All issues > Volume 38(8); 1995

Original Article

J Korean Pediatr Soc. 1995;38(8):1077-1086. Published online August 15, 1995.

Detection of Mycoplasma pneumoniae in clinical Samples from Pediatric Patients by Polymerase Chain Reaction

Baik-Lin BL Eun¹, Sang Hee SH Park¹, Young Chang YC Dockgo¹, Sang Chul SC Seong²

¹Department of Pediatrics, Korea University College of Medicine, Seoul, Korea
²Seoul Clinical Laboratories, Seoul Medicl Science Institute

Abstract

Purpose
: Mycoplasma pneumoniae is a common cause of a wide rage of upper and lower respiratory tract infections, especially in children and young adults. Routine laboratory diagnosis of M.pneumoniae infection is based mainly on serology and, to lesser extent, on cultivation. The cultivation of M.pneumoniae, a fastidious microorganism, is time-consuming and may require 1-3 weeks for results. Serological procedures are the most widely used, but they usually require paired sera to demonstrate rises in antibody titer. It takes too long for results of both of these diagnostic methods to be obtained to allow for the rapid application of an effective treatment. Recently, an in vitro technique was developed to amplify short segments of DNA. This is referred to as the polymerase chain reaction(PCR). This technique has aiready been used for the diagnosis of genetic diseases and viral infections. It is also an effective tool for bacteriological diagnosis. In this prospective study, we have evaluated the use to PCR to detect M.pneumoniae in chilnical samples(nasopharyngeal aspirations of throat swaps) obtained from 101 children. The results are compared with serological data for M.pneumoniae.
Methods
: Clinical specimens were obtained from 101 children admitted to Korea University Medical Center Ansan Hospital between February and October 1994. Clinical samples obtained for M.pneumoniae DNA amplification were nasopharyngeal aspirations(NPA) (n=101) or throat swaps(TS) (n=64), and paired sera were obtained for M.pneumomiae antibody detection and cold agglutinin titer.
Results
: 1) Among the 101 children tested, 45 cases had M.pneumoniae antibody titer> 160 or seroconversion in paired sera. PCR positive results were concordant with serlogy in 33 cases (73.7%). 2) NPA-PCR was concordant with TS-PCR in 66.7%(12 cases). 3) All eight PCR-positive children with negative antibody in acute-phase serum experienced serconversion in convalescent-phase serum. 4) Among the 45 mycoplasma antibody postive cases, the number of positive cases of cold agglutinin test were 27 cases(60.0%).
Conclusion
: The poor sensitivity of culture and the possibility of impaired serological responses make the PCR assay promising for diagnosis of Mycoplasma pneumoniae infections. In addition, PCR is fast enough to allow for the early application of therapy with a specific antibiotics.

Keywords :Mycoplasma pneumoniae, Polymerase chain reaction(PCR), Naso pharyngeal aspirations, Throat swaps