Detection of H275Y mutation in influenza A H1N1 pdm09 virus by droplet digital PCR assay
10.19485/j.cnki.issn2096-5087.2022.11.012
- Author:
Xiuyu LOU
;
Hao YAN
;
Yi SUN
;
Xinying WANG
;
Yin CHEN
;
Haiyan MAO
- Publication Type:Journal Article
- Keywords:
influenza A H1N1 pdm09； influenza virus；H275Y mutation；droplet digital PCR
- From:
Journal of Preventive Medicine
2022;34(11):1139-1144
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluate the effectiveness of droplet digital PCR (ddPCR) assay for detection of neuraminidase (NA) H275Y mutations in influenza A H1N1 pdm09 virus.
Methods:The primers and dual probes were designed based on the sequence of the H1N1 pdm09 NA gene fragment which contained 275 amino acid sites, and the annealing temperature of ddPCR assay was optimized to establish a method for detection of H275 drug-sensitive genes and H275Y drug-resistant genes in H1N1 pdm09 virus. The sensitivity of ddPCR assay and fluorescent quantitative PCR (qPCR) assay was compared using the detection limit, and the specificity of ddPCR and qPCR assays was compared for detection of 14 respiratory virus samples. In addition, 64 clinical samples and 5 influenza isolates were tested to calculate the abundance of H275Y mutations, and the mutation abundance of 5 influenza isolates was compared with next-generation sequencing results.
Results: The optimal annealing temperature was 62.2 ℃. The detection limits of ddPCR assay were 5.28 (95%CI: 4.28-7.45) copies/reaction for H1N1 pdm09 H275 drug-sensitive plasmids and 6.51 (95%CI: 5.25-9.37) copies/reaction for H1N1 pdm09 H275Y drug-resistant plasmids, and the detection limits of qPCR assay were 5.70 (95%CI: 4.83-7.45) copies/reaction for H1N1 pdm09 H275Y drug-sensitive plasmids and 7.06 (95%CI: 5.92-9.40) copies/reaction for H1N1 pdm09 H275Y drug-resistant plasmids. Both ddPCR and qPCR assays detected H275 and H275Y drug-resistant plasmids in H1N1 pdm09 viral samples but did not detect H275 and H275Y drug-resistant plasmids in other 11 respiratory virus samples, and these two assays showed consistent results. Of the 64 clinical samples, ddPCR assay detected H275Y mutation in three pharyngeal swab specimens from a severe pneumonia patients infected with H1N1 pdm09 virus, and the greatest mutation abundance was detected in samples collected on day 4 post-treatment with oseltamivir phosphate (53.37%). ddPCR assay detected 0.63, 88.93%% and 1.27% H275Y mutation abundance in samples collected on days 2, 4 and 5 post-treatment with oseltamivir phosphate, and next-generation sequencing detected 89.46% H275Y mutation abundance in samples collected on day 4 post-treatment with oseltamivir phosphate; however, no H275Y mutation was detected in samples collected on days 2 or 5 post-treatment with oseltamivir phosphate.
Conclusions:ddPCR presents a higher sensitivity and specificity than qPCR assay for detection of H275Y mutations in H1N1 pdm09 virus, and presents a higher sensitivity than next-generation sequencing for detection of low-frequency mutations, which is effective for quantitative detection of H275Y mutations in the NA fragment of the H1N1 pdm09 virus.
- Full text:应用ddPCR检测甲型H1N1 pdm09流感病毒H275Y突变研究.pdf
