紫外线照射对腺病毒气溶胶活力和粒级分布的影响

Effect of ultraviolet irradiation on vitality and size distribution of adenovirus aerosols

目的研究紫外线照射对腺病毒气溶胶活力和粒级分布的影响。方法在2000L的腔室中通过TK-3微生物气溶胶发生器将绿色荧光蛋白（GFP）标记的腺病毒形成气溶胶，暴露在预先设定波长的紫外线下，用多级撞击式空气微生物采样器进行采样。对采样样品进行实时荧光定量PCR（FQ-PCR）检测基因组拷贝数。通过在荧光显微镜下计数带绿色荧光的PK15细胞数可直观检测病毒的感染力及活力。结果带有绿色荧光的PK15细胞数及FQ．PCR检测结果均提示所采集的病毒气溶胶主要分布在第6级。波长为254nm的紫外线照射5min时，在显微镜下观察到的荧光数明显减少。波长为254nm紫外线照射30min时，6个级别的细胞内均未见绿色荧光。波为365nm紫外线照射30min时，绿色荧光数仍较多。波长为254nm的紫外线照射30min时没有观察到有绿色荧光的细胞，但是FQ-PCR结果提示病毒基因组拷贝数仍较高。结论波长为254nm的紫外线比365nm的紫外线照射灭活腺病毒气溶胶的效果更显著。两种波长的紫外线照射对腺病毒气溶胶的粒级分布没有显著影响。病毒基因组的存在并不能代表病毒有感染力。

Objective To investigate the effect of ultraviolet （UV） irradiation on vitality and size distribution of adenovirus aerosols. Methods The adenovirus was aerosolized in a 2000 L chamber using a TK-3 aerosol generator, exposed to 254 nm or 365 nm UV, and sampled using a FA-1 six-grade impact sampler. The relative genome copy number of virus in the aerosol was detected by real-time fluorescence quantitative（FQ） PCR. The number of virus-infected PK15 cells was examined by counting cells with green fluorescence under a fluorescent microscope. Results The FQ-PCR results and virus-infected PK15 cells counts showed that virus in aerosols was most abundant in grade 6. 254 nm UV irradiation for 5 min led to a sharp decrease of the cells with green fluorescence. No fluorescence cells were found after 30 min irradiation. 365 nm UV irradiation for 30 min did not change the green fluorescence cell count obviously. Although no adenovirus infected cells were observed by 254 nm UV irradiation for 30 min, the PCR results showed that there was still high number of virus genome detected in the aerosol. Conclusions 254 nm UV is more effective than 365 nm UV for inactivating adenovirus aerosols. The UV Irradiation does not interfere with the adenovirus aerosolsize distribution. Detecting of the virus genome copy number may not represent the vitality of virus.