Efficiency of the novel quenching-probe PCR method to detect 23S rRNA mutations in children with Mycoplasma pneumoniae infection.

An automated rapid molecular diagnostic kit (Smart Gene Myco) was recently developed for individual detection of Mycoplasma pneumoniae (MP) genes. This new testing approach requires no special equipment and skills and can be completed within 50 min. We prospectively evaluated this diagnostic kit, along with other conventional tests, for pneumonia diagnosis in children. Samples from 98 children (50 boys and 48 girls; aged 1-14 years; mean: 4.7 ± 2.1 years; median: 4 years) clinically diagnosed with pneumonia were tested for MP using real-time polymerase chain reaction (RT-PCR) as a reference method. Results from three molecular diagnostic tests, serum anti-MP antibodies, and MP culture were compared to RT-PCR data. Among the 98 children, 38 were positive for MP. All molecular diagnostic results showed complete concordance with the RT-PCR data. The sensitivity of the culture was 64%, whereas the sensitivities of the ImmunoCard Mycoplasma and SERODIA Myco II kits were lower (39% and 29%, respectively). Furthermore, a significant positive correlation was found between MP copy numbers and the culture test sensitivity (r = 0.95, p = 0.048). Macrolide-resistance mutations in the 23S ribosomal RNA gene were detected in 24 of 38 children using Smart Gene Myco based on quenching-probe PCR, which was confirmed by direct sequencing, revealing all mutations as A2063G. This is the first study to evaluate the clinical utility of the Smart Gene Myco kit, demonstrating that it is a fast and reliable method to support timely therapeutic decisions in children with MP pneumonia.