Genotyping and refractory risk factors of mycoplasma pneumoniae pneumonia in Suzhou, China.

OBJECTIVE: To investigate the genotyping and drug resistance of Mycoplasma pneumoniae (MP) epidemic strains in children and analyze the risk factors for refractory Mycoplasma pneumoniae pneumonia (RMPP). METHOD: Nasopharyngeal aspirates (NPA) were collected from hospitalized children with MP infection from September to October 2023. Tracheoscopy was performed when necessary, and Bronchoalveolar Lavage Fluid (BALF) was collected. Polymerase Chain Reaction (PCR) capillary electrophoresis were used to detect respiratory pathogens, and a nested PCR based on the MP P1 gene monitored MP subtypes. The MP-23 S rRNA V region was amplified and sequenced. Clinical data and laboratory results were analyzed for RMPP risk factors. RESULT: From 261 children diagnosed with Mycoplasma pneumoniae pneumonia (MPP), cough (100%) and fever (93.1%) were the most common symptoms. Moist rales (65.5%) were the prevalent pulmonary signs. Bronchoscopy was required in 44.4% of cases. Drug resistance genes were detected in 258 cases (98.9%). Genotyping showed 192 cases (73.56%) as type I and 69 cases (26.4%) as type II. Type I required more bronchoscope interventions (54.2%) compared to type II (17.4%, P < 0.001). Among the children, 92 (35.2%) were classified as RMPP. The RMPP group had longer hospitalization (9.14 ± 4.38 vs. 6.7 ± 1.81 days), higher fever ratio (100% vs. 89.9%), and longer febrile duration (8.72 ± 2.52 vs. 4.56 ± 2.50 days) (all P < 0.05). Higher rates of shortness of breath (7.6% vs. 1.2%) and decreased breath sounds (30.4% vs. 16.6%) were noted in the RMPP group (P < 0.05). Additionally, higher proportions of elevated CRP, ALT, AST, LDH, and D-D dimer were found in the RMPP group, along with a greater need for bronchoscopy (70.7% vs. 43.2%). Multivariate logistic regression identified total febrile duration, mucus plug formation, elevated AST, LDH, and D-D dimer as RMPP risk factors. Receiver operator characteristic (ROC) curve indicated that total febrile duration, LDH, and D-D dimer could serve as predictive markers for RMPP. CONCLUSION: Type I predominated among MP strains in Suzhou, with a high prevalence of drug resistance. Type I infections were associated with a higher likelihood of requiring bronchoscopy. Prolonged fever, mucus plug formation, elevated AST, LDH, and D-D dimer were independent risk factors for RMPP, with total febrile duration, LDH, and D-D dimer serving as predictive markers. CLINICAL TRIAL NUMBER: Not applicable.