[characteristics of field isolates of newcastle disease virus isolated in the course of outbreaks in the poultry plant in the leningrad region in 2000]. | a field isolate of newcastle disease virus (ndv) was isolated in the russko-vysotskaya poultry farm, leningrad region. within four days after infection, the isolate caused 100% mortality in 60-day-old susceptible chickens. the ha titer of the allantoic fluid samples collected after one passage in spf-chicken embryos was 1:512, and it reacted only with the ndv specific antiserum in hi test. intracerebral pathogenicity index and mean embryo death time were 1.97 and 49 hours, respectively. the isol ... | 2002 | 12508684 |