Abstract: Objective Via observing the clinical characteristics of refractory Mycoplasma pneumoniae pneumonia (RMPP) caused by macrolide-resistant Mycoplasma pneumoniae (MRMP) infection in children, to explore its clinical significance in the timely diagnosis and treatment of children with RMPP. Method The clinical data of 1226 hospitalized children with RMPP from January 2022 to December 2023 in the Hainan Women and Children's Medical Center were analyzed retrospectively. Bronchoscopy and bronchoalveolar lavage fluid (BALF) were performed on each subject and MRMP-DNA in the BALF were taken to detect the 23S rRNA V region mutation sites. Children with RMPP were divided into macrolide-resistant group and control group (non-macrolide-resistant group) depending on the gene detection results. Result A total of 1226 children with RMPP were recruited, including 869 cases in the macrolide-resistant group and 357 cases in the control group. Among them, there were 369 males (51.7%) and 555 females (48.3%). The average age in the macrolide-resistant group [(6.12±2.98) y] was higher than that in the control group [(2.82±2.19) y] (P<0.001). The fever time in the macrolide-resistant group [(6.61±1.77) d] was longer than that in the control group [(5.33±1.09) d] (P<0.001). Compared with the children with RMPP in the control group, the values of white blood cell count(WBC), percentage of neutrophil (NE%), high sensitive C-reactive protein (hs-CRP), lactate dehydrogenase (LDH), and interleukin-6 (IL-6) were higher in the macrolide-resistant group, the differences were statistically significant (P<0.05); Compared with the children with RMPP in the control group, the incidences of severe MPP (SMPP)/fulminant MPP (FMPP), extra-pulmonary complications, severe mucosal lesions(erosion, ulcer or necrosis), endotracheal plastic phlegm plug, pleural effusion and necrotic pneumonic were higher in the macrolide-resistant group, the differences were statistically significant (P<0.05). The average hospitalization day in the macrolide-resistant group [(6.59±1.63) d] was longer than that in the control group [(5.32±1.38) d] (P<0.001). Conclusion The clinical manifestations of RMPP children caused by MRMP infection were more serious, with longer fever time, longer hospital stay, more severe inflammatory reaction and more intrapulmonary and extrapulmonary complications. Timely implementing bronchoscopy in children with RMPP and collecting BALF samples for testing may have important values for guiding the correct clinical diagnosis and treatment.

Key words: Mycoplasma pneumonia, Macrolides resistant, Gene mutation, Refractory mycoplasma pneumoniae pneumonia, Bronchoalveolar lavage fluid, Fiberoptic bronchoscopy