Ultrasensitive Visualization of Virus via Explosive Catalysis of an Enzyme Muster Triggering Gold Nano-aggregate Disassembly.

Sensitive and accurate diagnosis of viral infection is important for human health and social safety. Herein, by means of explosive catalysis from an enzyme muster, a powerful naked-eye readout platform has been successfully constructed for ultrasensitive immunoassay of viral entities. Liposomes were used to encapsulate multiple enzymes into an active unit. In addition, its triggered rupture could boost the disassembly of gold nano-aggregates that were cross-linked by peptides with opposite charges. As a result, plasmonically colorimetric signals were rapidly generated for naked-eye observation. Further harnessing the immunocapture, enterovirus 71 (EV71), a class of highly infective virus, was sensitively assayed with a detection limit down to 16 copies/µL. It is superior to the single enzyme-anchored immunoassay system. Most importantly, the colorimetric assay was demonstrated with 100% clinical accuracy, displaying strong anti-interference capability. It is expectable that this sensitive, accurate, and convenient strategy could provide a prospective alternative for viral infection analysis, especially in resource-constrained settings.

Differences in the Transmission of Dengue Fever by Different Serotypes of Dengue Virus.

Dengue fever is the most common arbovirus in the world, and all four serotypes are infectious and pathogenic, but dengue virus (DENV)-1 and DENV-2 are the most prevalent in Guangdong Province. To investigate the differences in serotypes, we evaluated the replication, pathogenicity, and NS1 expression of DENV-2 and DENV-3 in cells, and further investigated the effects of NS1 on viral replication and transmission. The results of this study indicated that DENV-2 replicated faster and was more pathogenic than DENV-3. In Vero cells, DENV-2 secreted more NS1 protein than DENV-3, and NS1 protein promoted the infection of Aedes albopictus and A. aegypti by DENV. The spread of DENV and the severity of the disease depend on many factors. Further research on the differences between different serotypes of DENV will help us understand the epidemiology of DENV infection. This will provide a scientific basis for the prevention and control of the dengue epidemic.

Discovery and high prevalence of Phasi Charoen-like virus in field-captured Aedes aegypti in South China.

Arboviruses have caused significant global health concerns during the past decade. In this regard, continuous viral surveillance is essential to timely identify emerging arboviruses and other novel viruses. Here, a novel isolate of Phasi Charoen-like virus (PCLV Zhanjiang01) was identified from field-captured Aedes aegypti mosquitoes in Zhanjiang by next generation sequencing. Phylogenetic analysis suggested that PCLV Zhanjiang01 belonged to the genus Phasivirus in the family Phenuiviridae. The presence of PCLV in three batches of Aedes aegypti confirmed its high prevalence in nature. Further detection of PCLV in progenies and adult males suggested vertical transmission in mosquitoes. In parallel, PCLV was detected from multiple organs indicating its broad tissue distribution in the infected mosquitoes. To the best of our knowledge, this is the first report of PCLV in China. Our results expanded the global biogeographic distribution of PCLV. Further investigations of PCLV on the arboviral transmission and control strategies are warranted.

Genome Sequence of a Novel Strain of a Phasi Charoen-Like Virus Identified in Zhanjiang, China.

Here, we report the genome sequence of a novel strain of a Phasi Charoen-like virus, isolated from Aedes aegypti mosquitoes caught in Zhanjiang province of China. Phylogenetic analysis suggested that this virus belongs to a new genus, Goukovirus, in the family Bunyaviridae This is the first reported genome sequence of a Phasi Charoen-like virus identified in China.