Repeated titrations of strains of Newcastle disease virus (NDV) are more conveniently undertaken in cell cultures rather than in embryonated eggs. This is relatively easy with mesogenic and velogenic strains that are cytopathic to various cell lines, but is difficult with avirulent Australian isolates that are poorly cytopathic. Strain V4 for example has been shown to be pathogenic iin vitro only to of chicken embryo liver cells. Strain I-2 was reported to produce cytopathic effect (CPE) on chicken embryo kidney (CEK) cells. The present studies confirmed this observation and developed a quantal assay. CEK cells infected with strain I-2 developed CPE characterized by degeneration, rounding, granularity and vacuolation, and the formation of synctia. End points were readily established by microscopic examination of fixed and stained cells. In virus infectivity studies on strain I-2, where multiple titrations are required and where large numbers of samples are used, titration using CEK cell grown in microtitre plates is recommended. Such studies may not be feasible in embryonated eggs.

Development of a cell culture method for quantal assay of strain I-2 of Newcastle disease virus.

http://prr.hec.gov.pk/jspui/bitstream/123456789/7756/1/Faisal_Siddique_2015_Microbiology_UAF.pdf

Preparation and field evaluation of cell culture adapted lyophilized thermostable newcastle disease vaccine

Lasota strain of Newcastle disease virus was successfully adapted to BHK 21 cell-culture. BHK 21 cell-culture adapted virus showed reduced virus infectivity. MDT and HA with chicken and equine RBC and elevated ICPI when compared with Lasota virus of chick embryo origin. Thermostability of the virus was unaffected. Serological response and challenge test results of the chicks vaccinated with BHK 21 -adapted vaccine showed encouraging results.

G. S. Reddy

Papers

Evaluation of BHK21 cell-line adapted Newcastle disease vaccine