Mycoplasma pneumoniae (MP) is a key pathogen of respiratory tract infections, and the development of rapid, sensitive, and simple point-of-care testing (POCT) methods is of great clinical significance. In this study, enzymatic recombinase amplification (ERA) was combined with a colloidal gold-based lateral flow dipstick (LFD) to establish a novel MP detection method. Specific primers targeting the P1 protein gene were designed, with the downstream primer and probe labeled with biotin and 6-carboxyfluorescein (FAM) at their 5' ends, respectively, and the primer pair combinations, reaction temperature, and time were optimized to construct the ERA-LFD method. The detection performance for different MP strains was evaluated using reference samples and compared with a commercial fluorescent quantitative polymerase chain reaction (qPCR) kit. Subsequently, specificity, sensitivity, and clinical applicability were assessed using clinical specimens. The results showed that the target gene fragment of MP could be successfully amplified at 37 °C within 15 min, and the ERA amplification products could be visualized on the colloidal gold LFD by the naked eye. The limit of detection (LoD) of the assay was as low as 10 copies/μL, which was 1,000-fold more sensitive than conventional PCR, with no cross-reactivity to nucleic acids from other common respiratory pathogens. Evaluation of 158 clinical samples using qPCR as the gold standard demonstrated that the method achieved 98.0% sensitivity, 100.0% specificity, 98.7% overall agreement, and a Kappa value of 0.973. Collectively, this study developed a simple, rapid, and sensitive MP detection method that is suitable for both routine clinical applications and POCT scenarios.

IntroductionMycoplasma pneumoniae is one of the important pathogens of community-acquired pneumonia (CAP), and P1 adhesin serves as a pathogenic protein and an immune protein involved in the pathogenesis of mycoplasma pneumoniae. The aim of this study was to investigate the P1 adhesin genotype in Mycoplasma pneumoniae and its association with disease severity in patients with CAP from 2017 to 2019.MethodsM. pneumoniae was identified in patient samples by real-time quantitative polymerase chain reaction (qPCR). The P1 genotypes of samples were determined using a culture-independent P1 typing method.ResultsIn total, 1,907 clinical samples were collected from 13 tertiary hospitals in Beijing, Shenyang, and Baotou, including 1488 samples from children and 419 from adults. Of these, 820 samples (43.00%), including 777 from children and 43 from adults, were positive for M. pneumoniae. 797 samples were successfully typed using the culture-independent P1 typing method (P1-1, 605; P1- 2, 192). The M. pneumoniae detection rate and P1-1 detection rate differed significantly between children and adults (both p < 0.01), with P1-1 remaining the dominant genotype. The proportion of P1-2 samples increased in children from 16.75% in 2017 to 28.76% in 2019.DiscussionNo relationship between the P1 genotype and disease severity was identified. Monitoring the genotype changes of P1 adhesin in local populations may positively impact the epidemiological prevention and control of M. pneumoniae infections.

In previous study, lower levels of serum GP130 were reported in children with MPP. GP130 is an important signal transducer, the down regulation of which may influence host immune responses. In this study, we aimed to analyze the regulatory mechanism of GP130 during MP infection. Firstly, the mRNA and protein levels of GP130 both decrease and then increase with increasing multiplicity of infection (MOI: 1 to 40) of MP. The lowest levels of GP130 were detected at MOI of 5. Then, heat treated MP but not trypsin treated MP or MP extracted proteins show regulatory effect to the expression of GP130. These indicate that the down regulation of GP130 is related to protein mediate adhesion process of MP. Gene expression analysis revealed that MP affected apoptosis and the TLR4 pathway in infected cells, and the mRNA level of IL-6 was correlated with that of GP130. Further, Z-VAD-FMK (pan-caspase inhibitor) can suppress the apoptosis induced by MP infection and restore GP130 at protein level. Further studies revealed that MP infection promoted TLR4 internalization but did not activate the NF-κB pathway. The levels of surface TLR4 showed correlation with the transcription of IL-6 and GP130. TAK242 (TLR4 inhibitor) and PS341 (proteasome inhibitor) can restore the decreased transcription of GP130, both of which were able to promote NF-κB pathway activation in MP-infected cells. These suggested that the regulation of TLR4/NF-κB pathway and induced apoptosis post MP infection are involved in the down-regulation of GP130 at transcription and protein levels, respectively.

The prevalence of macrolide-resistant MPs increased the difficulty in treatment of MP infections and posed potential threats to children's health. Epidemiological studies showed a high prevalence of IR-resistant strains (mainly A2063G in 23S rRNA) in these years.

目的:探讨乙酰吉他霉素干混悬剂对肺炎支原体(MP)的体外抗菌作用.方法:选择2016—2019年本实验室保存的呼吸系统感染患者的MP临床分离株51株,以阿奇霉素、红霉素对照药物,采用微量倍比稀释法测定乙酰吉他霉素干混悬剂对MP的体外最低抑菌浓度(MIC).结果:51株临床分离株中,43例耐药株,含23 SrRNA 2063位点突变,8例敏感株,无耐药相关位点突变.微量倍比稀释法的结果显示:乙酰吉他霉素干混悬剂对MP标准株FH和M129的MIC值均为0.125 mg·L-1,对MP临床耐药株的MIC值为8～32 mg·L-1,MIC50为16 mg·L-1,MIC90为32 mg·L-1;对MP临床敏感株的MIC值为0.063～0.125 mg·L-1,MIC50和MIC90均为0.125 mg·L-1.红霉素对MP临床耐药株MIC范围为256～1024 mg·L-1,MIC50和MIC90分别为512和1024 mg·L-1;阿奇霉素对MP临床耐药株MIC范围为64～512 mg·L-1,MIC50和MIC90分别为256和512 mg·L-1;红霉素和阿奇霉素对MP临床敏感株的MIC值均<0.5 mg·L-1.结论:肺炎支原体对大环内酯类抗生素呈不同程度的耐药,乙酰吉他霉素干混悬剂体外对MP敏感株有较好的抑菌活性,对MP耐药株的MIC值水平较低,临床上对肺炎支原体感染的作用需要进一步研究.

目的:运用药物经济学分析方法,探讨阿奇霉素序贯疗法、阿奇霉素-米诺环素转换疗法治疗肺炎支原体肺炎的最佳药物治疗方案,以最低成本获得最佳效果.方法:回顾性选取2016年8月至2018年12月该院儿科收治的8岁以上肺炎支原体肺炎患儿322例,根据治疗方案分为A组(阿奇霉素序贯治疗)160例和B组(阿奇霉素-米诺环素转换疗法)162例.通过决策树及SPSS软件,对两组方案进行成本-效果分析.结果:A组患儿入院后咳嗽好转时间、入院后发热好转时间、入院后肺部体征好转时间和平均住院时间明显长于B组,差异均有统计学意义(P<0.05).A组、B组患儿的总有效率分别为89.4％(143/160)、92.6％(150/162),差异无统计学意义(P=0.529).A组、B组每治愈1例肺炎支原体肺炎患儿的成本分别为3840、3570元.两组患儿在治疗过程中均未发现明显不良反应.结果:对于8岁以上肺炎支原体肺炎患儿,阿奇霉素序贯疗法与阿奇霉素-米诺环素替换治疗的效果相当,阿奇霉素-米诺环素替换治疗的成本偏低.

目的 了解儿童急性呼吸道感染病原分布情况,并评估多重聚合酶链反应(PCR)技术的临床应用价值.方法 收集2018年1月–2019年1月北京地区多个医院268例呼吸道感染患儿的咽拭子及支气管肺泡灌洗液,采用多重PCR技术测定13种病原的核酸,同时应用荧光定量PCR法检测肺炎支原体核酸,分析儿童急性呼吸道感染病原分布情况,并比较两种检测方法的一致性.结果 268例呼吸道标本,231例(86.19％)检出至少一种以上的病原,51例(19.03％)检出两种或两种以上病原.肺炎支原体(MP)和流感病毒占所检病原的前两位,检出的病原体按例数分别为MP 109例、H1N143例、InfA 36例、RSV 29例、H3N214例、HRV 14例、HMPV 13例、InfB 10例、HAdV 9例、HCoV 6例、HPIV 5例、HBoV 1例、CP 1例.多重PCR方法检测出MP阳性109例(40.67％),实时定量PCR法检测出MP阳性123例(45.90％),两种检测方法阳性率比较差异无统计学意义(P=0.262),一致性分析显示两种检测方法具有高度的一致性(Kappa=0.879).结论 MP及流感病毒是北京地区儿童呼吸道感染的重要病原,而且混合感染的情况并不少见.对于MP,多重PCR技术和实时荧光定量PCR法敏感性基本一致,两者具有高度的一致性,多重PCR技术可同时检测病毒、MP、CP等多种病原体,特异性强,可提高样本使用率,具有良好的应用价值.

BackgroundInfluenza and Mycoplasma pneumonia (MP) infection are common winter diseases in northern China, both of which have similar clinical symptoms. There are few studies on the infection of MP in individuals with influenza-like illness (ILI) .ObjectiveTo study the presence and drug resistance of MP in throat swabs from ILI patients.MethodsThroat swab specimens of 915 outpatients with ILI were collected from 17 grade A tertiary healthcare institutions in 15 regions of China (Weifang, Kaifeng, Harbin, Inner Mongolia, Beijing, Tianjin, Tongchuan, Xianyang, Qinhuangdao, Dandong, Hanzhong, Taiyuan, Benxi, Luohe, Nanyang) during two winters (one was from December 2018 to February 2019, and the other from December 2019 to February 2020) . The Influenza A+B Antigen Test Kit (Colloidal Gold) was used to identify influenza viral antigens. PCR was used to detect the nucleic acid from pneumonia pathogens. DNA sequencing was used to detect the drug-resistant gene associated with MP.ResultsOf the specimens, 578 were from children (<18 years) and 337 from adults (≥18 years) . The overall detection rate of influenza viral antigens was 45.25% (414/915) . The positive rate of influenza A was 91.06% (377/414) . Pediatric and adult cases had no statistical difference in the detection rate of influenza viral antigens〔44.29% (256/578) vs 46.88% (158/337) , χ2=0.577, P=0.447〕. The overall detection rate of MP was 11.91% (109/915) . Pediatric and adult cases had no statistical difference in the detection rate of MP〔4.34% (25/578) vs 24.93% (84/337) , χ2= 86.094, P<0.001〕. Of the MP-positive specimens, 74.31% (81/109) had A2063G mutations, 1.83% (2/109) had A2064G mutations, and 1.83% (2/109) had A2063G and A2064G mutations. In children's MP-positive specimens, 48.00% (12/25) had A2063G mutations, 8.00% (2/25) had A2064G mutations, and 8.00% (2/25) had A2063G and A2064G mutations, the other 36.00% (9/25) had drug-susceptible strains. Of the adult MP-positive specimens, 82.14% (69/84) had A2063G mutation, 17.86% (15/84) had drug-susceptible strains, and no A2064G mutation was found. The rate of presence of drug-resistant gene A2063G mutations in adult specimens was higher than that in pediatric specimens (χ2=11.765, P=0.001) . Both influenza viruses and MP were detected in 2.84% (26/915) of the specimens. The rate of co-presence of influenza viruses and MP in adult specimens was higher than that in pediatric specimens〔4.75% (16/337) vs 1.73% (10/578) , χ2=7.022, P=0.008〕.ConclusionDuring winters in 2018—2020, influenza A was the major type of influenza prevailing in northern China. MP infection was not rare in patients with ILI, and it was more common in adults than in children. The resistance rate of MP to macrolide antibiotics was relatively high. A2063G mutation in the 23SrRNA gene was the major type of mutations. Some cases were coinfected with influenza viruses and MP.

Mycoplasma pneumoniae (MP) is an important respiratory pathogen of human. The infection of MP can cause direct damage and immune damage in lung, resulting in Mycoplasma pneumoniae pneumonia (MPP). In this study, we aim to investigate the pathogenesis of MPP by detecting the proliferation of MP under conditions of cell damages and neutrophils in vitro. Firstly, we found the supplements of intracellular fluid, protein and RNA derived from intracellular fluid of A549 cells contribute to the survival of MP, thereby promoting the infection of MP. Cell damage can also significantly contribute to the survival of MP without supplements. At the same time, the additions of supplements contribute to apoptosis and the expression of IL-8 and IL-1β. Further, we found live neutrophils show bactericidal activity to MP, and the phagocytosis of MP promotes apoptosis of neutrophils. When co-incubated with MP and A549 cells, the proliferation of MP in the high neutrophils proportion groups were accelerated with functional decline of neutrophils, and the level of extracellular IL-1β showed a time and dose dependent manner to neutrophils. These results suggest that the release of intracellular nutrients by damaged cells and functional decline of neutrophils can promote the infection of MP and play roles in the activation of inflammatory response. Therefore, lung damage and infiltration of neutrophils would be important factors affecting the development of MPP.

目的 探讨PCR测序法、AS-PCR法、多重荧光PCR法检测肺炎支原体(MP)及大环内酯类耐药肺炎支原体(MRMP)的临床意义.方法 采集呼吸道感染患儿的咽拭子样本116例,使用PCR测序法、AS-PCR法、多重荧光PCR法检测MP和MRMP,探讨三种方法的特点和临床价值.结果 共采集116份咽拭子样本,PCR测序法检测MP阳性69例,阳性率59.48％,其中耐药株67例,包含1株耐药株与敏感株混合感染,耐药率97.1％,均为A2063G点突变,敏感株2例.AS-PCR法检测MP阳性63例,阳性率54.31％,其中耐药株58例,耐药率92.06％,敏感株5例,58例耐药株中混合感染21例,混合感染率33.33％(21/63),混合感染中18例耐药株比例超过50％.与PCR测序法比较,对MP阳性检测结果一致性极好(Kappa=0.86),对MRMP检测结果有较高的一致性(Kappa=0.652).多重荧光PCR法检测MP阳性共67例,阳性率57.76％,其中耐药株61例,耐药率91.04％,敏感株6例,与PCR测序法相比,对MP阳性检测结果有极好的一致性(Kappa=0.929),对MRMP检测结果中度一致(Kappa=0.476).结论 PCR测序法、AS-PCR法和多重荧光PCR法检测敏感性和特异性均较高,三种方法均可同时进行MP和MRMP检测.AS-PCR法和多重荧光PCR法操作简单,适合临床应用,能为临床诊疗快速提供MP和MRMP检测结果.AS-PCR法能检测MP耐药株和敏感株混合感染,检测敏感性好.三种检测方法可为临床医生合理用药提供数据支持.

Mycoplasma pneumoniae (MP) is an important human pathogen that mainly affects children causing general and severe Mycoplasma pneumoniae pneumonia (G/SMPP). In the present study, a comprehensive immune response data (33 cytokines) was obtained in school-age children (3–9 years old) during MPP, aiming to analyze the immune response patterns during MPP. At acute phase, changes of cytokines were both detected in GMPP (24/33) and SMPP (23/33) groups compared to the healthy group (p < 0.05), with 20 identical cytokines. Between MPP groups, the levels of 13 cytokines (IL-2, IL-10, IL-11, IL-12, IL-20, IL-28A, IL-32, IL-35, IFN-α2, IFN-γ, IFN-β, BAFF, and TSLP) were higher and three cytokines (LIGHT, OPN and CHI3L1) were lower in the SMPP group than in the GMPP group (p < 0.05). Function analysis reveals that macrophage function (sCD163, CHI3L1) are not activated in both MPP groups; difference in regulatory patterns of T cells (IL26, IL27, OPN, LIGHT) and defective activation of B cells (BAFF) were detected in the SMPP group compared to the GMPP group. Besides, the level of osteocalcin; sIL-6Rβ and MMP-2 are both decreased in MPP groups at acute and convalescent phases compared to the healthy group, among which the levels of sIL-6Rβ and MMP-2 showed negative correlations (p < 0.1) to the application of bronchial lavage in SMPP group, indicating their roles in the development of MPP. At the convalescent phase, more cytokines recovered in GMPP (18) than SMPP (11), revealing better controlled immune response during GMPP. These results reveal different immune response patterns during GMPP and SMPP. In addition, the differentiated cytokines may serve as potential indicators of SMPP; early intervention on immune response regulations may be helpful in reducing the severity of SMPP.

Objective:We investigated changes in the intestinal flora of children with Mycoplasma pneumoniae pneumonia (MPP).Methods:Between September 2019 and November 2019, stool samples from 14 children with MPP from The Fourth Hospital of Baotou city, Inner Mongolia Autonomous Region, were collected and divided into general treatment (AF) and probiotic (AFY) groups, according to the treatment of "combined Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus cereus tablets live". High-throughput 16S rDNA sequencing was used to identify intestinal flora.Results:Intestinal flora abundance and diversity in children with MPP were decreased. Both Shannon and Simpson indices were lower in the AF group when compared with healthy controls ( P < 0.05). When compared with healthy controls, the proportion of Enterorhabdus was lower in the AF group, while the proportion of Lachnoclostridium was higher ( P < 0.05). The proportion of Bifidobacteria and Akkermansia was lower in the AFY group but Enterococcus, Lachnoclostridium, Roseburia, and Erysipelatoclostridium proportions were higher. The proportion of Escherichia coli- Shigella in the AFY group after treatment was decreased ( P < 0.05).Conclusions:The intestinal flora of children with MPP is disturbed, manifested as decreased abundance and diversity, and decreased Bifidobacteria. Our probiotic mixture partly improved intestinal flora disorders.

Objective:To investigate drug resistance gene in Mycoplasma pneumoniae(MP) and the distribution of 13 respiratory pathogens in bronchoalveolar lavage fluid(BALF) of children with Mycoplasma pneumoniae pneumonia(MPP).Methods:A total of 100 BALF of children with MPP in Peking University Third Hospital and Peking University First Hospital from January 2018 to January 2019 were collected.Fluorogenic quantitative PCR was used to detect nucleic acid and it′s drug resistance gene of MP and multiple PCR method was adopted to detect influenza A virus, influenza A virus-H 1N 1, influenza A virus-H 3N 2, influenza B, human parainfluenza virus, adenovirus, human bocavirus, human rhinovirus, Chlamydia pneumoniae, human metapneumovirus, MP, human coronavirus, and respi-ratory syncytial virus gene, and the results were compared by using Chi square test. Results:In 100 BALF samples, MP and drug resistance gene were detected by fluorogenic quantitative PCR.Totally, 83 cases (83.00%) were MP positive and 78 cases (93.98%) were drug resistant.All of them had the point mutations A2063G in V region of 23S rRNA domain.A total of 13 kinds of respiratory pathogens were detected by multiplex PCR method, and 89 cases (89.00%) were positive.Totally, 79 cases (79.00%) were MP positive, of which 74 cases (74.00%) detected only MP, and 5 cases (5.00%) detected MP combined with other pathogens.Other pathogens were detected in 10 cases (10.00%). The virus detection rate of 0-4 years old group was higher than that of >4-6 years old group ( P=0.042) and >6 years old group ( P=0.002), and the differences were statistically significant. Conclusions:MP can be detected in most BALF samples of MPP children, the drug resistance phenomenon is serious, and the main point mutation is A2063G.There were other respiratory pathogens and 2 or 3 pathogens were detected in a small number of BALF samples.

Background: Mycoplasma pneumoniae is a leading cause of community-acquired respiratory infections. Infantile Feire Kechuan Oral Solution (IFKOS) is effective for treatment of M. pneumoniae infection. The aim of this study was to explore the potential mechanism of IFKOS against M. pneumoniae infection in basal epithelial human lung adenocarcinoma A549 cells. Methods: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine the effects of IFKOS on the viability of A549 cells infected with M. pneumoniae. Optical microscopy was used to observe cell morphology and a Muse cell analyzer was used to assess apoptosis and the cell cycle phase. Enzymelinked immunosorbent assays were employed to assess the expression levels of interleukin (IL)-4, IL-6, IL-8, IL17, tumor necrosis factor (TNF)-alpha, interferon (IFN)-alpha, and IFN-gamma. Results: Under certain conditions, M. pneumoniae infection reduced the viability and inhibited the proliferation of A549 cells, promoted early apoptosis, and arrested cells in the G0/G1 phase, thus shortening the S and G2/M phases (all p < 0.05). M. pneumoniae also upregulated expression of IL-8 and TNF-alpha and downregulated that of IL6 (p < 0.05), which switched the immune balance of Th1/Th2 to Th1 cells. IFKOS (5.531 mg/mL) improved the viability and proliferation of M. pneumoniae-infected A549 cells, mitigated early apoptosis, and reversed cell cycle arrest in the G0/G1 phase, thereby extending the S and G2/M phases (all, p < 0.05). IFKOS downregulated expression of IL-8 and TNF-alpha and upregulated that of IL-6 (p < 0.01), thereby reversing the immune imbalance of Th1/Th2. Secretion of IL-4, IL-17, IFN-alpha, and IFN-gamma was not observed. Conclusion: IFKOS played a protective role in the regulation of cell viability, apoptosis, the cell cycle, and Th1/ Th2 immune imbalance induced by M. pneumoniae infection and conveyed an anti-inflammatory effect in A549 cells.

目的 探究成人流感样病例中13种病原体分布情况及多重聚合酶链反应(PCR)毛细电泳片段分析法在病原体检测中的应用价值.方法 收集2019年12月至2020年2月北方地区189份流感样病例咽拭子标本,采用多重RT-PCR与毛细电泳片段分析法联用技术得到病原体的检测结果.检测病原体包括甲型流感病毒(InfA)、人腺病毒(HADV)、博卡病毒(Boca)、人鼻病毒(HRV)、甲型流感病毒H1N1(2009)(InfA-H1N1)、季节性流感病毒(InfA-H3N2)、副流感病毒(HPIV)、人偏肺病毒(HMPV)、乙型流感病毒(InfB)、肺炎支原体(MP)、肺炎衣原体(CP)、冠状病毒(HCOV)、人呼吸道合胞病毒(RSV)13种病原体.结果 189份流感样病例咽拭子标本中有180份(95.24％)检测出病原体,9份(4.76％)未检测出病原体.180份病原体阳性标本单一病原体150份(83.33％),多种病原体30份(16.67％);145份(80.56％)检测出流感病原体,35份(19.44％)检测出非流感病原体.3种最常见的单一病原体是InfA-H3N2(94份,49.74％),MP(26份,13.76％),InfA(16份,8.47％);3种最常见的多种病原体是InfA-H3N2合并MP感染(15份,7.93％),InfA合并MP感染(7份,3.70％),MP合并HRV感染(3份,1.59％).结论 2019年12月至2020年2月冬季我国北方地区的成人流感病毒主要以InfA-H3N2为主;非流感病毒也可引起流感样病例,以MP感染较多见;部分流感样病例可见混合感染.多重PCR毛细电泳片段分析法有助于全面了解成人流感样病例中病原体分布情况.

目的 探讨多重聚合酶链反应(PCR)检测方法在儿童流感样病例病原检测中的临床应用价值,了解儿童流感样病例病原情况.方法 收集2018年11月至2019年2月北京地区94例儿童流感样病例咽拭子标本,采用多重PCR核酸检测技术测定甲型流感病毒(InfA)、甲型流感病毒H1N1(InfA-H1N1)、甲型流感病毒H3N2(InfA-H3N2)、乙型流感病毒(InfB)、人副流感病毒、呼吸道合胞病毒(RSV)、人腺病毒(HADV)、人鼻病毒(HRV)、人博卡病毒、人偏肺病毒(HMPV)、人冠状病毒(HCoV)和肺炎支原体(MP)、衣原体13种病原核酸.结果 94例标本中78例(82.98％)可测出病原,其中69例(73.40％)检出1种病原,9例(9.57％)检出2种病原;94例标本中52例(55.32％)检出流感病原,26例(27.66％)检出非流感病原.单一病原检出由多到少为InfA-H1N1 31例,InfA-H3N2 10例,RSV 9例,HMPV 7例,InfA、HRV、HADV各3例,InfB、HCoV及MP各1 例.9例检出2种病原的标本中,6例检出流感分别合并其他病毒(HRV、HADV、RSV、HCoV、HMPV),1例检出甲流H1N1和H3N2,2例分别检出RSV、HRV及HCoV、HADV.结论 非流感病原微生物引起流感样病例并不少见,多重PCR检测有助于全面了解流感样病例的病原和混合感染情况.

目的 探讨肺炎支原体感染大叶性肺炎学龄期儿童支气管镜治疗的临床效果.方法 回顾性分析2017年7月至2018年12月在首都医科大学附属北京友谊医院儿科住院并明确诊断为肺炎支原体感染大叶性肺炎的124例学龄期儿童临床资料,根据不同治疗方式分为支气管镜组(56例)和对照组(68例).对照组给予常规治疗,支气管镜组在常规治疗基础上给予支气管镜下治疗.比较两组儿童发热、咳嗽、肺部体征、白细胞,中性粒细胞比例、C反应蛋白、乳酸脱氢酶、胸部CT/胸部X线片等指标的改善情况.结果 支气管镜治疗有助于改善咳嗽症状,缩短住院时间,两组比较差异有显著性(P<0.05).支气管镜组治愈率和总有效率高于对照组,差异有显著性(P<0.05).结论 对学龄期儿童肺炎支原体感染大叶性肺炎,早期行支气管镜治疗可促进肺部病灶吸收,缩短住院时间.

目的 探讨儿童肺炎支原体感染大叶性肺炎的危险因素.方法 回顾性分析2018年1月至2019年1月在首都医科大学附属北京友谊医院儿科住院并诊断为肺炎支原体肺炎的203例患儿的临床资料,将其中81例肺炎支原体感染大叶性肺炎患儿作为大叶性肺炎组,其余122例肺炎支原体感染支气管肺炎患儿作为支气管肺炎组,比较分析两组的临床资料,并进行多因素非条件logistic回归分析疾病的危险因素.结果 两组患儿年龄、热程、大环内酯类药开始使用时间、中性粒细胞百分比、C反应蛋白(C-reaction protein,CRP)、乳酸脱氢酶、血沉比较差异有显著性(P<0.05).儿童肺炎支原体感染大叶性肺炎与年龄、热程、大环内酯类药开始使用时间、CRP有关(P<0.05).结论 大龄儿童、热程长、大环内酯类药开始使用时间晚、CRP高是儿童肺炎支原体感染大叶性肺炎的危险因素.

Objective The aim of this study is to investigate the macrolide resistance rate and molecular type with multiple-locus variable-number tandem-repeat analysis (MLVA) of Mycoplasma pneumoniae of Beijing in 2016 in pediatric patients. Methods Real-time quantitative polymerase chain reaction (PCR) was used to identify M. pneumoniae, and MLVA was performed. The domain V of the 23S rRNA was sequenced to detect macrolide-resistant point mutations. We also investigated the activities of antibiotics against M. pneumoniae isolates in vitro. Results The PCR detection rate of M. pneumoniae in children in Beijing was 40%, and the macrolide resistance rate was 66%. The A2063G mutation in the 23S rRNA V region is the dominant mutation (137/146, 93.84%), whereas the A2064G mutation is rare (9/146, 6.16%). Seventy-three samples were typed successfully by MLVA typing, including 86.3% (63/73) were MLVA type 4-5-7-2, and 13.7% (10/73) were MLVA type 3-5-6-2. No other types were found. No strains were resistant to levofloxacin or tetracycline. Conclusion In 2016, a specific decrease in the macrolide resistance rate occurred in Beijing. The detection rate and macrolide resistance rate of outpatients are lower than those of inpatients. The A2063G mutants M. pneumoniae have high levels of resistance to erythromycin and azithromycin. The primary MLVA type is 4-5-7-2, followed by 3-5-6-2. No other MLVA types were detected. No strains resistant to tetracycline or levofloxacin were found in vitro.

Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired respiratory tract infections (RTIs). We aimed to investigate the prevalence of M. pneumoniae infection, antibiotic resistance and genetic diversity of M. pneumoniae isolates across multiple centers in Beijing, China. P1 protein was detected by Nested PCR to analyze the occurrence of M. pneumoniae in pediatric patients with RTI. M. pneumoniae isolates were cultured and analyzed by Nested-PCR to determine their genotypes. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of antibiotics. Out of 822 children with RTI admitted to 11 hospitals in Beijing, 341 (41.48%) were positive for M. pneumoniae by Nested PCR and 236 (69.21%) samples had mutations in 23S rRNA domain V. The highest proportion of M. pneumoniae positive samples was observed in school-age children (118/190; 62.11%) and in pediatric patients with pneumonia (220/389; 56.56%). Out of 341 M. pneumoniae positive samples, 99 (12.04%) isolates were successfully cultured and the MIC values were determined for 65 M. pneumoniae strains. Out of these, 57 (87.69%) strains were resistant to macrolides, and all 65 strains were sensitive to tetracyclines or quinolones. M. pneumoniae P1 type I and P1 type II strains were found in 57/65 (87.69%) and 8/65 (12.31%) of cultured isolates, respectively. Overall, we demonstrated a high prevalence of M. pneumoniae infection and high macrolide resistance of M. pneumoniae strains in Beijing. School-age children were more susceptible to M. pneumoniae, particularly the children with pneumonia. Thus, establishment of a systematic surveillance program to fully understand the epidemiology of M. pneumoniae is critical for the standardized use of antibiotics in China.