Studies on inactivated vaccine against infectious bovine rhinotracheitis virus [IBRV], I. influence of DEAE-dextran on the yield of IBR virus propagated on different cell culture systems

ABSTRACT

Infectivity titre of IBR virus in MDBK cells using monolayer, suspension and roller system revealed that the roller system produced the highest infectivity titre with an increase of log[10] 1.0 than their corresponding monolayer cell culture. On the other hand, the infectivity titres in cell suspension cultures were log[10] 0.6-log[10] 0.8 lower than their corresponding monolayer cell culture system. Influence of DEAE-dextran for the enhancement of IBR virus infectivity in different cell culture systems, 25 microg DEAE-dextran per ml is considered the safest concentration to the MDBK and VERO cell lines and giving these results: 1- Infectivity titre of IBR virus was markedly increased under the effect of both serial passages and DEAE-dextran in MDBK and VERO cells which showed an increase of log[10] 1.2 and log[10] 1.0, respectively more than their respective non treated passages. 2- In the roller system, DEAE-dextran enhanced the growth of virus by about 0.9, 0.7 log[10] more than growth of untreated virus in both MDBK and VERO cell lines, respectively. 3- The highest titre obtained when using DEAE-dextran MDBK roller system was log[10] 9.2 TCID[50]/ml