Reports of Biochemistry and Molecular Biology

en Impact of Laboratory Methods and Gene Targets on Detection of Streptococcus pneumoniae in Isolates and Clinical Specimens میکروب شناسی Microbiology مقالات اصلی Original Article <div style="text-align: justify;">Background: Timely identification of Streptococcus pneumoniae infections can lead to a decrease in mortality rates. Differentiation of S. pneumoniae from other similar species using traditional culture-based and molecular methods is problematic. In this study, we assessed the efficacy of identifying the blpA and lytA for the detection of S. pneumoniae from isolates and various clinical samples using molecular methods. Methods: A total of 440 clinical samples were collected from patients with suspected invasive pneumococcal infections during February 2016 to October 2018. Biochemical tests were used to confirm the dubious colonies on 5% sheep blood agar. Fifty-seven confirmed isolates, 57 culture-positive samples, and 57 culture-negative samples were analyzed for the presence of blpA and lytA using both conventional and real-time PCR. Results: All the isolates and culture-positive samples were positive for blpA and lytA by both PCR methods. Of the 57 culture-negative samples, conventional and real-time PCR amplified blpA from six and two samples, and lytA from seven and two samples, respectively. Conclusions: The specificity of real-time PCR assay was significantly higher than that of conventional PCR for the identification of S. pneumoniae. In addition, it is suggested that respiratory secretions are not suitable specimen for direct diagnosis of pneumococcal infections.</div> blpA, Molecular Detection, Molecular Diagnostic Techniques, Real-Time Polymerase Chain Reaction, Streptococcus pneumoniae. 216 222 http://rbmb.net/browse.php?a_code=A-10-431-1&slc_lang=en&sid=1 Mehrdad Mosadegh 100319475328460017618 100319475328460017618 No Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Rozita Asadian Asadianrozita@gmail.com 100319475328460017619 100319475328460017619 No Department of Medical Laboratory Sciences, School of Paramedicine, Guilan University of Medical Sciences, Langeroud, Iran. Amir Darb Emamie 100319475328460017620 100319475328460017620 No Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mohammadreza Rajabpour 100319475328460017621 100319475328460017621 No Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Elmira Najafinasab 100319475328460017622 100319475328460017622 No Department of Microbiology, Khoy University of Medical Sciences, Khoy, Iran. Mohammad Reza Pourmand mpourmand@tums.ac.ir 100319475328460017623 100319475328460017623 Yes Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Mohammad Azarsa* m_azarsa@khoyums.ac.ir 100319475328460017624 100319475328460017624 No Department of Microbiology, Khoy University of Medical Sciences, Khoy, Iran.