The pathogenicity of swan derived H5N1 virus in birds and mammals and its gene analysis

Abstract

BackgroundHighly pathogenic avian influenza (HPAI) H5N1 viruses continue to circulate in poultry and can infect and cause mortality in birds and mammals; the genetic determinants of their increased virulence are largely unknown. The main purpose of this work was to determine the correlation between known molecular determinants of virulence in different avian influenza virus (AIV) genes and the results of experimental infection of birds and mammals with AIV strain A/swan/Mangistau/3/06 (H5N1; SW/3/06).Methods and resultsWe examined the virulence of SW/3/06 in four species of birds (chickens, ducks, turkeys, geese) and five species of mammals (mice, guinea pigs, cats, dogs, pigs), and identified the molecular determinants of virulence in 11 genes (HA, NA, PB1, PB1-F2, PB2, PA, NS1, NS2, M1, M2 and NP). SW/3/06 does not possess the prime virulence determinant of HPAIV – a polybasic HA cleavage site – and is highly pathogenic in chickens. SW/3/06 replicated efficiently in chickens, ducks, turkeys, mice and dogs, causing 100% mortality within 1.6–5.2 days. In addition, no mortalities were observed in geese, guinea pigs, cats and pigs. The HI assay demonstrated all not diseased animals infected with the SW/3/06 virus had undergone seroconversion by 14, 21 and 28 dpi. Eleven mutations in the seven genes were present in SW/3/06. These mutations may play a role in the pathogenicity of this strain in chickens, ducks, turkeys, mice and dogs. Together or separately, mutations 228S-103S-318I in HA may play a role in the efficient replication of SW/3/06 in mammals (mice, dogs, pigs).ConclusionsThis study provides new information on the pathogenicity of the newly-isolated swan derived H5N1 virus in birds and mammals, and explored the role of molecular determinants of virulence in different genes; such studies may help to identify key virulence or adaptation markers that can be used for global surveillance of viruses threatening to emerge into the human population.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-014-0207-y) contains supplementary material, which is available to authorized users.

MicroRNA expression profiles from HEK293 cells expressing H5N1 avian influenza virus non-structural protein 1

“…New vaccines against highly pathogenic AIV have been strongly discussed worldwide. 17–20 In the process of AIV infection in birds, NS1 proteins mediate the translation and replication of viral proteins by affecting host signaling pathways. There were reports that the poly ADP-ribose polymerase 10 (PARP10) protein was synergistic with H5N1 subtype AIV NS1 protein and co-regulated the replication process of AIV virus.…”

Registered Influenza Viral Vector Based Brucella abortus Vaccine for Cattle in Kazakhstan: Age-Wise Safety and Efficacy Studies

“…The vaccine formulation was prepared with IVV Flu-NS1-124-L7/L12-H5N1, Flu-NS1-124-Omp16-H5N1, Flu-NS1-124-L7/L12-H1N1 and Flu-NS1-124-Omp16-H1N1; the IVV were reproduced in 10-day-old chicken embryos (CE) at 34°C for 48 h. The titer of the IVV was determined in CE, as previously described ( Tabynov et al., 2014c ; Tabynov et al., 2015 ). Briefly, the obtained allantoic suspensions of viral constructs with the same antigenic structure (H5N1 or H1N1) were combined in a single pool in a 1:1 ratio to obtain the bivalent vaccine formulation.…”

“…A G G -3 ' a n d a n t i s e n s e 5 ' -CAAGATCCCAATGAT-3'), and were used for viral isolation (with two consecutive passages) in 10-day CE (Alel Agro, Kazakhstan) as described (Tabynov et al, 2014c) with a few modifications. In brief, for virus isolation, the nasal swab samples were clarified by centrifugation at 3.000×g for 10 min and by filtration through 0.2 µm filter.…”

Near-Complete Genome Sequence of an H5N1 Avian Influenza Virus Strain Isolated from a Swan in Southwest Kazakhstan in 2006

“…1) suggested that the HA gene segment of this SW/3/ 2006 H5N1 virus belonged to the Eurasian lineage, EA-nonGsGD clade, which does not have the main factor determining the virulence of HPAI H5N1 viruses-a polybasic HA cleavage site. Nevertheless, the intravenous pathogenicity index (N) was 2.34, and it allowed the strain to be considered highly pathogenic (7).…”