonies, significantly contributing to colony mortality. In response, Varroa-resistant honey bee breeding programs have developed as a promising and sustainable long-term strategy to control Varroa mite infestations in managed colonies. These breeding programs drive the coevolution of hygienic bees and Varroa mites, however the impact of such coevolution on bee and mite viral dynamics remains poorly understood. To address this gap, we investigated how Varroa-resistant traits influence the tripartite interaction among honey bees, Varroa mites, and viruses. Two apiaries were established: one in Greensboro, North Carolina, consisting of high and low UBeeO colonies, and another in Stoneville, Mississippi, consisting of Pol-line and Commercial colonies. Worker bees and Varroa mites were collected from each colony throughout the beekeeping season and screened for 7 viruses. Hygienic selection significantly reduced the Varroa mite infestation level and influenced the dynamics of viruses in worker bees and Varroa mites. Specifically, titers of Varroa-associated viruses were significantly reduced in worker bees and in mites collected from hygienic colonies. Additionally, hygienic selection altered the co-occurrence patterns and correlations among multiple critically important viruses in mites and worker bees. These findings highlight the value of selective breeding as an effective strategy for improving honey bee health and colony survival and shed light on the complex tripartite relationships between honey bees, Varroa mites, and viruses.

Dry bubble disease, attributed to the filamentous fungus Lecanicillium fungicola (Cordycipitaceae) results in huge yield losses in mushroom (Agaricus bisporus) cultivation worldwide. The possibilities for controlling the disease using commercial fungicides are highly limited, and therefore, there is an increasing demand for novel, alternative means of pest management. Our research objective was the comprehensive examination of viruses in the causal agents of dry bubble disease, which may open up an avenue for its virocontrol in the future. Out of 57 fungal isolates obtained from dry bubble-affected A. bisporus crops in various countries, 47 (82%) were confirmed by ITS (Internal Transcribed Spacer) sequence analysis as L. fungicola. In addition, different members of the genera Akanthomyces and Simplicillium (7 and 3 isolates, respectively), yet unknown to cause dry bubble symptoms, have also been detected. Cellulose column chromatography revealed the presence of double-stranded (ds) RNA in seven L. fungicola and three Akanthomyces sp. isolates, suggesting viral infection. The ten dsRNA-positive and eight randomly selected dsRNA-negative fungal strains were subjected to rRNA-depletion high-throughput RNA-sequencing analysis. The presence of seven new viruses representing four new species in the established families, Partitiviridae, Polymycoviridae, Botourmiaviridae and the narna-like virus group, and three previously established/proposed species in the families Chrysoviridae and "Mycovirgaviridae" were confirmed. The impact of the detected and identified viruses on their host fungi, and their potential applicability for virocontrol purposes will be examined in the future. This study provides the first detailed report on viruses of mushroom pathogenic fungi.