Metagenomic Analysis of Environmental Samples from Wildlife Rescue Station at Poyang Lake, China / 生物医学与环境科学（英文）

OBJECTIVE@#To improve the understanding of the virome and bacterial microbiome in the wildlife rescue station of Poyang Lake, China.@*METHODS@#Ten smear samples were collected in March 2019. Metagenomic sequencing was performed to delineate bacterial and viral diversity. Taxonomic analysis was performed using the Kraken2 and Bracken methods. A maximum-likelihood tree was constructed based on the RNA-dependent RNA polymerase (RdRp) region of picornavirus.@*RESULTS@#We identified 363 bacterial and 6 viral families. A significant difference in microbial and viral abundance was found between samples S01-S09 and S10. In S01-S09, members of Flavobacteriia and Gammaproteobacteria were the most prevalent, while in S10, the most prevalent bacteria class was Actinomycetia. Among S01-S09, members of Myoviridae and Herelleviridae were the most prevalent, while the dominant virus family of S10 was Picornaviridae. The full genome of the pigeon mesivirus-like virus (NC-BM-233) was recovered from S10 and contained an open reading frame of 8,124 nt. It showed the best hit to the pigeon mesivirus 2 polyprotein, with 84.10% amino acid identity. Phylogenetic analysis showed that RdRp clustered into Megrivirus B.@*CONCLUSION@#This study provides an initial assessment of the bacteria and viruses in the cage-smeared samples, broadens our knowledge of viral and bacterial diversity, and is a way to discover potential pathogens in wild birds.

Generation and immunogenicity evaluation of Senecavirus A virus-like particles / 生物工程学报

To develop Senecavirus A (SVA) virus-like particles (VLPs), a recombinant prokaryotic expression plasmid pET28a-SVA-VP031 was constructed to co-express SVA structural proteins VP0, VP3 and VP1, according to the genomic sequence of the field isolate CH-FJ-2017 after the recombinant proteins were expressed in E .coli system, and purified by Ni+ ion chromatographic method. The SVA VLPs self-assemble with a high yield in vitro buffer. A typical VLPs with an average diameter of 25-30 nm which is similar to native virions by using TEM detection. Animals immunized by SVA VLPs shown that the VLPs induced high titers neutralizing antibodies in Guinea pigs. This study indicated that the VLPs produced with co-expressing SVA structural proteins VP0, VP3 and VP1 in prokaryotic system is a promising candidate and laid an important foundation for the development of a novel SVA VLPs vaccine.

Human virome in nasopharynx and tracheal secretion samples

BACKGROUND In Brazil the implementation of the Sentinel Surveillance System of Influenza began in 2000. Central public health laboratories use reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for diagnosis of respiratory viruses, but this protocol identifies only specific targets, resulted in inconclusive diagnosis for many samples. Thus, high-throughput sequencing (HTS) would be complementary method in the identification of pathogens in inconclusive samples for RT-qPCR or other specific detection protocols. OBJECTIVES This study aimed to detect unidentified viruses using HTS approach in negative samples of nasopharynx/tracheal secretions by the standard RT-qPCR collected in the Federal District, Brazil. METHODS Nucleic acids were extracted from samples collected in winter period of 2016 and subjected to HTS. The results were confirmed by the multiplex PR21 RT-qPCR, which identifies 21 respiratory pathogens. FINDINGS The main viruses identified by HTS were of families Herpesviridae, Coronaviridae, Parvoviridae and Picornaviridae, with the emphasis on rhinoviruses. The presence of respiratory viruses in the samples was confirmed by the PR21 multiplex RT-qPCR. Coronavirus, enterovirus, bocavirus and rhinovirus were found by multiplex RT-qPCR as well as by HTS analyses. MAIN CONCLUSIONS Wide virus diversity was found by different methodologies and high frequency of rhinovirus occurrence was confirmed in population in winter, showing its relevance for public health.

The role of microRNAs in enteroviral infections

ABSTRACTThe genus Enterovirus, a member of thePicornavirus family, are RNA viruses that can cause poliomyelitis, hand-food-mouth disease, viral meningitis or meningoencephalitis, viral myocarditis and so on. MicroRNAs are a class of highly conserved, small noncoding RNAs recognized as important regulators of gene expression. Recent studies found that MicroRNAs play a significant role in the infection ofEnterovirus, such as enterovirus 71, coxsackievirus B3 and other Enterovirus. Enteroviral infection can alter the expression of cellular MicroRNAs, and cellular MicroRNAs can modulate viral pathogenesis and replication by regulating the expression level of viral or host's genes. Herein, this review summarizes the role of MicroRNAs in enteroviral infection.

Rhinovirus detection using different PCR-based strategies

Human rhinoviruses (HRVs) are the major cause of the common cold. HRVs were recently reclassified into the Enterovirus genus (HEV) in the Picornaviridae family. HRVs and other members of the HEV genus share many common features, including sense RNA genomes and partial nucleotide sequence identity. The aim of this study was to evaluate different HRV detection strategies. Samples from adults with acute respiratory infection (n = 291) who were treated in Sao Paulo Hospital (2001-2003) were tested using three assays. The first assay detected picornaviruses by RT-PCR and hybridization, the second detected rhinoviruses using RT-PCR/sequencing, and the third differentiated HRV from HEV using duplex semi-nested-RT-PCR. Analysis of the results obtained from the first two strategies revealed 83% concordance. Discordant samples were then evaluated by the third protocol, and 82% were negative. The picornavirus detection protocol was more sensitive but less specific than the rhinovirus detection protocols. The semi-nested protocol utilized in the present study was less sensitive and was not useful in differentiating HRV from HEV. Sequencing assays examining different genes would address the best strategy of confirming rhinovirus and enterovirus infections.