Sample type is crucial to the diagnosis of Mycoplasma pneumoniae pneumonia by PCR

Diagnostic Stewardship for Multiplex Respiratory Testing: What We Know and What Needs to Be Done

Syndromic respiratory panels are now widely available in clinical microbiology laboratories and health care institutions. These panels can rapidly diagnose infections and detect antimicrobial resistance genes allowing for more rapid therapeutic optimization compared to standard microbiology approaches. However, given reimbursement concerns and limitations of multiplex molecular testing and results interpretation, maximum clinical utility and positive clinical outcomes depend on active diagnostic stewardship. Here, the authors review clinical outcomes of both upper and lower respiratory panels and present diagnostic stewardship strategies for optimal use of respiratory panels.

A real-time PCR assay for the quantification of Mycoplasma equirhinis in tracheal wash samples from Thoroughbred horses

Mycoplasma equirhinis is the predominant equine Mycoplasma sp. isolated from clinically normal horses and is suspected to be associated with inflammatory airway disease in which cough is the primary sign. Quantitative evaluation of bacterial counts is useful in assessing the association between the bacteria in samples and observed clinical signs, but this evaluation has been difficult with conventional culture methods of M. equirhinis given the need for pre-enrichment using liquid cultures. We established a quantitative real-time PCR (qPCR) assay for the quantification of M. equirhinis, targeting the hypothetical protein FJM08_00025. We confirmed its high species-specificity for M. equirhinis and a limit of detection of 2.9 copies/reaction. We quantified M. equirhinis in tracheal wash samples from 20 clinically normal horses and 22 coughing horses. The copy numbers detected by qPCR in 18 of the 22 samples from clinically affected horses were within the range detected in the 20 clinically normal horses (0-84 copies/reaction). The remaining 4 samples had considerably higher copy numbers (734-1,620,000 copies/reaction), suggesting the likely involvement of M. equirhinis infection. Quantitative evaluation of M. equirhinis over time using our qPCR assay may allow a more accurate assessment of M. equirhinis infection in coughing horses compared to culture methods.

Comparative study of diagnostic efficacy of sputum and bronchoalveolar lavage fluid specimens in community-acquired pneumonia children treated with fiberoptic bronchoscopy

BACKGROUND

Community-acquired pneumonia (CAP) is usually diagnosed in children, and the type of respiratory specimen is critical. Differences in pathogens detection between induced sputum (IS) and bronchoalveolar lavage fluid (BALF) have not been evaluated.

METHODS

In 2018, paired sputum and BALF samples from CAP hospitalised children with indications for bronchoalveolar lavage (BAL) were subjected to multiplex PCR for the detection of 11 common respiratory pathogens.

RESULTS

A total of 142 children with paired sputum and BALF were tested. The overall positivity rate was 85.9% (122/142) for sputum and 80.3% (114/142) for BALF. The two specimens presented almost perfect agreement between the detection on M. pneumoniae, influenza A, influenza B, bocavirus and RSV. In contrast, adenovirus had the lowest kappa value of 0.156, and a false negative rate (FNR) of 66.7%. Rhinovirus had the highest false positive rate (FPR) as 18.5%. The consistent rate was significantly higher in school-age children than those under 1 year old (p = .005). Bacterial co-infection in BALF specimens were observed in 14.8% (21/142). Of the 11 discordant pairs of specimens, 9 cases were sputum(+)/BALF(-) with adenovirus predominating.

CONCLUSION

Our findings suggest that the consistency of results between sputum and BALF is pathogen specific. Careful consideration needs to be given to whether sputum can be used as a substitute for BALF when children are young or co-infections with bacteria are suspected.

Ocular involvement in Mycoplasma induced rash and mucositis: A systematic review of the literature

Mycoplasma pneumoniae induced rash and mucositis (MIRM) is a relatively newly identified clinical entity which is characterized by mucocutaneous manifestations in the setting of Mycoplasma infection. Though a clinically distinct disease, MIRM exists on a diagnostic continuum with entities including erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and the recently described reactive infectious mucocutaneous eruption (RIME). In this systematic review, we discuss published findings on the epidemiology, clinical manifestations, diagnosis, and management of MIRM, with an emphasis on ocular disease. Lastly, we discuss some of the most recent developments and challenges in characterizing MIRM with respect to the related diagnosis of RIME.

Atypical Pathogens in Adult Community-Acquired Pneumonia and Implications for Empiric Antibiotic Treatment: A Narrative Review

Atypical pathogens are intracellular bacteria causing community-acquired pneumonia (CAP) in a significant minority of patients. Legionella spp., Chlamydia pneumoniae and psittaci, Mycoplasma pneumoniae, and Coxiella burnetii are commonly included in this category. M. pneumoniae is present in 5-8% of CAP, being the second most frequent pathogen after Streptococcus pneumoniae. Legionella pneumophila is found in 3-5% of inpatients. Chlamydia spp. and Coxiella burnetii are present in less than 1% of patients. Legionella longbeachae is relatively frequent in New Zealand and Australia and might also be present in other parts of the world. Uncertainty remains on the prevalence of atypical pathogens, due to limitations in diagnostic means and methodological issues in epidemiological studies. Despite differences between CAP caused by typical and atypical pathogens, the clinical presentation alone does not allow accurate discrimination. Hence, antibiotics active against atypical pathogens (macrolides, tetracyclines and fluoroquinolones) should be included in the empiric antibiotic treatment of all patients with severe CAP. For patients with milder disease, evidence is lacking and recommendations differ between guidelines. Use of clinical prediction rules to identify patients most likely to be infected with atypical pathogens, and strategies of narrowing the antibiotic spectrum according to initial microbiologic investigations, should be the focus of future investigations.

The investigation of P1 gene in Mycoplasma pneumonia isolated from atypic pneumonia by molecular methods, determine IgG antibody and MIC to ciprofloxacin antibiotic

Mycoplasma pneumoniae, which causes atypical pneumonia, is a well-established pathogen of the respiratory tract. This bacterium is intrinsically susceptible to fluoroquinolones. But recently, drug-resistant forms of this bacterium have been reported. This study aims to determine the prevalence of this bacterium by ELISA and PCR and MIC to ciprofloxacin. The clinical samples (blood and nasopharyngeal swab) were collected from 100 patients, who were referred to selective hospitals in Tehran with respiratory complaints, were enrolled in 2017. Nasopharyngeal swab sample collections were cultured on PPLO broth and PPLO agar. After culturing and DNA extraction, PCR was performed by specific P1 genes primers. Ciprofloxacin's MIC of Mycoplasma pneumonia isolated was determined by the Micro-broth dilution method. The serum of IgG antibody titers was also measured by ELISA Mycoplasma pneumonia. In this study, out of 100 samples, 12 bacteria were isolated on PPLO agar. Using specific primers, 7 samples of Mycoplasma speciesism-specific were positive for the presence of M.pneumoniae and 2 Ciprofloxacin resistant isolates were evaluated. ELISA results show that IgG titer antibody is existent in 19 samples and 5 samples are intermediate as well. IgG antibody titer average in the whole sample is 27/66 U/ml, but it is in Positive samples by P1 PCR is 45/75 U/ml. This study showed that PCR is a sensitive and reliable method for rapid detection of M. pneumoniae bacteria in respiratory infectious samples, but the results of this method are different from the ELISA method. Additionally, it seems that the resistance to ciprofloxacin is relatively common among M. pneumoniae.

Evaluation of a novel immunochromatographic assay using silver amplification technology for detection of Mycoplasma pneumoniae from throat swab samples in pediatric patients

Objectives

Mycoplasma pneumoniae is one of the common causative pathogens of community-acquired respiratory tract infections mainly in children and young adults. Rapid and accurate diagnostic techniques for identifying the causative pathogen would be useful for initiating treatment with an appropriate antibiotic. The purpose of the present study was to evaluate the sensitivity and specificity of a novel immunochromatographic assay using silver amplification technology using FUJI DRI-CHEM IMMUNO AG2 and FUJI DRI-CHEM IMMUNO AG cartridge Myco (FUJIFILM Co., Tokyo, Japan) for detection of M. pneumoniae.

Methods

Throat swab samples were collected from 170 pediatric patients who were diagnosed with bronchitis or pneumonia. The silver amplification immunochromatographic (SAI) assay was performed using these samples and the results were compared with those of real-time PCR. The time required for the SAI assay is approximately 20 min (5 min for sample preparation and 15 min for waiting time after starting the assay).

Results

The sensitivity and specificity of the SAI assay for detection of M. pneumoniae were 85.2 and 99.1%, respectively, and the assay showed positive and negative predictive values of 98.1 and 92.3%, respectively, compared with the results of real-time PCR. The diagnostic accuracy was 94.1%.

Conclusions

FUJI DRI-CHEM IMMUNO AG2 and FUJI DRI-CHEM IMMUNO AG cartridge Myco are appropriate for clinical use. The optimal timing of this assay is five days or more after the onset of M. pneumoniae infection. However, PCR or other molecular methods are superior, especially with regard to sensitivity and negative predictive value.

Early Confirmation of Mycoplasma pneumoniae Infection by Two Short-Term Serologic IgM Examination

The aim of the present study is to re-evaluate the clinical application of two-times serologic immunoglobulin M (IgM) tests using microparticle agglutination assay (MAA), an enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) assay in diagnosing Mycoplasma pneumoniae (MP) infection. A retrospective analysis of 62 children with MP pneumonia during a recent epidemic (2019–2020) was conducted. The MAA and ELISA immunoglobulin M (IgM) and IgG measurements were conducted twice at admission and around discharge, and MP PCR once at presentation. Diagnostic rates in each test were calculated at presentation and at discharge. The seroconverters were 39% (24/62) of patients tested by MAA and 29% (18/62) by ELISA. At presentation, the diagnostic positive rates of MAA, ELISA, and PCR tests were 61%, 71%, and 52%, respectively. After the second examination, the rates were 100% in both serologic tests. There were positive correlations between the titers of MAA and the IgM values of ELISA. The single serologic IgM or PCR tests had limitations to select patients infected with MP in the early stage. The short-term, paired IgM serologic tests during hospitalization can reduce patient-selection bias in MP infection studies.

Comparison of different detection methods for Mycoplasma pneumoniae infection in children with community-acquired pneumonia

BACKGROUND

Due to the lack of a sensitive, specific and rapid detection method, aetiological diagnosis of pneumonia caused by Mycoplasma pneumoniae (M. pneumoniae, MP) is a constantly challenging issue. This retrospective study aimed to compare the diagnostic methods for Mycoplasma pneumoniae in children and evaluate their values.

METHODS

From November 2018 to June 2019, 830 children with community-acquired pneumonia were selected from the Department of Respiratory Medicine, Shanghai Children's Medical Center. On the first day of hospitalization, sputum, throat swab and venous blood samples were collected to analyse MP-IgM (particle agglutination, PA), MP-IgM (immune colloidal gold technique, GICT), MP-DNA, MP-RNA (simultaneous amplification and testing, SAT) and MP-DNA (real-time polymerase chain reaction, RT-PCR).

RESULTS

Among these 830 children, RT-PCR showed that the positive rate was 36.6% (304/830), in which the positive rate of macrolide resistance (A2063G mutation) accounted for 86.2% of cases (262/304). Using RT-PCR as the standard, MP-RNA (SAT) had the highest specificity (97.5%), and MP-IgM (PA) had the highest sensitivity (74.0%) and Youden index (53.7%). If MP-RNA (SAT) was combined with MP-IgM (PA), its Kappa value (0.602), sensitivity (84.2%), specificity (78.7%) and Youden index (62.9%) were higher than those of single M. pneumoniae detection.

CONCLUSIONS

Our research indicated that a combination of MP-RNA (SAT) plus MP-IgM (PA) might lead to reliable results as an early diagnostic method for children with clinical manifestations of Mycoplasma pneumoniae pneumonia.

Hydroxymethylbilane synthase (HMBS) gene-based endogenous internal control for avian species

With PCR becoming one of the most important and widely-used diagnostic tools for infectious diseases of poultry, an urgent need has developed for an endogenous internal control (EIC) that monitors the quality and quantity of poultry DNA in test samples. In this study we developed a SYBR-qPCR to target the poultry homolog of the hydroxymethylbilane synthase (HMBS) gene as an EIC for avian species. The avian HMBS-based qPCR was very sensitive, detecting one HMBS gene copy in a 20 µL reaction, and is highly specific for avian species. It amplified DNA from 11 organs and tissues of chickens showing it can be used as an EIC on a large variety of samples. The application of the established EIC on clinically and experimentally infected samples demonstrated that false negativity and result variations could result from samples being collected using different operators, techniques, preservatives, and storage times. The high sensitivity and specificity of the avian HMBS-based qPCR, its ability to quantify DNAs extracted from a wide range of tissues and poultry species along with its usefulness in reducing false negativity in PCR results associated with inadequate sampling and storage degradation makes it an ideal EIC for poultry DNA and RNA PCR diagnostics. The study also highlights the importance of appropriate sampling and storage of samples in ensuring accuracy of molecular diagnostic testing.

Mycoplasma pneumoniae Carriage With De Novo Macrolide-Resistance and Breakthrough Pneumonia

Mycoplasma pneumoniae pneumonia is prevalent in children and can be followed by upper airway carriage for months. Treatment of M pneumoniae pneumonia with macrolides is widespread and can lead to the development of macrolide resistance. The clinical consequences of chronic M pneumoniae carriage are unknown. In this article, we describe a child with acute lymphoblastic leukemia who developed macrolide-susceptible M pneumoniae pneumonia confirmed by nasopharyngeal secretions polymerase chain reaction and culture with good response to azithromycin. Five months later, the patient developed another M pneumoniae pneumonia that was diagnosed with positive macrolide-resistant M pneumoniae polymerase chain reaction and culture from the bronchoalveolar lavage. The child responded well to fluoroquinolones and eventually was discharged from the hospital. The M pneumoniae recovered from the second pneumonia is a novel strain and is genetically identical to the M pneumoniae that caused the first pneumonia, apart from the macrolide-resistance 23S ribosomal RNA gene. Both isolates are identical in both P1 (subtype 2 with a novel variant, 2bv) and multiple-locus variable number tandem repeat analysis type (53662). This is indicative of chronic M pneumoniae carriage with de novo macrolide-resistance mutation and subsequent breakthrough pneumonia that is reported for the first time here. Children with immunosuppression may be at increased risk of life-threatening macrolide-resistant pneumonia after M pneumoniae carriage. Further studies are required to evaluate the impact of this phenomenon. This will then guide strategies to limit the associated morbidity, such as testing for macrolide resistance, treatment of M pneumoniae pneumonia in high-risk children with bactericidal antibiotics (such as fluoroquinolones), and possibly eradication protocols of M pneumoniae carriage to prevent subsequent life-threatening infections.

Comparing the yield of oropharyngeal swabs and sputum for detection of 11 common pathogens in hospitalized children with lower respiratory tract infection

Background

Advances in molecular laboratory techniques are changing the prospects for the diagnosis of viral infectious diseases. Multiplex polymerase chain reaction assay (multiplex-PCR) can detect dozens of pathogens simultaneously, greatly reducing turnaround time (TAT) and improving detection sensitivity. But as a double-edged sword, due to the high sensitivity of PCR, the type of respiratory specimens is critical to diagnosis. In this work, we performed a head-to-head comparison to evaluate the multiplex-PCR yields between two samples, sputum and flocked oropharyngeal swabs (OPS).

Methods

Eleven common respiratory pathogens were tested in hospitalized children< 13 years of age who met the criteria for lower respiratory tract infection by GeXP-based multiplex-PCR of paired OPS and sputum.

Results

From January to June 2018, 440 children with paired OPS and sputum were tested. The positive rate was 84% (369/440) for OPS and 88% (386/440) for sputum (p = .007). The frequency of detection of HRV, RSV, Influenza A virus, HMPV, parainfluenza virus, adenovirus, M. pneumoniae, coronavirus, bocavirus and C. pneumoniae in sputa was higher than that of OPSs (all p < .001). Both types of specimens had similarly very good kappa values for most of pathogens, except for Mycoplasma pneumonia (κ = 0.61) and Chlamydia pneumoniae (κ = 0.24). Additionally, 79.3% (349/440) of cases showed consistent results between the two types of samples, and they were significantly younger than patients with inconsistent results (p = .002).

Conclusions

Flocked oropharyngeal swabs and sputum performed similarly for the detection of common respiratory pathogens in hospitalized children by multiplex-PCR, except for Mycoplasma pneumoniae and Chlamydia pneumoniae. Young patients are likely to have consistent results between the two specimens.

Electronic supplementary material

The online version of this article (10.1186/s12985-019-1177-x) contains supplementary material, which is available to authorized users.

An adult case of severe life-threatening Mycoplasma pneumoniae pneumonia due to a macrolide-resistant strain, Japan: a case report

Background

Until now, the prevalence of macrolide-resistant Mycoplasma pneumoniae (MP) infection among adult patients has been low, and severe MP pneumonia due to a macrolide-resistant strain has seldom been reported. Here, we describe a rare case of severe life-threatening MP pneumonia due to a macrolide-resistant strain in an adult, which was finally treated with fluoroquinolone and tetracycline after failed treatment with macrolide and corticosteroid.

Case presentation

A 39-year-old apparently healthy woman complained of fever and productive cough. Three days after onset, she was admitted to a local general hospital. On admission, her vital signs were stable except for high-grade fever. The patient’s chest X-ray and chest computed tomography images revealed subsegmental consolidation in her right lower lobe. Treatment with ampicillin/sulbactam, and azithromycin were initiated under a clinical diagnosis of community-acquired pneumonia. After treatment initiation, her fever had not subsided, and the pulmonary lesion had extended to the entire lower lobe. Thus, treatment with prednisolone as steroid pulse therapy was initiated from clinical day 7. However, neither her symptoms nor her pulmonary lesion improved; therefore, she was transferred to our hospital for further examination and treatment. On admission (clinical day 14), her indirect hemagglutination titer for MP was elevated at 1:2560, and bronchoalveolar fluid examination yielded positive results for the mycoplasma antigen. Based on these clinical findings, we confirmed a case of severe life-threatening MP pneumonia. Since her respiratory condition was extremely severe, we initiated levofloxacin and tetracycline. Two days later (clinical day 16), her fever, malaise, and hypoxia resolved, and her pulmonary lesions had significantly improved.

Further molecular identification yielded the DNA of MP from her bronchoalveolar fluid, and mutation of A2063G in the 23S rRNA gene was revealed. Based on these results and the clinical course, we confirmed our case as severe MP pneumonia due to a macrolide-resistant strain.

Conclusion

More awareness is needed on the emergence of macrolide-resistant MP infection in adults, because severe infection could develop despite initial treatment with macrolide and steroid therapy, which are generally considered as standard therapy for MP.

Epidemiology and Molecular Identification and Characterization of Mycoplasma pneumoniae, South Africa, 2012-2015

During 2012-2015, we tested respiratory specimens from patients with severe respiratory illness (SRI), patients with influenza-like illness (ILI), and controls in South Africa by real-time PCR for Mycoplasma pneumoniae, followed by culture and molecular characterization of positive samples. M. pneumoniae prevalence was 1.6% among SRI patients, 0.7% among ILI patients, and 0.2% among controls (p<0.001). Age <5 years (adjusted odd ratio 7.1; 95% CI 1.7-28.7) and HIV infection (adjusted odds ratio 23.8; 95% CI 4.1-138.2) among M. pneumonia-positive persons were associated with severe disease. The detection rate attributable to illness was 93.9% (95% CI 74.4%-98.5%) in SRI patients and 80.7% (95% CI 16.7%-95.6%) in ILI patients. The hospitalization rate was 28 cases/100,000 population. We observed the macrolide-susceptible M. pneumoniae genotype in all cases and found P1 types 1, 2, and a type 2 variant with multilocus variable number tandem repeat types 3/6/6/2, 3/5/6/2, and 4/5/7/2.

Early Diagnosis of Mycoplasma pneumoniae in Children: Simultaneous Amplification and Testing (SAT) Is the Key

Objective: The effective diagnosis of Mycoplasma pneumoniae (MP) pneumonia (MPP) in children has been hampered by the difficulty of achieving an early diagnosis. The simultaneous amplification and testing (SAT) has the potential for early diagnosis of MP in children. Methods: Of the 1,180 children enrolled in this study, 169 were MPP antibody (Ab) seroconversion positive, 641 showed MPP positivity with a single Ab test, and 370 were MPP negative. Sera and pharyngeal swabs were collected for antibody testing and SAT detection, respectively, on admission. When the samples were Ab negative, the paired -Ab test was requested for MP 7 days later. Results: Using the Ab results as the diagnostic standard, the sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) for SAT were 72.8, 95.1, 97.0, and 61.5%, respectively. SAT had superior diagnostic value in the MPP group who had undergone Ab seroconversion (sensitivity: 82.2%; NPV: 92.1%) and in the short-course group also (sensitivity: 81.0%; NPV: 81.3%). Good agreement was observed between SAT and the paired-Ab results (kappa value = 0.79; P < 0.001), but there was a lack of consistency between SAT and the single-Ab test results on admission (kappa value = 0.54, P < 0.001). Conclusions: SAT is a rapid, sensitive, and specific method for MP diagnosis in pediatric patients. Our results indicate its value as an effective diagnostic tool for detecting MPP at the initial stage of an infection.

A case report of Legionella and Mycoplasma pneumonia: Co-incidence or co-infection?

RATIONALE

Concurrent or sequential coinfections of Legionella pneumophila and Mycoplasma pneumoniae have been reported in the past though infrequently. Distinguishing a true co-infection from cross reactivity is often challenging as the diagnosis is mostly dependent on serological testing.

PATIENT CONCERNS

A 77-year-old male presented with worsening dyspnea, cough with yellow sputum, diarrhea and fever of 2-days duration. Patient had history of chronic obstructive pulmonary disease (COPD) on home oxygen, bronchiectasis, rheumatoid arthritis (on methotrexate and leflunomide), treated pulmonary tuberculosis and 30-pack-year smoking. Chest X-ray showed bilateral interstitial changes with left lower lobe infiltrate. On day 5, his urine antigen for L pneumophila serogroup 1 was reported positive. The following day his serum M pneumoniae IgM antibody titers were reported elevated at 6647 U/mL. Patient was started on antibiotics and placed on non-invasive positive pressure ventilation.

DIAGNOSIS

The patient was diagnosed with possible Legionella and Mycoplasma co-infection.

OUTCOMES

Sputum Mycoplasma polymerase chain reaction (PCR) and serum cold agglutinins were obtained on day 6 and later reported negative. He was treated with azithromycin for 10 days with clinical improvement.

LESSONS

Serological testing alone is an indirect measure with poor sensitivity and specificity and has its own limitations. Urine antigen detection confirms L pneumophila serogroup 1 infection in a patient with suggestive symptoms. However, diagnosis of M pneumonia should be based on combination of tests including serology and PCR to confirm true co-infection.

Review on the laboratory diagnosis of Mycoplasma pneumoniae infection

Mycoplasma pneumoniae(MP) is an important pathogen of community-acquired pneumonia in children. As a type of self-limited disease, most MP infections cause mild clinical symptoms, but they can also lead to severe pneumonia or extrapulmonary complications. The resistance rate of MP has increased in recent years. Early and rapid diagnosis of MP infection is important for the treatment and prognosis of the disease. Current methods for diagnosing MP infection include isolation culture, serological diagnosis, and molecular biological diagnosis. This review summarizes the recent research progress in the internal and external laboratory diagnoses of MP infection both at home and abroad and the advantages and disadvantages of various diagnostic methods.

Mycoplasma pneumoniae Pneumonia with Worsening Pleural Effusion Despite Treatment with Appropriate Antimicrobials: Case report

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia. As M. pneumoniae pneumonia is usually a mild and self-limiting disease, complications such as pleural effusion occur only rarely. We report a 22-year-old woman who presented to the Emergency Medicine Department of the Sultan Qaboos University Hospital, Muscat, Oman, in 2017 with an eight-day history of fever associated with coughing, chills and rigors. She was diagnosed with M. pneumoniae pneumonia, but subsequently developed pleural effusion which worsened despite treatment with appropriate antimicrobials. The pleural effusion required drainage, which revealed that it was of the more severe exudative type. Following drainage, the patient improved dramatically. She was discharged and advised to continue taking antibiotics.

Clinical spectrum and diagnostic yields of Mycoplasma pneumoniae as a causative agent of community-acquired pneumonia

INTRODUCTION

Infection with Mycoplasma pneumoniae (M. pneumonia) occurs worldwide which accounts for 15%-20% of cases of community-acquired pneumonia and indistinguishable clinically from other infectious causes of pneumonia.

AIM

The aim of this study was to evaluate the real-time polymerase chain reaction (PCR) and to correlate it with other diagnostic methods such as culture, serology (ELISA), and conventional PCR along with the clinical signs and symptoms produced by M. pneumonia.

MATERIALS AND METHODS

A total of 130 patients of all age groups presenting with clinical features of lower respiratory tract infections were enrolled over a period of 1 year and 2 months in a tertiary care hospital in Delhi. M. pneumoniae in throat swab samples was detected by real-time PCR, compared with culture, serology, conventional PCR, and clinical signs and symptoms. Univariate analyses were conducted to determine the association of M. pneumoniae infection among different categories of patients.

RESULTS

Out of a total of 130 patients, 18 patients (14%) were positive for M. pneumoniae by any test; culture was positive in nine patients (50%), serology (IgM) in eight patients (44.4%), PCR in five patients (27.7%), and real-time PCR was positive in six patients (33.3%). Clinical signs and symptoms were higher in incidence in M. pneumoniae-positive patients. Age-matched healthy controls (30) were included in the study, and all were negative for any diagnostic test performed (P = 0.026).

CONCLUSION

It was concluded that combination of M. pneumoniae-specific testing modalities is required for the diagnosis of this etiological agent rather than a single diagnostic method.

Genotyping and macrolide resistance of Mycoplasma pneumoniae identified in children with community-acquired pneumonia in Medellín, Colombia

•

The majority of the Mycoplasma pneumoniae isolates obtained from the children with community-acquired pneumonia in this study were a variant of type 2.

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There was an absence of the mutations in the 23S rRNA gene related to macrolide resistance.

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Induced sputum sample has higher percentage of positive PCR to diagnose Mycoplasma pneumoniae compared to nasopharyngeal swab.

Objectives

The aim of this study was to describe the genotypes and the main characteristics of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae in hospitalized children in Medellín and neighboring municipalities during the period 2011–2012.

Methods

The M. pneumoniae genotype was determined by PCR and sequencing of the p1 and 23S rRNA genes from induced sputum samples and nasopharyngeal swabs (NPS). Samples were obtained from children with CAP who were hospitalized in 13 healthcare centers. In addition, a spatio-temporal analysis was performed to identify the potential risk areas and clustering of the cases over time.

Results

A variant of type 2 was the dominant genotype in the induced sputum (96.1%) and NPS (89.3%) samples; the type 1 variant was identified in 3.9% and 10.7% of these samples, respectively. No strains with mutations in the 23S rRNA gene associated with macrolide resistance were found. The cases in Medellín were mainly concentrated in the northeastern areas and western districts. However, no temporal relationship was found among these cases.

Conclusions

A variant of type 2 of M. pneumoniae prevailed among children with CAP during the study period. No strains with mutations associated with macrolide resistance were found.

Immunochromatography test for rapid diagnosis of Mycoplasma pneumoniae infection

The sensitivity and specificity of a new rapid Mycoplasma pneumoniae antigen immunochromatography (IC) test, DK-MP-001, were determined using particle agglutination (PA) antibody response and loop-mediated isothermal amplification (LAMP) gene detection as the gold standard. Of 165 patients, 59 were diagnosed with M. pneumoniae infection based on a ≥fourfold rise of serum PA antibody during the course of the illness. Of the first visit swabs, 60 were positive for M. pneumoniae on LAMP, and 49 were positive for M. pneumoniae antigen on IC test. Compared with PA antibody and LAMP, the sensitivity/specificity of the IC test were 81.4% (48/59) and 99.1% (105/106); and 81.7% (49/60) and 100% (105/105), respectively. IC test detected antigen in pharyngeal swabs more sensitively than in nasal swabs for the same subjects (P < 0.05). The IC test performs well enough to be used with pharyngeal swabs at the first examination.

Comparison of Oropharyngeal and Nasopharyngeal Swab Specimens for the Detection of Mycoplasma pneumoniae in Children with Lower Respiratory Tract Infection

The oropharyngeal swab specimen was superior to the nasopharyngeal swab specimen for the detection of Mycoplasma pneumoniae in children with lower respiratory tract infection. The oropharyngeal loop-mediated isothermal amplification had 100% sensitivity and specificity compared with polymerase chain reaction testing, whereas the oropharyngeal rapid antigen detection test using immunochromatographic assay had relatively low sensitivity (66%) and reasonable specificity (90.7%).

Multi-system manifestations of Mycoplasma pneumoniae infection in a young patient

Introduction.Mycoplasma pneumoniae is a small cell-wall-lacking bacterium that belongs to the mycoplasma (Mollicutes) prokaryote micro-organisms. It is a common cause of both upper and lower respiratory tract infections in all age groups. Respiratory illness is the most common manifestation of M. pneumoniae infection; however, extrapulmonary involvement may be present or predominant. The skin, mucus membranes, central nervous system, cardiovascular system, haematopoietic system, kidneys and musculoskeletal system are the most commonly involved extrapulmonary sites. Immune thrombocytopenia purpura has been reported as a rare haematological manifestation of mycoplasma infection. Here, we report, with a literature review, the case of a young adult with M. pneumoniae infection, presenting with acute febrile illness, myringitis, erythema multiforme, mild Raynaud’s phenomenon symptoms and severe thrombocytopenia.

Case presentation. Our patient was a 24-year-old healthy man who presented to an emergency department with acute febrile illness, upper respiratory tract infection symptoms, myringitis, erythema multiforme skin lesions, severe thrombocytopenia, and pale and cold hands. Mycoplasma serology suggested acute M. pneumoniae infection. The patient had a complete resolution of symptoms and gradual recovery from the thrombocytopenia after a course of anti-Mycoplasma therapy with azithromycin. Our case illustrates the multi-system involvement of M. pneumoniae infection.

Conclusion.M. pneumoniae is a frequent cause of upper and lower respiratory tract infections in children and young adults. Multi-system involvement including the skin, vascular and haematological systems in young adults with upper or lower respiratory tract infection, as in our patient, should raise the suspicion of Mycoplasma infection. Our case also illustrates an excellent clinical response and recovery from thrombocytopenia shortly after anti-Mycoplasma antimicrobial therapy.

Mycoplasma pneumoniae from the Respiratory Tract and Beyond

Mycoplasma pneumoniae is an important cause of respiratory tract infections in children as well as adults that can range in severity from mild to life-threatening. Over the past several years there has been much new information published concerning infections caused by this organism. New molecular-based tests for M. pneumoniae detection are now commercially available in the United States, and advances in molecular typing systems have enhanced understanding of the epidemiology of infections. More strains have had their entire genome sequences published, providing additional insights into pathogenic mechanisms. Clinically significant acquired macrolide resistance has emerged worldwide and is now complicating treatment. In vitro susceptibility testing methods have been standardized, and several new drugs that may be effective against this organism are undergoing development. This review focuses on the many new developments that have occurred over the past several years that enhance our understanding of this microbe, which is among the smallest bacterial pathogens but one of great clinical importance.

Role of Serum Mycoplasma pneumoniae IgA, IgM, and IgG in the Diagnosis of Mycoplasma pneumoniae-Related Pneumonia in School-Age Children and Adolescents

Mycoplasma pneumoniae is an important causative pathogen of community-acquired pneumonia in children. Rapid and reliable laboratory diagnosis of M. pneumoniae infection is important so that appropriate antibiotic treatment can be initiated to reduce the misuse of drugs and resistance rates. Anti-M. pneumoniae immunoglobulin M (IgM) is an indicator of recent primary infection but can persist for several months after initial infection. It has been suggested that anti-M. pneumoniae immunoglobulin A (IgA) can be a reliable indicator for recent M. pneumoniae infection in adults. We investigated the clinical diagnostic value of M. pneumoniae IgA in school-age children and adolescents with M. pneumoniae-related pneumonia. Eighty children with pneumonia and seropositive for M. pneumoniae IgM or with a 4-fold increase of anti-M. pneumoniae immunoglobulin G (IgG) were enrolled from May 2015 to March 2016. The titers of M. pneumoniae IgA, IgM, and IgG, the clinical features, and laboratory examinations of blood, C-reactive protein, and liver enzymes were analyzed. The initial positivity rates for M. pneumoniae IgM and IgA upon admission to the hospital were 63.6 and 33.8%, respectively. One week after admission, the cumulative positivity rates for M. pneumoniae IgM and IgA increased to 97.5 and 56.3%, respectively. Detection of M. pneumoniae IgM was more sensitive than detection of M. pneumoniae IgA for the diagnosis of M. pneumoniae-related pneumonia in school-age children and adolescents; however, paired sera are necessary for a more accurate diagnosis.

Probiotic isolates from unconventional sources: a review

The use of probiotics for human and animal health is continuously increasing. The probiotics used in humans commonly come from dairy foods, whereas the sources of probiotics used in animals are often the animals’ own digestive tracts. Increasingly, probiotics from sources other than milk products are being selected for use in people who are lactose intolerant. These sources are non-dairy fermented foods and beverages, non-dairy and non-fermented foods such as fresh fruits and vegetables, feces of breast-fed infants and human breast milk. The probiotics that are used in both humans and animals are selected in stages; after the initial isolation of the appropriate culture medium, the probiotics must meet important qualifications, including being non-pathogenic acid and bile-tolerant strains that possess the ability to act against pathogens in the gastrointestinal tract and the safety-enhancing property of not being able to transfer any antibiotic resistance genes to other bacteria. The final stages of selection involve the accurate identification of the probiotic species.

Early Serologic Diagnosis of Mycoplasma pneumoniae Pneumonia: An Observational Study on Changes in Titers of Specific-IgM Antibodies and Cold Agglutinins

There have been some limitations on early diagnosis of Mycoplasma pneumoniae (MP) infection because of no immunoglobulin M (IgM) responses and variable detection rates of polymerase chain reaction in the early stage of the disease. We wanted to discuss regarding early diagnostic method using short-term paired titration of MP-specific IgM and cold agglutinins (CAs) in the early stage of MP pneumonia.The participants of this study were 418 children with MP pneumonia during 2 recent epidemics (2006-2007 and 2011), and they were diagnosed by an anti-MP IgM antibody test (Serodia Myco II) examined twice during hospitalization at presentation and around discharge (mean of 3.4 ± 1.3 days apart). CA titers were simultaneously examined twice during study period. Anti-MP IgM antibody titer ≥1:40 and CA titer ≥1:4 were considered positive, respectively. The relationships between 2 IgM antibodies in the early stage were evaluated.Regarding MP-specific antibody titers, 148 patients showed a seroconversion, 245 patients exhibited increased titers, and 25 patients had unchanged higher titers (≥1:640) during hospitalization. The median MP-specific antibody titers at each examination time were 1:80 and 1:640, respectively; those of CAs were 1:8 and 1:32, respectively. Illness duration prior to admission showed a trend of association with both titers, and patients with shorter illness duration had a higher rate of negative titers or lower titers at each examination time. CAs and MP-specific antibody titers were correlated in the total patients at presentation and at 2nd examination (P < 0.001, respectively), and the diagnostic corresponding rates of CAs to IgM antibody test were 81% to 96% in patient subgroups.Short-term paired MP specific-IgM determinations in the acute stage may be used as a definitive diagnostic method for MP pneumonia. Paired CA titers showed a correlation with MP-specific antibody titers, suggesting they can be used as an adjuvant diagnostic method.

Comparison of serological methods with PCR-based methods for the diagnosis of community-acquired pneumonia caused by atypical bacteria

Background

The diagnosis of community-acquired pneumonia (CAP) caused by Legionella pneumophila, Mycoplasma pneumoniae, and Chlamydophila pneumoniae is traditionally based on cultures and serology, which have special requirements, are time-consuming, and offer delayed results that limit their clinical usefulness of these techniques. We sought to develop a multiplex PCR (mPCR) method to diagnosis these bacterial infections in CAP patients and to compare the diagnostic yields obtained from mPCR of nasopharyngeal aspirates (NPAs), nasopharyngeal swabs (NPSs), and induced sputum (IS) with those obtained with specifc PCR commercial kits, paired serology, and urinary antigen.

Results

A total of 225 persons were included. Of these, 10 patients showed serological evidence of L. pneumophila infection, 30 of M. pneumoniae, and 18 of C. pneumoniae; 20 individuals showed no CAP. The sensitivities were mPCR-NPS = 23.1 %, mPCR-IS = 57.1 %, Seeplex®-IS = 52.4 %, and Speed-oligo®-NPA/NPS = 11.1 %, and the specificities were mPCR-NPS = 97.1 %, mPCR-IS = 77.8 %, Seeplex®-IS = 92.6 %, and Speed-oligo®-NPA/NPS = 96.1 %. The concordance between tests was poor (kappa <0.4), except for the concordance between mPCR and the commercial kit in IS (0.67). In individuals with no evidence of CAP, positive reactions were observed in paired serology and in all PCRs.

Conclusions

All PCRs had good specificity but low sensitivity in nasopharyngeal samples. The sensitivity of mPCR and Seeplex® in IS was approximately 60 %; thus, better diagnostic techniques for these three bacteria are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12952-016-0047-y) contains supplementary material, which is available to authorized users.

[Evaluation of a Rapid Antigen Detection Kit Targeting L7/L12 Ribosomal Protein for Mycoplasma pneumoniae]

We evaluated the usefulness of a rapid antigen detection assay for L7/L12 ribosomal protein (Ribotest Mycoplasma; Asahi Kasei Pharma) for diagnosis of Mycoplasma pneumoniae (M. pneumoniae) infection. Nasopharyngeal swabs were obtained from patients with pneumonia and/or bronchitis; real-time PCR and the L 7/L12 antigen assays were performed with each sample. Serum was also taken from each patient, and the particle agglutination (PA) method was used to detect anti-M. pneumoniae antibody in these samples. Macrolide-resistance genes were detected and M. pneumoniae P1 protein subtyping was performed on PCR-positive samples. PCR assays were positive for 85 of 212 specimens (40.1%). Sensitivity and specificity of the L7/L12 antigen assays relative to the PCR standard were 74.1% (63/85) and 81.1% (103/127), respectively. For PCR-positive specimens with a large quantity of M. pneumoniae nucleic acid, sensitivity of the L7/L12 antigen assays seemed to be high. In PCR-positive specimens with fewer than 1.0 x 10(6) copies/mL of M. pneumoniae nucleic acid, sensitivity of the L7/L12 antigen assays seemed to be low. When the PA method was used as the standard, the relative sensitivity and specificity of the L7/L12 antigen assays were 41.7% (5/12) and 75.3% (58/77), respectively, for single serum and 60.9% (14/23) and 85.7% (18/21), respectively, for paired sera. The macrolide-resistance gene A2063G was detected in 20 of the 30 tested PCR-positive specimens (66.7%). Of these 20 A2063G-positive specimens, 13 (65.0%) were positive for the L7/L12 antigen assays. Tne numbers of M. pneumoniae P1 subtypes were as follows: types I (22), IIa(2), IIc(1), and untypable (5). The L7/L12 antigen assays gave positive results for 17 of 21 (81.0%) subtype I, 1 of 2 (50.0%) IIa, and 1 of 1(100%) IIc specimens.

Epidemiological comparison of three Mycoplasma pneumoniae pneumonia epidemics in a single hospital over 10 years

Purpose

Mycoplasma pneumoniae (MP) pneumonia epidemics have occurred in 3- to 4-year cycles in Korea. We evaluated the epidemiologic characteristics of MP pneumonia in Daejeon, Korea, from 2003 to 2012.

Methods

We retrospectively analyzed 779 medical records of children (0-15 years of old) with MP pneumonia admitted to our institution and compared the data from 3 recent epidemics.

Results

In 779 patients, the mean age and male-to-female ratio were 5.0±2.2 years and 1:1, and most cases were observed in autumn. There were three epidemics during the study period, in 2003, 2006-2007, and 2011. In our comparison of the three epidemics, we found no differences in mean age, the male-to-female ratio, hospital stay, or the rate of seroconverters during hospitalization. All three epidemics began in early summer and peaked in September 2003 and 2011 and in October 2006 and then gradually decreased until the next year's spring season, although the 2006 epidemic extended further into 2007. The peak age groups in the children in 2003 and 2006 were 3-6 year-olds (57.5% and 56%, respectively), but in the 2011 epidemic, the peak group was 1-4 year-olds (46.5%). The proportion of the <2 years of age group was 20%, 15.7% and 28.8%, and >10 years of age group was 5.2%, 13.8%, and 14.8% of total patients, respectively.

Conclusion

MP pneumonia outbreaks occurred every 3-4 years. The pattern of 3 recent epidemics was similar in demographic characteristics and seasonality with some variations in each outbreak.

Atypical pneumonia

PURPOSE OF REVIEW

We present the key advances in the infections that clinicians conventionally associate with atypical pneumonia: legionellosis, Mycoplasma pneumonia, Chlamydophila species pneumonia and Q fever.

RECENT FINDINGS

There have been significant developments in molecular diagnosis to include Mycoplasma pneumoniae and Chlamydophila pneumoniae in multiplex PCR of respiratory specimens. There are diagnostic challenges in distinguishing carriage from infection, which is recognized in C. pneumoniae and now also evident in M. pneumoniae. Macrolide-resistant M. pneumoniae has emerged in Asia. There are new antimicrobials on the horizon in the ketolide class with activity against typical and atypical pathogens and useful empirical agents.

SUMMARY

There are few advances in our knowledge of the epidemiology of atypical pathogens or the effectiveness of antimicrobial therapy--empirical or pathogen specific. However, if molecular testing becomes widely implemented, there will be an increased understanding of the epidemiology and presentation of atypical pneumonia and a shift to more targeted antimicrobial therapy.

Novel aspects on the pathogenesis of Mycoplasma pneumoniae pneumonia and therapeutic implications

Mycoplasma pneumoniae (Mp) is a leading cause of community acquired pneumonia. Knowledge regarding Mp pneumonia obtained from animal models or human subjects has been discussed in many different reports. Accumulated expertise concerning this critical issue has been hard to apply clinically, and potential problems may remain undiscovered. Therefore, our multidisciplinary team extensively reviewed the literature regarding Mp pneumonia, and compared findings from animal models with those from human subjects. In human beings, the characteristic pathological features of Mp pneumonia have been reported as alveolar infiltration with neutrophils and lymphocytes and lymphocyte/plasma cell infiltrates in the peri-bronchovascular area. Herein, we demonstrated the novel aspects of Mp pneumonia that the severity of the Mp pneumonia seemed to depend on the host innate immunity to the Mp, which might be accelerated by antecedent Mp exposure (re-exposure or latent respiratory infection) through up-regulation of Toll-like receptor 2 expression on bronchial epithelial cells and alveolar macrophages. The macrolides therapy might be beneficial for the patients with macrolide-resistant Mp pneumonia via not bacteriological but immunomodulative effects. This exhaustive review focuses on pathogenesis and extends to some therapeutic implications such as clarithromycin, and discusses the various diverse aspects of Mp pneumonia. It is our hope that this might lead to new insights into this common respiratory disease.

Accuracy of IgM antibody testing, FQ-PCR and culture in laboratory diagnosis of acute infection by Mycoplasma pneumoniae in adults and adolescents with community-acquired pneumonia

Background

Diagnosis of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae in adults and adolescents is hampered by a lack of rapid and standardized tests for detection.

Methods

CAP patients from 12 teaching hospitals were prospectively and consecutively recruited. Basic and clinical information, throat swabs and paired sera were collected. Mycoplasma pneumoniae was detected by IgG and IgM antibody tests, fluorescence quantitative polymerase chain reaction (FQ-PCR) and culture. A comparative study of the diagnostic values of three methods, including sensitivity, specificity, positive and negative predictive values and positive likelihood ratio (PLR) was conducted. A fourfold or greater increase of IgG antibody titers of paired sera was set as the diagnostic “gold standard”.

Results

One hundred and twenty-five CAP patients (52.8% males, median age 47 years, range 14–85) were enrolled. Twenty-seven (21.6%) patients were diagnosed with acute Mycoplasma pneumoniae infections by the “gold standard”. Specificity values of all three methods were around 90%. An increasing trend of sensitivity, positive predictive value and PLR was found, with the lowest in IgM testing (7.4%, 28.6% and 1.45), intermediate in FQ-PCR (40.7%, 50% and 3.63), and highest in culture (55.6%, 75% and 10.9).

Conclusions

In the defined group of patients, there was a good agreement between positive rate of MP cultivation of throat swabs and acute M. pneumoniae infection (PLR of 10.9). Since the sensitivity is low in all of the evaluated methods, the logical approach would be to incorporate PCR, culture and serological tests for optimum diagnosis of acute Mycoplasma pneumoniae infections in adults and adolescents.

Investigation of Mycoplasma pneumoniae infection in pediatric population from 12,025 cases with respiratory infection

Although Mycoplasma pneumoniae (MP) is a major pathogen of primary atypical pneumonia in children, the clinical and laboratory characteristics of MP infection in large pediatric population are less reported. Here, we retrospectively analyzed 12,025 hospitalized children with respiratory infection by using serology and polymerase chain reaction (PCR) methods simultaneously. The results showed that 2433 (20.23%) children had MP infection, which mainly occurred in November to April. The presence of sore throat and pharyngitis was peculiar to MP infection. The positive percentage of MP-DNA was higher than that of MP-IgM in children aged <1 (P < 0.0001) and 1-3 years (P < 0.0001). Moreover, the positive rate of P1 gene, the key adhesion gene for MP infection, was higher in children with MP infection than in those with other pathogens (P < 0.0001). Our work provides the clinical information of children MP infection and highlights the superiority of PCR and potential usage of P1 as a diagnosis target for MP infection.

Molecular methods for the detection of Mycoplasma and ureaplasma infections in humans: a paper from the 2011 William Beaumont Hospital Symposium on molecular pathology

Mycoplasma and Ureaplasma species are well-known human pathogens responsible for a broad array of inflammatory conditions involving the respiratory and urogenital tracts of neonates, children, and adults. Greater attention is being given to these organisms in diagnostic microbiology, largely as a result of improved methods for their laboratory detection, made possible by powerful molecular-based techniques that can be used for primary detection in clinical specimens. For slow-growing species, such as Mycoplasma pneumoniae and Mycoplasma genitalium, molecular-based detection is the only practical means for rapid microbiological diagnosis. Most molecular-based methods used for detection and characterization of conventional bacteria have been applied to these organisms. A complete genome sequence is available for one or more strains of all of the important human pathogens in the Mycoplasma and Ureaplasma genera. Information gained from genome analyses and improvements in efficiency of DNA sequencing are expected to significantly advance the field of molecular detection and genotyping during the next few years. This review provides a summary and critical review of methods suitable for detection and characterization of mycoplasmas and ureaplasmas of humans, with emphasis on molecular genotypic techniques.

Comparison of sputum and nasopharyngeal swab specimens for molecular diagnosis of Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila

Background

Differentiation of atypical pathogens is important for community-acquired pneumonia (CAP). In this study, we compared sputum and nasopharyngeal swabs (NPS) for use in detection of Mycoplasma pneumoniae (MP), Chlamydophila pneumoniae (CP), and Legionella pneumophila (LP), using Seeplex PneumoBacter ACE Detection Assay (PneumoBacter; Seegene).

Methods

Sputum and NPS specimens were collected from patients in 15 hospitals. DNA was extracted from sputum using QIAamp DNA Stool Mini Kit (Qiagen) and from NPS using easyMAG (bioMérieux). Both types of specimens were evaluated by multiplex PCR using PneumoBacter. To determine the diagnostic performance of this assay, sputum samples were also tested using BD ProbeTec ET Atypical Pneumonia Assay (APA; Becton Dickinson).

Results

Among 217 sputum and NPS, 20 (9.2%), 2 (0.9%), and 0 sputum were positive for MP, LP, and CP, respectively, whereas 8 (3.7%) NPS were positive for MP. The sputum APA test yielded 186, 206, and 204 interpretable results for MP, LP, and CP, respectively. Of these, 21 (11.3%) were positive for MP, 2 (1.0%) were positive for LP, and 0 samples were positive for CP. Compared to APA, the sensitivity and specificity of the sputum assay for MP were 95.2% and 100.0%, respectively, whereas for the NPS assay, these were 38.1% and 93.9%. Sputum testing was more sensitive than NPS testing (P=0.002). For LP and CP diagnosis, PneumoBacter and APA tests agreed 100%.

Conclusions

Specimen type is crucial and sputum is preferred over NPS for simultaneous detection of MP, LP, and CP using multiplex PCR in CAP.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Detection of Mycoplasma pneumoniae in different respiratory specimens

Mycoplasma pneumoniae (M. pneumoniae) is an important community-acquired pneumonia pathogen. Serological test and polymerase chain reaction (PCR) assay are the two main laboratory tests to detect M. pneumoniae now. Little information was compared about the sensitivity and specificity of PCR using different specimens including bronchoalveolar lavage (BAL) and nasopharyngeal aspirate (NPA). The aim of the present study was to evaluate diagnostic values of different specimens by fluorescence quantitative real-time PCR and to find clinical features helpful to diagnose M. pneumoniae pneumonia (MPP). Four hundred and six hospitalized pneumonia children were studied. M. pneumoniae DNA in NPA and BAL samples were detected by fluorescence quantitative real-time PCR. M. pneumoniae-specific IgM was tested by ELISA. MPP were diagnosed based on positive M. pneumoniae-specific IgM in 101 (24.9%) children. The median ages of MPP and non-MPP children were 4.1 and 2.4 years, respectively, with significant difference between them (p < 0.001). Laboratory results including leukocyte count, neutrophil percentage, immunoglobulins, except serum IgM, subgroups of T lymphocyte, and BAL cell count had no significant differences in MPP and non-MPP. BAL macrophage cell percentage was lower in BAL-PCR positive children (p = 0.003), while BAL neutrophil percentage was higher in BAL-PCR positive children (p = 0.007). PCR from NPA and BAL were similar in diagnostic parameters, including sensitivity, specificity, PPV, and NPV (78.6%, 63.4%, 39.8%, and 90.6% for NPA-PCR, respectively; 70.3%, 58.7%, 36.0%, and 85.6% for BAL-PCR, respectively).

CONCLUSIONS

NPA is better than BAL as PCR sample in MPP diagnosis for similar performance in PCR assay, cheap, and less invasive. BAL is useful in defining local inflammatory condition. Age is the only prefigurative factor in MPP.

Detection of Mycoplasma pneumoniae in adult community-acquired pneumonia by PCR and serology

Diagnosis of pneumonia caused by Mycoplasma pneumoniae in adults is hampered by a lack of rapid and standardized tests for detection. This prospective study was conducted to compare the diagnostic values of an indirect immunofluorescence assay and a 16S rRNA gene PCR for the diagnosis of M. pneumoniae pneumonia in adults. From February 2005 to January 2008, 357 patients (53.8 % males, median age 63 years, range 18-94) admitted for community-acquired pneumonia (CAP) to two hospitals in Santiago, Chile, were enrolled in the study. Thirty-two patients (9.0 %) met the criteria of current or recent M. pneumoniae infection, and laboratory diagnosis was definitive in 26 cases (81.2 %) and presumptive in six cases (18.8 %). Among the 32 M. pneumoniae infections, the PCR assay was positive in 23 (71.9 %) and the serology in 27 (84.4 %) of the cases. IgM was positive in acute-phase serum specimens in 13 cases (40.6 %) of M. pneumoniae infections. Using serology as the gold standard, the sensitivity, specificity, and positive and negative predictive values of the PCR were 66.7, 98.5, 78.3 and 97.3 %, respectively, whereas the global agreement of the methods was 343/357 (96.1 %). The frequency of M. pneumoniae CAP cases declined significantly during the second year of study, suggesting the end of an epidemic period. In conclusion, although good global agreement was found between PCR and serology, the lower sensitivity of the PCR leads us to recommend the use of both procedures in parallel to confirm M. pneumoniae in CAP in adults.

New insights into the pathogenesis and detection of Mycoplasma pneumoniae infections

Mycoplasma pneumoniae is a common cause of upper and lower respiratory tract infections in persons of all ages and may be responsible for up to 40% of community-acquired pneumonias. A wide array of extrapulmonary events may accompany the infections caused by this organism, related to autoimmunity or direct spread. This review includes a discussion of the latest knowledge concerning the molecular pathological basis of mycoplasmal respiratory disease, how the organism interacts with the host immune system and its association with the development of chronic conditions such as asthma, recent emergence of macrolide resistance and the status of laboratory diagnostic methods.