Waterfowl are considered the natural reservoir of low-virulence Newcastle disease viruses (loNDVs) and low-pathogenic avian influenza viruses (LPAIVs). The objective of this study was to investigate the effect of co-infections with loNDV and LPAIV on the infectivity and excretion of these viruses in mallards. One-month-old mallards were inoculated intranasally with 10(6) median embryo infectious doses of a wild-bird-origin loNDV and A/Mallard/MN/199106/99 (H3N8) LPAIV on the same day or received the LPAIV 2 or 5 days after loNDV inoculation. All mallards became infected with both viruses based on detection of seroconversion and viral shedding. Co-infection resulted in a higher number of cloacal swabs detected positive for LPAIV and a lower number of cloacal swabs detected positive for loNDV in some groups, although differences between groups were not statistically significant. Co-infection did not affect replication of LPAIV in epithelial cells of the lower intestine and bursa of Fabricius. In summary, the results of this study indicate that co-infection with LPAIV and loNDV does not affect the ability of mallards to be infected with either virus although it may have minimal effects on patterns (source and timing) of viral shedding.
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http://dx.doi.org/10.1080/03079457.2013.876530 | DOI Listing |
Viruses
November 2024
Exotic and Emerging Avian Viral Disease Research Unit, Southeast Poultry Research Laboratory, US National Poultry Research Center, 934 College Station Road, Athens, GA 30605, USA.
Post-transcriptional gene regulation mediated by microRNAs (miRNAs) relies on sequence complementarity between the miRNA seed site and the target gene transcript(s). This complementarity can completely inhibit or reduce translation into protein. We hypothesized that viruses employ sequence complementarity/similarity with host miRNAs to inhibit or increase the miRNA-mediated regulation of host gene expression specifically during viral infection(s).
View Article and Find Full Text PDFSci Rep
August 2024
Exotic and Emerging Avian Viral Disease Research Unit, Southeast Poultry Research Laboratories, US National Poultry Research Center, 934 College Station Road, Athens, GA, 30605, USA.
Newcastle disease (ND), an economically important disease in poultry, is caused by virulent strains of the genetically diverse Orthoavulavirus javaense (OAVJ). Laboratories rely on quantitative real-time reverse transcription PCR (qRT-PCR) to detect OAVJ and differentiate between OAVJ pathotypes. This study demonstrates that a fusion cleavage site based molecular beacon with reverse transcription loop mediated isothermal amplification (MB-RT-LAMP) assay can detect and differentiate OAVJ pathotypes in a single assay.
View Article and Find Full Text PDFAvian Dis
March 2023
Exotic and Emerging Avian Viral Diseases Research Unit, Southeast Poultry Research Laboratory, U.S. National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, GA 30605,
A complete genome sequence of a VG/GA -like strain of avian orthoavulavirus 1 (AOAV-1) was identified by nontargeted next-generation sequencing of an oropharyngeal swab sample collected from a carcass of a 12-mo-old backyard chicken. The isolate has a fusion (F) protein cleavage site motif consistent with a low virulent AOAV-1, but it has a unique motif with phenylalanine at position 117 (G-R-Q-G-R↓F), which is typical for virulent AOAV-1 strains. The one nucleotide difference at the cleavage site compared to other low-virulence viruses made the isolate detectable by F-gene-specific real-time reverse transcription-PCR (rRT-PCR) developed as a diagnostic test to specifically detect virulent strains.
View Article and Find Full Text PDFEmerging RNA virus infections are a growing concern among domestic poultry industries due to the severe impact they can have on flock health and economic livelihoods. Avian paramyxoviruses (APMV; avulaviruses, AaV) are pathogenic, negative-sense RNA viruses that cause serious infections in the respiratory and central nervous systems. APMV was detected in multiple avian species during the 2017 wild bird migration season in Ukraine and studied using PCR, virus isolation, and sequencing.
View Article and Find Full Text PDFViruses
April 2022
State Key Laboratory for Zoonotic Diseases, Key Laboratory of Zoonosis Research, Ministry of Education, College of Veterinary Medicine, Jilin University, Xi'an Road 5333, Changchun 130062, China.
The highly virulent Newcastle disease virus (NDV) isolates typically result in severe systemic pathological changes and high mortality in Newcastle disease (ND) illness, whereas avirulent or low-virulence NDV strains can cause subclinical disease with no morbidity and even asymptomatic infections in birds. However, understanding the host's innate immune responses to infection with either a highly virulent strain or an avirulent strain, and how this response may contribute to severe pathological damages and even mortality upon infection with the highly virulent strain, remain limited. Therefore, the differences in epigenetic and pathogenesis mechanisms between the highly virulent and avirulent strains were explored, by transcriptional profiling of chicken embryonic visceral tissues (CEVT), infected with either the highly virulent NA-1 strain or the avirulent vaccine LaSota strain using RNA-seq.
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