Screening and evaluation of seven standard strains of 2019-nCoV
10.3760/cma.j.cn112866-20231129-00066
- VernacularTitle:七种新型冠状病毒候选标准株的筛选和评价
- Author:
Pingping ZHOU
1
;
Xiaofang PENG
;
Wei LI
;
Xiaoling DENG
;
Huanying ZHENG
;
Runyu YUAN
;
Changwen KE
Author Information
1. 广东省公共卫生研究院，广州 511430
- Keywords:
2019-nCoV;
Plaque purification;
Standard strain
- From:
Chinese Journal of Experimental and Clinical Virology
2024;38(3):304-310
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To prepare seven standard strains of 2019 novel coronavirus (2019-nCoV), including wild type (WT) strain, Beta variant, Delta variant, Omicron variants (BA.2, BA.5, BQ.1, XBB.1 branches), which could be used to apply for national standard strains.Methods:According to cytopathic effect (CPE), virus titer, whole-virus-genome-sequencing and detection of mycoplasma, the basic biological characteristics of clonal isolation were determined through plaque purification technology.Results:The CPE was mainly characterized by cell shrinkage and exfoliation in Vero cells after infection with seven 2019-nCoV clonal isolations (WT, Beta, Delta, Omicron, BA.2, BA.5, BQ.1 and XBB.1 branches). The result of mycoplasma detection were negative and titers of the clonal isolation from 2nd to 5th generations were stable at 10 5-10 8 TCID 50/ml; the electron microscope showed that the virions were all round or elliptical, with a diameter between 60 nm and 140 nm. The subtypes of 7 strains were identified by whole-virus-genome-sequencing and phylogenetic analysis, with genomic stability after the fifth successive generations of clonal isolation. Conclusions:The series clonal isolation of 2019-nCoV with typical CPE of coronavirus, clear morphological structure, good viral activity and stable genetic characteristics were prepared, and they could be used to apply for national standard strains.
