Diagnostic value of multiplex real-time polymerase chain reaction for mycoplasma and trachomatis infection in respiratory tract infection children

Abstract

Objective To investigate the diagnostic value of multiplex real-time PCR (TaqMan probe) for simultaneous detection of Mycoplasma pneumoniae (MP) , Chlamydophila pneumonia (CP) and Chlamydia trachomatis (CT) in hospitalized children with respiratory tract infection. Methods The standard curves were plotted based on recombinant plasmids that was amplified after gradient dilution, so as to measure the amplification efficiency of the multiplx real-time PCR method, and the sensitivity, specificity and reproducibility were verified. There were 151 throat swab samples from hospitalized children with suspected respiratory tract infection collected. The MP, CP and CT gene fragments were detected by multiplex real-time PCR. There were 128 samples identified by MP-IgM and CP-IgM serological detection to evaluate the diagnostic value in clinical detection. Results The amplification efficiency of MP, CP and CT primers and probes reached up to 109.20%, 116.90% and 112.80%; and the minimum detectable concentration were 50, 25 and 25 pg/μL, respectively. No cross reactions with other known pathogens was observed, and coefficients of variation among different amplification reactions were all less than 3%. In 151 samples, the positive rates of MP, CP and CT by multiplex real-time PCR were 23.84% (36 samples) , 17.88% (27 samples) and 2.65% (4 samples) . In 128 samples, the positive rates of MP-IgM and CP-IgM were 22.65% and 14.06%, respectively. Conclusions The multiplex real-time PCR method can provide rapid and reliable evidence for early pathogen detection in children with respiratory tract infection. Key words: Polymerase chain reaction; Respiratory tract infection; Mycoplasma pneumonia; Chlamydophila pneumonia; Chlamydia trachomatis