scholarly journals Reverse‐transcription recombinase‐aided amplification assay for H7 subtype avian influenza virus

2019 ◽  
Vol 67 (2) ◽  
pp. 877-883 ◽  
Author(s):  
Suchun Wang ◽  
Baoxu Huang ◽  
Xuejun Ma ◽  
Ping Liu ◽  
Yang Wang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reverse Transcription ◽  
Amplification Assay ◽  
H7 Subtype

scholarly journals Reverse-transcription recombinase-aided amplification assay for H5 subtype avian influenza virus

2020 ◽  
Author(s):  
Suchun Wang ◽  
Yang Li ◽  
Nan Jiang ◽  
Fuyou Zhang ◽  
Qingye Zhuang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reverse Transcription ◽  
Economic Losses ◽  
Clinical Samples ◽  
Analytical Sensitivity ◽  
Single Temperature ◽  
Amplification Assay ◽  
H5 Subtype

AbstractThe H5 subtype Avian Influenza Virus has caused huge economic losses to the poultry industry and is a threat to human health. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse-transcription recombinase-aided amplification assay for the detection of H5 subtype avian influenza virus. Assays were performed at a single temperature (39°C), and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus. The analytical sensitivity was 103 RNA copies per reaction at a 95% confidence interval according to probit regression analysis, with 100% specificity. Compared with published reverse-transcription quantitative real-time polymerase chain reaction assays, the κ value of the reverse transcription recombinase-aided amplification assay in 365 avian clinical samples was 0.970 (p < 0.001). The sensitivity for avian clinical sample detection was 94.44% (95%CI, 70.63% - 99.71%), and the specificity was 100% (95%CI, 98.64% - 100%). These results indicated that our reverse-transcription recombinase-aided amplification assay may be a valuable tool for detecting H5 subtype avian influenza virus.

scholarly journals Comparison of Avian Influenza Virus Contamination in the Environment Before and After Massive Poultry H5/H7 Vaccination in Zhejiang Province, China

2019 ◽  
Vol 6 (6) ◽  
Author(s):  
Wei Cheng ◽  
Ka Chun Chong ◽  
Steven Yuk-Fai Lau ◽  
Xiaoxiao Wang ◽  
Zhao Yu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Sharp Decrease ◽  
Type A ◽  
Zhejiang Province ◽  
Increased Risk ◽  
Before And After ◽  
Live Poultry ◽  
H7 Subtype

Abstract Background Information regarding comparison of the environmental prevalence of avian influenza virus (AIVs), before and after massive poultry vaccinations, is limited. Our study aimed to detect differences in the prevalence of AIVs type A and subtypes H5, H7, and H9 before and after the September 2017 massive poultry vaccination, across different sampling places and types. Methods We collected 55 130 environmental samples from 11 cities in Zhejiang Province (China) between March 2013 and December 2018. Multivariate logistic regression analyses were conducted to determine the prevalence of AIV type A and subtypes H5, H7, and H9 across different sampling places and types, before and after massive poultry vaccination. Results After the vaccination, contamination risk of AIV type A (adjusted odds ratio [aOR] = 1.08; 95% confidence interval [CI], 1.03–1.14) and subtype H9 (aOR = 1.58; 95% CI, 1.48–1.68) increased, and that of subtype H7 (aOR = 0.12; 95% CI, 0.10–0.14) decreased. Statistically significant decreased risk for H7 subtype contamination and increased risk for H9 subtype contamination were observed in backyard poultry flocks, live poultry markets, and slaughtering/processing plants. Swabs from poultry cages and slaughtering tables showed a statistically significant increased risk for H5 subtype contamination. The prevalence of H7 subtype decreased statistically significantly, whereas that of H9 subtype increased across the 5 sample types (poultry cages swabs, slaughtering table swabs, poultry feces, poultry drinking water, and poultry sewage). Conclusions Despite the sharp decrease in H7 subtype prevalence, reduction measures for AIV circulation are still imperative, given the high type A prevalence and the increase in H9 subtype contamination across different sampling places and types.

A Fully Automated Procedure for the High-Throughput Detection of Avian Influenza Virus by Real-Time Reverse Transcription–Polymerase Chain Reaction

2007 ◽  
Vol 51 (s1) ◽  
pp. 235-241 ◽  
Author(s):  
Montserrat Agüero ◽  
Elena San Miguel ◽  
Azucena Sánchez ◽  
Concepción Gómez-Tejedor ◽  
Miguel Angel Jiménez-Clavero
Keyword(s):  
Polymerase Chain Reaction ◽  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Real Time ◽  
High Throughput ◽  
Reverse Transcription ◽  
Chain Reaction ◽  
High Throughput Detection ◽  
Polymerase Chain

scholarly journals Acquisition of a Polybasic Hemagglutinin Cleavage Site by a Low-Pathogenic Avian Influenza Virus Is Not Sufficient for Immediate Transformation into a Highly Pathogenic Strain

2009 ◽  
Vol 83 (11) ◽  
pp. 5864-5868 ◽  
Author(s):  
Olga Stech ◽  
Jutta Veits ◽  
Siegfried Weber ◽  
Daniela Deckers ◽  
Diana Schröer ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Cleavage Site ◽  
Influenza Viruses ◽  
Avirulent Strain ◽  
Wild Type ◽  
Highly Pathogenic ◽  
Pathogenic Avian Influenza ◽  
H7 Subtype

ABSTRACT Highly pathogenic avian influenza viruses (HPAIV) differ from all other strains by a polybasic cleavage site in their hemagglutinin. All these HPAIV share the H5 or H7 subtype. In order to investigate whether the acquisition of a polybasic cleavage site by an avirulent avian influenza virus strain with a hemagglutinin other than H5 or H7 is sufficient for immediate transformation into an HPAIV, we adapted the hemagglutinin cleavage site of A/Duck/Ukraine/1/1963 (H3N8) to that of the HPAIV A/Chicken/Italy/8/98 (H5N2), A/Chicken/HongKong/220/97 (H5N1), or A/Chicken/Germany/R28/03 (H7N7) and generated the recombinant wild-type and cleavage site mutants. In contrast to the wild type, multicycle replication of these mutants in tissue culture was demonstrated by positive plaque assays and viral multiplication in the absence of exogenous trypsin. Therefore, in vitro all cleavage site mutants resemble an HPAIV. However, in chicken they did not exhibit high pathogenicity, although they could be reisolated from cloacal swabs to some extent, indicating enhanced replication in vivo. These results demonstrate that beyond the polybasic hemagglutinin cleavage site, the virulence of HPAIV in chicken is based on additional pathogenicity determinants within the hemagglutinin itself or in the other viral proteins. Taken together, these observations support the notion that acquisition of a polybasic hemagglutinin cleavage site by an avirulent strain with a non-H5/H7 subtype is only one among several alterations necessary for evolution into an HPAIV.

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