38 research outputs found
The Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Does Not Replicate in Syrian Hamsters
In 2012 a novel coronavirus, MERS-CoV, associated with severe respiratory disease emerged in the Arabian Peninsula. To date, 55 human cases have been reported, including 31 fatal cases. Several of the cases were likely a result of human-to-human transmission. The emergence of this novel coronavirus prompts the need for a small animal model to study the pathogenesis of this virus and to test the efficacy of potential intervention strategies. In this study we explored the use of Syrian hamsters as a small animal disease model, using intratracheal inoculation and inoculation via aerosol. Clinical signs of disease, virus replication, histological lesions, cytokine upregulation nor seroconversion were observed in any of the inoculated animals, indicating that MERS-CoV does not replicate in Syrian hamsters
The human sodium iodide symporter as a reporter gene for studying Middle East respiratory syndrome coronavirus pathogenesis
Single photon emission computed tomography (SPECT) is frequently used in oncology and cardiology to evaluate disease progression and/or treatment efficacy. Such technology allows for real-time evaluation of disease progression and when applied to studying infectious diseases may provide insight into pathogenesis. Insertion of a SPECT-compatible reporter gene into a virus may provide insight into mechanisms of pathogenesis and viral tropism. The human sodium iodide symporter (hNIS), a SPECT and positron emission tomography reporter gene, was inserted into Middle East respiratory syndrome coronavirus (MERS-CoV), a recently emerged virus that can cause severe respiratory disease and death in afflicted humans to obtain a quantifiable and sensitive marker for viral replication to further MERS-CoV animal model development. The recombinant virus was evaluated for fitness, stability, and reporter gene functionality. The recombinant and parental viruses demonstrated equal fitness in terms of peak titer and replication kinetics, were stable for up to six in vitro passages, and were functional. Further in vivo evaluation indicated variable stability, but resolution limits hampered in vivo functional evaluation. These data support the further development of hNIS for monitoring infection in animal models of viral disease.IMPORTANCE Advanced medical imaging such as single photon emission computed tomography with computed tomography (SPECT/CT) enhances fields such as oncology and cardiology. Application of SPECT/CT, magnetic resonance imaging, and positron emission tomography to infectious disease may enhance pathogenesis studies and provide alternate biomarkers of disease progression. The experiments described in this article focus on insertion of a SPECT/CT-compatible reporter gene into MERS-CoV to demonstrate that a functional SPECT/CT reporter gene can be inserted into a virus
Filovirus RefSeq Entries: Evaluation and Selection of Filovirus Type Variants, Type Sequences, and Names
Sequence determination of complete or coding-complete genomes of viruses is becoming common practice for supporting the work of epidemiologists, ecologists, virologists, and taxonomists. Sequencing duration and costs are rapidly decreasing, sequencing hardware is under modification for use by non-experts, and software is constantly being improved to simplify sequence data management and analysis. Thus, analysis of virus disease outbreaks on the molecular level is now feasible, including characterization of the evolution of individual virus populations in single patients over time. The increasing accumulation of sequencing data creates a management problem for the curators of commonly used sequence databases and an entry retrieval problem for end users. Therefore, utilizing the data to their fullest potential will require setting nomenclature and annotation standards for virus isolates and associated genomic sequences. The National Center for Biotechnology Information’s (NCBI’s) RefSeq is a non-redundant, curated database for reference (or type) nucleotide sequence records that supplies source data to numerous other databases. Building on recently proposed templates for filovirus variant naming [ ()////-], we report consensus decisions from a majority of past and currently active filovirus experts on the eight filovirus type variants and isolates to be represented in RefSeq, their final designations, and their associated sequences
Virus nomenclature below the species level : a standardized nomenclature for filovirus strains and variants rescued from cDNA
Specific alterations (mutations, deletions,
insertions) of virus genomes are crucial for the functional
characterization of their regulatory elements and their expression products, as well as a prerequisite for the creation
of attenuated viruses that could serve as vaccine
candidates. Virus genome tailoring can be performed either
by using traditionally cloned genomes as starting materials,
followed by site-directed mutagenesis, or by de novo synthesis
of modified virus genomes or parts thereof. A systematic
nomenclature for such recombinant viruses is
necessary to set them apart from wild-type and laboratoryadapted
viruses, and to improve communication and collaborations
among researchers who may want to use
recombinant viruses or create novel viruses based on them.
A large group of filovirus experts has recently proposed
nomenclatures for natural and laboratory animal-adapted
filoviruses that aim to simplify the retrieval of sequence
data from electronic databases. Here, this work is extended
to include nomenclature for filoviruses obtained in the
laboratory via reverse genetics systems. The previously
developed template for natural filovirus genetic variant
naming,\virus name[(\strain[/)\isolation host-suffix[/
\country of sampling[/\year of sampling[/\genetic
variant designation[-\isolate designation[, is retained, but we propose to adapt the type of information added to each
field for cDNA clone-derived filoviruses. For instance, the
full-length designation of an Ebola virus Kikwit variant
rescued from a plasmid developed at the US Centers for
Disease Control and Prevention could be akin to ‘‘Ebola
virus H.sapiens-rec/COD/1995/Kikwit-abc1’’ (with the
suffix ‘‘rec’’ identifying the recombinant nature of the virus
and ‘‘abc1’’ being a placeholder for any meaningful isolate
designator). Such a full-length designation should be used
in databases and the methods section of publications.
Shortened designations (such as ‘‘EBOV H.sap/COD/95/
Kik-abc1’’) and abbreviations (such as ‘‘EBOV/Kik-abc1’’)
could be used in the remainder of the text, depending on
how critical it is to convey information contained in the
full-length name. ‘‘EBOV’’ would suffice if only one
EBOV strain/variant/isolate is addressed.http://link.springer.com/journal/705hb201
Virus nomenclature below the species level : a standardized nomenclature for laboratory animal-adapted strains and variants of viruses assigned to the family Filoviridae
The International Committee on Taxonomy of Viruses (ICTV) organizes the classification of
viruses into taxa, but is not responsible for the nomenclature for taxa members. International
experts groups, such as the ICTV Study Groups, recommend the classification and naming of
viruses and their strains, variants, and isolates. The ICTV Filoviridae Study Group has recently
introduced an updated classification and nomenclature for filoviruses. Subsequently, and
together with numerous other filovirus experts, a consistent nomenclature for their natural
genetic variants and isolates was developed that aims at simplifying the retrieval of sequence
data from electronic databases. This is a first important step toward a viral genome annotation
standard as sought by the US National Center for Biotechnology Information (NCBI). Here, this
work is extended to include filoviruses obtained in the laboratory by artificial selection through
passage in laboratory hosts. The previously developed template for natural filovirus genetic
variant naming ( //<year of
sampling>/-) is retained, but it is proposed to
adapt the type of information added to each field for laboratory animal-adapted variants. For
instance, the full-length designation of an Ebola virus Mayinga variant adapted at the State
Research Center for Virology and Biotechnology “Vector” to cause disease in guinea pigs after
seven passages would be akin to “Ebola virus VECTOR/C.porcellus-lab/COD/1976/Mayinga-
GPA-P7”. As was proposed for the names of natural filovirus variants, we suggest using the fulllength
designation in databases, as well as in the method section of publications. Shortened
designations (such as “EBOV VECTOR/C.por/COD/76/May-GPA-P7”) and abbreviations (such
as “EBOV/May-GPA-P7”) could be used in the remainder of the text depending on how critical it is to convey information contained in the full-length name. “EBOV” would suffice if only one
EBOV strain/variant/isolate is addressed.This work was funded in part by the Joint Science and Technology Office for Chem Bio Defense (proposal #TMTI0048_09_RD_T to SB).http://www.springerlink.com/content/0304-8608/hb2013ab201
The Impact of Regulations, Safety Considerations and Physical Limitations on Research Progress at Maximum Biocontainment
We describe herein, limitations on research at biosafety level 4 (BSL-4) containment laboratories, with regard to biosecurity regulations, safety considerations, research space limitations, and physical constraints in executing experimental procedures. These limitations can severely impact the number of collaborations and size of research projects investigating microbial pathogens of biodefense concern. Acquisition, use, storage, and transfer of biological select agents and toxins (BSAT) are highly regulated due to their potential to pose a severe threat to public health and safety. All federal, state, city, and local regulations must be followed to obtain and maintain registration for the institution to conduct research involving BSAT. These include initial screening and continuous monitoring of personnel, controlled access to containment laboratories, accurate and current BSAT inventory records. Safety considerations are paramount in BSL-4 containment laboratories while considering the types of research tools, workflow and time required for conducting both in vivo and in vitro experiments in limited space. Required use of a positive-pressure encapsulating suit imposes tremendous physical limitations on the researcher. Successful mitigation of these constraints requires additional time, effort, good communication, and creative solutions. Test and evaluation of novel vaccines and therapeutics conducted under good laboratory practice (GLP) conditions for FDA approval are prioritized and frequently share the same physical space with important ongoing basic research studies. The possibilities and limitations of biomedical research involving microbial pathogens of biodefense concern in BSL-4 containment laboratories are explored in this review
ABSL-4 Aerobiology Biosafety and Technology at the NIH/NIAID Integrated Research Facility at Fort Detrick
The overall threat of a viral pathogen to human populations is largely determined by the modus operandi and velocity of the pathogen that is transmitted among humans. Microorganisms that can spread by aerosol are considered a more challenging enemy than those that require direct body-to-body contact for transmission, due to the potential for infection of numerous people rather than a single individual. Additionally, disease containment is much more difficult to achieve for aerosolized viral pathogens than for pathogens that spread solely via direct person-to-person contact. Thus, aerobiology has become an increasingly necessary component for studying viral pathogens that are naturally or intentionally transmitted by aerosol. The goal of studying aerosol viral pathogens is to improve public health preparedness and medical countermeasure development. Here, we provide a brief overview of the animal biosafety level 4 Aerobiology Core at the NIH/NIAID Integrated Research Facility at Fort Detrick, Maryland, USA
The Impact of Regulations, Safety Considerations and Physical Limitations on Research Progress at Maximum Biocontainment
Aerosol exposure to intermediate size Nipah virus particles induces neurological disease in African green monkeys.
Nipah virus (NiV) infection can lead to severe respiratory or neurological disease in humans. Transmission of NiV has been shown to occur through contact with virus contaminated fomites or consumption of contaminated food. Previous results using the African green monkey (AGM) model of NiV infection identified aspects of infection that, while similar to humans, don't fully recapitulate disease. Previous studies also demonstrate near uniform lethality that is not consistent with human NiV infection. In these studies, aerosol exposure using an intermediate particle size (7μm) was used to mimic potential human exposure by facilitating virus deposition in the upper respiratory tract. Computed tomography evaluation found some animals developed pulmonary parenchymal disease including consolidations, ground-glass opacities, and reactive adenopathy. Despite the lack of neurological signs, magnetic resonance imaging identified distinct brain lesions in three animals, similar to those previously reported in NiV-infected patients. Immunological characterization of tissues collected at necropsy suggested a local pulmonary inflammatory response with increased levels of macrophages in the lung, but a limited neurologic response. These data provide the first clear evidence of neurological involvement in the AGM that recapitulates human disease. With the development of a disease model that is more representative of human disease, these data suggest that NiV infection in the AGM may be appropriate for evaluating therapeutic countermeasures directed at virus-induced neuropathogenesis