Comparison of virulence of different SARS-CoV-2 strains in K18-hACE2 mice
10.13200/j.cnki.cjb.003853
- VernacularTitle:SARS-CoV-2不同毒株在K18-hACE2小鼠体内的毒力比较
- Author:
ZHANG Qiu
- Publication Type:Journal Article
- From:
Chinese Journal of Biologicals
2023;36(12):1455-1464
- CountryChina
- Language:Chinese
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Abstract:
Objective To investigate the infection effects of different strains(Prototype,Delta,Beta,and Omicron BA. 1)of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)on transgenic mice K18-hACE2 expressing angiotensinconverting enzyme 2(ACE2)by nasal drip.MethodsMice were challenged with each strain of different gradients of doses by nasal drip,which were monitored for body mass and survival daily for 6 d in Beta group and 14 d in the other three groups. The median lethal dose(LD_(50))was calculated by IBM SPSS Statistics 26 analysis software,and the virulence of different SARS-CoV-2 strains were compared by detection of the viral nucleic acid loads of lung,brain and turbinate tissues and the lesion of lung tissues.ResultsBeta strain showed the strongest virulence and the highest lethality,and the lowest dose(1 CCID_(50))was 100% lethal with a LD_(50)less than 1 CCID_(50);The LD_(50) of Delta,Prototype and Omicron BA.1 strains were 0. 52,0. 60 and 52. 92 CCID50respectively. The copy number of viral nucleic acid in lung tissue of mice infected with different strains elevated with the increase of challenge dose,and the copy number of viral nucleic acid in brain tissue of dead mice reached 10~8～ 10~(11) copies/mL. The lung tissues of mice infected with different strains of different doses showed different degrees of pathological damage.ConclusionThe virulence of different SARS-CoV-2 strains in K18-hACE2 mice from high to low were Beta,Delta,Prototype and Omicron BA.1.
