Molecular diagnosis of Streptococcus pneumoniae in middle ear fluids from children with otitis media with effusion

Sung Wan Byun, Han Wool Kim, Seo Hee Yoon, In Ho Park, Kyung Hyo Kim

Research output: Contribution to journalArticlepeer-review


Purpose: The long-term administration of antibiotics interferes with bacterial culture in the middle ear fluids (MEFs) of young children with otitis media with effusion (OME). The purpose of this study is to determine whether molecular diagnostics can be used for rapid and direct detection of the bacterial pathogen in culture-negative MEFs. Methods: The specificity and sensitivity of both polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) to the lytA gene of Streptococcus pneumoniae were comparatively tested and then applied for pneumococcal detection in the clinical MEFs. Results: The detection limit of the PCR assay was approximately 104 colony forming units (CFU), whereas that of LAMP was less than 10 CFU for the detection of S. pneumoniae. Both PCR and LAMP did not amplify nucleic acid at over 106 CFU of H. influenzae or M. catarrhalis, both of which were irrelevant bacterial species. Of 22 culture-negative MEFs from children with OME, LAMP positivity was found in twelve MEFs (54.5%, 12/22), only three of which were PCR-positive (25%, 3/12). Our results showed that the ability of LAMP to detect pneumococcal DNA is over four times higher than that of PCR (P <0.01). Conclusions: As a high-resolution tool able to detect nucleic acid levels equivalent to <10 CFU of S. pneumoniae in MEFs without any cross-reaction with other pathogens, lytA -specific LAMP may be applied for diagnosing pneumococcus infection in OME as well as evaluating the impact of a pneumococcal conjugate vaccine against OME.

Original languageEnglish
Pages (from-to)106-112
Number of pages7
JournalPediatric Infection and Vaccine
Issue number2
StatePublished - 1 Jan 2015

Bibliographical note

Publisher Copyright:
© 2015, The Korean Society of Pediatric Infectious Diseases, All rights reserved.


  • Loop-mediated isothermal amplification (LAMP)
  • Molecular diagnosis
  • Otitis media with effusion (OME)
  • Polymerase chain reaction (PCR)
  • Streptococcus pneumoniae


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