Evaluation of the improved method for isolation of A(H1N1) pandemic 2009 and seasonal A(H3N2) influenza virus in embryonated chicken eggs
10.3760/cma.j.cn112866-20250325-00069
- VernacularTitle:甲型H1N1和季节性H3N2流感病毒鸡胚分离改良方法效果评估
- Author:
Hongwei ZHU
1
;
Lei TANG
;
Wei CHU
;
Xue ZHAO
;
Yiqun LOU
;
Xiaojie CHU
;
Lili SONG
;
Yu WANG
;
Zheng TENG
Author Information
1. 上海市黄浦区疾病预防控制中心(上海市黄浦区卫生健康监督所)，上海 200023
- Publication Type:Journal Article
- Keywords:
Influenza virus;
H1N1pdm09;
H3N2snl;
Embryonated chicken eggs isolation
- From:
Chinese Journal of Experimental and Clinical Virology
2025;39(3):378-382
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To improve the isolation and culture method of seasonal influenza virus in embryonated chicken eggs (ECEs), and evaluate their isolation efficiency.Methods:We randomly selected 80 positive samples of H1N1 (H1N1pdm09) and seasonal H3N2 (H3N2snl) influenza virus nucleic acid, and inoculated them into the amniotic and urinary sac cavities of 10-day-old (traditional method) and 14-day-old (improved method) ECEs respectively to adapt the virus to the ECEs (E1-E2). Both method were used to inoculate 10-day-old urinary sac amplification virus (E2-E3), and the final virus isolation positive rates of the two method were compared; using fluorescence quantitative PCR method to detect viral nucleic acids in the improved amniotic and urinary sac cultures, and evaluate the viral proliferation at different inoculation sites; we analyzed the correlation between virus content and isolation positivity rate in the original specimen based on the CT value of nucleic acid testing and the final virus isolation positivity rate using the improved method.Results:The improved method obtained 42 strains of H1N1pdm09 strain, with a positive rate of 52.5% ( χ2=38.571, P<0.01); obtained 54 strains of H3N2snl strain, with a positive rate of 67.5% ( χ2=40.921, P<0.01). Significant differences were observed in the isolation efficiency of H1N1pdm09 samples when the improved method was applied to different inoculation sites of chicken embryos ( χ2=30.476, P<0.01), and similar differences were noted for H3N2snl samples ( χ2=4.928, P=0.026). There was no significant difference in the isolation rate of different CT value intervals of the original samples ( χH1N1pdm092=10.226, χH3N2snl2=3.764, P>0.05). Conclusions:The improved method of inoculating 14-day old ECEs adapted the virus, and the final number of strains obtained was significantly higher than the traditional method of inoculating 10 day old ECEs, which can significantly improve the positive isolation rate of H1N1pdm09 and H3N2snl influenza virus in ECEs. The amniotic cavity is more sensitive to H1N1pdm09 and H3N2snl influenza viruses, which helps the virus adapt in ECEs. There was no significant difference in the sample isolation rate and total positive rate of virus isolation among different CT value ranges, and further verification is needed.
