Survey of Mycoplasma pneumoniae in Iranian children with acute lower respiratory tract infections

ObjectivesMycoplasma pneumoniae is an atypical pathogen, which is one of the major causes of lower respiratory tract infections (LRTIs) worldwide. This study was performed to determine the role of M. pneumoniae in acute LRTIs in children, who were referred to main pediatric hospitals in Shiraz, Iran, with the diagnosis of LRTI. Polymerase chain reaction method on a throat-swab specimen was utilized to detect M. pneumoniae.ResultsOne hundred patients with acute LRTIs were investigated in this study. There were 10 positive PCR for M. pneumoniae (10%), including 6 of 62 hospitalized patients and 4 of 38 outpatients. All patients with LRTIs due to M. pneumoniae had cough. Fever, flu like symptoms, dyspnea, pulmonary rales, wheezing, and conjunctivitis were other common signs and symptoms.ConclusionsThe percentage of cases with M. pneumoniae infection in our population is similar to the reported in other parts of Asia. Precise and early detection of pathogen and appropriate antibiotic therapy are the key points in management of patients with LRTIs.     

Rapid diagnosis of Mycoplasma pneumoniae by polymerase chain reaction in community-acquired lower respiratory tract infections

Two hundred children hospitalized for community-acquired lower respiratory tract infections (LRTIs) were investigated for Mycoplasma pneumoniae employing serological tests and a P1 adhesin gene-based polymerase chain reaction assay (PCR) on nasopharyngeal aspirates. Serological evidence of M. pneumoniae infection was observed in 68 (34%) patients and PCR was positive in 20 (10%) children. Together PCR and/or enzyme immuno assay detected M. pneumoniae in 71(35.5%) children. Our data underline the role of M. pneumoniae in Indian children with community-acquired LRTIs even in children aged < 24 months.     

多重实时荧光定量PCR对下呼吸道感染病原体检测分析

目的比较多重实时荧光定量PCR(multiplex real-time polymerase chain reaction, MRT-PCR)和间接免疫荧光法(indirect immunofluorescence assay, IFA)对成人呼吸道病毒及非典型病原体检测结果。 方法收集2014年1月至2017年12月间呼吸内科210例成人呼吸道感染的标本,采用MRT-PCR检测8种常见呼吸道病原体,同时应用IFA检测血清8种病原体IgM抗体,并全部进行PCR及测序分析,比较两种方法的特异性及敏感性,评估MRT-PCR的临床应用价值。 结果210例下呼吸道感染标本经MRT-PCR和IFA检测,阳性率分别为58.57%和38.10%,混合感染率分别为7.62%和4.76%。两种方法的灵敏度分别为94.74%和35.96%,特异度分别为84.38%和59.38%。灵敏度和特异度差异有统计学意义(P<0.05)。 结论与IFA相比,MRT-PCR灵敏度、特异度好,检测性能优于IFA。     

Detection of Mycoplasma pneumoniae in children with lower respiratory tract infections

Mycoplasma pneumoniae is known to be a major cause of lower respiratory tract infections (LRTIs) in children. We studied 75 children who had been hospitalized for community-acquired LRTIs for the detection of M. pneumoniae by serological analysis and polymerase chain reaction (PCR) to amplify a 277-base pair region of 16S rDNA gene of M. pneumoniae applied to throat swab specimens. Serological and/or PCR positive results diagnosed M. pneumoniae infection in 23 (30.7%) patients.     

Detection of Chlamydia trachomatis by polymerase chain reaction]

A polymerase chain reaction (PCR) procedure was developed for detection of Chlamydia trachomatis. Two oligonucleotide primers based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used. A single DNA fragment was amplified, when C. trachomatis DNA was template for the PCR. No amplified product was detected in Chlamydia psittaci DNA, Chlamydia pneumoniae DNA or other bacterial DNAs. The amplified DNA fragment was detected, when DNA of greater than or equal to 10(2) C. trachomatis per reaction was used as template for the PCR. Thus, the PCR was shown to be specific for C. trachomatis and more sensitive than the enzyme immunoassays for detection of chlamydial antigen and the chlamydial rRNA:DNA probe hybridization method.     

Role of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community-acquired lower respiratory tract infections.

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae, we studied 613 children aged 2-14 years who were hospitalized for community-acquired lower respiratory tract infections (LRTIs). The patients were enrolled in the study by 21 centers in different regions of Italy from May 1998 through April 1999. Paired serum samples were obtained on admission and after 4-6 weeks to assay the titers of M. pneumoniae and C. pneumoniae antibodies. Nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae were obtained on admission. Acute M. pneumoniae infections in 210 patients (34.3%) and acute C. pneumoniae infections in 87 (14.1%) were diagnosed. Fifteen of the 18 children with M. pneumoniae and/or C. pneumoniae infections whose treatments were considered clinical failures 4-6 weeks after enrollment had not been treated with macrolides. Our study confirms that M. pneumoniae and/or C. pneumoniae plays a significant role in community-acquired LRTIs in children of all ages and that such infections have a more complicated course when not treated with adequate antimicrobial agents.     

套工聚合酶链反应及DNA测序法检测急性上呼吸道感染 …

目的 应用套式聚合酶链反应（ｎＰＣＲ）及ＤＮＡ序列测定技术探讨生殖支原体（Ｍｇ）与儿童急性上呼吸道感染（上感）之间的关系。方法 收集６２例上感儿童和８０例健康儿童之咽拭子标本,进行Ｍｇ１６ＳｒＲＮＡ基因第Ⅰ～Ⅱ可变区序列和第Ⅴ－Ⅶ可变区序列２种Ｍｇ种特异的ｎＰＣＲ检测,并对阳性产物进行ＤＮＡ序列测定。结果 健康儿童Ｍｇ阳性率为５％（４／８０）,而上感儿童为２１％（１３／６２）。后者明显高于前者（Ｐ     

肺结核并下呼吸道感染临床分析

目的分析肺结核患者并下呼吸道感染临床资料及病原菌分布、耐药等情况。方法分析94例肺结核并下呼吸道感染患者临床资料及病原菌培养和药敏结果。结果肺结核并下呼吸道感染患者主要病原菌中前四位为鲍曼不动杆菌、铜绿假单胞菌、肺炎克雷伯菌及大肠埃希菌,多为多重耐药菌株;此类患者临床症状重,合并症多,治疗效果较差。结论肺结核并下呼吸道感染,早期诊断及合理应用抗生素是治疗关键。     

Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses

Please cite this paper as: Esposito et al. (2012) Impact of viral infections in children with community‐acquired pneumonia: results of a study of 17 respiratory viruses. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00340.x. Background Little is known about the prevalence of viral infections in children with community‐acquired pneumonia (CAP). Objectives To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom 17 respiratory viruses were sought in respiratory secretion samples during the acute phase of the disease. Patients and methods The study involved 592 children with radiographically confirmed CAP whose respiratory secretion samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which simultaneously detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV)‐A and ‐B, parainfluenzavirus‐1, ‐2, ‐3, and ‐4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus/rhinovirus, and bocavirus. A real‐time PCR assay was used to identify the rhinovirus in the enterovirus/rhinovirus‐positive samples. Results A total of 435 children (73·5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31·7%), followed by rhinovirus (n = 144, 24·3%), bocavirus (n = 60, 10·1%), influenza viruses (n = 57, 9·6), and hMPV (n = 49, 8·2%). Viral co‐infections were found in 117 children (19·7% of the enrolled children; 26·9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co‐infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections (OR 1·72, 95% CI 1·05–2·81). Conclusions The findings of this study highlight the importance of respiratory viruses (mainly RSV and rhinovirus) in children with CAP and show the characteristics of both the single infections and co‐infections associated with the disease.     

1426例成人呼吸系统感染住院患者肺炎衣原体感染状况分析

目的了解成人急慢性呼吸系统感染患者肺炎衣原体(Chlamydia pneumoniae,CP)Ig M抗体阳性率在性别、年龄和季节分布上的趋势。方法采用ELISA法检测1426例住院治疗的呼吸系统感染患者血清CP Ig M抗体。结果 1426例CP Ig M抗体阳性率为13.7%;男女患者CP Ig M抗体阳性率差异无统计学意义;各年龄组中,青年组CP Ig M抗体阳性率为37.4%,明显高于中年组和老年组;春、夏季CP Ig M抗体阳性率分别为16.7%和22.5%,明显高于秋、冬季。结论对于在春、夏季出现的急慢性呼吸系统感染的青年患者应考虑CP感染的可能性。     

Isolation and polymerase chain reaction detection of Mycoplasma pneumoniae in Malaysian patients with respiratory tract infections.

Isolation and polymerase chain reaction (PCR) were performed for detection of Mycoplasma pneumoniae from respiratory tract specimens obtained from 200 adult and 200 pediatric patients. M. pneumoniae was isolated from bronchoalveolar lavage fluid of 1(0.5%) adult patient and 4(2.0%) tracheal aspirates of pediatric patients. PCR was positive for only one (0.5%) broncoalveolar lavage fluid of an adult patient and fifteen (7.5%) tracheal aspirates of pediatric patients. This study suggested that M. pneumoniae was more frequently detected in pediatric patients and PCR appears to have advantages over isolation, in terms of rapidity and sensitivity.     

Importance of acute Mycoplasma pneumoniae and Chlamydia pneumoniae infections in children with wheezing.

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae in reactive airway disease, 71 children aged 2-14 yrs with an acute episode of wheezing and 80 age-matched healthy children were studied. Sera for the determination of specific antibody levels and nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae deoxyribonucleic acid were obtained on admission and after 4-6 weeks. All children with wheezing received a standard therapy with inhaled corticosteroids and bronchodilators for 5-7 days; when antibiotic was added on the basis of the judgement of the paediatrician in charge, clarithromycin 15 mg.kg body weight(-1).day(-1) for 10 days was used. Acute M. pneumoniae and C. pneumoniae infections were detected significantly more often in children with wheezing than in controls. In patients infected with one of the two pathogens, a history of recurrent wheezing was significantly more frequent than in those without either infection. During a 3-month follow-up period, among nonantibiotic-treated children, those with acute M. pneumoniae and/or C. pneumoniae infection showed a significantly higher recurrence of wheezing than those without acute M. pneumoniae and/or C. pneumoniae infection (p=0.03). These results highlight the apparently significant relationship of Mycoplasma pneumoniae and Chlamydia pneumoniae with wheezing in children, particularly in subjects with a history of recurrent episodes, and the possible improvement in the course of reactive airway disease within paediatric patients with acute Mycoplasma pneumoniae and/or Chlamydia pneumoniae infection.     

铜绿假单胞菌致下呼吸道感染的药敏分析

目的探讨下呼吸道铜绿假单胞菌（PA）感染的药敏情况，供临床用药参考。方法对82例3次痰培养为PA的慢性阻塞性肺疾病（COPD）、支气管扩张症及呼吸机相关性肺炎（VAP）患者进行药敏分析。结果VAP耐药率最高，COPD、支气管扩张症相似；敏感性较高的药物依次为头孢哌酮-舒巴坦、哌拉西林-他唑巴坦、阿米卡星、美洛培南及亚胺培南。结论下呼吸道感染PA耐药率高，且VAP高于COPD及支气管扩张症。     

外周血人β-防御素2在下呼吸道感染患者的急、慢性气道炎症中的临床研究

目的 评价外周血中人β-防御素2(hBD-2)在下呼吸道感染患者急、慢性气道炎症的临床价值.方法 选取2007年3月至2008年10月下呼吸道感染患者92例,其中下呼吸道感染患者分别包括社区获得性肺炎40例,慢性阻塞性肺疾病急性加重36例,支气管扩张合并感染(急性期)16例,门诊体检者20例作为对照组,所有下呼吸道感染患者和对照组均留取血浆标本,采用酶联免疫吸附试验法检测下呼吸道感染各疾病组和对照组外周血中hBD-2、白介素1β(IL-1β)和IL-8的浓度.结果 下呼吸道感染患者外周血中hBD-2、1L-1β均明显高于对照组(P值分别为0.047、0.020);社区获得性肺炎组外周血中hBD-2浓度高于对照组(P=0.026),支气管扩张合并感染(急性期)和慢性阻塞性肺疾病急性加重组外周血中hBD-2与对照组比较差异无统计学意义(P值分别为0.334、0.227);外周血中hBD-2与炎性因子IL-1β呈正相关(r=0.280,P=0.01).结论 外周血中hBD-2可以较好反映下呼吸道感染疾病中的急性气道炎症状态.可能是气道局部炎性状态的标记物.     

The inter‐observer variation of chest radiograph reading in acute lower respiratory tract infection among children

This study assessed the inter‐observer agreement in the interpretation of several radiographic features in the chest radiographs (CXR) of 803 children aged 2–59 months with non‐severe acute lower respiratory tract infection (ALRI). Inclusion criteria comprised: report of respiratory complaints, detection of lower respiratory findings, and presence of pulmonary infiltrate on the CXR taken on admission and read by the pediatrician on duty. Data on demographic and clinical findings on admission were collected from children included in a clinical trial on the use of amoxicillin (ClinicalTrials.gov Identifier NCT01200706). CXR was later read by two independent pediatric radiologists blinded to clinical information and pneumonia was finally diagnosed if there was agreement on the presence of pulmonary infiltrate or pleural effusion. The kappa index (κ) of agreement was calculated. The radiologists agreed that 774 (96.4%) and 3 (0.4%) CXR were appropriate or inappropriate for reading, respectively, and that 222 (28.7%) and 459 (59.3%) CXR presented or did not present pneumonia. In intent to treat analysis, that is, considering the 803 enrolled patients, κ for the presence of pneumonia was 0.725 (95% CI: 0.675–0.775). The overall agreement was 78.7% (normal CXR [n = 385, 60.9%], pneumonia [n = 222, 35.1%], other radiological diagnosis [n = 22, 3.5%], inappropriate for reading [n = 3, 0.5%]). The most frequent radiological findings were alveolar infiltrate (33.2%) and consolidation (32.9%) by radiologist 1 and consolidation (28.3%) and alveolar infiltrate (19.3%) by radiologist 2. Concordance for consolidation was 86.7% (k = 0.683, 95%CI: 0.631–0.741). Agreement was good between two pediatric radiologists when diagnosis of pneumonia among children with non‐severe ALRI was compared. Pediatr Pulmonol. 2013; 48:464–469. © 2012 Wiley Periodicals, Inc.     

Acute lower respiratory tract infections by human metapneumovirus in children in Southwest China: A 2‐year study

Human metapneumovirus (hMPV) has been reported to cause both upper and lower respiratory tract diseases in susceptible populations, particularly in children and the elderly. In this study, we describe a hospital‐based epidemiological study of hMPV in patients presenting to a children's hospital and show the demographic and clinical characteristics associated with hMPV infection in China, retrospectively. Specimens were collected over a 2‐year period from children hospitalized with acute lower respiratory tract infections (ALRTI) and analyzed for the presence of hMPV using real‐time RT‐PCR assays. The presence of hMPV was detected in 227 (25.9%) of the 878 children studied and may circulate year‐round in the area, peaking during the winter–spring season. Younger children (aged less than 6 months) had the highest positive rate. Infections by hMPV showed similar epidemiology and clinical manifestations as for respiratory syncytial virus (RSV) and were found in high co‐infections with RSV. Subgroup A2 hMPV was the most predominant genotype identified during the study period. This study indicates that hMPV is one of the major respiratory pathogens found in children in southwest China and vaccine development should be under consideration. Pediatr. Pulmonol. 2010; 45:824–831. © 2010 Wiley‐Liss, Inc.     

The pathophysiological significance of prognostic factors for fatal outcome in lower respiratory tract infections

OBJECTIVE: The aim of this study was to determine prognostic factors for outcome in patients with lower respiratory tract infections (LRTI). LRTI are an heterogeneous group of disorders, including acute bronchitis, pneumonia, superinfection of chronic bronchitis and influenza. METHODOLOGY: A total of 616 patients with LRTI were retrospectively reviewed with regard to epidemiological, clinical, laboratory and radiographical data. Prognostic analysis included a univariate as well as a multivariate approach, in order to identify parameters associated with death. RESULTS: The parameters found to be significantly different between survivors and non-survivors in the univariate analysis, were respiratory rate, PaO2, heart rate, systolic and diastolic blood pressure, platelet count, urea, creatinine, previous admission to the hospital in the last year and cavitations visible on the chest radiograph. CONCLUSIONS: LRTI remain a widespread problem and have a significant impact on primary healthcare resources. The great variability seen in rates of hospital admission and lengths of stay in part reflects uncertainty among physicians in assessing the severity of the illness. According to our data, PaO2 and heart rate were most closely associated with patient death and are readily defined and available at presentation.     

Circulating levels of pro-atrial natriuretic peptide in lower respiratory tract infections

OBJECTIVE: To analyse the mid region of plasma N-terminal pro-atrial natriuretic peptide (MR-proANP) levels in patients with lower respiratory tract infections to evaluate its prognostic use for the severity of disease and outcome. DESIGN: Prospective observational study. Setting. Emergency department of a university hospital. SUBJECTS: A total of 545 consecutive patients with lower respiratory tract infections and 50 healthy controls. Interventions. MR-proANP was measured in serum from all patients using a new sandwich immunoassay. RESULTS: MR-proANP levels (median [IQR], in pmol L(-1)) were significantly higher in patients with lower respiratory tract infections when compared with controls (138.0 [74.1-279.0] vs. 72.7 [62.5-89.5], P < 0.001), with highest levels in patients with community-acquired pneumonia (CAP). MR-proANP, but not C-reactive protein (CRP) levels, gradually increased with increasing severity of CAP, classified according to the pneumonia severity index (PSI) score (P < 0.001). On admission, MR-proANP levels were significantly higher in nonsurvivors when compared with survivors (293.0 [154.0-633.0] vs. 129.0 [71.4-255.0], P < 0.001). In a receiver operating characteristic (ROC) analysis for the prediction of survival of patients with CAP the area under the ROC curve (AUC) for MR-proANP was 0.69, similar when compared with the PSI (AUC 0.74, P = 0.31), and better when compared with other biomarkers, i.e. procalcitonin (AUC 0.57, P = 0.08), CRP (AUC 0.52, P = 0.02), and leucocyte count (AUC 0.56, P = 0.07). CONCLUSIONS: MR-proANP levels are increased in lower respiratory tract infections, especially in CAP. Together with other clinical, radiographic and laboratory findings, MR-proANP levels might be helpful for the risk stratification in CAP.     

Detection of viral and bacterial pathogens in acute respiratory infections

Objectives

The role of bacteria in acute respiratory illnesses (ARI) of adults and interactions with viral infections is incompletely understood. This study tested the hypothesis that bacterial co-infection during ARI adds to airway inflammation and illness severity.

Methods

Two groups of 97 specimens each were randomly selected from multiplex-PCR identified virus-positive and virus-negative nasal specimens obtained from adults with new onset ARI, and 40 control specimens were collected from healthy adults. All specimens were analyzed for Haemophilus influenzae(HI), Moraxella catarrhalis(MC) and Streptococcus pneumoniae(SP) by quantitative-PCR. General linear models tested for relationships between respiratory pathogens, biomarkers (nasal wash neutrophils and CXCL8), and ARI-severity.

Results

Nasal specimens from adults with ARIs were more likely to contain bacteria (37% overall; HI = 28%, MC = 14%, SP = 7%) compared to specimens from healthy adults (5% overall; HI = 0%, MC = 2.5%, SP = 2.5%; p < 0.001). Among ARI specimens, bacteria were more likely to be detected among virus-negative specimens compared to virus-positive specimens (46% vs. 27%; p = 0.0046). The presence of bacteria was significantly associated with increased CXCL8 and neutrophils, but not increased symptoms.

Conclusion

Pathogenic bacteria were more often detected in virus-negative ARI, and also associated with increased inflammatory biomarkers. These findings suggest the possibility that bacteria may augment virus-induced ARI and contribute to airway inflammation.     

Detection of Chlamydia trachomatis from urethral swab in male urethritis by polymerase chain reaction]

A polymerase chain reaction (PCR) with Chlamydia trachomatis-specific primers was applied for detection of C. trachomatis from urethral swab in male urethritis. The results were compared with those of culture method for detection of C. trachomatis. Of 18 clinical specimens tested in this study, inclusion bodies of C. trachomatis were detected in 11 specimens by the culture method. For PCR, sample DNA was prepared from transport medium in which urethral smear was suspended and two oligonucleotides based on sequences within the major outer membrane protein gene from C. trachomatis serovar L2 were used as extension primers. In 12 of the 18 specimens, 242bp DNA fragment was amplified by PCR and demonstrated to be the DNA fragment of C. trachomatis by Southern blot hybridization. No DNA of 242bp was amplified by PCR from five specimens in which any inclusion bodies of C. trachomatis were observed or from a specimen in which one inclusion body per cover slip was detected by culture method. C. trachomatis DNA of 242bp was amplified from all specimens in which 14 and more inclusion bodies per cover slip were detected by culture method. In two specimens concluded s negative by culture method, amplified C. trachomatis DNA were detected by PCR. Thus, the PCR would be a more simple and sensitive method for detection of C. trachomatis, compared with the culture method.