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Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae
Published on: February 24, 2023
[Evaluation of a Rapid Antigen Detection Kit Targeting L7/L12 Ribosomal Protein for Mycoplasma pneumoniae]
Abstract:
We evaluated the usefulness of a rapid antigen detection assay for L7/L12 ribosomal protein (Ribotest Mycoplasma; Asahi Kasei Pharma) for diagnosis of Mycoplasma pneumoniae (M. pneumoniae) infection. Nasopharyngeal swabs were obtained from patients with pneumonia and/or bronchitis; real-time PCR and the L 7/L12 antigen assays were performed with each sample. Serum was also taken from each patient, and the particle agglutination (PA) method was used to detect anti-M. pneumoniae antibody in these samples. Macrolide-resistance genes were detected and M. pneumoniae P1 protein subtyping was performed on PCR-positive samples. PCR assays were positive for 85 of 212 specimens (40.1%). Sensitivity and specificity of the L7/L12 antigen assays relative to the PCR standard were 74.1% (63/85) and 81.1% (103/127), respectively. For PCR-positive specimens with a large quantity of M. pneumoniae nucleic acid, sensitivity of the L7/L12 antigen assays seemed to be high. In PCR-positive specimens with fewer than 1.0 x 10(6) copies/mL of M. pneumoniae nucleic acid, sensitivity of the L7/L12 antigen assays seemed to be low. When the PA method was used as the standard, the relative sensitivity and specificity of the L7/L12 antigen assays were 41.7% (5/12) and 75.3% (58/77), respectively, for single serum and 60.9% (14/23) and 85.7% (18/21), respectively, for paired sera. The macrolide-resistance gene A2063G was detected in 20 of the 30 tested PCR-positive specimens (66.7%). Of these 20 A2063G-positive specimens, 13 (65.0%) were positive for the L7/L12 antigen assays. Tne numbers of M. pneumoniae P1 subtypes were as follows: types I (22), IIa(2), IIc(1), and untypable (5). The L7/L12 antigen assays gave positive results for 17 of 21 (81.0%) subtype I, 1 of 2 (50.0%) IIa, and 1 of 1(100%) IIc specimens.
Insights
This study assessed a rapid antigen test for Mycoplasma pneumoniae (M. pneumoniae) infection. The test showed moderate sensitivity and specificity, performing better with higher pathogen loads, impacting diagnosis of M. pneumoniae.
Area of Science:
- Medical Microbiology
- Diagnostic Assays
- Infectious Diseases
Background:
- Mycoplasma pneumoniae (M. pneumoniae) is a significant cause of respiratory infections.
- Accurate and rapid diagnostic tools are crucial for effective M. pneumoniae infection management.
- Current diagnostic methods may have limitations in speed or sensitivity.
Purpose of the Study:
- To evaluate the clinical utility of a rapid L7/L12 ribosomal protein antigen detection assay for diagnosing M. pneumoniae infections.
- To compare the performance of the antigen assay against real-time PCR and serological methods.
- To investigate the assay's performance in relation to bacterial load and macrolide resistance genes.
Main Methods:
- Nasopharyngeal swabs and serum samples were collected from patients with pneumonia/bronchitis.
- Real-time PCR was used as the primary reference standard for M. pneumoniae detection.
- A rapid L7/L12 antigen assay, particle agglutination (PA) test, and macrolide-resistance gene detection were performed.
Main Results:
- PCR confirmed M. pneumoniae in 40.1% of specimens.
- The L7/L12 antigen assay demonstrated 74.1% sensitivity and 81.1% specificity versus PCR.
- Assay sensitivity was higher with greater M. pneumoniae nucleic acid quantities and varied by P1 subtype.
Conclusions:
- The rapid L7/L12 antigen assay offers a potentially useful diagnostic tool for M. pneumoniae, particularly when pathogen load is high.
- Performance varies compared to PCR and serological tests, indicating a role as an adjunct diagnostic.
- Further studies may optimize its use in clinical settings, considering resistance gene prevalence.
