Establishment Of Real-time Quantitative PCR Detection Platform And Molecular Epidemiological Characteristics For Respiratory Syncytial Virus

Respiratory syncytial virus(RSV),as a worldwide epidemic pathogen,is one of the most common virus causing acute respiratory tract infection in infants,immunodeficiency and the elderly all over the world.The infants before 2 years almost infected with RSV,half of them will reinfect.In addition,complications and deaths may occur in the elderly after RSV infection.Medical and financial burden to society and family,but there is still no available vaccine,monoclonal antibody palivizumab(Synagis(?))is the only approved drug for use in the prevention of RSV infection,due to the large dosage,high cost,limited to prevent immune deficiency and congenital heart disease and other high-risk neonates from RSV infection.The prevalence of RSV was regional and seasonal,and the dominant subtype changed with the time.The molecular epidemiological investigation of respiratory syncytial virus will be of great significance to the evolution of the virus,the exploration of the correlation between virus factors and clinical manifestations,and the development of highly effective and safe vaccines.In order to diagnose this pathogen quickly and accurately,in this study,a real-time quantitative PCR(for M gene)and a typing detection platform(for N and F genes)for respiratory syncytial virus were established.Both platforms have good specificity,repeatability and amplification efficiency;for sensitivity,the detection limit for standard plasmid was 5 copies/reaction,and the detection limits for RSV subtype A and B viruses were 0.1 PFU/mL.The throat swab samples of 678 hospitalized children with acute respiratory infections in Xiamen Maternal and Child Health Hospital(2016-201 9)were detected nucleic acid of RSV The results showed that the comparative advantage subtypes were converted with different years during the survey:B-B-B-A;There was no significant difference between RSV subtypes A and B virus in clinical manifestations and hospitalization time.At the same time,the first molecular epidemiology survey in Xiamen was conducted,and 7 G genes of ON1 genotype were identified,and 6 strains showed H258Q and H266L specific substitution,and formed a unique cluster;two G genes of BA9 genotypes,also appeared T254I and A271V specific substitution;clinical strain F gene in the known immune target area although highly conservative,but there are still a small number of mutations;The RSV-A/62-10-F strain in Xiamen showed the substitution of the palivizumab with the viral antigen binding site N276S.Whether the drug resistance remains to be studied.RSV molecular epidemiological analysis can improve clinical management of RSV infection.There are no reports on the Xiamen area.The results of this study can help us understand the antigenic mechanism of RSV infection and provide more guidance for antiviral therapy.