广东省流感病毒亚型双重感染病例分离株的基因变异和进化分析

Genetic variation and evolution of influenza viruses isolated from co-infection cases in Guangdong Province

目的分析并揭示广东省流感病毒双重感染病例的毒株基因进化特征和变异特点。方法采集4例H1N1pdm和H3N2双重感染患者的咽拭子,分离毒株,进行抗原分析及神经氨酸酶药物敏感性试验。高通量测序方法测定3例患者的咽拭子和1株毒株序列并进行基因变异分析。结果分离获得4株流感病毒,血清型为1株H1N1pdm及3株H3N2亚型流感病毒,皆为2022—2023年疫苗株的类似株。甲型H1pdm和H3基因分别为6B.1A.5a.2a和2a.3a.1分支,与广东地区同期的流行株为同一分支。N1和N2基因未发现耐药位点的变异,对奥司他韦和扎那米韦均敏感。结论双重感染病例的毒株传代分离中,H1pdm比H3亚型复制能力更强。H1N1pdm和H3N2亚型流感病毒基因与广东地区同期流行的毒株基因型相近,无明显基因差异。H1N1pdm和H3N2对奥司他韦和扎那米韦均敏感,可以继续使用此类药物进行流感病毒单一或双重感染病例的治疗。

ObjectiveTo analyze and reveal the genetic evolution and variation of influenza viruses in cases of co-infection in Guangdong Province.MethodsThroat swab samples were collected from four cases of H1N1pdm and H3N2 co-infection for viral isolation.The isolated strains were subjected to antigen analysis and neuraminidase inhibitor susceptibility test.High-throughput sequencing was used to detect the sequences of strains in three throat swab samples and one virus strain,and then genetic variations were analyzed.ResultsFour influenza viruses were isolated with one strain of H1N1pdm and three of H3N2 subtype,and all of them were genetically similar to the vaccine strain in 2022-2023.The HA genes of H1N1pdm and H3N2 strains belonged to clade 6B.1A.5a.2a and 2a.3a.1,respectively.The isolated strains belonged to the same clade as the strains prevalent in Guangdong during the same period.No drug-resistant variations were detected in N1 or N2 gene,and the isolated strains were sensitive to oseltamivir and zanamivir.ConclusionsH1pdm subtype had stronger replication ability than H3 subtype in the influenza viruses isolated from co-infected cases.H1N1pdm and H3N2 subtype influenza viruses were genetically similar to the strains circulating in Guangdong at the same time.The isolated H1N1pdm and H3N2 strains were sensitive to both oseltamivir and zanamivir,indicating that they could continue to be used in the treatment of influenza virus infections caused by one or two genotypes.