Dataset Information

Detection of Streptococcus pneumoniae antigen in bronchoalveolar lavage fluid samples by a rapid immunochromatographic membrane assay.

ABSTRACT: We conducted a retrospective study to evaluate an immunochromatographic membrane test (ICT), applied to bronchoalveolar lavage (BAL) fluid samples obtained in patients with suspected pneumonia, for the detection of Streptococcus pneumoniae antigen. The NOW Streptococcus pneumoniae test was assessed on 96 BAL fluid samples. Sensitivity was tested in 20 samples obtained from patients diagnosed as having pneumococcal pneumonia (growth of S. pneumoniae in blood cultures and/or in BAL fluid samples of > or =10(4) CFU/ml). Specificity was tested in BAL fluid samples of nonpneumococcal etiology (n = 41) and in samples with no respiratory pathogen and a total bacterial count of <10(4) CFU/ml (n = 35). Using the ICT, pneumococcal antigen was detected in 29 (30.2%) BAL fluid samples, with a sensitivity of 95.0% (95% confidence interval [CI], 90.6% to 99.4%) and a specificity of 86.8% (95% CI, 80.1% to 93.8%). The ICT was easy to perform and revealed unequivocal and reproducible results. No interference was observed with high cell counts, red blood cells, or elevated protein levels. Four out of 10 false-positive readings occurred in samples with S. pneumoniae counts below the 10(4) CFU/ml threshold limit of pneumonia. In BAL fluid samples obtained after pneumococcal bacteremia, positive test results were found for up to 35 days after bacteremia. The ICT test applied to BAL fluid specimens is reproducible and accurate in the diagnosis of pneumococcal antigen. Further studies are required to establish the impact of the ICT on patient care.

SUBMITTER: Jacobs JA

PROVIDER: S-EPMC1233991 | biostudies-literature | 2005 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Detection of Streptococcus pneumoniae antigen in bronchoalveolar lavage fluid samples by a rapid immunochromatographic membrane assay.

Jacobs Jan A JA Stobberingh Ellen E EE Cornelissen Elisa I M EI Drent Marjolein M

Journal of clinical microbiology 20050801 8

We conducted a retrospective study to evaluate an immunochromatographic membrane test (ICT), applied to bronchoalveolar lavage (BAL) fluid samples obtained in patients with suspected pneumonia, for the detection of Streptococcus pneumoniae antigen. The NOW Streptococcus pneumoniae test was assessed on 96 BAL fluid samples. Sensitivity was tested in 20 samples obtained from patients diagnosed as having pneumococcal pneumonia (growth of S. pneumoniae in blood cultures and/or in BAL fluid samples o ...[more]

PMID: 16081947

Similar Datasets

Project description:BackgroundIt is now possible to comprehensively characterize the microbiota of the lungs using culture-independent, sequencing-based assays. Several sample types have been used to investigate the lung microbiota, each presenting specific challenges for preparation and analysis of microbial communities. Bronchoalveolar lavage fluid (BALF) enables the identification of microbiota specific to the lower lung but commonly has low bacterial density, increasing the risk of false-positive signal from contaminating DNA. The objectives of this study were to investigate the extent of contamination across a range of sample densities representative of BALF and identify features of contaminants that facilitate their removal from sequence data and aid in the interpretation of BALF sample 16S sequencing data.ResultsUsing three mock communities across a range of densities ranging from 8E+?02 to 8E+?09 16S copies/ml, we assessed taxonomic accuracy and precision by 16S rRNA gene sequencing and the proportion of reads arising from contaminants. Sequencing accuracy, precision, and the relative abundance of mock community members decreased with sample input density, with a significant drop-off below 8E+?05 16S copies/ml. Contaminant OTUs were commonly inversely correlated with sample input density or not reproduced between technical replicates. Removal of taxa with these features or physical concentration of samples prior to sequencing improved both sequencing accuracy and precision for samples between 8E+?04 and 8E+?06 16S copies/ml. For the lowest densities, below 8E+?03 16S copies/ml BALF, accuracy and precision could not be significantly improved using these approaches. Using clinical BALF samples across a large density range, we observed that OTUs with features of contaminants identified in mock communities were also evident in low-density BALF samples.ConclusionRelative abundance data and community composition generated by 16S sequencing of BALF samples across the range of density commonly observed in this sample type should be interpreted in the context of input sample density and may be improved by simple pre- and post-sequencing steps for densities above 8E+?04 16S copies/ml.

Dataset Information

Detection of Streptococcus pneumoniae antigen in bronchoalveolar lavage fluid samples by a rapid immunochromatographic membrane assay.

Publications

Detection of Streptococcus pneumoniae antigen in bronchoalveolar lavage fluid samples by a rapid immunochromatographic membrane assay.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets