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Objective: In-time diagnosis of Streptococcus pneumoniae (S. pneumonia) can play a significant role in decreasing morbidity and mortality rate. Applying molecular methods has gained popularity due to the existing limits of routine diagnostic methods. Examining the expression of different genes of this bacterium through different molecular methods suggests that lytA gene has a higher sensitivity and specificity in diagnosis of Streptococcus pneumoniae. The aim of this study was to evalutate lytA gene expression in diagnosis of invasive S. pneumonia in culture positive specimens by real-time polymerase chain reaction (PCR). Materials and Methods: IIn this a descriptive study, All received specimens were isolated to identify S. pneumoniae. DNA was then extracted and after optimizing the test and determining the detection limit, samples were tested by real-time PCR using lytA gene primers. Results: Twenty seven isolates were diagnosed as S. pneumoniae. In all, the extracted DNA was positive in real-time method. The electrophoresis of the products also confirmed the presence of single product b along with the 53 base pair fragment. The detection limit of the test was less 6 colony forming unit (CFU). Conclusion: Real-Time PCR seems to provide reliable and rapid results. We suggest that this test should be conducted on the preliminary isolated specimens, since applying various biochemical tests need one extra working day. [ABSTRACT FROM AUTHOR]

Background: Identifying regional types and evaluating the frequency of pneumococcal strains has become increasingly important especially in vaccination. The purpose of this study was the identification and frequency determination of our regional serotype and evaluation of the performance of recent type specific multiplex PCR for the diagnosis of streptococcus pneumonia serotypes., Methods: All isolated S. pneumonia from suspected patients in Tehran and Isfahan Hospitals from June to December of 2012 were evaluated. All specimens and their serotypes were identified through a conventional method and specific antisera. Serotype specific multiplex PCR was applied and ran in seven reactions consisting of 34 S. pneumonia primer pairs plus a primer pair as an internal control for this purpose., Results: Overall, 14 genotype specific serotypes (including two subtypes for 19 and 23) were detected and had identical results with stereotyping method except for serotype 28 and one of the identified serotype 23. The serotypes 19, 6 and 23 were dominant with the frequency of 51.8%. A cross reactivity was also observed between genotypes 1 and 9A/9V., Conclusion: Applied multiplex PCR format can be suitable and cost effective tool for identification of S. pneumonia serotypes.