scholarly journals Diversity and Reassortment Rate of Influenza A Viruses in Wild Ducks and Gulls

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1010
Author(s):  
Yulia Postnikova ◽  
Anastasia Treshchalina ◽  
Elizaveta Boravleva ◽  
Alexandra Gambaryan ◽  
Aydar Ishmukhametov ◽  
...  
Keyword(s):  
Influenza A ◽  
Phylogenetic Trees ◽  
Point Mutations ◽  
Viral Gene ◽  
Viral Diversity ◽  
Influenza A Viruses ◽  
Significant Difference ◽  
Complete Genomes ◽  
Gene Reassortment ◽  
Wild Mallard

Influenza A viruses (IAVs) evolve via point mutations and reassortment of viral gene segments. The patterns of reassortment in different host species differ considerably. We investigated the genetic diversity of IAVs in wild ducks and compared it with the viral diversity in gulls. The complete genomes of 38 IAVs of H1N1, H1N2, H3N1, H3N2, H3N6, H3N8, H4N6, H5N3, H6N2, H11N6, and H11N9 subtypes isolated from wild mallard ducks and gulls resting in a city pond in Moscow, Russia were sequenced. The analysis of phylogenetic trees showed that stable viral genotypes do not persist from year to year in ducks owing to frequent gene reassortment. For comparison, similar analyses were carried out using sequences of IAVs isolated in the same period from ducks and gulls in The Netherlands. Our results revealed a significant difference in diversity and rates of reassortment of IAVs in ducks and gulls.

scholarly journals PRESENCE OF RESPIRATORY VIRUSES IN EQUINES IN BRAZIL

2014 ◽  
Vol 56 (3) ◽  
pp. 191-195
Author(s):  
Dalva Assunção Portari Mancini ◽  
Aparecida Santo Pietro Pereira ◽  
Rita Maria Zucatelli Mendonça ◽  
Adelia Hiroko Nagamori Kawamoto ◽  
Rosely Cabette Barbosa Alves ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Viruses ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Equine Influenza ◽  
Hemagglutination Inhibition Test ◽  
Parainfluenza Viruses ◽  
Significant Difference ◽  
Antibody Titers ◽  
The Difference

Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective titers (≥ 80 HIU/25µL) H7N7 and H3N8 subtypes of influenza A viruses, respectively. All horses (72) also responded with protective titers (≥ 80) HIU/25µL against the parainfluenza virus. The difference between mean antibody titers to H7N7 and H3N8 subtypes of influenza A viruses was not statistically significant (p > 0.05). The mean titers for influenza and parainfluenza viruses, on the other hand, showed a statistically significant difference (p < 0.001). These results indicate a better antibody response from equines to parainfluenza 3 virus than to the equine influenza viruses. No statistically significant differences in the responses against H7N7 and H3N8 subtypes of influenza A and parainfluenza 3 viruses were observed according to the gender (female, male) or the age (≤ 2 to 20 years-old) groups. This study provides evidence of the concomitant presence of two subtypes of the equine influenza A (H7N7 and H3N8) viruses and the parainfluenza 3 virus in equines in Brazil. Thus, it is advisable to vaccinate equines against these respiratory viruses.

scholarly journals Biological Cloth Face Coverings - The Reduction of SARS-CoV-2 and Influenza (H1N1) Infectivity by ViruferrinTM Treatment

2021 ◽  
Author(s):  
Emily Medina Magues ◽  
Anna Stedman ◽  
Paul Hope ◽  
Jorge E. Osorio
Keyword(s):  
Influenza A ◽  
Infectious Virus ◽  
Positive Control ◽  
Influenza A Viruses ◽  
Virus Particles ◽  
Significant Difference ◽  
Untreated Material ◽  
Fabric Material ◽  
Influenza H1n1 ◽  
Time Point

Fabric material was coated with Viruferrin&trade; and tested for its inactivating properties against the pandemic severe acute respiratory syndrome 2 (SARS-CoV-2) and influenza A viruses. A statistically significant (p&lt;0.0001) decrease in the number of infectious virus particles exposed to Viruferrin-treated fabric when compared with the cotton control for both SARS-CoV-2 and influenza A viruses was observed. For both SARS-CoV-2 and influenza A, Viruferrin-treated fabrics experienced a &gt; 99% virus reduction without saliva after five minutes of contact when compared to the positive control at time point 0. Furthermore, the reusability of the Viruferrin treated fabric was demonstrated by stability for up to 10 washes. The level of anti-viral (SARS-CoV-2) activity remained constant from 5 to 10 washes and demonstrated a significant difference (p&lt;0.0001) from the unwashed untreated material. Applications for this treated fabric are far-reaching, and as a biological face covering offers not only a unique 2-way protection but also is unlikely to cause onward touch transmission.

scholarly journals Non-Uniform and Non-Random Binding of Nucleoprotein to Influenza A and B Viral RNA

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 522 ◽  
Author(s):  
Valerie Le Sage ◽  
Adalena Nanni ◽  
Amar Bhagwat ◽  
Dan Snyder ◽  
Vaughn Cooper ◽  
...  
Keyword(s):  
Influenza A ◽  
Gene Segment ◽  
Influenza Viruses ◽  
Viral Rna ◽  
Influenza B Virus ◽  
Viral Gene ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Binding Profile ◽  
Random Manner

The genomes of influenza A and B viruses have eight, single-stranded RNA segments that exist in the form of a viral ribonucleoprotein complex in association with nucleoprotein (NP) and an RNA-dependent RNA polymerase complex. We previously used high-throughput RNA sequencing coupled with crosslinking immunoprecipitation (HITS-CLIP) to examine where NP binds to the viral RNA (vRNA) and demonstrated for two H1N1 strains that NP binds vRNA in a non-uniform, non-random manner. In this study, we expand on those initial observations and describe the NP-vRNA binding profile for a seasonal H3N2 and influenza B virus. We show that, similar to H1N1 strains, NP binds vRNA in a non-uniform and non-random manner. Each viral gene segment has a unique NP binding profile with areas that are enriched for NP association as well as free of NP-binding. Interestingly, NP-vRNA binding profiles have some conservation between influenza A viruses, H1N1 and H3N2, but no correlation was observed between influenza A and B viruses. Our study demonstrates the conserved nature of non-uniform NP binding within influenza viruses. Mapping of the NP-bound vRNA segments provides information on the flexible NP regions that may be involved in facilitating assembly.

scholarly journals Upstream translation initiation expands the coding capacity of segmented negative-strand RNA viruses

2019 ◽  
Author(s):  
Elizabeth Sloan ◽  
Marta Alenquer ◽  
Liliane Chung ◽  
Sara Clohisey ◽  
Adam M. Dinan ◽  
...  
Keyword(s):  
Translation Initiation ◽  
Influenza A ◽  
Viral Infections ◽  
Rna Viruses ◽  
Influenza Viruses ◽  
Open Reading Frames ◽  
Viral Gene ◽  
Influenza A Viruses ◽  
Negative Strand ◽  
Coding Potential

AbstractSegmented negative-strand RNA viruses (sNSVs) include the influenza viruses, the bunyaviruses, and other major pathogens of humans, other animals and plants. The genomes of these viruses are extremely short. In response to this severe genetic constraint, sNSVs use a variety of strategies to maximise their coding potential. Because the eukaryotic hosts parasitized by sNSVs can regulate gene expression through low levels of translation initiation upstream of their canonical open reading frames (ORFs), we asked whether sNSVs could use upstream translation initiation to expand their own genetic repertoires. Consistent with this hypothesis, we showed that influenza A viruses (IAVs) and bunyaviruses were capable of upstream translation initiation. Using a combination of reporter assays and viral infections, we found that upstream translation in IAVs can initiate in two unusual ways: through non-AUG initiation in virally encoded ‘untranslated’ regions, and through the appropriation of an AUG-containing leader sequence from host mRNAs through viral cap-snatching, a process we termed ‘start-snatching.’ Finally, while upstream translation of cellular genes is mainly regulatory, for sNSVs it also has the potential to create novel viral gene products. If in frame with a viral ORF, this creates N-extensions of canonical viral proteins. If not, it allows the expression of cryptic overlapping ORFs, which we found were highly conserved in IAV and widely distributed in peribunyaviruses. Thus, by exploiting their host’s capacity for upstream translation initiation, sNSVs can expand still further the coding potential of their extremely compact RNA genomes.

scholarly journals Notorious Novel Avian Influenza Viruses H10N8 and H7N9 in China in 2013 Co-originated from H9N2

2014 ◽  
Author(s):  
Liang Chen ◽  
Feng Zhu ◽  
Chenglong Xiong ◽  
Zhijie Zhang ◽  
Lufang Jiang ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Large Scale ◽  
Southern China ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Virus Reassortment ◽  
Epidemiological Characteristics

In 2013, two new avian influenza viruses (AIVs) H7N9 and H10N8 emerged in China caused worldwide concerns. Previous studies have studied their originations independently; this study is the first time to investigate their co-originating characteristics. Gene segments of assorted subtype influenza A viruses, as well as H10N8 and H7N9, were collected from public database. With the help of series software, small and large-scale phylogenetic trees, mean evolutionary rates, and divergence years were obtained successionally. The results demonstrated the two AIVs co-originated from H9N2, and shared a spectrum of mutations in common on many key sites related to pathogenic, tropism and epidemiological characteristics. For a long time, H9N2 viruses had been circulated in eastern and southern China; poultry was the stable and lasting maintenance reservoir. High carrying rate of AIVs H9N2 in poultry had an extremely high risk of co-infections with other influenza viruses, which increased the risk of virus reassortment. It implied that novel AIVs reassortants based on H9N2 might appear and prevail at any time in China; therefore, surveillance of H9N2 AIVs should be given a high priority.

scholarly journals Temperature-Sensitive Lesions in Two Influenza A Viruses Defective for Replicative Transcription Disrupt RNA Binding by the Nucleoprotein

1999 ◽  
Vol 73 (9) ◽  
pp. 7349-7356 ◽  
Author(s):  
Liz Medcalf ◽  
Emma Poole ◽  
Debra Elton ◽  
Paul Digard
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Rna Binding ◽  
Point Mutations ◽  
Temperature Shift ◽  
Binding Activity ◽  
Temperature Sensitive ◽  
Nonpermissive Temperature ◽  
Coding Region ◽  
Influenza A Viruses

ABSTRACT The negative-sense segmented RNA genome of influenza virus is transcribed into capped and polyadenylated mRNAs, as well as full-length replicative intermediates (cRNAs). The mechanism that regulates the two forms of transcription remains unclear, although several lines of evidence imply a role for the viral nucleoprotein (NP). In particular, temperature-shift and biochemical analyses of the temperature-sensitive viruses A/WSN/33ts56 and A/FPV/Rostock/34/Giessen tsG81 containing point mutations within the NP coding region have indicated specific defects in replicative transcription at the nonpermissive temperature. To identify the functional defect, we introduced the relevant mutations into the NP of influenza virus strain A/PR/8/34. Both mutants were temperature sensitive for influenza virus gene expression in transient-transfection experiments but localized and accumulated normally in transfected cells. Similarly, the mutants retained the ability to self-associate and interact with the virus polymerase complex whether synthesized at the permissive or the nonpermissive temperatures. In contrast, the mutant NPs were defective for RNA binding when expressed at the nonpermissive temperature but not when expressed at 30°C. This suggests that the RNA-binding activity of NP is required for replicative transcription.

scholarly journals A30 Avian influenza viruses in wild birds: Virus evolution in a multi-host ecosystem

2019 ◽  
Vol 5 (Supplement_1) ◽  
Author(s):  
Divya Venkatesh ◽  
Marjolein J Poen ◽  
Theo M Bestebroer ◽  
Rachel D Scheuer ◽  
Oanh Vuong ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Host Species ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
East African ◽  
Bird Populations ◽  
Under Sampling ◽  
The Republic

Abstract Wild ducks and gulls are the major reservoirs for avian influenza A viruses (AIVs). The mechanisms that drive AIV evolution are complex at sites where various duck and gull species from multiple flyways breed, winter, or stage. The Republic of Georgia is located at the intersection of three migratory flyways: the Central Asian Flyway, East Asian/East African Flyway, and Black Sea/Mediterranean Flyway. For six consecutive years (2010–6), we collected AIV samples from various duck and gull species that breed, migrate, and overwinter in Georgia. We found substantial subtype diversity of viruses that varied in prevalence from year to year. Low pathogenic (LP)AIV subtypes included H1N1, H2N3, H2N5, H2N7, H3N8, H4N2, H6N2, H7N3, H7N7, H9N1, H9N3, H10N4, H10N7, H11N1, H13N2, H13N6, H13N8, and H16N3, plus two H5N5 and H5N8 highly pathogenic (HP)AIVs belonging to clade 2.3.4.4. Whole-genome phylogenetic trees showed significant host species lineage restriction for nearly all gene segments and significant differences for LPAIVs among different host species in observed reassortment rates, as defined by quantification of phylogenetic incongruence, and in nucleotide diversity. Hemagglutinin clade 2.3.4.4 H5N8 viruses, circulated in Eurasia during 2014–5 did not reassort, but analysis after its subsequent dissemination during 2016–7 revealed reassortment in all gene segments except NP and NS. Some virus lineages appeared to be unrelated to AIVs in wild bird populations in other regions with maintenance of local AIV viruses in Georgia, whereas other lineages showed considerable genetic inter-relationship with viruses circulating in other parts of Eurasia and Africa, despite relative under-sampling in the area.

scholarly journals Avian Influenza A Viruses Reassort and Diversify Differently in Mallards and Mammals

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 509
Author(s):  
Ketaki Ganti ◽  
Anish Bagga ◽  
Juliana DaSilva ◽  
Samuel S. Shepard ◽  
John R. Barnes ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Host Species ◽  
Guinea Pigs ◽  
Influenza A ◽  
Model System ◽  
Mammalian Host ◽  
Viral Diversity ◽  
Influenza A Viruses ◽  
Longitudinal Patterns ◽  
Novel Host

Reassortment among co-infecting influenza A viruses (IAVs) is an important source of viral diversity and can facilitate expansion into novel host species. Indeed, reassortment played a key role in the evolution of the last three pandemic IAVs. Observed patterns of reassortment within a coinfected host are likely to be shaped by several factors, including viral load, the extent of viral mixing within the host and the stringency of selection. These factors in turn are expected to vary among the diverse host species that IAV infects. To investigate host differences in IAV reassortment, here we examined reassortment of two distinct avian IAVs within their natural host (mallards) and a mammalian model system (guinea pigs). Animals were co-inoculated with A/wildbird/California/187718-36/2008 (H3N8) and A/mallard/Colorado/P66F1-5/2008 (H4N6) viruses. Longitudinal samples were collected from the cloaca of mallards or the nasal tract of guinea pigs and viral genetic exchange was monitored by genotyping clonal isolates from these samples. Relative to those in guinea pigs, viral populations in mallards showed higher frequencies of reassortant genotypes and were characterized by higher genotype richness and diversity. In line with these observations, analysis of pairwise segment combinations revealed lower linkage disequilibrium in mallards as compared to guinea pigs. No clear longitudinal patterns in richness, diversity or linkage disequilibrium were present in either host. Our results reveal mallards to be a highly permissive host for IAV reassortment and suggest that reduced viral mixing limits avian IAV reassortment in a mammalian host.

scholarly journals The Evolutionary Dynamics of Influenza A Viruses Circulating in Mallards in Duck Hunting Preserves in Maryland, USA

2020 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
Nídia S. Trovão ◽  
Jacqueline M. Nolting ◽  
Richard D. Slemons ◽  
Martha I. Nelson ◽  
Andrew S. Bowman
Keyword(s):  
Influenza A ◽  
Evolutionary Dynamics ◽  
Bird Species ◽  
Wild Birds ◽  
Viral Gene ◽  
Influenza A Viruses ◽  
High Genetic Diversity ◽  
Wild Duck ◽  
Cost Efficient

Duck hunting preserves (DHP) have resident populations of farm-raised mallard ducks, which create potential foci for the evolution of novel influenza A viruses (IAVs). Through an eleven-year (2003–2013) IAV surveillance project in seven DHPs in Maryland, USA, we frequently identified IAVs in the resident, free-flying mallard ducks (5.8% of cloacal samples were IAV-positive). The IAV population had high genetic diversity, including 12 HA subtypes and 9 NA subtypes. By sequencing the complete genomes of 290 viruses, we determined that genetically diverse IAVs were introduced annually into DHP ducks, predominantly from wild birds in the Anatidae family that inhabit the Atlantic and Mississippi flyways. The relatively low viral gene flow observed out of DHPs suggests that raised mallards do not sustain long-term viral persistence nor do they serve as important sources of new viruses in wild birds. Overall, our findings indicate that DHPs offer reliable samples of the diversity of IAV subtypes, and could serve as regional sentinel sites that mimic the viral diversity found in local wild duck populations, which would provide a cost-efficient strategy for long-term IAV monitoring. Such monitoring could allow for early identification and characterization of viruses that threaten bird species of high economic and environmental interest.

scholarly journals Amantadine Variants Activity Against Multiple Influenza A Viruses

2021 ◽  
Author(s):  
Μarianna Stampolaki ◽  
Christina Tzitzoglaki ◽  
Christos Liolios ◽  
Anja Hoffmann ◽  
Brent Johnson ◽  
...  
Keyword(s):  
Influenza A ◽  
Early Stage ◽  
Biological Activities ◽  
Point Mutations ◽  
New Drugs ◽  
Host Cells ◽  
Wild Type ◽  
Influenza A Viruses ◽  
Proton Current ◽  
Antigenic Shift

Future pandemic influenza necessitates the development of new drugs against the current circulating, amantadine and rimantadine drugs resistant, influenza A M2 S31N viruses. The possibility of an antigenic shift to M2 S31 necessitates ranking the biological activities of amantadine variants. Several amantadine variants have been tested by different laboratories, but various M2 wild type influenza A strains have been used with different sensitivity against amantadine and the unambiguous comparison between potencies is not straightforward. Here, we compared the anti-influenza activities of 57 synthetic amantadine variants against influenza A WSN/33 viruses with amantadine-sensitive M2 WT, with a range of over three digits providing a reference set of potencies for structure-activity relationships, and amantadine-resistant M2 S31N proteins (and observed no potent compounds). 17 compounds were selected and tested against M2 L26F, V27A, A30T, G34E viruses. We tested few reference compounds using electrophysiology and explored point mutations which both showed that M2 is the target of potent antiviral potency against the M2 WT, L26F, V27A viruses. Major findings are: (a) Several amantadine variants from Kolocouris group block only M2 WT and M2 L26F-mediated proton current and the corresponding viruses replication. (b) A compound from Vazquez’s group is a triple blocker of M2 WT, L26F, V27A channels and viruses replication. (c) A compound from Vazquez’s group blocks only M2 L26 channel and virus replication. (d) Several compounds from Kolocouris group have potent activity against several influenza A M2 WT and three M2 S31N viruses, eg. the pandemic A/H1N1/California/07/2009 (H1N1pdm09) or A/H1N1/PuertoRico/08/1934 without blocking M2 S31N. The compounds and their cocktails while not to be more toxic than amantadine might be useful for re-purposing of amantadine class of drugs in the case (i) of the prevalence of M2 L26F and or M2 V27A strains (ii) of an antigenic shift of the virus to M2 WT and (iii) because they inhibited a broad panel of M2 WT and M2 S31N viruses including the H1N1pdm09). (d) We showed that the mechanism of antiviral activity against A/California/07/2009 or A/PR/08/1934 and possibly also M2 WT viruses compared to WSN/33 viruses is not due to inhibition of an early stage of virus infection or a late stage of M2 channel function during endocytosis or inhibition of HA binding to host cells or a different pH for HA fusion or a lysosomotropic effect.

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