Common bacteria in oropharynx of children with Mycoplasma pneumoniae pneumonia and its clinical significance / 中华实用儿科临床杂志

ABSTRACT

Objective:To investigate the common bacteria in the oropharynx of children with Mycoplasma pneumoniae pneumonia (MPP) and its clinical significance.Methods:A total of 134 children with MPP who were hospitalized in the Department of Pediatric Respiratory, Shengjing Hospital of China Medical University from December 2016 to June 2017 were selected as the research subjects, and 42 healthy children in the same hospital were selected retrospectively as the healthy control group during the same period.Fluorescent quantitative polymerase chain reaction Taqman probe was used to detect common oropharyngeal bacteria[ Streptococcus pneumoniae(SP), Moraxella catarrhalis(CTA), Haemophilus influenza(HI)] for the enrolled children.Firstly, the bacterial detection rate of MPP children and healthy children was compared.Then, according to age(<1 years old, 1-<3 years old, 3-<6 years old and 6-14 years old), bacterial detection[Mycoplasma pneumoniae(MP), MP+ bacteria]and bacterial species(MP+ SP, MP+ CTA, MP+ HI), 134 children with MPP were divided into groups to compare.Moreover, the relevant clinical datas were retrospectively analyzed by rank sum test and chi- square test. Results:Among 134 children with MPP, 79 (58.96%) children were detected bacteria, and 17 (40.48%) children were detected bacteria among 42 healthy children, with statistically significant differences( χ2=4.404, P<0.05). Compared with the MP group, the level of white blood cell (WBC)[8.5(6.7, 12.0)×10 9/L vs.7.8(5.8, 9.3)×10 9/L, Z=-2.232], C reactive protein(CRP)[19.2(7.2, 35.0) mg/L vs.8.4(3.4, 24.6) mg/L, Z=-2.810], lactate dehydrogenase(LDH)[286(244, 365) U/L vs.250(210, 302) U/L, Z=-2.474] and the incidence of lobar pneumonia[40.51%(32/79 cases) vs.18.18%(10/55 cases), χ2=7.510], pleural effusion[13.92%(11/79 cases) vs.3.64%(2/55 cases), χ2=3.917], refractory Mycoplasma pneumoniae pneumonia (RMPP)[34.18%(27/79 cases) vs.18.18%(10/55 cases), χ2=4.151] in MP+ bacteria group were higher; the course of fever[10(7, 12) d vs.8(6, 10) d, Z=-2.706] and duration of antibiotic use[16(13, 19) d vs.12(9, 16) d, Z=-3.747] in MP+ bacteria group were longer (all P<0.05). The level of WBC in MP+ SP group[12.20(7.80, 17.30)×10 9/L] was higher than that in MP+ HI group [6.75(5.37, 9.44)×10 9/L], and the differences were statistically significant( Z=11.574, P<0.05), and the incidence of lobar pneumonia in MP+ SP group [56.67%(17/30 cases)]was higher than that in MP+ CTA group [0(0/3 cases)]and MP+ HI group[18.75%(3/16 cases)], and the differences were statistically significant( χ2=9.770, P<0.05). Conclusions:Bacterial colonization or infection is more likely to occur in the oropharynx of children with MPP.When WBC, CRP, and LDH are significantly increased and the image shows a large consolidation or pleural effusion, it may indicate mixed bacterial infection, longer course of fever and higher incidence of RMPP, and the common mixed bacteria is SP.