OBJECTIVES: To analyze the molecular and the clinical characteristics of Mycoplasma pneumoniae (Mp) pneumonia (MPP) and to explore the related factors predicting severe MPP (SMPP). METHODS: A total of 423 pediatric cases of MPP were retrospectively analyzed, in 2013-2017, in Beijing, China. Clinical information was collected from the medical records. Mp-positive specimens were characterized using P1 typing and multiple locus variable-number tandem repeat analysis (MLVA). The macrolide resistance-associated mutations were also detected. RESULTS: The predominant genotype was P1-1 (88.2%) and M4-5-7-2 (87.5%), whereas percentages of type P1-2 and M3-5-6-2 increased across the 5-year period. The mutation rate of genotype M4-5-7-2 (365/370, 98.6%) was significantly higher than that of the genotype M3-5-6-2 (15/48, 32.25%; P = 0.000). Overall, 180 (42.6%) of the 423 Mp-positive patients were coinfected with other pathogens. Respiratory syncytial virus coinfection (24/180, 13.3%) was more common in cases typed M3-5-6-2 (4/23, 17.4%) than that of M4-5-7-2 (20/155, 12.9%; P = 0.038). Pleural effusion accounted for 52.6% (169/321) of the observed complications. In the mono-infection cases, cases typed M3-5-6-2 (56%, 14/25) were significantly (P = 0.020) associated with pleural effusion compared with those typed M4-5-7-2 (32.6%, 70/215); 84% (21/25) of specimens typed M3-5-6-2 were diagnosed as SMPP, whereas 63.7% (137/215) of specimens typed M4-5-7-2 were diagnosed as SMPP (P = 0.043). CONCLUSIONS: In our study, we proposed for the first time that the mono-infection patients with Mp typed M3-5-6-2 appear to have a higher risk for progressing to SMPP. MLVA typing can provide hints on the clinical characteristics of Mpp.
OBJECTIVES: To analyze the molecular and the clinical characteristics of Mycoplasma pneumoniae (Mp) pneumonia (MPP) and to explore the related factors predicting severe MPP (SMPP). METHODS: A total of 423 pediatric cases of MPP were retrospectively analyzed, in 2013-2017, in Beijing, China. Clinical information was collected from the medical records. Mp-positive specimens were characterized using P1 typing and multiple locus variable-number tandem repeat analysis (MLVA). The macrolide resistance-associated mutations were also detected. RESULTS: The predominant genotype was P1-1 (88.2%) and M4-5-7-2 (87.5%), whereas percentages of type P1-2 and M3-5-6-2 increased across the 5-year period. The mutation rate of genotype M4-5-7-2 (365/370, 98.6%) was significantly higher than that of the genotype M3-5-6-2 (15/48, 32.25%; P = 0.000). Overall, 180 (42.6%) of the 423 Mp-positive patients were coinfected with other pathogens. Respiratory syncytial virus coinfection (24/180, 13.3%) was more common in cases typed M3-5-6-2 (4/23, 17.4%) than that of M4-5-7-2 (20/155, 12.9%; P = 0.038). Pleural effusion accounted for 52.6% (169/321) of the observed complications. In the mono-infection cases, cases typed M3-5-6-2 (56%, 14/25) were significantly (P = 0.020) associated with pleural effusion compared with those typed M4-5-7-2 (32.6%, 70/215); 84% (21/25) of specimens typed M3-5-6-2 were diagnosed as SMPP, whereas 63.7% (137/215) of specimens typed M4-5-7-2 were diagnosed as SMPP (P = 0.043). CONCLUSIONS: In our study, we proposed for the first time that the mono-infectionpatients with Mp typed M3-5-6-2 appear to have a higher risk for progressing to SMPP. MLVA typing can provide hints on the clinical characteristics of Mpp.
Authors: L Xiao; A E Ratliff; D M Crabb; E Mixon; X Qin; R Selvarangan; Y-W Tang; X Zheng; J Dien Bard; T Hong; M Prichard; E Brooks; S Dallas; L B Duffy; K B Fowler; T P Atkinson; K B Waites Journal: J Clin Microbiol Date: 2020-09-22 Impact factor: 5.948