Performance of a Pneumolysin Enzyme-Linked Immunosorbent Assay for Diagnosis of Pneumococcal Infections

Abstract

A pneumolysin-specific enzyme-linked immunosorbent assay (PLY-ELISA) for the detection of pneumolysin in urine was developed and evaluated in comparison with the commercially available Binax Now Streptococcus pneumoniae test (Binax, Portland, ME) for the diagnosis of pneumococcal infections. Assay sensitivity was evaluated using urine from 108 patients with culture-confirmed pneumococcal infections. In adults, the sensitivity and specificity of the PLY-ELISA were 56.6% and 92.2%, respectively. In children with nasopharyngeal pneumococcal carriage, PLY-ELISA and Binax Now S. pneumoniae test sensitivities were 62.5% and 87.5%, respectively, while specificities were 94.4% and 27.8%, respectively. In children with nonnasopharyngeal pneumococcal carriage, PLY-ELISA and Binax Now S. pneumoniae test sensitivities were 68.7% and 93.7%, respectively, and test specificities were 94.1% and 41.2%, respectively. The persistence of pneumolysin in urine of pneumococcal pneumonia patients decreased significantly after 4 to 6 days of treatment. Our data suggest that combining the high specificity of the PLY-ELISA with the high sensitivity of the Binax Now S. pneumoniae test would enable pneumococcal infections to be accurately diagnosed in children.

Novel Approaches to the Identification ofStreptococcus pneumoniaeas the Cause of Community‐Acquired Pneumonia

“…An ELISA for urinary pneumolysin detection in children has been recently developed. Compared with the immunochromatographic membrane assay (ICT) Binax Now S. pneumoniae (Binax), the urinary pneumolysin ELISA achieved lower sensitivity for pneumococcal infection in children with and without nasopharyngeal carriage, but markedly improved specificity [38]. The low sensitivity of 56.6% in adults likely does not suggest much added benefit in this age group [38].…”

“…Compared with the immunochromatographic membrane assay (ICT) Binax Now S. pneumoniae (Binax), the urinary pneumolysin ELISA achieved lower sensitivity for pneumococcal infection in children with and without nasopharyngeal carriage, but markedly improved specificity [38]. The low sensitivity of 56.6% in adults likely does not suggest much added benefit in this age group [38]. The detection of pneumococcal C-polysaccharide with the ICT Binax NOW S. pneumoniae assay allows a bedside diagnosis of pneumococcal disease within 15 min after receipt of a urine sample [39].…”

Clinical Potential of C-Reactive Protein and Procalcitonin Serum Concentrations To Guide Differential Diagnosis and Clinical Management of Pneumococcal and Legionella Pneumonia

“…Pneumonia was diagnosed on the basis of clinical criteria and laboratory evidence of infection and was confirmed by radiographic evidence. For species diagnosis, urinary antigen tests for S. pneumoniae or L. pneumophila, the latter detecting serotype 1 (BinaxNOW; Inverness Medical, ME), were used (1,4,5,10,17).Baseline laboratory parameters were determined by routine automated tests, and data were available from day 1 (admission) and days 5 to 7. PCT levels were determined by a timeresolved amplified cryptate emission technology assay (Brahms AG, Henningsdorf, Germany) (2).…”

“…Pneumonia was diagnosed on the basis of clinical criteria and laboratory evidence of infection and was confirmed by radiographic evidence. For species diagnosis, urinary antigen tests for S. pneumoniae or L. pneumophila, the latter detecting serotype 1 (BinaxNOW; Inverness Medical, ME), were used (1,4,5,10,17).…”

Improving diagnosis of pneumococcal disease by multiparameter testing and micro/nanotechnologies

“…The value of pneumolysin detection in urine was investigated and compared to the Binax NOW test in adults and children in another investigation (28). The pneumolysin ELISA required 3 h processing time.…”