Identification of bacteria in the tracheal swabs of farmed ostriches and their effect on the viability of influenza A virus

2021 ◽  
pp. 104063872110344
Author(s):  
Celia Abolnik ◽  
Christine Strydom ◽  
Debbie Landman ◽  
Reneé Pieterse
Keyword(s):  
Influenza A ◽  
Substantial Reduction ◽  
Fungal Species ◽  
Influenza Surveillance ◽  
Influenza A Viruses ◽  
Virus Inhibition ◽  
Extracellular Metabolites ◽  
Identification Of Bacteria ◽  
Acinetobacter Spp ◽  
Clostridium Spp

Avian influenza surveillance is a requirement for commercial trade in ostrich products, but influenza A viruses (IAVs) have proven difficult to isolate from ostrich tracheal swabs that test positive using molecular methods. We hypothesized that microbes unique to the ostrich trachea propagate in the transport medium after sampling and affect viral viability. We cultured tracheal swabs from 50 ostriches on 4 farms in South Africa, and recovered and identified 13 bacterial, 1 yeast, and 2 fungal species. Dietzia sp. had not been identified previously in the oropharyngeal tract of a bird, to our knowledge. The bacteria were tested for antimicrobial susceptibility, and most aerobic species, except for Streptococcus sp. and Pseudomonas sp., were sensitive to enrofloxacin; all were susceptible to sulfonamide. Virus inhibition experiments determined that ostrich-source Streptococcus sp., Pantoea sp., and Citrobacter freundii produced extracellular metabolites that caused a substantial reduction in the IAV titers of 99.9%. Streptomyces, Corynebacterium, Staphylococcus, Arthrobacter gandavensis, Pseudomonas putida, and Acinetobacter spp. similarly reduced the viability of IAV from 77.6% to 24.1%. Dietzia appeared to have no effect, but Rothia dentocariosa, Rhodotorula spp., and Clostridium spp. slightly increased the viability of IAV by 25.9, 34.9, and 58.5%, respectively.

scholarly journals Improving pandemic influenza risk assessment

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Colin A Russell ◽  
Peter M Kasson ◽  
Ruben O Donis ◽  
Steven Riley ◽  
John Dunbar ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Sequence Data ◽  
Virus Genome ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Human Influenza ◽  
Influenza A Viruses ◽  
Virus Genotype

Assessing the pandemic risk posed by specific non-human influenza A viruses is an important goal in public health research. As influenza virus genome sequencing becomes cheaper, faster, and more readily available, the ability to predict pandemic potential from sequence data could transform pandemic influenza risk assessment capabilities. However, the complexities of the relationships between virus genotype and phenotype make such predictions extremely difficult. The integration of experimental work, computational tool development, and analysis of evolutionary pathways, together with refinements to influenza surveillance, has the potential to transform our ability to assess the risks posed to humans by non-human influenza viruses and lead to improved pandemic preparedness and response.

scholarly journals Detection of Antigenic Variants of Subtype H3 Swine Influenza A Viruses from Clinical Samples

2017 ◽  
Vol 55 (4) ◽  
pp. 1037-1045 ◽  
Author(s):  
Brigitte E. Martin ◽  
Andrew S. Bowman ◽  
Lei Li ◽  
Jacqueline M. Nolting ◽  
David R. Smith ◽  
...  
Keyword(s):  
Influenza A ◽  
Large Population ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Proximity Ligation Assay ◽  
Clinical Samples ◽  
Influenza Surveillance ◽  
Influenza A Viruses ◽  
Virus Propagation ◽  
Vaccination Programs

ABSTRACT A large population of genetically and antigenically diverse influenza A viruses (IAVs) are circulating among the swine population, playing an important role in influenza ecology. Swine IAVs not only cause outbreaks among swine but also can be transmitted to humans, causing sporadic infections and even pandemic outbreaks. Antigenic characterizations of swine IAVs are key to understanding the natural history of these viruses in swine and to selecting strains for effective vaccines. However, influenza outbreaks generally spread rapidly among swine, and the conventional methods for antigenic characterization require virus propagation, a time-consuming process that can significantly reduce the effectiveness of vaccination programs. We developed and validated a rapid, sensitive, and robust method, the polyclonal serum-based proximity ligation assay (polyPLA), to identify antigenic variants of subtype H3N2 swine IAVs. This method utilizes oligonucleotide-conjugated polyclonal antibodies and quantifies antibody-antigen binding affinities by quantitative reverse transcription-PCR (RT-PCR). Results showed the assay can rapidly detect H3N2 IAVs directly from nasal wash or nasal swab samples collected from laboratory-challenged animals or during influenza surveillance at county fairs. In addition, polyPLA can accurately separate the viruses at two contemporary swine IAV antigenic clusters (H3N2 swine IAV-α and H3N2 swine IAV-ß) with a sensitivity of 84.9% and a specificity of 100.0%. The polyPLA can be routinely used in surveillance programs to detect antigenic variants of influenza viruses and to select vaccine strains for use in controlling and preventing disease in swine.

scholarly journals Characterization of a Novel Influenza A Virus Hemagglutinin Subtype (H16) Obtained from Black-Headed Gulls

2005 ◽  
Vol 79 (5) ◽  
pp. 2814-2822 ◽  
Author(s):  
Ron A. M. Fouchier ◽  
Vincent Munster ◽  
Anders Wallensten ◽  
Theo M. Bestebroer ◽  
Sander Herfst ◽  
...  
Keyword(s):  
Influenza A ◽  
Rapid Identification ◽  
Influenza Surveillance ◽  
Influenza A Viruses ◽  
Receptor Binding Site ◽  
Full Spectrum ◽  
Putative Receptor ◽  
Detection And Identification ◽  
Definition Of

ABSTRACT In wild aquatic birds and poultry around the world, influenza A viruses carrying 15 antigenic subtypes of hemagglutinin (HA) and 9 antigenic subtypes of neuraminidase (NA) have been described. Here we describe a previously unidentified antigenic subtype of HA (H16), detected in viruses circulating in black-headed gulls in Sweden. In agreement with established criteria for the definition of antigenic subtypes, hemagglutination inhibition assays and immunodiffusion assays failed to detect specific reactivity between H16 and the previously described subtypes H1 to H15. Genetically, H16 HA was found to be distantly related to H13 HA, a subtype also detected exclusively in shorebirds, and the amino acid composition of the putative receptor-binding site of H13 and H16 HAs was found to be distinct from that in HA subtypes circulating in ducks and geese. The H16 viruses contained NA genes that were similar to those of other Eurasian shorebirds but genetically distinct from N3 genes detected in other birds and geographical locations. The European gull viruses were further distinguishable from other influenza A viruses based on their PB2, NP, and NS genes. Gaining information on the full spectrum of avian influenza A viruses and creating reagents for their detection and identification will remain an important task for influenza surveillance, outbreak control, and animal and public health. We propose that sequence analyses of HA and NA genes of influenza A viruses be used for the rapid identification of existing and novel HA and NA subtypes.

scholarly journals Discordant Correlation between Serological Assays Observed When Measuring Heterosubtypic Responses against Avian Influenza H5 and H7 Viruses in Unexposed Individuals

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Eleonora Molesti ◽  
Francesca Ferrara ◽  
Giulia Lapini ◽  
Emanuele Montomoli ◽  
Nigel Temperton
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Vaccine Development ◽  
Critical Role ◽  
Haemagglutination Inhibition ◽  
Influenza Surveillance ◽  
Complex Nature ◽  
Italian Population ◽  
Influenza A Viruses ◽  
Serum Samples

The human population is constantly exposed to multiple influenza A subtypes due to zoonotic spillover and rapid viral evolution driven by intrinsic error-prone replication and immunological pressure. In this context, antibody responses directed against the HA protein are of importance since they have been shown to correlate with protective immunity. Serological techniques, detecting these responses, play a critical role for influenza surveillance, vaccine development, and assessment. As the recent human pandemics and avian influenza outbreaks have demonstrated, there is an urgent need to be better prepared to assess the contribution of the antibody response to protection against newly emerged viruses and to evaluate the extent of preexisting heterosubtypic immunity in populations. In this study, 68 serum samples collected from the Italian population between 1992 and 2007 were found to be positive for antibodies against H5N1 as determined by single radial hemolysis (SRH), but most were negative when evaluated using haemagglutination inhibition (HI) and microneutralisation (MN) assays. As a result of these discordant serological findings, the increased sensitivity of lentiviral pseudotypes was exploited in pseudotype-based neutralisation (pp-NT) assays and the results obtained provide further insight into the complex nature of humoral immunity against influenza A viruses.

scholarly journals Birth Cohort Effects in Influenza Surveillance Data: Evidence That First Influenza Infection Affects Later Influenza-Associated Illness

2019 ◽  
Vol 220 (5) ◽  
pp. 820-829 ◽  
Author(s):  
Alicia P Budd ◽  
Lauren Beacham ◽  
Catherine B Smith ◽  
Rebecca J Garten ◽  
Carrie Reed ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Birth Cohort ◽  
Influenza A ◽  
Influenza Infection ◽  
Surveillance Data ◽  
Influenza Surveillance ◽  
Severe Illness ◽  
Birth Cohorts ◽  
Influenza A Viruses ◽  
Cohort Differences

Abstract Background The evolution of influenza A viruses results in birth cohorts that have different initial influenza virus exposures. Historically, A/H3 predominant seasons have been associated with more severe influenza-associated disease; however, since the 2009 pandemic, there are suggestions that some birth cohorts experience more severe illness in A/H1 predominant seasons. Methods United States influenza virologic, hospitalization, and mortality surveillance data during 2000–2017 were analyzed for cohorts born between 1918 and 1989 that likely had different initial influenza virus exposures based on viruses circulating during early childhood. Relative risk/rate during H3 compared with H1 predominant seasons during prepandemic versus pandemic and later periods were calculated for each cohort. Results During the prepandemic period, all cohorts had more influenza-associated disease during H3 predominant seasons than H1 predominant seasons. During the pandemic and later period, 4 cohorts had higher hospitalization and mortality rates during H1 predominant seasons than H3 predominant seasons. Conclusions Birth cohort differences in risk of influenza-associated disease by influenza A virus subtype can be seen in US influenza surveillance data and differ between prepandemic and pandemic and later periods. As the population ages, the amount of influenza-associated disease may be greater in future H1 predominant seasons than H3 predominant seasons.

scholarly journals Avian Influenza Surveillance in the Danube Delta Using Sentinel Geese and Ducks

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Alexandru Coman ◽  
Daniel Narcis Maftei ◽  
Razvan M. Chereches ◽  
Elena Zavrotchi ◽  
Paul Bria ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Danube Delta ◽  
Influenza A Viruses ◽  
Highly Pathogenic ◽  
Domestic Bird ◽  
Hpai H5n1 ◽  
Migrating Birds

Highly pathogenic avian influenza (HPAI) H5N1 virus incursions from migrating birds have occurred multiple times in Romania since 2005. Beginning in September 2008 through April 2013, seasonal sentinel surveillance for avian influenza A viruses (AIVs) using domestic geese (Anser cygnoides) and ducks (Anas platyrhynchos) in the Danube Delta was established by placing 15 geese and 5 ducks at seven sites. Tracheal and cloacal swabs, and sera collections (starting in 2009) were taken monthly. We studied a total of 580 domestic birds and collected 5,520 cloacal and tracheal swabs from each and 2,760 sera samples. All swabs were studied with real-time reverse transcription polymerase chain reaction (rRT-PCR) for evidence of AIV. Serological samples were studied with hemagglutination inhibition assays against avian H5, H7, and H9 influenza viruses. From 2009 to 2013, 47 swab specimens from Cot Candura, Enisala, and Saon screened positive for AIV; further subtyping demonstrated that 14 ducks and 20 geese had cloacal evidence of H5N3 carriage. Correspondingly, 4 to 12 weeks after these molecular detections, sentinel bird sera revealed elevated HI titers against H5 virus antigens. We posit that domestic bird surveillance is an effective method to conduct AIV surveillance among migrating birds in delta areas.

scholarly journals COMPARISON OF INFLUENZA A VIRUS INHIBITION IN VITRO BY SIRNA COMPLEXES WITH CHITOSAN DERIVATIVES, POLYETHYLENEIMINE AND HYBRID POLYARGININE-INORGANIC MICROCAPSULES

2017 ◽  
Vol 62 (6) ◽  
pp. 259-265
Author(s):  
A. V. Petrova-Brodskaya ◽  
A. B. Bondarenko ◽  
A. S. Timin ◽  
M. A. Plotnikova ◽  
M. V. Afanas’Ev ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Influenza A ◽  
Sirna Delivery ◽  
Virus Genome ◽  
Small Interfering Rnas ◽  
Influenza A Viruses ◽  
Limited Effect ◽  
Virus Inhibition ◽  
Interfering Rna

Anti-influenza drugs and vaccines have a limited effect due to the high mutation rate of virus genome. The direct impact on the conservative virus genome regions should significantly improve therapeutic effectiveness. The RNA interference mechanism (RNAi) is one of the modern approaches used to solve this problem. In this work, we have investigated the antiviral activity of small interfering RNA (siRNA) against the influenza A/PR/8/34 (H1N1), targeting conserved regions of NP and PA. Polycations were used for intracellular siRNA delivery: chitosan’s derivatives (methylglycol and quaternized chitosan), polyethyleneimine, lipofectamine, and hybrid organic/non-organic microcapsules. A comparative study of these delivery systems with fluorescent labeled siRNA was conducted. The antiviral activity of three small interfering RNAs targeting the NP (NP-717, NP-1496) and PA (PA-1630) influenza A viruses genes was demonstrated, depending on the chosen carrier. The most effective intracellular delivery and antiviral activity were observed for hybrid microcapsules.

scholarly journals Impact assessment of non-pharmaceutical interventions against COVID-19 and influenza in Hong Kong: an observational study

2020 ◽  
Author(s):  
Benjamin J. Cowling ◽  
Sheikh Taslim Ali ◽  
Tiffany W. Y. Ng ◽  
Tim K. Tsang ◽  
Julian C. M. Li ◽  
...  
Keyword(s):  
Hong Kong ◽  
Influenza A ◽  
Adult Population ◽  
Substantial Reduction ◽  
Influenza Surveillance ◽  
Virus Infections ◽  
Social Distancing ◽  
Influenza A H1n1 ◽  
General Adult Population ◽  
Influenza Transmission

ABSTRACTBackgroundA range of public health measures have been implemented to delay and reduce local transmission of COVID-19 in Hong Kong, and there have been major changes in behaviours of the general public. We examined the effect of these interventions and behavioral changes on the incidence of COVID-19 as well as on influenza virus infections which may share some aspects of transmission dynamics with COVID-19.MethodsWe reviewed policy interventions and measured changes in population behaviours through two telephone surveys, on January 20-23 and February 11-14. We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt), for COVID-19 and influenza A(H1N1).FindingsCOVID-19 transmissibility has remained at or below 1, indicating successful containment to date. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% confidence interval, CI: 34% to 53%) reduction in transmissibility in the community, and a 33% (95% CI: 24% to 43%) reduction in transmissibility based on paediatric hospitalization rates. In the two surveys we estimated that 74.5% and 97.5% of the general adult population wore masks when going out, and 61.3% and 90.2% avoided going to crowded places, respectively.ImplicationsContainment measures, social distancing measures and changes in population behaviour have successfully prevented spread of COVID-19. The social distancing measures and behavioural changes led to a substantial reduction in influenza transmission in early February 2020. However, it may be challenging to avoid fatigue and sustain these measures and population behaviours as COVID-19 continues to spread globally.FundingHealth and Medical Research Fund, Hong Kong

scholarly journals Virological surveillance of influenza viruses in the WHO European Region in 2019/20 – impact of the COVID-19 pandemic

2020 ◽  
Vol 25 (46) ◽  
Author(s):  
Angeliki Melidou ◽  
Dmitriy Pereyaslov ◽  
Olav Hungnes ◽  
Katarina Prosenc ◽  
Erik Alm ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Influenza A ◽  
Influenza Viruses ◽  
European Region ◽  
Influenza Surveillance ◽  
Influenza A Viruses ◽  
Virological Surveillance

The COVID-19 pandemic negatively impacted the 2019/20 WHO European Region influenza surveillance. Compared with previous 4-year averages, antigenic and genetic characterisations decreased by 17% (3,140 vs 2,601) and 24% (4,474 vs 3,403). Of subtyped influenza A viruses, 56% (26,477/47,357) were A(H1)pdm09, 44% (20,880/47,357) A(H3). Of characterised B viruses, 98% (4,585/4,679) were B/Victoria. Considerable numbers of viruses antigenically differed from northern hemisphere vaccine components. In 2020/21, maintaining influenza virological surveillance, while supporting SARS-CoV-2 surveillance is crucial.

TMPRSS2 is essential for pathogenicity of H7N9 and H1N1 influenza A viruses in mice

Pneumologie ◽  
2014 ◽  
Vol 68 (02) ◽  
Author(s):  
C Tarnow ◽  
G Engels ◽  
A Arendt ◽  
F Schwalm ◽  
H Sediri ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Influenza ◽  
Influenza A Viruses
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