Screening of pneumococcal pneumonia by amplification of pneumolysin gene in children visiting hospitals in Lahore, Pakistan

ABSTRACT

Streptococcus pneumoniae is a common worldwide potential pathogen causing pneumonia among children and the detection of pneumococcal infections by conventional culturing techniques is cumbersome. The present study describes a comparative analysis of sensitive nested-PCR and bacterial culture in pediatric patients with clinical and radiological indication of S. pneumoniae infection. PCR was performed using outer primers to amplify a 348-bp region and inner primers a 208-bp region of the pneumolysin gene. For pneumolysin PCR assay, DNA from peripheral blood and middle ear fluid [MEF] samples was extracted by salting out method. The sensitivity of the assay was evaluated with about 0.06 pg of purified S. pneumoniae genomic DNA. Among 90 MEF culture negative samples from acute otitis media pediatric patients, 8.8% pneumolysin-PCR positivity was detected, demonstrating the sensitivity and reliability of PCR for rapid pneumonia evaluation. Binomial test of proportionality performed on [SPSS 17] gives P<0.05 indicating that PCR technique is statistically significant and sensitive in the diagnosis of S. pneumoniae infection. The research work evaluated the effectiveness and efficacy of nested-PCR for detecting S. pneumoniae in pediatric patients with clinical and radiological confirmation of bacterial infection. This simplified method permitted quick selection of the patients and played a significant role in preliminary management of pneumococcal infections