Clinical evaluation of a novel point-of-care assay to detect Mycoplasma pneumoniae and associated macrolide resistant mutations.

The recent increase in macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae) in Asia has become a continuing problem. A point-of-care testing method that can quickly detect M. pneumoniae and macrolide-resistant mutations (MR mutations) is critical to proper antimicrobial use. Smart Gene TM (MIZUHO MEDY Co., Ltd. Tosu-City, Saga, Japan) is a compact and inexpensive fully automatic gene analyzer that combines amplification with polymerase chain reaction (PCR) and the quenching probe method to specify the gene and MR mutations simultaneously. We performed a clinical evaluation of this device and its reagents on pediatric patients with M. pneumoniae-suspected respiratory infections and evaluated the impact of the assay on antimicrobial selection. Using real-time PCR as a comparison control, the sensitivity of Smart Gene TM was 97.8% (44/45), its specificity was 93.3% (98/105) and its overall concordance rate was 94.7% (142/150). The overall concordance rate of Smart Gene TM diagnosis of MR mutations in comparison with sequence analysis was 100% (48/48). The ratio of MR mutations was significantly higher at high-level medical institutions than at a primary medical clinic (P = 0.023), and changes in antibiotic therapy to drugs other than macrolides was significantly more common in patients with MR mutations (P = 0.00024). Smart Gene TM demonstrated excellent utility in the diagnosis of M. pneumoniae and the selection of appropriate antimicrobials for MR mutations at primary medical institutions, which play a central role in community-acquired pneumonia care. The use of this device may reduce referrals to high-level medical institutions for respiratory infections, thereby reducing the medical and economic burden on patients.