USE OF PRIMARY QUAIL EMBRYO FIBROBLAST CELLS FOR PROPAGATION AND ASSAY OF AVIAN VIRUSES

A primary fi broblast cells from embryos of brown quail Coturnix ypsilophora has been established and partially characterized. The cells were maintained in Modifi ed Eagle’s medium (MEM) supplemented with 10% fetal bovine serum. The cells were able to grow at temperatures between 35°C and 38°C with optimum temperature of 37°C. The growth rate of primary quail fi broblast cells increased as the FBS proportion increased from 5% to 20% at 37°C with optimum growth at the concentrations of 10% or 15% FBS. The cells showed no microbial contamination throughout the period of experiment and the total chromosome number of a diploid cell was 78, according to karyotyping and chromosome analysis. The susceptibility of quail primary cells for avian viruses was investigated in this study after inoculation with ND and IB viruses. Both viruses showed a satisfactory CPE development and the infectivity were assayed by virus titration (TCID50). This suggests that the quail primary cells can be used for isolation of various avian viruses with further steps of infectivity confi rmation in the future. INTRODUCTION Although embryonating eggs can support the growth of a broad range of avian viruses, many fi eld viruses do not readily grow in eggs. Therefore, obtaining a sufficient number of reliable, high-quality eggs to avoid false negatives (sample mishandling) is a considerable limitation in their use. Many attempts have been made to fi nd suitable alternatives to the use of eggs for avian virus isolation and research purposes. However, all the previously studied cell lines for avian viruses were mammalian in origin, and limitations (including the restricted host specifi city of the cell and a possible change in receptor specifi city) arise when using a mammalian cell line for avian virus study. Thus, it would be ideal to use a well-established avian-origin cell line for avian virus study. Infectious bronchitis virus (IBv) infects the respiratory tract, kidneys and oviduct of poultry of all ages, causing delay in growth, mortality, reduced egg production and poor egg shell quality and in many countries the disease remains one of the main problems affecting existing or USE OF PRIMARY QUAIL EMBRYO FIBROBLAST CELLS FOR PROPAGATION AND ASSAY OF AVIAN VIRUSES MAYADA F. HASOON*, MAJED H. MOHAMMED AND JALADET M.S. JUBRAEL Scientific Research Center, Faculty of Science, Duhok University,Kurdistan Region, Iraq * Corresponding author: mayada.hasoon@uod.ac MALAYSIAN JOURNAL OF VETERINARY RESEARCH VOLUME 6 NO. 1 JANUARY 2015 10 developing poultry industries. Until now, there is no cure for the disease (OIE, 1996). Prevention is to import birds from diseasefree fl ocks only or through vaccination. broilers are normally vaccinated at 1 day of age with live attenuated vaccines (Cavanagh & Naqi, 1997). In addition, breeders and egg layers are also vaccinated at approximately 8 week intervals with live attenuated vaccines, and with inactivated vaccines after they start laying eggs (Cook et al., 1999). NDv causes Newcastle disease (ND), which is an acute highly contagious viral disease of domestic poultry as well as other species of birds regardless of age and sex variation (Alexander, 2003). According to the strain variation of NDV, the rate of morbidity and mortality of poultry in a fl ock due to ND varies from 90-100%, thereby poultry industry all over the world facing serious economic losses every year. However IBv and NDv infections can also be diagnosed by detection of viral RNA, which make the diagnostic rapid and also dependable (Capua et al., 1999; Cavanagh, 2001), but researchers used to produce the virus by growing in embryonated chicken eggs and this takes long time and requires large area for egg incubation. Thus, cell cultures considered are more suitable and less expensive than eggs and also convenient to inspect microscopically for indication of viral proliferation (Dhinakar & Jones, 1997; de Wit et al., 1997). There is therefore a serious need to improve IB virus isolation technologies based on quail fi broblast cells (QFC). In this study, the authors evaluated the characteristics of quail fi broblast cells to investigate their ability to support the growth of avian viruses MATERIALS AND METHODS The 8-day-old embryos of quail in this research were provided by chicken breeding farm of faculty of Agricultural, Dept. Animal Production, Duhok Univ. Kurdistan Region, Iraq. MEM (Gibco, USA), special grade fetal bovine serum (Biochrom, German), DMSO (Sigma, USA), Hoechst 33258 (Invitrogen, USA) were used in this study. Reference strains of IB (QX strain) and ND (AG68,1968 Iraq. VI. 4a. AF001108) viruses were kindly provided by Al-Kindi Company for Veterinary Vaccines & Drugs, Baghdad, Iraq. This study was performed and accomplished at Animal Biotechnology Lab. , Scientifi c Research Center/Faculty of Science/ Duhok Univ.