Hepatocyte growth factor can guide treatment of Mycoplasma pneumoniae pneumonia in children

Combination of azithromycin and methylprednisolone alleviates Mycoplasma pneumoniae induced pneumonia by regulating miR‑499a‑5p/STAT3 axis

Mycoplasma pneumoniae (M. pneumoniae) is a contributing factor to community-acquired pneumonia in children. The present study sought to explain the underlying mechanism of azithromycin (AZM) combined with methylprednisolone (MP) in the treatment of M. pneumoniae infection. Peripheral blood samples were obtained from patients with M. pneumoniae and healthy volunteers for analysis. A549 cells were infected with M. pneumoniae to construct an in vitro cell model with M. pneumoniae, followed by treatment with AZM and MP. Cell Counting Kit-8 and TUNEL assays were conducted to detect cell viability and apoptosis. RT-qPCR was employed to measure the expression levels of microRNA (miR)-499a-5p and STAT3. Western blotting was performed to measure the expression of STAT3 and apoptosis-related proteins. Luciferase report assay was performed to verify the binding site between miR-499a-5p and STAT3. The production of inflammatory cytokines was determined using ELISA kits. The results exhibited the downregulated miR-499a-5p and dysregulated inflammatory cytokines in peripheral blood of patients and M. pneumoniae-infected A549 cells. AZM and MP treatment alone or combined significantly inhibited inflammatory response, cell viability loss and promoted apoptosis in A549 cells infected with M. pneumoniae, which was partly reversed by inhibition of miR-499a-5p. Furthermore, miR-499a-5p could negatively regulate its direct target STAT3. In addition, STAT3 is also regulated by AZM and MP. Collectively, the present results suggested that combination treatment of AZM and MP could inhibit M. pneumoniae infection-induced inflammation, cell viability loss and promoted apoptosis partly by regulating miR-499a-5p/STAT3 axis.

The Diagnostic Value of High-Resolution Computed Tomography Features Combined with Mycoplasma Pneumoniae Ribonucleic Acid Load Detection for Refractory Mycoplasma Pneumonia

The aim of this study was to investigate the value of high-resolution computed tomography (CT) images and mycoplasma pneumoniae (MP) ribonucleic acid (RNA) load detection in the early diagnosis of refractory mycoplasma pneumoniae (RMP) and provide more methods for the diagnosis and treatment of RMP. Seventy children with MP were divided into the RMP group (H1 group, 31 cases) and the MP group (H2 group, 39 cases) according to pathological findings, and all of them underwent CT scanning. MP-RNA load and genotype distribution were analyzed in both groups, and the diagnostic efficacy of CT combined with MP-RNA load for RMP was calculated. The sensitivity of children in the H1 group to erythromycin (59.17% vs 71.56%) and clarithromycin (53.21% vs 67.03%) was lower than that in the H2 group, and the resistance rate of children in the H1 group to erythromycin (71.43% vs 67.53%) and clarithromycin (64.24% vs 50.37%) was higher than that in the H2 group (P < 0.05); the regression coefficients between lactate dehydrogenase (LDH) and the MPLI value of RMP were −0.064 and −0.413, respectively, which were significantly negatively correlated (P < 0.05); the accuracy (96.5%), sensitivity (92.5%), and specificity (88%) of CT + MP-RNA in the diagnosis of RMP were significantly higher than those of CT alone (91%, 88%, and 82%) and MP-RNA alone (88%, 84.5%, and 74%), which were significantly different (P < 0.05). The results of high MP-RNA load detection can be used as an indicator to predict RMP, and the diagnostic efficacy is significantly improved after combination with high-resolution CT, with high clinical application value.