scholarly journals Serological Evidence of Multiple Zoonotic Viral Infections among Wild Rodents in Barbados

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 663
Author(s):  
Kirk Osmond Douglas ◽  
Claire Cayol ◽  
Kristian Michael Forbes ◽  
Thelma Alafia Samuels ◽  
Olli Vapalahti ◽  
...  
Keyword(s):  
Viral Infections ◽  
Lymphocytic Choriomeningitis ◽  
Viral Rna ◽  
Cowpox Virus ◽  
Human Pathogens ◽  
Wild Rodents ◽  
Rt Pcr ◽  
Serological Evidence ◽  
Wild Mice ◽  
Zoonotic Pathogens

Background: Rodents are reservoirs for several zoonotic pathogens that can cause human infectious diseases, including orthohantaviruses, mammarenaviruses and orthopoxviruses. Evidence exists for these viruses circulating among rodents and causing human infections in the Americas, but much less evidence exists for their presence in wild rodents in the Caribbean. Methods: Here, we conducted serological and molecular investigations of wild rodents in Barbados to determine the prevalence of orthohantavirus, mammarenavirus and orthopoxvirus infections, and the possible role of these rodent species as reservoirs of zoonotic pathogens. Using immunofluorescent assays (IFA), rodent sera were screened for the presence of antibodies to orthohantavirus, mammarenavirus (Lymphocytic choriomeningitis virus—LCMV) and orthopoxvirus (Cowpox virus—CPXV) infections. RT-PCR was then conducted on orthohantavirus and mammarenavirus-seropositive rodent sera and tissues, to detect the presence of viral RNA. Results: We identified antibodies against orthohantavirus, mammarenavirus, and orthopoxvirus among wild mice and rats (3.8%, 2.5% and 7.5% seropositivity rates respectively) in Barbados. No orthohantavirus or mammarenavirus viral RNA was detected from seropositive rodent sera or tissues using RT–PCR. Conclusions: Key findings of this study are the first serological evidence of orthohantavirus infections in Mus musculus and the first serological evidence of mammarenavirus and orthopoxvirus infections in Rattus norvegicus and M. musculus in the English-speaking Caribbean. Rodents may present a potential zoonotic and biosecurity risk for transmission of three human pathogens, namely orthohantaviruses, mammarenaviruses and orthopoxviruses in Barbados.

scholarly journals Inhibition of dengue virus replication by mycophenolic acid and ribavirin

2006 ◽  
Vol 87 (7) ◽  
pp. 1947-1952 ◽  
Author(s):  
Ratree Takhampunya ◽  
Sukathida Ubol ◽  
Huo-Shu Houng ◽  
Craig E. Cameron ◽  
Radhakrishnan Padmanabhan
Keyword(s):  
Mycophenolic Acid ◽  
Viral Rna ◽  
Guanine Nucleotide ◽  
Inosine Monophosphate Dehydrogenase ◽  
Human Pathogens ◽  
Rt Pcr ◽  
Rna Translation ◽  
The Family ◽  
Viral Replicase

Dengue viruses (DEN), mosquito-borne members of the family Flaviviridae, are human pathogens of global significance. The effects of mycophenolic acid (MPA) and ribavirin (RBV) on DEN replication in monkey kidney (LLC-MK2) cells were examined. MPA (IC50=0.4±0.3 μM) and RBV (IC50=50.9±18 μM) inhibited DEN2 replication. Quantitative real-time RT-PCR of viral RNA and plaque assays of virions from DEN2-infected and MPA (10 μM)- and RBV (⩾200 μM)-treated cells showed a fivefold increase in defective viral RNA production by cells treated with each drug. Moreover, a dramatic reduction of intracellular viral replicase activity was seen by in vitro replicase assays. Guanosine reversed the inhibition of these compounds, suggesting that one mode of antiviral action of MPA and RBV is by inhibition of inosine monophosphate dehydrogenase and thereby depletion of the intracellular GTP pool. In addition, RBV may act by competing with guanine-nucleotide precursors in viral RNA translation, replication and 5′ capping.

Detection of Nucleic Acids in Cells or Tissue Sections Using In situ Polymerase Chain Reaction (PCR)

1996 ◽  
Vol 54 ◽  
pp. 16-17
Author(s):  
J. R. Hully ◽  
K. R. Luehrsen ◽  
K. Aoyagi ◽  
C. Shoemaker ◽  
R. Abramson
Keyword(s):  
Nucleic Acids ◽  
Viral Infections ◽  
Anatomical Location ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Cellular Source ◽  
Gene Transcripts ◽  
Initial Description ◽  
In Cells

The development of PCR technology has greatly accelerated medical research at the genetic and molecular levels. Until recently, the inherent sensitivity of this technique has been limited to isolated preparations of nucleic acids which lack or at best have limited morphological information. With the obvious exception of cell lines, traditional PCR or reverse transcription-PCR (RT-PCR) cannot identify the cellular source of the amplified product. In contrast, in situ hybridization (ISH) by definition, defines the anatomical location of a gene and/or it’s product. However, this technique lacks the sensitivity of PCR and cannot routinely detect less than 10 to 20 copies per cell. Consequently, the localization of rare transcripts, latent viral infections, foreign or altered genes cannot be identified by this technique. In situ PCR or in situ RT-PCR is a combination of the two techniques, exploiting the sensitivity of PCR and the anatomical definition provided by ISH. Since it’s initial description considerable advances have been made in the application of in situ PCR, improvements in protocols, and the development of hardware dedicated to in situ PCR using conventional microscope slides. Our understanding of the importance of viral latency or viral burden in regards to HIV, HPV, and KSHV infections has benefited from this technique, enabling detection of single viral copies in cells or tissue otherwise thought to be normal. Clearly, this technique will be useful tool in pathobiology especially carcinogenesis, gene therapy and manipulations, the study of rare gene transcripts, and forensics.

scholarly journals Viral Infections and Autoimmune Disease: Roles of LCMV in Delineating Mechanisms of Immune Tolerance

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 885
Author(s):  
Georgia Fousteri ◽  
Amy Dave Jhatakia
Keyword(s):  
Immune System ◽  
Autoimmune Disease ◽  
Viral Infections ◽  
Molecular Mimicry ◽  
Short Review ◽  
Organ Damage ◽  
Lymphocytic Choriomeningitis ◽  
Immune Deviation ◽  
Viral Pathogen ◽  
Lcmv Infection

Viral infections are a natural part of our existence. They can affect us in many ways that are the result of the interaction between the viral pathogen and our immune system. Most times, the resulting immune response is beneficial for the host. The pathogen is cleared, thus protecting our vital organs with no other consequences. Conversely, the reaction of our immune system against the pathogen can cause organ damage (immunopathology) or lead to autoimmune disease. To date, there are several mechanisms for virus-induced autoimmune disease, including molecular mimicry and bystander activation, in support of the “fertile field” hypothesis (terms defined in our review). In contrast, viral infections have been associated with protection from autoimmunity through mechanisms that include Treg invigoration and immune deviation, in support of the “hygiene hypothesis”, also defined here. Infection with lymphocytic choriomeningitis virus (LCMV) is one of the prototypes showing that the interaction of our immune system with viruses can either accelerate or prevent autoimmunity. Studies using mouse models of LCMV have helped conceive and establish several concepts that we now know and use to explain how viruses can lead to autoimmune activation or induce tolerance. Some of the most important mechanisms established during the course of LCMV infection are described in this short review.

Microelectrothermofluidic packaging for single chip integrated viral RNA extraction and RT-PCR microdevices

2010 ◽  
Author(s):  
Tae Goo Kang ◽  
Hong Miao Ji ◽  
Siow Pin Melvin Tan ◽  
Guang Kai Ignatius Tay ◽  
Ming Yi Daniel Ang ◽  
...  
Keyword(s):  
Rna Extraction ◽  
Viral Rna ◽  
Single Chip ◽  
Rt Pcr

scholarly journals Detection of Schmallenberg Virus RNA in Bull Semen in Poland

2016 ◽  
Vol 19 (3) ◽  
pp. 655-657 ◽  
Author(s):  
J. Kęsik-Maliszewska ◽  
M. Larska
Keyword(s):  
Extraction Method ◽  
Rna Extraction ◽  
Viral Rna ◽  
Schmallenberg Virus ◽  
Rt Pcr ◽  
Bovine Semen ◽  
Bull Semen ◽  
Virus Rna ◽  
Virus Excretion ◽  
Venereal Transmission

Abstract The detection of Schmallenberg virus (SBV) in the breeding bull semen raised the question of the possibility of venereal transmission of SBV which could result in cost-intensive restrictions in the trade of bovine semen. In order to evaluate the presence of SBV RNA in bovine semen, 131 bull semen samples from four locations in Poland collected between 2013 and 2015 were analysed by RT-PCR for viral RNA. SBV RNA was detected in 5.3% of the samples. The study has revealed that application of an appropriate RNA extraction method is crucial to detect virus excretion via semen.

scholarly journals Lentiviral Transduction of Dendritic Cells Confers Protective Antiviral Immunity In Vivo

2004 ◽  
Vol 78 (14) ◽  
pp. 7843-7845 ◽  
Author(s):  
Shohreh Zarei ◽  
Shahnaz Abraham ◽  
Jean-Francois Arrighi ◽  
Olivier Haller ◽  
Thomas Calzascia ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Viral Infections ◽  
Cytotoxic T Lymphocyte ◽  
Antiviral Immunity ◽  
Lymphocytic Choriomeningitis ◽  
Lymphocyte Response ◽  
Vaccine Candidates ◽  
Virus Model ◽  
Cytotoxic T Lymphocyte Response

ABSTRACT Control of a viral infection in vivo requires a rapid and efficient cytotoxic-T-lymphocyte response. We demonstrate that lentivirus-mediated introduction of antigen in dendritic cells confers a protective antiviral immunity in vivo in a lymphocytic choriomeningitis virus model. Therefore, lentiviral vectors may be excellent vaccine candidates for viral infections.

scholarly journals Hantavirus and arenavirus antibody prevalence in rodents and humans in Trentino, Northern Italy

2005 ◽  
Vol 134 (4) ◽  
pp. 830-836 ◽  
Author(s):  
H. KALLIO-KOKKO ◽  
J. LAAKKONEN ◽  
A. RIZZOLI ◽  
V. TAGLIAPIETRA ◽  
I. CATTADORI ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
Neutralization Assay ◽  
Lymphocytic Choriomeningitis ◽  
Clethrionomys Glareolus ◽  
Common Finding ◽  
Wild Rodents ◽  
Serum Samples ◽  
Bank Voles ◽  
Dobrava Virus ◽  
Low Prevalence

The spatial and temporal distribution of hantavirus and arenavirus antibody-positive wild rodents in Trentino, Italy, was studied using immunofluorescence assays (IFA) in two long-term sites trapped in 2000–2003, and six other sites trapped in 2002. The overall hantavirus seroprevalence in the bank voles, Clethrionomys glareolus (n=229) screened for Puumala virus (PUUV) antibodies was 0·4%, and that for Apodemus flavicollis mice (n=1416) screened for Dobrava virus (DOBV) antibodies was 0·2%. Antibodies against lymphocytic choriomeningitis virus (LCMV) were found in 82 (5·6%) of the 1472 tested rodents; the seroprevalence being 6·1% in A. flavicollis (n=1181), 3·3% in C. glareolus (n=276), and 14·3% in Microtus arvalis (n=7). Of the serum samples of 488 forestry workers studied by IFA, 12 were LCMV-IgG positive (2·5%) and one DOBV-IgG positive (0·2%), however, the latter could not be confirmed DOBV-specific with a neutralization assay. Our results show a widespread distribution but low prevalence of DOBV in Trentino, and demonstrate that the arenavirus antibodies are a common finding in several other rodent species besides the house mouse.

scholarly journals Quantitative measurement of infectious virus in SARS-CoV-2 Alpha, Delta and Epsilon variants reveals higher infectivity (viral titer:RNA ratio) in clinical samples containing the Delta and Epsilon variants.

2021 ◽  
Author(s):  
Hannah W Despres ◽  
Margaret G Mills ◽  
David J Shirley ◽  
Madaline M Schmidt ◽  
Meei-Li Huang ◽  
...  
Keyword(s):  
Quantitative Measurement ◽  
Infectious Virus ◽  
Viral Rna ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Genome Copy ◽  
Live Virus ◽  
High Degree ◽  
The Relationship ◽  
Rna Levels

ABSTRACT Background Novel SARS-CoV-2 Variants of Concern (VoC) pose a challenge to controlling the COVID-19 pandemic. Previous studies indicate that clinical samples collected from individuals infected with the Delta variant may contain higher levels of RNA than previous variants, but the relationship between viral RNA and infectious virus for individual variants is unknown. Methods We measured infectious viral titer (using a micro-focus forming assay) as well as total and subgenomic viral RNA levels (using RT-PCR) in a set of 165 clinical samples containing SARS-CoV-2 Alpha, Delta and Epsilon variants that were processed within two days of collection from the patient. Results We observed a high degree of variation in the relationship between viral titers and RNA levels. Despite the variability we observed for individual samples the overall infectivity differed among the three variants. Both Delta and Epsilon had significantly higher infectivity than Alpha, as measured by the number of infectious units per quantity of viral E gene RNA (6 and 4 times as much, p=0.0002 and 0.009 respectively) or subgenomic E RNA (11 and 7 times as much, p<0.0001 and 0.006 respectively). Conclusion In addition to higher viral RNA levels reported for the Delta variant, the infectivity (amount of replication competent virus per viral genome copy) may also be increased compared to Alpha. Measuring the relationship between live virus and viral RNA is an important step in assessing the infectivity of novel SARS-CoV-2 variants. An increase in the infectivity of the Delta variant may further explain increased spread and suggests a need for increased measures to prevent viral transmission.

scholarly journals A new subclass of exoribonuclease resistant RNA found in multiple Flaviviridae genera

2020 ◽  
Author(s):  
Matthew J. Szucs ◽  
Parker J. Nichols ◽  
Rachel A. Jones ◽  
Quentin Vicens ◽  
Jeffrey S. Kieft
Keyword(s):  
Rna Structure ◽  
Three Dimensional ◽  
Viral Rna ◽  
Human Pathogens ◽  
Virus Family ◽  
Innovative Strategies ◽  
Virus Rna ◽  
High Resolution Structure ◽  
Cellular Machinery ◽  
Rna Maturation

ABSTRACTViruses have developed innovative strategies to exploit the cellular machinery and overcome the host antiviral defenses, often using specifically structured RNA elements. Examples are found in flaviviruses; during flaviviral infection, pathogenic subgenomic flaviviral RNAs (sfRNAs) accumulate in the cell. These sfRNAs are formed when a host cell 5’ to 3’ exoribonuclease degrades the viral genomic RNA but is blocked by an exoribonuclease resistant RNA structure (xrRNA) located in the viral genome’s 3’untranslated region (UTR). Although known to exist in several Flaviviridae genera the full distribution and diversity of xRNAs in this virus family was unknown. Using the recent high-resolution structure of an xrRNA from the divergent flavivirus Tamana bat virus (TABV) as a reference, we used bioinformatic searches to identify xrRNA in the Pegivirus, Pestivirus, and Hepacivirus genera. We biochemically and structurally characterized several examples, determining that they are genuine xrRNAs with a conserved fold. These new xrRNAs look superficially similar to the previously described xrRNAs but possess structural differences making them distinct from previous classes of xrRNAs. Our findings thus require adjustments of previous xrRNA classification schemes and expand on the previously known distribution of the xrRNA in Flaviviridae, indicating their widespread distribution and illustrating their importance.IMPORTANCEThe Flaviviridae comprise one of the largest families of positive sense single stranded (+ssRNA) and it is divided into the Flavivirus, Pestivirus, Pegivirus, and Hepacivirus genera. The genus Flavivirus contains many medically relevant viruses such as Zika Virus, Dengue Virus, and Powassan Virus. In these, a part of the virus’s RNA twists up into a very special three-dimensional shape called an xrRNA that blocks the ability of the cell to “chew up” the viral RNA. Hence, part of the virus’ RNA remains intact, and this protected part is important for viral infection. This was known to occur in Flaviviruses but whether it existed in the other members of the family was not known. In this study, we not only identified a new subclass of xrRNA found in Flavivirus but also in the remaining three genera. The fact that this process of viral RNA maturation exists throughout the entire Flaviviridae family makes it clear that this is an important but underappreciated part of the infection strategy of these diverse human pathogens.

scholarly journals An ultra-sensitive, ultra-fast whole blood monocyte CD169 assay for COVID-19 screening

2020 ◽  
Author(s):  
Moïse Michel ◽  
Fabrice Malergue ◽  
Inès Ait Belkacem ◽  
Pénélope Bourgoin ◽  
Pierre-Emmanuel Morange ◽  
...  
Keyword(s):  
Whole Blood ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Early Stage ◽  
Polymorphonuclear Neutrophil ◽  
Blood Monocyte ◽  
Rt Pcr ◽  
Neutrophil Cd64 ◽  
Asymptomatic Patients ◽  
Hla Dr

AbstractCoVID-19 is an unprecedented epidemic, globally challenging health systems, societies, and economy. Its diagnosis relies on molecular methods, with drawbacks revealed by current use as mass screening. Monocyte CD169 upregulation has been reported as a marker of viral infections, we evaluated a flow cytometry three-color rapid assay of whole blood monocyte CD169 for CoVID-19 screening.Outpatients (n=177) with confirmed CoVID-19 infection, comprising 80 early-stage (≤14 days after symptom onset), 71 late-stage (≥15 days), and 26 asymptomatic patients received whole blood CD169 testing in parallel with SARS-CoV-2 RT-PCR. Upregulation of monocyte CD169 without polymorphonuclear neutrophil CD64 changes was the primary endpoint. Sensitivity was 98% and 100% in early-stage and asymptomatic patients respectively, specificity was 50% and 84%. Rapid whole blood monocyte CD169 evaluation was highly sensitive when compared with RT-PCR, especially in early-stage, asymptomatic patients whose RT-PCR tests were not yet positive.Diagnostic accuracy, easy finger prick sampling and minimal time-to-result (15-30 minutes) rank whole blood monocyte CD169 upregulation as a potential screening and diagnostic support for CoVID-19. Secondary endpoints were neutrophil CD64 upregulation as a marker of bacterial infections and monocyte HLA-DR downregulation as a surrogate of immune fitness, both assisting with adequate and rapid management of non-CoVID cases.

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