African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12486

Full Length Research Paper

Detection and quantification of Streptococcus pneumoniae from Iranian patients with pneumonia and individual carriers by real time PCR

Bizhan Nomanpour1, Arash Ghodousi1, Toraj Babaei2, Seyd AliJavad Mousavi3, Soroor Asadi4 and Mohammad Mehdi Feizabadi1*
1Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2Department of Cardiac Anesthesiology, Shaheed Rajaie Cardiovascular Medical & Research Center, Tehran, Iran. 3Department of Pulmonary Medicine, Rasul-e-Akram Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 4Department of Infectious Diseases, Labbafinejad Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Email: [email protected]

  •  Accepted: 01 September 2011
  •  Published: 05 October 2011

Abstract

The aim of this study was to develop a real time polymerase chain reaction (PCR) for quantitative detection of Streptococcus pneumoniae from clinical respiratory specimens. Initially, 184 respiratory specimens from patients with community acquired pneumonia (CAP) (n = 129) and 55 cases with hospital associated pneumonia (HAP) were bacteriologically investigated. To check the colonization status among the healthy individuals, 32 preschool and 31 adults were screened in parallel. All specimens were cultured on selective culture media to isolate S. pneumoniaeLegionella spp. and Mycoplasma spp. A 166 bp fragment corresponding to cbp A gene of S. pneumoniae was amplified from clinical specimens using Taqman probe real time PCR. Culture showed 14, but real time PCR showed 15 specimens as being positive for S. pneumoniae. The specificity and sensitivity of real time PCR was 99.14% and 100 respectively. Co-infections ofS. pneumoniae with Legionella pneumophila, Chlamydophila pneumoniae, Mycoplasma pneumoniae and Staphylococcus aureus were observed in 5 cases (35.72%). S. pneumoniae was counted <103 cfu/ml from the co-infected cases. Using real time PCR, a cutoff of 103cfu/ml is introduced to differentiate colonization from infection in respiratory tract. This is the first report on the prevalence CAP withS. pneumoniae in Iran (12.40%).

 

Key words: Streptococcus pneumoniae, community acquired pneumonia (CAP), real time polymerase chain reaction (PCR), choline binding protein A (cbp A).