Comparative Analysis for the Detection and Monitoring of Mycoplasma hyopneumoniae Infection by Nested PCR(n-PCR) and Real time PCR(q-PCR) from Field Swine Herds

[Objective] 303 nasal swabs samples were collected from pigs in farms located in Taizhou city, Jiangsu Province, China from March to December 2012 for the purpose of detecting the presence of Mycoplasma hyopneumoniae, the primary agent of Enzootic porcine pneumonia （EPP） in pig herds using the nested PCR and Real time PCR techniques. [Method] Nasal swabs were collected from pigs of different ages＇ i.e. 7, 14, 21, 28, 30 and 35 days old, soaked in sterile 1 xPBS overnight at 4 ℃ and DNA extracted using the TIANamp（R） bacterial DNA kit. The DNA samples underwent amplification under the Mhyo 183 q-PCR and P36 primer Nested PCR systems. [Result] With the Nested PCR assay, 38 （12.5%） out of 303 samples tested positive for the presence of M. hyopneumoniae; with the real time PCR assay 152 （50.2%） tested positive for M. hyopneumoniae. The two assays matched to positively detect Mhyo in 22 （7.3%） samples and again matched in 127 （41.9%） samples negative for Mhyo infection. The pattern of infection in both assays was similar where 7- and 35-day-old piglets in both assays had the highest rates of infection i.e. 15.6% and 18.4% for n-PCR and 53.1% and 56.6% for q-PCR for 7- and 35-day-old piglets respectively. [Conclusion] The results highlight the suitability of both PCR assays in establishing the herd infection status of pigs in field conditions.

Chinese herbal medicine combined with Western medicine for Mycoplasma pneumoniae pneumonia in children:An overview of systematic reviews

Objective:To summarize the characteristics and evaluate the quality of the methodology and evidence within systematic reviews(SRs)of Chinese herbal medicine(CHM)for Mycoplasma pneumoniae pneumonia(MPP)inchildren.Methods:SRs of randomized controlled trials were searched using PubMed,the Cochrane Library,Embase,the Chinese National Knowledge Infrastructure Databases(CNKI),the Chinese Scientific Journals Database(VIP),Wanfang,and the SinoMed Database.SRs on the use of CHM alone or in combination with Western medications for MPP in children were included.The study compared the effects of Western medicine alone with those of CHM.The evidence quality using the A Measurement Tool to Assess Systematic Reviews(AMSTAR)2,the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)2020,and the Grading of Recommendations,Assessment,Development,and Evaluation(GRADE)criteria.The primary indicators were the total effective rate,fever subsidence time,and cough disappearance time.The secondary outcomes were pulmonary rale disappearance time,average hospitalization time,lung X-ray infiltrate disappearance time,immunological indices,and inflammatory cytokine levels.Results:Twelve relevant SRs were included;75%(9/12)were assessed as very low quality,and 25%(3/12)Were rated as low quality using the AMSTAR 2 criteria.According to the PRISMA 2020 checklist,the average SR score was 20.3 out of a 27 point maximum.In all SRs,CHM demonstrated improvement in symptoms and signs among children with MPP.The evidence quality using the GRADE criteria ranged from"very low"(>50%)to"moderate"(<5%).The most common downgrading factor was imprecision,followed by publication bias and inconsistency.Conclusion:This overview highlights the limited quality of the methodology and evidence of the included SRs.Although the included studies showed the beneficial effects of CHM on MPP in children,it was difficult to draw firm conclusions owing to methodological flaws.

Serum inflammatory markers in children with Mycoplasma pneumoniae pneumonia and their predictive value for mycoplasma severity

BACKGROUND Mycoplasma pneumoniae pneumonia(MPP)significantly impacts pediatric health,necessitating markers for early severe disease identification.AIM To investigate the correlation between serum inflammatory marker and the severity of MPP in children.METHODS A prospective study was carried out from January 2023 to November 2023.A total of 160 children with MPP who underwent treatment were selected:80 had severe MPP and 80 had mild MPP.Clinical and laboratory data were collected at the time of hospital admission and during hospitalization.Receiver operating characteristic curves were utilized to assess the diagnostic and prognostic for severe MPP.RESULTS Fever duration and length of hospitalization in pediatric patients with severe MPP exceeded those with mild MPP.The incidence of pleural effusion,lung consolidation,and bronchopneumonia on imaging was markedly elevated in the severe MPP cohort compared to the mild MPP cohort.In contrast to the mild cohort,there was a notable increase in C-reactive protein(CRP),procalcitonin(PCT),erythrocyte sedimentation rate,lactic dehydrogenase,D-dimer,and inflammatory cytokines[interleukin(IL)-6,IL-8,IL-10 and tumor necrosis factor(TNF)-α]in the severe MPP group were significantly higher.CONCLUSION Serum inflammatory markers(CRP,PCT,IL-6,D-dimer,IL-10 and TNF-α)were considered as predictors in children with severe MPP.

Evaluating the role of interleukin-2 and interleukin-12 in pediatric patients with concurrent Mycoplasma pneumoniae and Epstein-Barr virus infections

BACKGROUND Mycoplasma pneumoniae(MP)frequently causes respiratory infections in children,whereas Epstein-Barr virus(EBV)typically presents subclinical manifestations in immunocompetent pediatric populations.The incidence of MP and EBV coinfections is often overlooked clinically,with the contributory role of EBV in pulmonary infections alongside MP remaining unclear.AIM To evaluate the serum concentrations of interleukin-2(IL-2)and interleukin-12(IL-12)in pediatric patients with MP pneumonia co-infected with EBV and assess their prognostic implications.METHODS We retrospectively analyzed clinical data from patients diagnosed with MP and EBV co-infection,isolated MP infection,and a control group of healthy children,spanning from January 1,2018 to December 31,2021.Serum IL-2 and IL-12 levels were quantified using enzyme-linked immunosorbent assay.Logistic regression was employed to identify factors influencing poor prognosis,while receiver operating characteristic(ROC)curves evaluated the prognostic utility of serum IL-2 and IL-12 levels in co-infected patients.RESULTS The co-infection group exhibited elevated serum IL-2 and C-reactive protein(CRP)levels compared to both the MP-only and control groups,with a reverse trend observed for IL-12(P<0.05).In the poor prognosis cohort,elevated CRP and IL-2 levels,alongside prolonged fever duration,contrasted with reduced IL-12 levels(P<0.05).Logistic regression identified elevated IL-2 as an independent risk factor and high IL-12 as a protective factor for adverse outcomes(P<0.05).ROC analysis indicated that the area under the curves for IL-2,IL-12,and their combination in predicting poor prognosis were 0.815,0.895,and 0.915,respectively.CONCLUSION Elevated serum IL-2 and diminished IL-12 levels in pediatric patients with MP and EBV co-infection correlate with poorer prognosis,with combined IL-2 and IL-12 levels offering enhanced predictive accuracy.

Lymph-node-first presentation of Kawasaki disease in a 12-year-old girl with cervical lymphadenitis caused by Mycoplasma pneumoniae:A case report

BACKGROUND To the best of our knowledge,cases of Kawasaki disease(KD)occurring at the age of 12 are rare,even in Asia where the incidence of KD is high.We report a case of lymph-node-first presentation of KD(NFKD)in a 12-year-old girl with Mycoplasma pneumoniae(M.pneumoniae)infection who presented with prolonged fever and lymphadenitis refractory to macrolide antibiotics.CASE SUMMARY A previously healthy 12-year-old girl presented with fever,myalgia,sore throat,swelling,and tenderness on the right side of the neck.She was initially diagnosed with lymphadenitis caused by M.pneumoniae refractory to macrolide antibiotics.She had elevated brain natriuretic peptide(BNP)levels.Finally,the patient was diagnosed with KD.After receiving intravenous immunoglobulin,the fever resolved,and her symptoms improved.CONCLUSION NFKD should be differentiated from adolescent lymphadenitis presenting with prolonged fever by checking the BNP level early.

Kawasaki disease, <i>Mycoplasma pneumoniae</i>infection and anaplastic large cell lymphoma: An uncommon association

Kawasaki disease (KD) is an acute febrile systemic vasculitis occurring predominantly in young children less than 5 years of age. Although imperfectly known, the aetiopathogenesis of KD would be secondary to immunological abnormalities that could constitute a favourable terrain for neoplasms. We report on a case in a 2-year-old girl who presented clinical manifestations compatible with Kawasaki disease complicated by coronary aneurysm. Aetiopathological investigations revealed M. pneumoniae infection as specific IgM were present in the serum (Elisa). The patient was initially treated by intravenous immunoglobulins (IVIG) and aspirin to anti-inflammatory dose. Following a few days of desquamation, resolution of the symptomatology occurred. Four weeks later she developed disseminated tumorous syndrome. Lymph node biopsy revealed massive infiltration by large cells lymphomatous proliferation. Histologic and immunophenotypic findings were characteristic of ALK-1+ anaplastic large cell lymphoma. Four weeks later, the patient died from a severe nosocomial infection complicated by septic shock. Our observation is the first cases describing the association between anaplastic large cell lymphoma, KD and M. pneumoniae. Immunologic disorder due to KD and M. pneumoniae infection may play probably a central role for malignancy.

Understanding serum inflammatory markers in pediatric Mycoplasma pneumoniae pneumonia

This editorial reflects on the research,which investigates the potential of serum markers to predict the severity of Mycoplasma pneumoniae infections.Mycoplasma pneumoniae pneumonia(MPP)is a prevalent cause of respiratory infections in children,often leading to significant morbidity.Predicting the severity of MPP can significantly enhance patient management and outcomes.This editorial reviews the role of specific laboratory markers:(1)Lactate dehydrogenase;(2)Interleukin(IL)-6;(3)IL-10;(4)Tumor necrosis factor-α;and(5)D-dimer in predicting the severity of MPP in pediatric patients.Elevated levels of these markers are strongly associated with severe cases of MPP,providing clinicians with valuable tools for early diagnosis and targeted intervention.

The Predictive Value of NLR, IL-6, CRP, and PCT in Mycoplasmal Pneumonia with Complicated Myocardial Injury

Objective:To evaluate the dynamic changes in neutrophil-to-lymphocyte ratio(NLR),interleukin-6(IL-6),C-reactive protein(CRP),and procalcitonin(PCT)levels in children with Mycoplasma pneumoniae pneumonia(MPP)complicated by myocardial injury and to determine their predictive value both individually and in combination.Methods:150 children diagnosed with MPP at Jiujiang Maternal and Child Health Hospital between June 2023 and June 2024 were selected.Patients were divided into the myocardial damage group(MD group,n=65)and the non-myocardial damage group(non-MD group,n=85),based on the presence of myocardial injury.Ninety hospitalized children without MPP served as the control group(Con group).Myocardial enzyme profile indicators,including lactate dehydrogenase(LDH),α-hydroxybutyrate dehydrogenase(α-HBDH),aspartate aminotransferase(AST),high-sensitivity cardiac troponin I(hs-cTnI),creatine kinase(CK),and creatine kinase-MB(CK-MB),were measured using a chemiluminescent immunoassay analyzer.Serum NLR,IL-6,CRP,and PCT levels were determined using appropriate analyzers.The correlation between these markers and myocardial enzyme indicators was analyzed using Spearman correlation analysis.Multivariate logistic regression was applied to identify risk factors for myocardial injury in MPP patients.Results:Serum levels of NLR,IL-6,CRP,and PCT in the MD and non-MD groups were significantly higher than in the Con group(P<0.05),with the MD group showing higher levels than the non-MD group(P<0.05).These markers were positively correlated with myocardial enzyme indicators.Logistic regression identified elevated NLR,IL-6,CRP,PCT,LDH,α-HBDH,AST,hs-cTnI,CK,and CK-MB as risk factors for myocardial injury in MPP patients(P<0.05).Conclusion:Elevated levels of NLR,IL-6,CRP,PCT,and myocardial enzymes are significant risk factors for myocardial injury in children with MPP,offering valuable insights for prevention and prognosis.

Analysis of the Role of D-Dimer,Interleukin-6,and Interleukin-18 in Differential Diagnosis of Pediatric Refractory Mycoplasma pneumoniae Pneumonia

Objective:To analyze the value of D-dimer(D-D),interleukin-6(IL-6),and IL-18 in the differential diagnosis of children with refractory Mycoplasma pneumoniae pneumonia(RMPP).Methods:The medical records of 92 children with Mycoplasma pneumoniae pneumonia(MPP)treated in the hospital were selected for retrospective analysis from January 2023 to January 2024.After comprehensive examinations such as computed tomography examination of the chest,48 children with general Mycoplasma pneumoniae pneumonia(GMPP)were put in the GMPP group and 44 children with RMPP were grouped in the RMPP group.The IL-6,IL-18,and D-D levels were compared between the two groups,and the receiver operating characteristic(ROC)curves were plotted to analyze their value for differential diagnosis of RMPP.Results:The levels of IL-6,IL-18,and D-D in the RMPP group were higher than those in the GMPP group(P<0.05);the ROC curves showed that the specificity of the differential diagnosis of IL-6,IL-18,and D-D was higher,and their diagnostic value was significant.Conclusion:Determination of IL-6,IL-18,and D-D levels in children with MPP can further diagnose the children’s condition,which can help physicians formulate targeted treatment plans,and is of great significance to the improvement of the children’s condition,which is worthy of attention.

Research Progress on Combined Chinese and Western Medicine Treatment of Mycoplasma pneumoniae Pneumonia in Children

With the continuous development of medical technology,combined treatment of Chinese and Western medicine has gradually become a research hotspot.As a common disease in pediatrics,the treatment of Mycoplasma pneumoniae pneumonia(MPP)in children is also being explored and improved.This article summarizes the research progress of combined Chinese and Western medicine treatment of MPP in children in recent years,aiming to provide a useful reference for the combined treatment of MPP in children.The article firstly introduces the etiology and pathogenesis of MPP in children,thereafter briefly introduces the Western anti-infective treatment and traditional Chinese medicine(TCM)diagnosis and treatment of MPP in children,and lastly introduces the methods of combined treatment of TCM and Western medicine in detail.The article points out that the combination of Chinese and Western medicine can give full play to the overall regulation of Chinese medicine and the precise treatment advantages of Western medicine,improve the therapeutic effect,reduce the use of antibiotics,and lower the recurrence rate of the disease,which is worthy of further research and promotion.

Correlation of serum complement and immunoglobulin contents with inflammatory stress response in children with Mycoplasma pneumoniae pneumonia

Objective:To study the correlation of serum complements C3 and C4 as well as immunoglobulins IgM, IgA and IgG contents with inflammatory stress response in children with mycoplasma pneumoniae pneumonia.Methods: The children who were diagnosed with Mycoplasma pneumoniae pneumonia in Xiangyang No. 1 People's Hospital, Hubei University of Medicine between February 2015 and January 2018 were selected as the MPP group, and healthy children who received physical examination during the same period were selected as the control group. The contents of complements, immunoglobulins and inflammatory stress mediators in serum as well as the expression of inflammatory stress molecules in peripheral blood were measured.Results: Serum C3, C4, IgM, sICAM-1, CD40L, HMGB1, Cor and MDA levels as well as peripheral blood TLR2, TLR4, CD11b, CD18, MPO and NOX2 expression intensity of MPP group were significantly higher than those of control group, IgA level was significantly lower than that of control group, and IgG level was not different from that of control group;serum C3, C4 and IgM levels of MPP group were positively correlated with serum sICAM-1, CD40L, HMGB1, Cor and MDA levels as well as peripheral blood TLR2, TLR4, CD11b, CD18, MPO and NOX2 expression intensity, and serum IgA level was negatively correlated with serum sICAM-1, CD40L, HMGB1, Cor and MDA levels as well as peripheral blood TLR2, TLR4, CD11b, CD18, MPO and NOX2 expression intensity. Conclusion: The changes of serum complements and immunoglobulins in children with Mycoplasma pneumoniae pneumonia are related to the excessive activation of inflammatory stress response in the course of disease.

Evaluation of humoral immunity and peripheral blood T lymphocyte subset levels after Mycoplasma pneumoniae infection

Objective:To evaluate humoral immunity and peripheral blood T lymphocyte subset levels after Mycoplasma pneumoniae infection. Methods:118 cases of children with Mycoplasma pneumoniae infection were selected as observation group, and 98 cases of healthy children receiving medical examination in our hospital during the same period were selected as control group. The differences in humoral immunity, T lymphocyte subsets, anti-inflammatory and pro-inflammatory factors, Th1/Th2 balance state, etc were compared between two groups of children. Results:Serum IgA level of observation group was lower than that of control group (P<0.05), and IgM level was higher than that of control group (P<0.05). Peripheral blood CD3+and CD4+T lymphocyte levels as well as CD4+/CD8+ratio were lower than those of control group (P<0.05), while CD8+T lymphocyte level was higher than that of control group (P<0.05). Serum pro-inflammatory factors IL-8 and TNF-αlevels were higher than those of control group (P<0.05), while anti-inflammatory factors IL-10 and IL-13 levels were lower than those of control group (P<0.05). Serum IL-4, IFN-γand IL-4/IFN-γlevels were higher than those of control group (P<0.05). Conclusions:Humoral immune and cellular immune suppression, high inflammatory state and so on after Mycoplasma pneumoniae infection are the important mechanisms leading to disease progression.

Advances in the Detection of Mycoplasma hyopneumoniae by Polymerase Chain Reaction (PCR) Technology

Mycoplasma hyopneumoniae is an important pathogen causing Mycoplasmal pneumonia of swine, which generally causes secondary infections and mixed infections, thus seriously threats the development of swine industry and resulting in huge economic losses. Using PCR technology has very important significance to the correct diagnosis of Mycoplasmal pneumonia at the early stage. In this paper, specific target genes of Mycoplasma hyopneumoniae, methods for clinical sample collection, key technical factors of DNA sample processing method, and the research progress, main advantages and disadvantages, and application of general PCR technology, multiple PCR technology, nested-PCR technology, real-time fluorescence quantitative PCR technology, gene chip detection technology and loop-mediated isothermal amplification in detection of Mycoplasma hyopneumoniae were summarized, which provided convenience for the effective diagnosis and prevention of Mycoplasmal pneumonia of swine.

支气管镜介入治疗对RMPP患儿的疗效及其对外周血CRP、SF、IL-8水平及CD4^(+)/CD8^(+)比值的影响

目的探讨支气管镜介入治疗对难治性肺炎支原体肺炎(RMPP)患儿的疗效及其对外周血C反应蛋白(CRP)、铁蛋白(SF)、白细胞介素(IL)-8水平及CD4^(+)/CD8^(+)比值的影响。方法选取2020年12月至2022年12月河北省儿童医院收治的195例确诊为RMPP患儿作为研究对象,采用随机数字表法分为对照组和介入组(病程≥14 d归为晚期介入组、病程<14 d归为早期介入组)。根据临床疗效将130例接受支气管镜介入治疗的患儿分为有效组和无效组。对照组进行常规治疗,晚期介入组和早期介入组在对照组的基础上实施支气管镜介入治疗。比较对照组、晚期介入组和早期介入组临床疗效、临床症状与体征改善情况;检测并比较对照组、晚期介入组和早期介入组外周血CRP、SF、IL-8水平及CD4^(+)/CD8^(+)比值;比较对照组、晚期介入组和早期介入组不良反应发生率;比较有效组和无效组外周血CRP、SF、IL-8水平及CD4^(+)/CD8^(+)比值。采用受试者工作特征(ROC)曲线分析外周血CRP、SF、IL-8、CD4^(+)/CD8^(+)比值对支气管镜介入治疗RMPP疗效的预测价值。结果早期介入组总有效率高于对照组和晚期介入组,差异均有统计学意义(P<0.05);对照组和晚期介入组总有效率比较,差异无统计学意义(P>0.05)。早期介入组咳嗽持续时间、发热持续时间、住院时间均短于对照组和晚期介入组,差异均有统计学意义(P<0.05)。对照组、晚期介入组和早期介入组治疗后外周血CD4^(+)/CD8^(+)比值均高于治疗前,CRP、SF、IL-8水平均低于治疗前,差异均有统计学意义(P<0.05);早期介入组治疗后外周血CD4^(+)/CD8^(+)比值均高于对照组和晚期介入组,CRP、SF、IL-8水平均低于对照组和晚期介入组,差异均有统计学意义(P<0.05)。早期介入组出现不良反应8例,晚期介入组出现不良反应10例,均暂停灌洗操作后很快恢复。对照组未出现上述不良反应。无效组外周血CRP、SF、IL-8水平均高于有效组,CD4^(+)/CD8^(+)比值低于有效组,差异均有统计学意义(P<0.05)。ROC曲线分析结果显示,CRP、SF、IL-8、CD4^(+)/CD8^(+)比值联合检测预测支气管镜介入治疗RMPP无效的曲线下面积、灵敏度、特异度分别为0.871、81.81%、83.80%。结论早期应用支气管镜介入治疗对RMPP的疗效较好,可改善患儿外周血CRP、SF、IL-8水平及CD4^(+)/CD8^(+)比值,且外周血CRP、SF、IL-8、CD4^(+)/CD8^(+)比值联合检测有助于预测支气管镜介入治疗RMPP的疗效。

不同时期RMPP患儿支气管肺泡灌洗液SPA表达及与肺功能的关系

目的探讨不同时期难治性支原体肺炎(refractory mycoplasma pneumoniae pneumonia,RMPP)患儿支气管肺泡灌洗液中表面活性物质相关蛋白-A(surfactant protein A,SPA)的表达水平及与肺功能的关系。方法选取2021年1月—2023年1月南通市第一人民医院收治的62例RMPP患儿为对象,以同期行支气管镜异物取出术且无肺部感染的50例患儿为对照组。RMPP患儿于急性期、恢复期行支气管肺泡灌洗液中SPA检测以及肺功能指标检测[第1秒用力呼气容积(forced expiratory volume in one second,FEV_(1))、用力肺活量(forced vital capacity,FVC)、FEV_(1)/FVC],对照组同样如此。比较三者检测结果差异,使用Pearson分析RMPP患儿支气管肺泡灌洗液中SPA水平与肺功能指标的相关性。结果RMPP患儿肺泡灌洗液中的SPA急性期(59.82±12.64)μg/L、恢复期(129.91±24.86)μg/L高于对照组,差异有统计学意义(P<0.05)。RMPP急性期、RMPP恢复期的FEV_(1)、FVC、FEV_(1)/FVC(80.95±6.88)%、(88.41±5.75)%较对照组低,差异有统计学意义(P<0.05);RMPP患儿于急性期时肺泡灌洗液中的SPA较恢复期低,FEV_(1)、FVC、FEV_(1)/FVC较恢复期低,差异有统计学意义(P<0.05);RMPP患儿肺泡灌洗液中SPA水平与FEV_(1)、FVC、FEV_(1)/FVC呈正相关(P<0.05)。结论RMPP患儿病情处于急性发展阶段的情况下其支气管肺泡灌洗液中的SPA表达相较病情恢复阶段更低,同时RMPP患儿支气管肺泡灌洗液中SPA水平与其肺功能指标呈正相关性。

Evaluation of a New Real-time PCR Assay for Detection of Mycoplasma Pneumoniae in Clinical Specimens

Objective To establish and evaluate a real-time PCR assay to detect Mycoplasma pneumoniae （M.pneumoniae） in clinical specimens. Methods By analysing the whole pl gene sequence of 60 M.pneurnoniae clinical isolates in Beijing of China, an optimized real-time PCR assay （MpP1） using pl gene conserved region was designed. The specificity and sensitivity of this assay were evaluated and compared with other two reported assays （RepMpl and Mp181） using 40 positive and 100 negative clinical specimens. Results The detection limit of the new assay was 8.1 fg （about 1-3CFU） M.pneumoniae DNA. The sensitivity of MpP1, RepMpl, and Mp181 assays appeared to be 100%, 100%, and 85%, respectively. Conclusion MpP1 assay is suitable for the detection of M.pneumoniae in Chinese clinical specimens.

Mycoplasma pneumoniae Macrolide Resistance and MLVA Typing in Children in Beijing,China,in 2016:Is It Relevant?

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 23 S 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 A2063 G mutation in the 23 S rRNA V region is the dominant mutation(137/146,93.84%),whereas the A2064 G 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 A2063 G 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.

Correlation Between the Clinical Severity, Bacterial Load, and Inflammatory Reaction in Children with Mycoplasma Pneumoniae Pneumonia

Given the lack of defining features in the clinical manifestations and radiographic findings for children with mycoplasma pneumoniae pneumonia(MPP),quantitative polymerase chain reaction(qPCR)has become a useful diagnostic method.This study was performed to explore the relationship between the qPCR findings,clinical symptoms,and inflammatory markers in children with MPP.Four hundred children with MPP have been enrolled in this retrospective analysis.All clinical and analytical information,including mycoplasma pneumoniae(MP)PCR results,has been collected.Based on the PCR results,the patients were divided into groups with load values(copy number)<105(54 cases),2105 and<106(71 cases),2106 and<107(112 cases),>107 and<108(114 cases),and>108(49 cases).The clinical features(including symptoms and signs)and inflammatory indicators were compared among the groups.The incidence of high fever(above 39℃),thermal peak during the entire hospitalization period,fever duration,days of hospitalization,and plasma lactate dehydrogenase(LDH)levels were statistically correlated with the MP PCR load value in children with MPP.The analysis of relevance degree showed the correlative order as a thermal peak of hospitalization>duration of fever>period of hospitalization>LDH value>C-reactive protein value.The host immune response was significantly greater in the complication group than in the non-complication group.

Using 16S rDNA Sequencing Technology to Preliminarily Analyze Intestinal Flora in Children with Mycoplasma pneumoniae Pneumonia

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”.Highthroughput 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<.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.

The Expression of PDGF-B Chain mRNA in Lung Tissue from Rats Repeatedly Infected with Mycoplasma Pneumoniae

In order to investigate the role played by platelet derived growth factor-BB (PDGF-BB) in the pathogenesis of pulmonary interstitial fibrosis in rats repeatedly infected with mycoplasma pneumoniae (MP), a rat MP infection model was developed by infecting rats with MP for 9 times during a period of 24 weeks with a technique of ultrasonic nebulizing inhalation. Then in situ hybridization was performed with PDGF-B chain cDNA probe and the results were quantitatively analyzed to measure the changes in PDGF-B chain mRNA expression in the lung tissue. The results showed that: (1) MP polymerase chain reaction (PCR) tests showed positive results in the bronchoalveolar lavage fluid (BALF ) from all of the MP-infected rats (n = 4) while they were all negative in BALF from the control animals (n = 4, P<0. 05) and in BALF from those rats both infected with MP and, at the same time, treated with erythromycin (n = 4, P<0. 05). Bacterial cultures of the bronchial and lung tissue were negative in all three groups. The observation under a transmission electron microscope indicated that the interalveo-lar septa were widened with increased amount of collagen in the MP-infected rats while there were no obvious abnormalities in the other two groups. (2) Strong positive expression of PDGF-B chain mRNA was found in the plasma of mono-cytes and macrophages located in the locally widened interalveolar septa and alveolar spaces in the lung tissue from the MP-infected animals with the integral optical densities being 37. 42 ±9. 05 (n = 4) which was significantly higher than the values of control group (0. 42 + 0. 08, n = 4, P<0. 01) and of the group with MP-infec-tion plus erythromycin treatment (1. 62 ± 0. 40, n = 4, P<0. 01). These results suggest that PDGF-BB may be involved in the process of the development of pulmonary interstitial fibrosis caused by the repeated MP-infection. It may be an important growth factor for mediating the roles of monocytes and macrophages to promote the aggregation and proliferation of fibroblasts which can then secrete collagen in large quantity in the pulmonary interstitium.