Study of the susceptibility of mice to Sendai strain Tianjin / 病毒学报

ABSTRACT

To explore the infectivity characteristics and susceptibility of Sendai strain Tianjin in 129Sv, DBA/2, Kunming and BALB/c mice and determine the optimal small rodent animal model for strain Tianjin research, the Sendai strain Tianjin was propagated for 72h in 9-11 day-old chicken embryos, the allantoic fluids were then harvested and the virus titer (11280) was detected by hemagglutination assay. Four different kinds of mice were intranasally inoculated with 5 microl and the diluted 30 microl virus solution. The weight loss of mice was monitored for 12 consecutive days and the survival rate was observed. Kunming and BALB/c mice were sacrificed on the first day prior to infection and on the fourth and seventh days post infection of the diluted 30 microl Sendai strain Tianjin. Their left lobes of lung were fixed with 4% formalin for histopathologic examination. The maximum percentage of average weight loss of 129Sv, DBA/2 were 13.0%, 4.7% with 100% survival rate when 129Sv, DBA/2, Kunming and BALB/c were inoculated with 5 microl virus solution, while the mice were inoculated with diluted 30 microl virus solution, the maximum percentage of average weight loss reached 21.7%, 30.3%, 16.7% and 9.7% with the survival rate of 20%, 0%, 80% and 100%. Lung infections of mice Kunming on the fourth and seventh day post infection were more severe than that of BALB/c, showing a large number of inflammatory cell exudation and thickening of the submucosa. It suggested that DBA/2 was the most susceptible to the infection of strain Tianjin. The mice susceptibility ranked as DBA/2>129Sv>Kunming>BALB/c. Mice DBA/2 and 129Sv could be used as the optimal small rodent animal models in the research of pathogenicity and vaccine of Sendai strain Tianjin.