Two Quality Control Exercises Involving Nucleic Acid Amplification Methods for Detection of Mycoplasma pneumoniae and Chlamydophila pneumoniae and Carried Out 2 Years Apart (in 2002 and 2004)

Abstract

The quality performance of laboratories for the detection of Mycoplasma pneumoniae and Chlamydophila pneumoniae by two quality control (QC) exercises with a 2-year interval was investigated. For the 2002 QC exercise, specimens were spiked with M. pneumoniae at concentrations of 5,000, 500, 50, and 0 color-changing units (CCU)/100 l. The limit of detectability was 50 CCU/100 l. A multitude of nucleic acid amplification tests (NAATs) have been described for the detection of Mycoplasma pneumoniae and Chlamydophila pneumoniae in respiratory specimens (6,17). In addition to in-house PCR tests, commercial kits are becoming available, such as the LCx for C. pneumoniae (Abbott Laboratories) (8) and the NucliSens Basic kit (bioMérieux), for which the primers and the target-specific biotinylated capture probe are to be synthesized for each target by the user (15).Although all tests aim to be rapid, sensitive, specific, and easy to perform, results of NAATs may be unreliable because of cross-contamination, inappropriate treatment of the clinical samples leading to loss of target nucleic acid, or the presence of inhibitors (2,5,12,14,26,27).To date, only one study compared the results of different NAATs for the detection of C. pneumoniae in respiratory specimens in different centers (8), and four studies compared the results of amplification methods performed in different centers for the detection of C. pneumoniae in atheroma specimens (2,3,11,21). To our knowledge, no such studies have been published for M. pneumoniae.The aim of this study was to assess the quality performance of laboratories for the detection of M. pneumoniae and C. pneumoniae by two quality control (QC) exercises with a 2-year interval. MATERIALS AND METHODSParticipating laboratories. The participating laboratories are as follows, in alphabetical order: Academisch Ziekenhuis Vrije Universiteit Brussel, Brussels, Belgium; Algemeen Ziekenhuis Sint Augustinus, Wilrijk, Belgium; Algemeen Ziekenhuis Sint Jan, Brugges, Belgium; bioMérieux, Boxtel, The Netherlands; Centre Hospitalier Régional de la Citadelle, Liège, Belgium; Cliniques Universitaires Université Catholique de Louvain de Mont-Godinne, Yvoir, Belgium; Groupement des Centres Hospitaliers de Jolimont-Lobbes et de Tubize-Nivelles, La Louvière, Belgium; Institut Jules Bordet, Brussels, Belgium; Institution de Pathologie et de Génétique-Loverval, Loverval, Belgium; Leids Universitair Medisch Centrum, Leiden, The Netherlands; Onze Lieve Vrouwe Ziekenhuis, Aalst, Belgium; Ospedale Maggiore di Milano, Milan, Italy; Public Health Laboratory Friesland, Leeuwarden, The Netherlands; Université Libre de Bruxelles-Erasme, Brussels, Belgium; University Medical Center-Brugmann, Brussels, Belgium; University of Antwerp, Wilrijk, Belgium; Universitair Ziekenhuis Katholieke Universiteit Leuven, Leuven, Belgium; University Hospital Antwerp, Edegem, Belgium; Virga Jesse Ziekenhuis, Hasselt, Belgium; and Ziekenhuizen Noord Antwerpen, Antwerp, Belgium.Preparation of proficiency panels. A stock suspension of M. pneumoniae...

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