Characterization and evaluation of a novel immunochromatographic assay for pharyngeal Mycoplasma pneumoniae ribosomal protein L7/L12 antigens

Abstract

Point-of-care testing for Mycoplasma pneumoniae infection may be ideal and useful because significant numbers of the cases will be seen as outpatients. Recently, a new immunochromatographic method (ICM) targeting M. pneumoniae ribosomal protein L7/L12 (RP-L7/L12) in pharyngeal swabs became available in Japan, although clinical data and basic information regarding efficacy and characterization of this ICM are limited. The present study examined the fate of M. pneumoniae RP-L7/L12 during in vitro growth and the correlation between M. pneumoniae concentration in clinical specimens and the sensitivity of the ICM test. The usefulness of the ICM was investigated in patients suspected of having M. pneumoniae pneumonia and upper respiratory tract infection (137 children and 39 adults). The limit of detection for the ICM test was 1.1×104 c.f.u. ml-1 of M. pneumoniae. Bacterial production of RP-L7/L12 correlated positively with the viable M. pneumoniae concentration in vitro; antigen was then degraded in culture broth, with an in vitro half-life of approximately 2 days. Five other Mycoplasma spp. and 14 representative respiratory pathogens were ICM assay negative at bacterial concentrations of 106 c.f.u. ml-1. The clinical sensitivity and specificity of the ICM assay were 57.1 % (20/35) and 92.2 % (130/141), respectively, in comparison with bacterial culture. Clinical specimens containing ≥106 c.f.u. ml-1 of M. pneumoniae burden were ICM positive in 13 of 18 cases (72.2 %). The ICM is a poorly sensitive but reasonably specific means for detecting M. pneumoniae infections.

Rapid Staphylococcus aureus Detection From Clinical Mastitis Milk by Colloidal Gold Nanoparticle-Based Immunochromatographic Strips

“…The anti-RP-L7/L12 mAbs used for manufacturing ICS were prepared by conventional methods described by Sano et al (13). Briefly, RP-L7/L12 was amplified by PCR using genomic DNA from S. aureus (ATCC25923) as template and the following oligonucleotide primers: forward, 5 ′ -CTAGGATCCATGGCTAATCATGAACAAATC-3 ′ , and reverse 5 ′ -CTAGAATTCTTATTTTAATTCTACAGTAGCTCCAAC-3 ′ .…”

“…Thus, ICS tests are suitable for on-site testing (12). Previous studies have reported the rapid diagnostic usefulness of RP-L7/L12 as a target for the diagnosis of Streptococcus pneumoniae and Mycoplasma pneumoniae infection by ICS tests (13,14). These results have suggested that ICS tests targeting bacterial RP-L7/L12 could be useful for the rapid diagnosis of a variety of infectious diseases, if specific monoclonal antibodies (mAbs) become available for the detection of certain bacterial RP-L7/L12.…”

Clinical features of Mycoplasma pneumoniae pneumonia in older adults

“…Even if an older patient does not meet the JRS criteria, clinicians should investigate a diagnosis of atypical pneumonia when the patient has a persistent cough, which occurred in 88.2% of our older patients with mycoplasma pneumonia (nearly as frequently as in the younger group). A mycoplasma antigen test is now available and might provide a more accurate diagnosis than a mycoplasma antibody test . In addition to the epidemic situation, patient history, physical findings, laboratory findings and radiological findings, and diagnostic tools should be utilized to ensure early treatment, because M. pneumoniae is a difficult pathogen to culture in community clinical settings.…”

Implementation of Point-of-Care Molecular Diagnostics for <i>Mycoplasma pneumoniae </i>Ensures the Correct Antimicrobial Prescription for Pediatric Pneumonia Patients

“…M. pneumoniae IgM has been alternatively used as a diagnostic test at the initial presentation, although there is a 10.1% false positivity rate and a 32.5% false negativity rate with this approach; therefore, testing paired sera of M. pneumoniae IgM is still necessary (Lee et al 2017). Recently, antigen testing for M. pneumoniae has been developed for the rapid detection of M. pneumoniae from nasopharyngeal samples, but the sensitivity is reported to be < 60% (Sano et al 2016).…”