[Comparison of culture and polymerase chain reaction methods for the detection of Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis in cerebrospinal fluids and middle ear effusions].

Although the availability of effective antimicrobial therapy, both otitis media with effusion (OME) and acute bacterial meningitis (ABM) are still important infections for children, leading serious health problems. The most frequently isolated bacteria from cerebrospinal fluid (CSF) of ABM patients are Haemophilus influenzae type b, Neisseria meningitidis and Streptococcus pneumoniae, and middle ear effusion (MEE) samples of OME patients are H. influenzae, S. pneumoniae, Moraxella catarrhalis, respectively. Since they are fastidious bacteria, various problems may arise in the rapid diagnosis in both ABM and OME settings. In this study, the diagnostic value of polymerase chain reaction (PCR) has been searched for the detection of bacterial DNA in CSF and MEE specimens and evaluated in comparison to conventional culture method accepted as the "gold standard". A total of 75 samples (53 CSF, 22 MEE) collected from meningitis and OME suspected children were included in the study. With the conventional culture method, one S. pneumoniae strain was isolated from a CSF sample, and one H. influenzae (non-type b) and two M. catarrhalis strains were isolated from three of MEE samples (total isolation rate: %5.3; 4/75). Standard PCR protocol was applied for the detection of H. influenzae, while multiplex PCR protocol was used for M. catarrhalis and S. pneumoniae, since H. influenzae and S. pneumoniae amplification products were of similar size. PCR revealed genomic DNA sequences of S. pneumoniae from five of the CSF samples, while three H. influenzae, three M. catarrhalis and two S. pneumoniae+M. catarrhalis were detected from MEE samples (total detection rate: %17.3; 13/75). Sensitivity and specificity rates of PCR method were found as 100% and 92.3% for CSF samples, and 100% and 73.7% for MEE samples, respectively, with a total sensitivity of 100%, specificity of 87.3%, positive predictive value of 30.8%, and negative predictive value of 100%. As a result it was concluded that PCR method could be considered as a rapid, reliable and feasible method for the detection of the most common fastidious bacteria that lead to meningitis and OME.