Highly diverse ribonucleic acid viruses in the viromes of eukaryotic host species in Yunnan province, China.

Background: The diversity in currently documented viruses and their morphological characteristics indicates the need for understanding the evolutionary characteristics of viruses. Notably, further studies are needed to obtain a comprehensive landscape of virome, the virome of host species in Yunnan province, China. Materials and methods: We implemented the metagenomic next-generation sequencing strategy to investigate the viral diversity, which involved in 465 specimens collected from bats, pangolins, monkeys, and other species. The diverse RNA viruses were analyzed, especially focusing on the genome organization, genetic divergence and phylogenetic relationships. Results: In this study, we investigated the viral composition of eight libraries from bats, pangolins, monkeys, and other species, and found several diverse RNA viruses, including the Alphacoronavirus from bat specimens. By characterizing the genome organization, genetic divergence, and phylogenetic relationships, we identified five Alphacoronavirus strains, which shared phylogenetic association with Bat-CoV-HKU8-related strains. The pestivirus-like virus related to recently identified Dongyang pangolin virus (DYPV) strains from dead pangolin specimens, suggesting that these viruses are evolving. Some genomes showed higher divergence from known species (e.g., calicivirus CS9-Cali-YN-CHN-2020), and many showed evidence of recombination events with unknown or known strains (e.g., mamastroviruses BF2-astro-YN-CHN-2020 and EV-A122 AKM5-YN-CHN-2020). The newly identified viruses showed extensive changes and could be assigned as new species, or even genus (e.g., calicivirus CS9-Cali-YN-CHN-2020 and iflavirus Ifla-YN-CHN-2020). Moreover, we identified several highly divergent RNA viruses and estimated their evolutionary characteristics among different hosts, providing data for further examination of their evolutionary dynamics. Conclusion: Overall, our study emphasizes the close association between emerging viruses and infectious diseases, and the need for more comprehensive surveys.

Metagenomic Next-Generation Sequencing in the Diagnosis of HHV-1 Reactivation in a Critically Ill COVID-19 Patient: A Case Report.

Background: Secondary infections pose tremendous challenges in Coronavirus disease 2019 (COVID-19) treatment and are associated with higher mortality rates. Clinicians face of the challenge of diagnosing viral infections because of low sensitivity of available laboratory tests. Case Presentation: A 66-year-old woman initially manifested fever and shortness of breath. She was diagnosed as critically ill with COVID-19 using quantitative reverse transcription PCR (RT-qPCR) and treated with antiviral therapy, ventilator and extracorporeal membrane oxygenation (ECMO). However, after the condition was relatively stabled for a few days, the patient deteriorated with fever, frequent cough, increased airway secretions, and increased exudative lesions in the lower right lung on chest X-rays, showing the possibility of a newly acquired infection, though sputum bacterial and fungal cultures and smears showed negative results. Using metagenomic next-generation sequencing (mNGS), we identified a reactivation of latent human herpes virus type 1 (HHV-1) in the respiratory tract, blood and gastrointestinal tract, resulting in a worsened clinical course in a critically ill COVID-19 patient on ECMO. Anti-HHV-1 therapy guided by these sequencing results effectively decreased HHV-1 levels, and improved the patient's clinical condition. After 49 days on ECMO and 67 days on the ventilator, the 66-year-old patient recovered and was discharged. Conclusions: This case report demonstrates the potential value of mNGS for evidence-based treatment, and suggests that potential reactivation of latent viruses should be considered in critically ill COVID-19 patients.

Metagenomic next-generation sequencing in the family outbreak of psittacosis: the first reported family outbreak of psittacosis in China under COVID-19.

Chlamydia psittaci infection in humans, also known as psittacosis, is usually believed to be an uncommon disease which mainly presents as community-acquired pneumonia (CAP). It is usually sporadic, but outbreaks of infection may occasionally occur. In outbreaks, diagnosis and investigations were usually hampered by the non-specificity of laboratory testing methods to identify C. psittaci. In this study, we use metagenomic next-generation sequencing (mNGS) in the diagnosis of a family outbreak of psittacosis under COVID-19. Three members of an extended family of 6 persons developed psittacosis with pneumonia and hepatic involvement with common symptoms of fever and weakness. Two newly purchased pet parrots, which had died successively, were probably the primary source of infection. Imagings show lung consolidations and infiltrates, which are difficult to be differentiated from CAP caused by other common pathogens. mNGS rapidly identified the infecting agent as C. psittaci within 48 h. The results of this work suggest that there are not characteristic clinical manifestations and imagings of psittacosis pneumonia which can differentiate from CAP caused by other pathogens. The use of mNGS can improve accuracy and reduce the delay in the diagnosis of psittacosis especially during the outbreak, which can shorten the course of the disease control. Family outbreak under COVID-19 may be related to the familial aggregation due to the epidemic. To our knowledge, this is the first reported family outbreak of psittacosis in China, and the first reported psittacosis outbreak identified by the method of mNGS in the world.

Community structure of environmental microorganisms associated with COVID-19 affected patients.

To clarify the characteristics and distribution of hospital environmental microbiome associated with confirmed COVID-19 patients. Environmental samples with varying degrees of contamination which were associated with confirmed COVID-19 patients were collected, including 13 aerosol samples collected near eight patients in different wards, five swabs from one patient's skin and his personal belongings, and two swabs from the surface of positive pressure respiratory protective hood and the face shield from a physician who had close contact with one patient. Metagenomic next-generation sequencing (mNGS) was used to analyze the composition of the microbiome. One of the aerosol samples (near patient 4) was detected positive for COVID-19, and others were all negative. The environmental samples collected in different wards possessed protean compositions and community structures, the dominant genera including Pseudomonas, Corynebacterium, Neisseria, Staphylococcus, Acinetobacter, and Cutibacterium. Top 10 of genera accounted for more than 76.72%. Genera abundance and proportion of human microbes and pathogens radiated outward from the patient, while the percentage of environmental microbes increased. The abundance of the pathogenic microorganism of medical supplies is significantly higher than other surface samples. The microbial compositions of the aerosol collected samples nearby the patients were mostly similar to those from the surfaces of the patient's skin and personal belongings, but the abundance varied greatly. The positive rate of COVID-19 RNA detected from aerosol around patients in general wards was quite low. The ward environment was predominantly inhabited by species closely related to admitted patients. The spread of hospital microorganisms via aerosol was influenced by the patients' activity. Supplementary Information: The online version contains supplementary material available at 10.1007/s10453-021-09708-5.

Advantages and challenges of metagenomic next-generation sequencing (mNGS) in the detection of 2019 novel coronavirus / 中华检验医学杂志

As one of the two methods for 2019 novel coronavirus (2019-nCoV), gene sequencing is different from quantitative real-time PCR (RT-PCR) in detection principles. Therefore, gene sequencing has its own pros and cons in clinical application. Currently, metagenomic next-generation sequencing (mNGS) is the most commonly used technology in clinical application. Due to its broad coverage of all types of pathogens, mNGS demonstrates incomparable advantage in rapid identification of novel pathogens such as 2019-nCoV. In addition, it can simultaneously identify other pathogens except 2019-nCoV and mixed infections. On the other hand, however, due to the complexity of mNGS and long detection time, it is unlikely to achieve the purpose of wide-range and rapid diagnosis of 2019 n-CoV. Therefore, mNGS can complement RT-PCR to achieve best clinical application.