2020年 · 第02卷第01期

A novel bat-origin coronavirus emerged in Wuhan, China in December 2019 and continues to spread across China and the world. At the time of writing, a massive global response has been implemented to control the disease as it spreads from person to person. Yet the high-risk human-wildlife interactions and interfaces that led to the emergence of SARS-CoV and of 2019-nCoV continue to exist in emerging disease hotspots globally. To prevent the next epidemic and pandemic related to these interfaces, we call for research and investment in three areas: 1) surveillance among wildlife to identify the high-risk pathogens they carry; 2) surveillance among people who have contact with wildlife to identify early spillover events; and 3) improvement of market biosecurity regarding the wildlife trade. As the emergence of a novel virus anywhere can impact the furthest reaches of our connected world, international collaboration among scientists is essential to address these risks and prevent the next pandemic.

The emergence of mobile Tigecycline-resistant tet(X3) and tet(X4) is believed to be a global threat to public health. Here, we investigated the prevalence of tet(X3) and tet(X4) in our metagenomic data of migratory birds. While tet (X4) was not identified in our samples, tet(X3) was found in two gut microbiomes of bird fecal samples, with 100% amino acid identity of sites 150–387. These results suggest that tet(X3) has been spreading into the environment for a long period of time and that there is an urgent need to control its further transmission.

Biosafety equipment is the key barrier enabling high containment laboratories to handle high risk agents that may cause serious and potentially lethal infections. This perspective thoroughly analyzes the development of many kinds of key biosafety technologies, and equipment for protection of laboratory workers and for high containment laboratory facilities in China. Over more than ten years of rapid development, China has had remarkable achievements in key biosafety technologies and equipment in high containment laboratories. These technologies basically meet the needs of high containment laboratories construction in China. Furthermore, according to the current global situation regarding the prevention and control of infectious diseases and the technical development level of biosafety equipment, this paper proposes targeted suggestions and notes that China still needs to increase investment in scientific research to provide further technical and equipment support enabling us to build a community with a bright future in terms of human biosafety.

The low success rates in the treatment of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant TB (XDR-TB), which account for 55% and 34% respectively, led the WHO to conclude that MDR/XDR-TB is a serious public health crisis. However, the virulence of MDR/XDR-Mycobacterium Tuberculosis(Mtb) has not been analyzed in details, which could provide a specific guidance for the control and prevention. In this review, we discuss different aspects of MDR/XDR-Mtb virulence and its relationship to fitness cost by probing the following questions: (1) what mediates the virulence of MDR/XDR-Mtb? (What is the relationship between fitness and virulence of Mtb? (2) Is it possible that drug-resistant Mtb(DR Mtb) can show higher fitness? (3) What is the definite effect on fitness of each drug-resistant mutant? (4) What other important factors affecting fitness in the mutant strain? (5) How to study the virulence of a large number of DR Mtb?And what prevention and control measures will be taken in the future, especially for the high virulent DR Mtb? We therefore summarized the congruent relationship between drug resistance and fitness from the global response-related genes to antibiotic resistance-contributing mutation, provided methods to explore the virulence of DR Mtb. This review may offer some critical information and concise guide to creating strategies for the prevention and control of drug-resistant Mtb.

Ebola virus (EBOV) is one of the most pathogenic viruses in humans which can cause a lethal hemorrhagic fever. Understanding the cellular entry mechanisms of EBOV can promote the development of new therapeutic strategies to control virus replication and spread. It has been known that EBOV virions bind to factors expressed at the host cell surface. Subsequently, the virions are internalized by a macropinocytosis-like process, followed by being trafficked through early and late endosomes. Recent researches indicate that the entry of EBOV into cells requires integrated and functional lipid rafts. Whilst lipid rafts have been hypothesized to play a role in virus entry, there is a current lack of supporting data. One major technical hurdle is the lack of effective approaches for observing viral entry. To provide evidence on the involvement of lipid rafts in the entry process of EBOV, we generated the fluorescently labeled Ebola virus like particles (VLPs), and utilized single-particle tracking (SPT) to visualize the entry of fluorescent Ebola VLPs in live cells and the interaction of Ebola VLPs with lipid rafts. In this study, we demonstrate the compartmentalization of Ebola VLPs in lipid rafts during entry process, and inform the essential function of lipid rafts for the entry of Ebola virus. As such, our study provides evidence to show that the raft integrity is critical for Ebola virus pathogenesis and that lipid rafts can serve as potential targets for the development of novel therapeutic strategies.

The virulence of influenza viruses is a complex multigenic trait. Previous studies about the virulence determinants of influenza viruses mainly focused on amino acid sites, ignoring the influence of nucleotide mutations. In this study, we collected >200 viral strains from 21 subtypes of influenza A viruses with virulence in mammals and obtained over 100 mammalian virulence-related nucleotide sites across the genome by computational analysis. Fifty of these nucleotide sites only experienced synonymous mutations. Experiments showed that synonymous mutations in three high-scoring nucleotide sites, i.e., PB1–2031, PB1–633, and PB1–720, enhanced the pathogenicity of the influenza A(H1N1) viruses in mice. Besides, machine-learning models with accepted accuracy for predicting mammalian virulence of influenza A viruses were built. Overall, this study highlighted the importance of nucleotide mutations, especially synonymous mutations in viral virulence, and provided rapid methods for evaluating the virulence of influenza A viruses. It could be helpful for early warning of newly emerging influenza A viruses.

Positive Pressure Protective Clothing (PPPC) is the most important personal protective equipment for BSL-4 laboratory and a primary barrier to avoid exposure to pathogenic microorganisms. However, during the process of storage, utilization, disinfection and inspection, it will be inevitable damaged in varying degrees. PPPC is expensive; therefore, effective repairs become an important procedure to prolong service life of PPPC and to ensure their protective function. This paper analyzed those common damages in PPPC during routine BSL-4 laboratory operations and provided repair plans which can be used as references for users and maintenance personnel.

This study aims to investigate cases of human plague in the Inner Mongolia Autonomous Region (IMAR), China, and to inform the development of plague prevention and control strategies. On 12th of November 2019, two herdsmen from Sunitezuo Banner, Xilingol League were diagnosed with pneumonic plague in Beijing, China. On November 16th, one resident of Xianghuang Banner, Xilingol League was diagnosed with bubonic plague in Huade County Hospital, Ulanqab, China. On 27th of November, one resident of Siziwang Banner was diagnosed with bubonic plague. In total, 78 close contacts were monitored over a period, but none of them developed symptoms. Plague outbreaks in animals had been reported in Sunitezuo Banner, Xianghuang Banner, and Siziwang Banner in 2019. Two of the four cases were related (husband and wife), but not the other two. All the cases may be associated with contact with rodents (hare) or infected fleas. The cases highlight the importance of early identification of plague cases in humans in order to stop further infection. This demonstrates the value of monitoring and ongoing vigilance on endemic diseases, the importance of updating medical training and raising public awareness about infectious diseases that even have not been observed over decades.

Bird infections with highly pathogenic avian influenza A(H5N6) viruses have been identified since 2014. With very limited occasion, the virus could sporadically spilled over to infect humans. It has been recognized that all human infections were within southern region of Mainland China until the case reported here in Beijing in Aug. 2019. This was the first human case infected with highly pathogenic avian influenza A(H5N6) virus in northern China. The infection was confirmed by real-time RT-PCR assay. The whole genome sequences were obtained from clinical sample. Genetic characteristics of the virus were identified similar to those of previous avian influenza A(H5N6) viruses, retaining the main features of the avian influenza virus.