TY - JOUR
T1 - Selective isolation of Avian influenza virus (AIV) from cloacal samples containing AIV and Newcastle disease virus
AU - El Zowalaty, Mohamed E.
AU - Chander, Yogesh
AU - Redig, Patrick T.
AU - Abd El Latif, Hemmat K.
AU - El Sayed, Mona A.
AU - Goyal, Sagar M.
PY - 2011
Y1 - 2011
N2 - Avian influenza viruses (AIVs) are important zoonotic pathogens whose natural reservoir is waterfowl. In addition to AIV, waterfowl are often coinfected with other viruses, such as the paramyxoviruses, of which Newcastle disease virus (NDV) is of particular importance because of the highly virulent nature of certain strains of this virus for domestic poultry. In routine surveillance of waterfowl for AIV, a number of cloacal samples were encountered that were positive for AIV by real-time reverse transcription polymerase chain reaction (RT-PCR), but did not yield AIV by inoculation in embryonated chicken eggs. On further testing, these samples were also positive for NDV by conventional RT-PCR. It was hypothesized that if both NDV and AIV are present in a sample, the former may overgrow AIV yielding false-negative AIV results. Such samples were treated with chicken anti-NDV polyclonal antiserum and then inoculated in embryonated chicken eggs. Several samples were found to be positive for different subtypes of AIV, indicating that, in the presence of mixed infection with NDV and AIV, it is imperative to remove the influence of NDV, so a true picture of AIV prevalence emerges. An additional benefit is that information on the circulation of NDV in these birds sheds light on their epidemiologic and ecologic significance.
AB - Avian influenza viruses (AIVs) are important zoonotic pathogens whose natural reservoir is waterfowl. In addition to AIV, waterfowl are often coinfected with other viruses, such as the paramyxoviruses, of which Newcastle disease virus (NDV) is of particular importance because of the highly virulent nature of certain strains of this virus for domestic poultry. In routine surveillance of waterfowl for AIV, a number of cloacal samples were encountered that were positive for AIV by real-time reverse transcription polymerase chain reaction (RT-PCR), but did not yield AIV by inoculation in embryonated chicken eggs. On further testing, these samples were also positive for NDV by conventional RT-PCR. It was hypothesized that if both NDV and AIV are present in a sample, the former may overgrow AIV yielding false-negative AIV results. Such samples were treated with chicken anti-NDV polyclonal antiserum and then inoculated in embryonated chicken eggs. Several samples were found to be positive for different subtypes of AIV, indicating that, in the presence of mixed infection with NDV and AIV, it is imperative to remove the influence of NDV, so a true picture of AIV prevalence emerges. An additional benefit is that information on the circulation of NDV in these birds sheds light on their epidemiologic and ecologic significance.
KW - Avian influenza
KW - Cloacal samples
KW - Mixed infection
KW - Newcastle disease
KW - Waterfowl
UR - http://www.scopus.com/inward/record.url?scp=78651479740&partnerID=8YFLogxK
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U2 - 10.1177/104063871102300222
DO - 10.1177/104063871102300222
M3 - Article
C2 - 21398457
AN - SCOPUS:78651479740
SN - 1040-6387
VL - 23
SP - 330
EP - 332
JO - Journal of Veterinary Diagnostic Investigation
JF - Journal of Veterinary Diagnostic Investigation
IS - 2
ER -