Comparison of the new InoDiag automated fluorescence multiplexed antigen microarray to the reference technique in the serodiagnosis of atypical bacterial pneumonia

Abstract

The aetiological diagnosis of pneumonia depends largely on culture-, antigen- or PCR-based tests. Atypical agents of pneumonia include Coxiella burnetii, Chlamydophila pneumoniae, Chlamydia psittaci, Legionella pneumophila, Francisella tularensis and Mycoplasma pneumoniae. In these cases, serological tests are commonly used for diagnosis. All of the above species were comparatively screened for by using the InoDiag multiplexed automatic immunofluorescence assay and established reference techniques. The InoDiag assay required 5 microL of serum, took 76 min per serum sample, and required an incubator, a fluorescence reader and interpretation software. In total, 248 single sera from patients were tested, for the diagnosis of pneumonia, and the results obtained with selected serum samples were compared with results obtained with the reference method. It was shown that, for the detection of Coxiella burnetii IgM, the automated assay had a sensitivity and specificity of 100%. For the detection of M. pneumoniae IgM, sensitivity was 100% and specificity was 98%. For the detection of Chlamydophila pneumoniae and Chlamydia psittaci IgG, sensitivity was 81% and specificity was 94%. For the detection of L. pneumoniae IgG, sensitivity was 63% and specificity was 98%. For the detection of F. tularensis IgG and IgM, sensitivity was 100% for both, and specificity was 95% and 100%, respectively. The performance of this serological assay was comparable to that of other assays reported in the literature. This preliminary study shows that the automatic InoDiag assay opens the way to immunofluorescence assay standardization.

Performance of an automated multiplex immunofluorescence assay for detection of Chlamydia trachomatis immunoglobulin G

“…It is well designed for small laboratories, since batches of only 2 to 4 samples can be tested with InoDiag. Several pathogens can be tested simultaneously, allowing pathology-driven testing instead of the common pathogen-driven testing (Gouriet et al, 2008a;Gouriet et al, 2008b;Raoult et al, 2004). Moreover, thank to the multiplex format of the Inodiag technology,…”

“…A total of 265 sera were tested for the presence of Chlamydia trachomatis IgG antibodies with the new automated "multiplexed serology test" (Mu.S.T) as previously described (Baud et al, 2010;Gouriet et al, 2008a;Gouriet et al, 2008b) pELISA, R-Biopharm, Darmstadt, Germany. All these 3 commercial tests were performed according to the manufacturers' instructions.…”

Proteomics paves the way for Q fever diagnostics

“…The InoDiag automated fluorescence multiplexed antigen microarray method [52] has been compared with the IFA reference method for the detection of C. burnetii IgM. The advantages of the InoDiag technique are speed of analysis, the need for only a small quantity of sampled serum (5 μl) and multiplexing [53].…”

“…The advantages of the InoDiag technique are speed of analysis, the need for only a small quantity of sampled serum (5 μl) and multiplexing [53]. The sensitivity and specificity obtained by automated assay for diagnosis of the acute form were excellent, and the serological parameters obtained for serodiagnosis of Q fever endocarditis were also adequate [52]. This is a first step towards IFA standardization [52,53].…”

Evaluation of a new serological test for the detection of anti-Coxiella and anti-Rickettsia antibodies

“…secondary antibody depositions, incubations, washing, drying, reading and interpretation) are performed automatically. This assay has previously been shown to be a promising tool for the serodiagnosis of Chlamydia trachomatis infection, culturenegative endocarditis and atypical pneumonia [8,9,3].…”