Abstract of research

IDENTIFICATION AND MOLECULAR CHARACTERIZATION OF VELOGENIC NEUROTROPIC NEWCASTLE DISEASE VIRUS AFFECTING CHICKENS IN EASTERN REGION OF SAUDI ARABIA

Maged Gomaa Hemida1, 2

Abstract

Newcastle disease virus (NDV) is one of the major threats of the poultry industry worldwide. NDV causes high morbidity, mortality among the affected chicken. The main goals of the current study were first; isolation and identification of the circulating NDV strains in the Eastern region of Saudi Arabia (ESA), second; utilization of the state of-Art-molecular based diagnostic techniques for the early detection of NDV, third; conducting seroprevalence of NDV among farms in Eastern Saudi Arabia, fourth; comparing the sensitivity of different techniques in early diagnosis of NDV. To achieve these goals, we collected oronasal swabs, lung, cecal tonsils, and brain from farms in Al-Ahsa, Dammam, and Abqaiq. Isolation of NDV was carried out by using 9-11 days old non NDV vaccinated baladi chicken eggs. Identification of the isolated strains was done by hemagglutination, RT-PCR and Real Time PCR. Our results showing high prevalence of velogenic neurotropic and velogenic visrotropic strains of NDV. Seroprevalence is showing high antibody titers against NDV in the sera of chickens using hemagglutination inhibition (HI) and Enzyme Linked Immunosorbent Assay (ELISA). The velogenic NDV-F gene strains specific probes revealed the presence of these strains in the Eastern region. Real time PCR is more superior to Reverse Transcriptase (RT-PCR) which is more superior to HA and ELISA in NDV detection. In conclusion, several velogenic NDV strains are currently circulating in the ESA. These strains require more molecular characterization. To the best of our knowledge this is the first study in ESA comparing the sensitivity of various techniques in the detection of NDV.