Analysis of respiratory pathogens for children respiratory tract infection by capillary electrophoresis-based multiplex PCR

Objective To investigate the effect of capillary electrophoresis-based multiplex PCR (CEMP) in detecting pathogens for children respiratory tract infection, and to provide scientific basis for clinical diagnosis and treatment rapidly and accurately. Methods The cases were defined according to the national monitoring program of febrile respiratory syndrome during the 12th Five-Year Plan, and the samples were collected from nasopharyngeal swabs, bronchoalveolar lavage fluid and sputum of children with respiratory tract infection hospitalized in Changchun Children′s Hospital from January 2017 to February 2018.Multiplex PCR amplification was performed by one-step method, then PCR products were separated by DNA length size with capillary electrophoresis and pathogens were analyzed by "Genemapper software" software.Detecting pathogens included Influenza A virus (InfA), Human Adenovirus (HADV), Boca virus (Boca), Human Rhinovirus (HRV), Novel InfA-09H1 (InfA-09H1) and Seasonal Influenza virus H3N2 (InfA-H3N2), Parainfluenza virus (HPIV), Human metapneumonia virus (HMPV), Influenza B virus (InfB), Mycoplasma pneumoniae (Mp), Chlamydia pneumoniae (CP), Human Coronavirus (HCOV), Human Respiratory Syncytial virus (HRSV). Results The effective detection rate of the CEMP assay was 95.71%.The positive detection rate of respiratory tract pathogens was 62.84% and the mixed infection rate was 9.61%.The mixed infection was mainly InfA and HRSV.The highest three positive rates were named InfA, HRSV and Mp.The positive rate of HRSV was significantly higher in the 0-3 age group than that in older group.Different pathogens were detected in different age groups, and the high-occurrence season of respiratory tract infection with virus was from December to March of the next year.InfA-09H1 was the main prevalent influenza virus in January, February and March 2017, InfA-H3N2 was the main prevalent influenza virus in November and December 2017, and the outbreak of InfB was happened in Changchun in late 2017 and early 2018.HRSV was detected only in the coldest season in Changchun from November to March of the next year.Different pathogens were detected in different respiratory infection.HRSV was the main pathogen detected in pneumonia; InfA-03H2 and HPIV were the main pathogens detected in acute bronchitis; HRV and InfA were the main pathogens detected in upper respiratory tract infection. Conclusion CEMP is an efficient, rapid and accurate method for the detection of pathogens in patients with respiratory tract infections, and it will have a broad application prospect to develop reagents suitable for clinical diagnosis. Key words: Capillary electrophoresis; Respiratory tract infection; Respiratory pathogen; Multiplex PCR