Temporal Pattern of Elution of Newcastle disease virus (V4 and Komarov strains) Following Haemagglutination of Chicken and Guinea Pig Erythrocytes

The temporal pattern of elution of V4 and Komarov strains of Newcastle disease virus (NDV) following haemagglutination of chicken and guinea pig red blood cells (RBCs) was investigated at different temperature conditions (4ᵒC, 25ᵒC, 37ᵒC and 45ᵒC). Chicken and guinea pig RBCs were haemagglutinated with V4 and Komarov strains of NDV and the haemagglutinated RBCs were centrifuged at 1,000 rpm for 5 minutes and the packed cells re-suspended in PBS, incubated at different temperatures and time intervals, centrifuged and the supernatants used to haemagglutinate fresh 2.5% suspension of chicken and guinea pig RBCs. The rate of elution of the two NDV strains increased with increase in incubation temperature against either RBC types. Significant elution pattern of the two virus strains were observed between the incubation temperatures of 45ᵒC compared to 4ᵒC and 25ᵒC using chicken RBC and between 45ᵒC and 4ᵒC using guinea pig RBC. Significant differences (≥4 fold rise in HA titre) in elution patterns between the chicken and guinea pig RBCs was only exhibited by the NDV Komarov strain at 37ᵒC and 45ᵒC. Only the chicken RBC showed notable difference in elution pattern between the two viruses at 4ᵒC. Maximum elution was recorded at 90-120 minutes of incubation, for both virus strains using the two RBCs and different incubation temperatures with the exception of NDV V4 at 45ᵒC using chicken RBC. Both virus strains demonstrated least elution at 4ᵒC and maximum elution at 45ᵒC using either RBC type. The 4ᵒC incubation temperature did not exhibit significant (≤4 fold rise in HA titre) elution by either virus strains against the different RBC types. In conclusion, the two NDV strains (Komarov and V4) were observed to elute from haemagglutinated chicken and guinea pig RBCs with increase in temperatures, with optimal elutions demonstrated at 45ᵒC and for 90 – 120 minutes of incubation and least elution at 4ᵒC throughout the period of incubation.