sodC-based real-time PCR for detection of Neisseria meningitidis.

Autor: Jennifer Dolan Thomas, Cynthia P Hatcher, Dara A Satterfield, M Jordan Theodore, Michelle C Bach, Kristin B Linscott, Xin Zhao, Xin Wang, Raydel Mair, Susanna Schmink, Kathryn E Arnold, David S Stephens, Lee H Harrison, Rosemary A Hollick, Ana Lucia Andrade, Juliana Lamaro-Cardoso, Ana Paula S de Lemos, Jenna Gritzfeld, Stephen Gordon, Ahmet Soysal, Mustafa Bakir, Dolly Sharma, Shabnam Jain, Sarah W Satola, Nancy E Messonnier, Leonard W Mayer
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: PLoS ONE, Vol 6, Iss 5, p e19361 (2011)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0019361
Popis: Real-time PCR (rt-PCR) is a widely used molecular method for detection of Neisseria meningitidis (Nm). Several rt-PCR assays for Nm target the capsule transport gene, ctrA. However, over 16% of meningococcal carriage isolates lack ctrA, rendering this target gene ineffective at identification of this sub-population of meningococcal isolates. The Cu-Zn superoxide dismutase gene, sodC, is found in Nm but not in other Neisseria species. To better identify Nm, regardless of capsule genotype or expression status, a sodC-based TaqMan rt-PCR assay was developed and validated. Standard curves revealed an average lower limit of detection of 73 genomes per reaction at cycle threshold (C(t)) value of 35, with 100% average reaction efficiency and an average R(2) of 0.9925. 99.7% (624/626) of Nm isolates tested were sodC-positive, with a range of average C(t) values from 13.0 to 29.5. The mean sodC C(t) value of these Nm isolates was 17.6±2.2 (±SD). Of the 626 Nm tested, 178 were nongroupable (NG) ctrA-negative Nm isolates, and 98.9% (176/178) of these were detected by sodC rt-PCR. The assay was 100% specific, with all 244 non-Nm isolates testing negative. Of 157 clinical specimens tested, sodC detected 25/157 Nm or 4 additional specimens compared to ctrA and 24 more than culture. Among 582 carriage specimens, sodC detected Nm in 1 more than ctrA and in 4 more than culture. This sodC rt-PCR assay is a highly sensitive and specific method for detection of Nm, especially in carriage studies where many meningococcal isolates lack capsule genes.
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