Development,characterization, and viral susceptibility of a feline (Felis catus) renal cell line (CRFK)

Summary Cell line CRFK, derived from kidney tissue of a normal domestic kitten, was initiated in 1964. With intermittent periods of storage in the frozen state, it has been grown in vitro during more than 200 passages, without apparent loss of susceptibility to selected viruses. Various herpesviruses and feline viruses belonging to differnet virus groups grow readily and with distinct, cytopathic features. The cells now grow as a smooth monolayer of epithelial-like cells; most have 37 chromosomes (2n−1) and are thus aneuploid for cat karyotype. Three distinct marker chromosomes are identified. The cell line, which is free of mycoplasmal contaimination, is useful in feline virus research and diagnostic medicine and has become of particular interest in cancer research. Supported in part by Contract E73-2001-NO1-CP-3-3237 within the Special Virus Cancer Program, National Cancer Institute, National Institutes of Health, Public Health Service and the Morris Animal Foundation and General Research Support funds of the New York State Veterinary College. CRFK cells from stock provided by C. G. Fabricant are available for distribution to investigators from the Cell Culture Laboratory, Naval Biomedical Research Laboratory.     

Rapid establishment of a frontline field laboratory in response to an imported outbreak of Ebola virus disease in western Uganda,June 2019

The Democratic Republic of the Congo (DRC) declared an Ebola virus disease (EVD) outbreak in North Kivu in August 2018. By June 2019, the outbreak had spread to 26 health zones in northeastern DRC, causing >2,000 reported cases and >1,000 deaths. On June 10, 2019, three members of a Congolese family with EVD-like symptoms traveled to western Uganda’s Kasese District to seek medical care. Shortly thereafter, the Viral Hemorrhagic Fever Surveillance and Laboratory Program (VHF program) at the Uganda Virus Research Institute (UVRI) confirmed that all three patients had EVD. The Ugandan Ministry of Health declared an outbreak of EVD in Uganda’s Kasese District, notified the World Health Organization, and initiated a rapid response to contain the outbreak. As part of this response, UVRI and the United States Centers for Disease Control and Prevention, with the support of Uganda’s Public Health Emergency Operations Center, the Kasese District Health Team, the Superintendent of Bwera General Hospital, the United States Department of Defense’s Makerere University Walter Reed Project, and the United States Mission to Kampala’s Global Health Security Technical Working Group, jointly established an Ebola Field Laboratory in Kasese District at Bwera General Hospital, proximal to an Ebola Treatment Unit (ETU). The laboratory consisted of a rapid containment kit for viral inactivation of patient specimens and a GeneXpert Instrument for performing Xpert Ebola assays. Laboratory staff tested 76 specimens from alert and suspect cases of EVD; the majority were admitted to the ETU (89.3%) and reported recent travel to the DRC (58.9%). Although no EVD cases were detected by the field laboratory, it played an important role in patient management and epidemiological surveillance by providing diagnostic results in <3 hours. The integration of the field laboratory into Uganda’s National VHF Program also enabled patient specimens to be referred to Entebbe for confirmatory EBOV testing and testing for other hemorrhagic fever viruses that circulate in Uganda.     

Current trends in large‐scale viral surveillance methods in mosquitoes

Vector‐borne and zoonotic infectious diseases are serious public health concerns that affect approximately half of the world's population. In particular, arthropod‐borne viruses (arboviruses) have contributed to more mortality and morbidity worldwide with the emergence of dengue, chikungunya, yellow fever, and Zika virus diseases. The infections have scaled up due to urbanization, globalization, and international mobility. Traditionally, the spread of mosquito‐borne viral diseases to humans was considered a low health priority concern. However, their categorization as emerging infectious diseases and public health emergencies of international concern has heightened the attention given by the government, academia, research, and industry for the development of timely, cost‐efficient, and sustainable solutions. The urgency has increased in the wake of global climate change. The focus on effective interventions includes epidemiological monitoring, vector control measures, molecular diagnostics, vaccines, and environmental determinants. In this review, we discuss the etiology and predisposition of mosquito‐borne viruses that are detrimental to public health and economically damaging when disseminated as epidemics. We focus on the large‐scale virus surveillance methods with special reference to innovations and interventions in molecular detection science and technologies that include viral nucleic acid isolation, polymerase chain reaction (PCR)‐based diagnostics, and high‐throughput sequencing technologies. In addition, we discuss the development of a viral RNA extraction and PCR‐based diagnostic kit (Invirustech) that can extract viral RNA from mosquitoes with verified applications in PCR‐based molecular diagnostics of Pan‐flavivirus.     

Bioinformatics databases and tools in virology research: an overview

Viruses are major factors of human infectious diseases. Understanding of the structure-function correlation in viruses is important for the identification of potential anti-viral inhibitors and vaccine targets. In virology research, virus-related databases and bioinformatic analysis tools are essential for discerning relationships within complex datasets about viruses and host-virus interactions. Bioinformatic analyses on viruses include the identification of open reading frames, gene prediction, homology searching, sequence alignment, and motif and epitope recognition. The predictions of features such as transmembrane domains, glycosylation sites, and protein secondary and tertiary structure are important for analyzing the structure-function relationship of proteins encoded in viral genomes. Biochemical pathway analysis can help elucidate information at the biological systems level. Microarray analysis provides methods for high throughput screening and gene expression profiling. Virus-related bioinformatics databases include those concerned with viral sequences, taxonomy, homologous protein families, structures, or dedicated to specific viruses such as influenza and herpes simplex virus (HSV). This review provides a guide and overview of computational programs for these analyses as a resource for genomics and proteomics studies in virology research. These resources are useful for understanding viral diseases, as well as for the design and development of anti-viral agents.     

Tobacco mosaic virus virulence and avirulence

In celebration of a century of research on tobacco mosaic virus that initiated the science of virology, I review recent progress relative to earlier contributions concerning how viruses cause diseases of plants and how plants defend themselves from viruses.     

Harnessed viruses in the age of metagenomics and synthetic biology: an update on infectious clone assembly and biotechnologies of plant viruses

Recent metagenomic studies have provided an unprecedented wealth of data, which are revolutionizing our understanding of virus diversity. A redrawn landscape highlights viruses as active players in the phytobiome, and surveys have uncovered their positive roles in environmental stress tolerance of plants. Viral infectious clones are key tools for functional characterization of known and newly identified viruses. Knowledge of viruses and their components has been instrumental for the development of modern plant molecular biology and biotechnology. In this review, we provide extensive guidelines built on current synthetic biology advances that streamline infectious clone assembly, thus lessening a major technical constraint of plant virology. The focus is on generation of infectious clones in binary T‐DNA vectors, which are delivered efficiently to plants by Agrobacterium. We then summarize recent applications of plant viruses and explore emerging trends in microbiology, bacterial and human virology that, once translated to plant virology, could lead to the development of virus‐based gene therapies for ad hoc engineering of plant traits. The systematic characterization of plant virus roles in the phytobiome and next‐generation virus‐based tools will be indispensable landmarks in the synthetic biology roadmap to better crops.     

Making a Virus Visible: Francis O. Holmes and a Biological Assay for Tobacco mosaic virus

In the early twentieth century, viruses had yet to be defined in a material way. Instead, they were known better by what they were not – not bacteria, not culturable, and not visible with a light microscope. As with the ill-defined “gene” of genetics, viruses were microbes whose nature had not been revealed. Some clarity arrived in 1929 when Francis O. Holmes, a scientist at the Boyce Thompson Institute for Plant Research (Yonkers, NY) reported that Tobacco mosaic virus (TMV) could produce local necrotic lesions on tobacco plants and that these lesions were in proportion to dilutions of the inoculum. Holmes’ method, the local lesion assay, provided the first evidence that viruses were discrete infectious particles, thus setting the stage for physicochemical studies of plant viruses. In a field where there are few eponymous methods or diseases, Holmes’ assay continues to be a useful tool for the study of plant viruses. TMV was a success because the local lesion assay “made the virus visible” and standardized the work of virology towards determining the nature of the virus.     

Emerging viral infections in a rapidly changing world

Emerging viral infections in both humans and animals have been reported with increased frequency in recent years. Recent advances have been made in our knowledge of some of these, including severe acute respiratory syndrome-associated coronavirus, influenza A virus, human metapneumovirus, West Nile virus and Ebola virus. Research efforts to mitigate their effects have concentrated on improved surveillance and diagnostic capabilities, as well as on the development of vaccines and antiviral agents. More attention needs to be given to the identification of the underlying causes for the emergence of infectious diseases, which are often related to anthropogenic social and environmental changes. Addressing these factors might help to decrease the rate of emergence of infectious diseases and allow the transition to a more sustainable society.     

Discovery of the first virus, the tobacco mosaic virus: 1892 or 1898?

Two scientists contributed to the discovery of the first virus, Tobacco mosaic virus. Ivanoski reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filter-candle. Bacteria are retained by such filters, a new world was discovered: filterable pathogens. However, Ivanovski probably did not grasp the full meaning of his discovery. Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic. He showed that the incitant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria. Ivanovski and Beijerinck brought unequal but decisive and complementary contributions to the discovery of viruses. Since then, discoveries made on Tobacco mosaic virus have stood out as milestones of virology history.     

Prospects for new viral vaccines

Animal virology has made outstanding contributions to preventive medicine by the development of vaccines for the control of infectious disease in man and animals. Cost-benefit analysis indicates substantial savings in health care costs from the control of diseases such as smallpox, poliomyelitis, yellow fever and measels. Areas for further development include vaccines for influenza (living, attenuated virus), the herpes group (varicella: cytomegalovirus), respiratory syncytial virus, rotavirus and hepatitis A, B, and non A/non B. The general options for vaccine formulation are discussed with particular emphasis on approaches with the use of viral genetics to 'tailor make' vaccine viruses with defined growth potential in laboratory systems, low pathogenicity, and defined antigens. Current progress with the development of an inactivated hepatitis B vaccine is reviewed as a case study in vaccine development. The impact of recent experiments in cloning hepatitis B virus DNA in E. coli on the production of a purified viral polypeptide vaccine is assessed.     

Global discovery of human-infective RNA viruses: A modelling analysis

RNA viruses are a leading cause of human infectious diseases and the prediction of where new RNA viruses are likely to be discovered is a significant public health concern. Here, we geocoded the first peer-reviewed reports of 223 human RNA viruses. Using a boosted regression tree model, we matched these virus data with 33 explanatory factors related to natural virus distribution and research effort to predict the probability of virus discovery across the globe in 2010–2019. Stratified analyses by virus transmissibility and transmission mode were also performed. The historical discovery of human RNA viruses has been concentrated in eastern North America, Europe, central Africa, eastern Australia, and north-eastern South America. The virus discovery can be predicted by a combination of socio-economic, land use, climate, and biodiversity variables. Remarkably, vector-borne viruses and strictly zoonotic viruses are more associated with climate and biodiversity whereas non-vector-borne viruses and human transmissible viruses are more associated with GDP and urbanization. The areas with the highest predicted probability for 2010–2019 include three new regions including East and Southeast Asia, India, and Central America, which likely reflect both increasing surveillance and diversity of their virome. Our findings can inform priority regions for investment in surveillance systems for new human RNA viruses.     

Arboviruses and epizootic viruses

Some viral diseases are transmitted to human by arthropods (arboviroses), or by animals (zoonoses). Among more than 500 arboviruses and epizootic viruses that are classified into seven families, only a few are responsible for zoonoses or cause severe human diseases. Infected patients may show an acute disease associated with different symptoms, ranging from high fever to encephalitis, pulmonary distress, and haemorrhages. Some diseases show one or more of these symptoms and the factors responsible for severe outcomes, either linked to the virus, or to the host, or to the vector, remain poorly understood. Arboviroses and zoonoses are emerging or re-emerging diseases that need a multidisciplinary effort to control the propagation of the infectious agent and the pathogenesis in infected patients. Some viruses could be used for bioterrorism attacks. In virology, studies on the interactions of the viruses with their vectors and vertebrate hosts and on the pathophysiology of the infections will allow a better prevention of these diseases.     

Tick‐borne viruses: Current trends in large‐scale viral surveillance

Ticks are ectoparasites that transmit pathogens, such as tick‐borne viruses, to their hosts. Tick‐borne viruses are diverse: they can be categorized into two orders, nine families, and at least 12 genera. Almost 25% of these viruses are infectious to humans and some are a serious threat to public health. The global rise in tick‐borne virus diseases has been linked to climate change which has reduced tick mortality in the winter and extended their active period. The spread of tick‐borne viral diseases to humans has received significant interest due to the increased threat to human life; epidemiological monitoring of tick‐borne viruses using molecular, immunological, and environmental methods is now a priority. Nevertheless, many tick‐borne diseases remain undiagnosed, which poses a challenge to public administration and health care officials. This review discusses three major tick‐borne RNA viruses that cause serious infection in humans: severe fever with thrombocytopenia syndrome (SFTS) virus, tick‐borne encephalitis (TBE), and Crimean–Congo hemorrhagic fever (CCHF) virus. Specifically, we discuss the epidemiological monitoring, vector control measures, molecular diagnostics, vaccines, and environmental determinants related to these viruses. Furthermore, we review the current surveillance of these tick‐borne viruses with a specific focus on diagnostic approaches that employ molecular interventions such as viral nucleic acid isolation, PCR‐based diagnostics, and high‐throughput sequencing technologies.     

Ethical inspection about laboratory animals

Laboratory animals and animal experiments are foundations and important support conditions for life sciences, especially for medical research. The animal experiments have drawn extensive attention from the society because of the ethical issue. This paper takes Wenzhou Medical University as an example to give a brief introduction to the ethical review about laboratory animals in the university so as to further draw attention and concerns from the public about the ethical issue of laboratory animals. We successively introduce its scientific projects, nurturing environment and ethical review of laboratory animals.     

Human papillomavirus infections: new perspectives for prevention and treatment

Human papillomaviruses (HPVs) have been recognized as the main etiologic agent of cervical cancer and other anogenital neoplasms, and a leading cause of death from cancer worldwide. In the last twenty years, extensive research has contributed to document the molecular mechanisms of virus persistence and malignant transformation, confirming a direct role of viral proteins in these processes. A clear understanding of the molecular epidemiology of HPVs and the availability of powerful molecular diagnostic techniques have provided the background for prevention strategies of HPV-related carcinomas. Since these viruses are highly prevalent in the general population, strict screening programs are still necessary. Recently, major breakthroughs have emerged from immunological studies. Indeed, these studies have paved the way for medical treatment of HPV infections and provided the first highly effective preventive vaccines. For these principal reasons, the time has come for a great effort towards the eradication of these important human pathogens. The present review summarizes the main aspects of the virology, molecular epidemiology and molecular biology of HPV infection and highlights the recent perspectives of prevention and treatment of the HPV-related disease.     

Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is an acute infectious disease caused by CCHF virus (CCHFV), a member of the family Bunyaviridae, genus Nairovirus. The case fatality rate of CCHF ranges from 10-40%. Because CCHF is not present in Japan, many Japanese virologists and clinicians are not very familiar with this disease. However, there remains the possibility of an introduction of CCHFV or other hemorrhagic fever viruses into Japan from surrounding endemic areas. Development of diagnostic laboratory capacity for viral hemorrhagic fevers is necessary even in countries without these diseases. At the National Institute of Infectious Diseases, Tokyo, Japan, laboratory-based systems such as recombinant protein-based antibody detection, antigen-capture and pathological examination have been developed. In this review article, epidemiologic and clinical data on CCHF in the Xinjiang Uygur Autonomous Region, compiled through field investigations and diagnostic testing utilizing the aforementioned laboratory systems, are presented. CCHFV infections are closely associated with the environmental conditions, life styles, religion, occupation, and human economic activities. Based on these data, preventive measures for CCHFV infections are also discussed.     

Exotic viral diseases

Marburg virus disease, Lassa fever, monkeypox, and Ebola virus diseases of humans have all been recognized since 1967. These are examples of some of the exotic virus diseases which through importation may present a potential public health problem in the United States. Some of these viruses are also highly hazardous to laboratory and medical personnel. This paper is a review of the general characteristics, the epidemiology, and laboratory diagnosis of the exotic viruses which have been described during the last 25 years.     

The effect of newer tubercle bacillus digestion and decontamination procedures on fungi causing pulmonary diseases

The paper concerns the effect of the newer tubercle bacillus digestion and decontamination procedures on the principal pulmonary mycotic disease agents in sputum The digestion-decontamination procedures used were: 1) N-acetyl-L-cysteine - sodium hydroxide, 2) dithiothreitol - sodium hydroxide, and 3) trisodium phosphate - Zephiran.A portion of a Dissertation submitted by the senior author to the University of North Carolina in partial fulfillment of the requirements for the degree of Doctor of Public Health in the School of Public Health. Training was provided by the Laboratory Director's Program which is supported by Training Grant 5 T1 GM 567 from the National Institute of General Medical Sciences, National Institutes of Health, United States Public Health Service. The laboratory research was performed at the Laboratory Division, Center for Disease Control, under the supervision of the junior author.     

常见肝炎病毒感染性疾病相关miRNA功能研究进展

病毒感染引发的疾病一直威胁着人类健康。Mi RNA是真核生物表达的一类重要的小分子RNA,可特异性的调节基因与蛋白的表达。mi RNA的研究为病毒性疾病的发生发展提供了新思路,为目前热点研究领域。随着mi RNA的研究深入,一些病毒感染中相关mi RNA的功能也被相继报道,如有些mi RNA具有抑制病毒感染宿主细胞的功能,有些mi RNA则可促进病毒在宿主细胞中的复制,有些mi RNA却参与病毒相关疾病的发生,还有些mi RNA则可作为病毒感染性疾病的特异性生物标志物。本文主要以两种常见肝炎病毒:HBV、HCV为例来系统阐述mi RNA在病毒感染中的相关功能。