加热灭活对下呼吸道病毒抗原检测结果影响的初步研究

Preliminary study on the effects of heating inactivation on the test results of lower respiratory tract virus antigens

目的探讨采用56℃、30 min,56℃、60 min,60℃、30 min,70℃、15 min加热灭活标本对直接免疫荧光法(DFA)检测7项下呼吸道病毒抗原检测结果的影响。方法收集2020年1月5日至4月29日64例因下呼吸道感染住院患儿的痰液标本进行7项呼吸道病毒抗原DFA检测,采用未灭活常规方法同56℃、30 min,56℃、60 min,60℃、30 min,70℃、15 min加热灭活方法进行检测结果比较。结果通过未灭活常规方法检出39份阳性标本、25份阴性标本,同时采用56℃、30 min,56℃、60 min,60℃、30 min,70℃、15 min加热灭活进行检测,阳性标本结果符合率为100.0%(39/39),阴性标本结果符合率为100.0%(25/25),加热灭活后与未灭活常规方法检测标本的结果具有极好一致性;对荧光显微镜下形态进行比较,阳性结果标本采用56℃、30 min,56℃、60 min,60℃、30 min加热灭活后与未灭活常规方法检测结果比较,阳性细胞荧光状态、阳性细胞数基本一致,采用70℃、15 min加热灭活后,阳性细胞数明显减少、阳性细胞荧光强度明显下降。结论采用加热灭活标本后再进行DFA检测下呼吸道病毒抗原实验,既能保证检测结果的一致性,同时可降低检验人员感染风险,保障实验室生物安全。

Objective To investigate the effect of heating inactivation under condition of 56℃30 min,56℃,60 min,60℃30 min,70℃15 min on the detection results of 7 lower respiratory virus antigens by direct immunofluorescence assay(DFA).Methods Sputum samples were collected for 7 respiratory virus antigen DFA tests from a total of 64 cases of children hospitalized for lower respiratory tract infections from January 5 to April 29,2020,and the test results of conventional uninactivated methods and heating inactivation methods of 56℃,30 min,56℃,60 min,60℃,30 min,70℃,and 15 min were compared.Results A total of 39 positive samples and 25 negative samples were detected by non inactivation method.By heat inactivation methods of 56℃,30 min,56℃,60 min,60℃,30 min,70℃,and 15 min,the consistency of positive results were 100.0%(39/39)and the consistency of negative results were 100.0%(25/25),the heating inactivated and the uninactivated sample test results had excellent consistency.When the morphology under fluorescence microscope was compared,the positive cell fluorescence state and the number of positive cells were basically the same between uninactivated and 56℃,30 min,56℃,60 min,60℃30 min heating inactivation methods,and after the inactivation at 70℃,15 min,the number of positive cells and the fluorescence intensity of the positive cells decreased significantly.Conclusion Using heated inactivated samples for DFA testing of lower respiratory tract virus antigen experiments,which can not only ensure the consistency of test results,but also reduce the risk of infection of inspectors and ensure laboratory biosecurity.