Low pathogenic avian influenza in zebra finch (Taeniopygia guttata): clinical signs, replication and excretion time

Hadi Tavakkoli, Mahmood Salehi
experiment may further help us to investigate the AIV properties in the wild and pet birds. Materials and methods Virus We use a A/Chicken/Iran/SH-110/99(H9N2) virus, obtained from the Razi Vaccine and Serum Research Institute, Iran. Experimental design Ten 3-month male zebra finches (Taeniopygia guttata) were intranasally inoculated (IN) with 100 µl allantoic fluid containing 10 6 EID50 of the viruses. The EID50 was calculated according to the Reed and Muench formula (Smith et al 2003). Prior
more » ... o challenge, all birds were tested using real time reverse transcriptase polymerase chain reaction (RRT-PCR) to confirm negative to AI virus. Viral antigen was not detected prior to challenge H9N2 virus. The zebra finches were monitored daily for seven days to assess the clinical signs and behavior. Swabs of trachea and cloaca were collected in sterile tubes on days two, three, five and seven PI. The swab samples were then used for detection and quantitation of H9N2 viral antigen. The experiment was performed according to the suggested European ethical guidelines for animals care in experimental investigations. RNA extraction Viral RNA was extracted using the QIAamp ® Viral RNA kit (Qiagen, Germany) according to the manufacturer's protocol. Briefly, samples were homogenized with 200 µl of DEPC water Abstract. Avian Influenza is a contagious viral disease of global concern. Wide ranges of bird species are susceptible to infection. The aim of this study is to assess the clinical signs, replication and excretion time of a low pathogenic avian influenza virus in zebra finch. Ten three-month zebra finches were inoculated intranasally with a low pathogenic A/Chicken/Iran/SH-110/99(H9N2) virus. Clinical signs and viral titer in the tracheal and cloacal swabs were determined using TaqMan real time PCR. Sixty percent of the inoculated birds showed mild clinical signs including decreased activity, lethargy, ruffled feathers, and decreased feed consumption. The virus was detected in tracheal and cloacal swabs of the infected finches, three and five days post inoculation, respectively. The maximum virus titer in tracheal and cloacal swabs was detected on days two and three post inoculation. In comparison to the trachea, the virus was recovered in cloaca for a longer time. The diversity of clinical signs and excretion pattern observed suggests that low pathogenic H9N2 avian influenza virus can replicate in the heterologous finch host with causing mild clinical disease and short excretion time.