Acute respiratory infection due to Mycoplasma pneumoniae: current status of diagnostic methods

Real-time fluorescent multiple cross displacement amplification for rapid and sensitive Mycoplasma pneumoniae detection

Mycoplasma pneumoniae is a significant pathogen responsible for community-acquired pneumonia, predominantly affecting children and adolescents. Here, we devised a rapid method for M. pneumoniae that combined multiple cross displacement amplification (MCDA) with real-time fluorescence technology. A set of ten primers, which were specifically designed for M. pneumoniae detection, were employed in a real-time fluorescence MCDA reaction. Of these, one primer incorporated a restriction endonuclease recognition sequence, a fluorophore, and a quencher, facilitating real-time fluorescence detection. The real-time (RT)-MCDA reactions were monitored in a simple real-time fluorescence instrument and conducted under optimised conditions (64°C for 40 min). The detection limit of the M. pneumoniae RT-MCDA assay for genomic DNA extracted from M. pneumoniae culture was down to 43 fg/µl. This assay accurately identified M. pneumoniae strains without cross-reacting with other bacteria. To validate its practical application, we tested the M. pneumoniae RT-MCDA assay using genomic DNA extracted from clinical samples. The assay's detection capability proved comparable with real-time PCR, MCDA-based biosensor detection, and visual inspection under blue light. The entire process, including rapid DNA extraction and real-time MCDA detection, was completed within 1 h. Overall, the M. pneumoniae RT-MCDA assay reported here is a simple and effective diagnostic tool for rapid M. pneumoniae detection, which holds significant potential for point-of-care testing and in resource-limited regions.

Research status and challenges of Mycoplasma pneumoniae pneumonia in children: A bibliometric and visualization analysis from 2011 to 2023

BACKGROUND

Mycoplasma pneumoniae (MP) infections occur in regional outbreaks every 3 to 7 years, lasting up to 2 years. Since this fall, there has been a significant rise in MP infections among children in China, indicating a regional epidemiological trend that imposes an increased national public health burden. To date, bibliometric methods have not been applied to studies on MP infection in children.

METHODS

We searched for all relevant English publications on MP pneumonia in children published from 2011 to 2023 using Web of Science. Analytical software tools such as Citespace and VOSviewer were employed to analyze the collected literature.

RESULTS

993 articles on MP pneumonia in children were published in 338 academic journals by 5062 authors affiliated with 1381 institutions across 75 countries/regions. China led in global productivity with 56.19%. Among the top 10 prolific organizations, 8 were Chinese institutions, with Soochow University being the most active, followed by Capital Medical University and Zhejiang University. Zhimin Chen from Zhejiang University School of Medicine exhibited the highest H-index of 32. Keyword co-occurrence network analysis revealed 7 highly relevant clusters.

CONCLUSION

The current research hotspots and frontiers in this field are primarily MP pneumonia, refractory MP pneumonia, lactate dehydrogenase, asthma, and biomarker. We anticipate that this work will provide novel insights for advancing scientific exploration and the clinical application of MP pneumonia in children.

In vitro and in vivo study of andrographolide nanoparticles for the treatment of Mycoplasma pneumoniae pneumonia

OBJECTIVE(S)

The emergence of antibiotic resistance has led to suboptimal treatment outcomes for Mycoplasma pneumoniae pneumonia (MPP). Exploring naturally occurring drug components that are both effective against MPP and non-toxic may be a promising choice. This study aimed to investigate the therapeutic effect of andrographolide nanoparticles on pneumonia caused by Mycoplasma pneumoniae infection.

METHODS

Andrographolide alginate-poloxamer nanoparticles (AND-ALG-POL/NPs) were obtained by wet medium grinding, and the characterization and in vitro release of the prepared andrographolide nanoparticles were examined by high performance liquid chromatography, particle size analyzer, zeta potential meter and transmission electron microscopy. The cytotoxicity and anti-inflammatory effects of AND-ALG-POL/NPs were evaluated in vitro by MP-infected lung epithelial cells BEAS-2B. Symptoms of pneumonia, total cell count, total protein content and inflammatory factor levels in BALF were assessed by MP-induced pneumonia in BALB/c mice treated with AND-ALG-POL/NPs, and histopathological studies were performed on lung tissues from experimental animals.

RESULTS

The results showed that the prepared AND-ALG-POL/NPs were homogeneous spherical with a diameter of 180 ± 23 nm, a zeta potential of (-14.4 ± 2.1) mV, an average encapsulation rate of 87.74 ± 0.87 %, and an average drug loading of 13.17 ± 0.54 %. AND-ALG-POL/NPs were capable of slow release in vitro and showed significant inhibitory ability against MP (P < 0.001). However, AND-ALG-POL/NPs were not cytotoxic to normal cells and alleviated MP infection-induced apoptosis and elevated inflammatory factors. In the in vivo experiments, AND-ALG-POL/NPs alleviated the symptoms of pneumonia in MPP mice, reduced the abnormally elevated total cell count, total protein content and inflammatory factor levels in BALF, and alleviated lung tissue edema, inflammatory cell infiltration and apoptosis (P < 0.001). Meanwhile, the therapeutic effects of AND-ALG-POL/NPs on MPP were similar to those of azithromycin (AZM) and higher than those of andrographolide (AND) free monotherapy (P < 0.001).

CONCLUSION

In summary, the prepared AND-ALG-POL/NPs can effectively inhibit MPP in vitro and in vivo, and the effect is similar to that of AZM. Therefore, AND- ALG - POL/NPs have the potential to replace AZM as a potential drug for the treatment of MPP.

Global research trends of Mycoplasma pneumoniae pneumonia in children: a bibliometric analysis

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP), attributable to Mycoplasma pneumoniae (MP), represents a predominant form of community-acquired pneumonia in pediatric populations, thereby posing a significant threat to pediatric health. Given the burgeoning volume of research literature associated with pediatric MPP in recent years, it becomes imperative to undertake a bibliometric analysis aimed at delineating the current research landscape and emerging trends, thereby furnishing a framework for subsequent investigations.

METHODS

A comprehensive literature search targeting pediatric MPP was conducted in the Web of Science Core Collection. After the removal of duplicate entries through Endnote software, the remaining articles were subject to scientometric analysis via Citespace software, VOSviewer software and R language, focusing on variables such as publication volume, contributing nations, institutions and authors, references and keywords.

RESULTS

A total of 1,729 articles pertinent to pediatric MPP were included in the analysis. China and the United States emerged as the nations with the highest publication output. Italian scholar Susanna Esposito and Japanese scholar Kazunobu Ouchi were the most influential authors in the domain of pediatric MPP. Highly-cited articles primarily focused on the epidemiological investigation of pediatric MPP, the clinical characteristics and treatment of macrolide-resistant MPP, and biomarkers for refractory Mycoplasma pneumoniae pneumonia (RMPP). From the corpus of 1,729 articles, 636 keywords were extracted and categorized into ten clusters: Cluster #0 centered on molecular-level typing of macrolide-resistant strains; Cluster #1 focused on lower respiratory tract co-infections; Clusters #2 and #6 emphasized other respiratory ailments caused by MP; Cluster #3 involved biomarkers and treatment of RMPP; Clusters #4 and #9 pertained to extrapulmonary complications of MPP, Clusters #5 and #7 addressed etiological diagnosis of MPP, and Cluster #8 explored pathogenic mechanisms.

CONCLUSIONS

The past few years have witnessed extensive attention directed towards pediatric MPP. Research in pediatric MPP principally revolves around diagnostic techniques for MP, macrolide resistance, complications of MPP, treatment and diagnosis of RMPP, and elucidation of pathogenic mechanisms. The present study provides pediatric clinicians and researchers with the research status and focal points in this field, thereby guiding the orientation of future research endeavors.

Epidemiological Study of Respiratory Virus Infections among Hospitalized Children Aged 14 Years and Younger during COVID-19 Pandemic in Wuhan, China, 2018-2022

Introduction

The viral etiological characteristics and prevalence of hospitalized children with acute respiratory tract infection were preliminary studied in Wuhan City during the COVID-19 pandemic, to provide a reliable scientific basis for better understanding of the role of various pathogens in cases and for the prevention and clinical treatment of acute respiratory tract infection.

Methods

A total of 69,086 children with acute respiratory infections hospitalized and treated in our department from January 2018 to December 2022 were enrolled as our research subjects. Sociodemographic and clinical data as well as nasopharyngeal samples were collected from patients. Respiratory syncytial virus (RSV), adenovirus (ADV), infuenza virus A (FluA), infuenza virus B (FluB), and parainfluenza virus (PIV) were detected by direct immunofluorescence (DFA) to understand and analyze the epidemic characteristics of respiratory pathogens in children during the COVID-19 pandemic.

Results

The total detection rate of respiratory pathogens was 24.52% of the 69,086 hospitalized children. The frequency of respiratory viruses in those ADV, RSV, FluA, FluB, and PIV was 14.67%, 46.40%, 7.76%, 5.23%, and 25.95%. There were significant differences between the various pathogens (P < 0.001). There were the fewest pathogen-positive patients and positive detection rate in 2020 during the COVID-19 pandemic. There were significant differences in the pathogen detection rate among different years (P < 0.001). In addition, the results showed that the total detection rate of respiratory virus tested in different age groups was significantly different (P < 0.001). The positive detection rate was highest in the 1-3-year-old age group, which is prone to acute respiratory infections. We also found that different pathogens showed obvious seasonal fluctuation and epidemic. RSV reached its peak in winter. ADV is mainly prevalent in spring and summer. FluA has a high detection rate in winter. Winter and spring are the peak seasons for FluB infection, whereas PIV is detected in all seasons, with a higher incidence rate in the spring and summer.

Conclusion

The epidemiological distribution of pathogens of acute respiratory tract infection in hospitalized children in Wuhan from 2018 to 2022 varies with gender, age, and season. Nonpharmaceutical interventions (NPIs) were implemented as control measures worldwide and reduced the transmission of respiratory pathogens. NPIs are likely to be the primary driver of the dramatic reduction in respiratory virus infection activity in the early stages of the COVID-19 pandemic, to dissolving NPIs can lead to a recurrence of viral infection pathogens, especially in children.

Rapid, ultrasensitive and highly specific diagnosis of Mycoplasma pneumoniae by a CRISPR-based detection platform

Mycoplasma pneumoniae (MP) is an important causative agent of morbidity and mortality among all age groups, especially among patients of extreme ages. Improved and readily available tests for accurate, sensitive and rapid diagnosis of MP infection is sorely needed. Here, we developed a CRISPR-Cas12b-based detection platform on the basis of recombinase polymerase amplification (RPA) for rapid, simple, and accurate diagnosis of MP infection, named MP-RPA-CRISPR. The RPA was employed for amplifying the community-acquired respiratory distress syndrome (CARDS) toxin gene of MP strains at the optimal reaction temperature 37°C. The resulting amplicons were decoded by the CRISPR-Cas12b-based detection platform, which was interpreted by real-time PCR system and by naked eye under blue light. The MP-RPA-CRISPR can detected down to 5 fg of genomic DNA templates of MP strains and accurately distinguish MP strains from non-MP strains without any cross-reactivity. A total of 96 bronchoalveolar lavage fluid (BALF)samples collected from patients suspected of respiratory infection were used to evaluate the clinical performance of the MP-RPA-CRISPR assay. As a result, our assay accurately diagnosed 45 MP-infected samples and 51 non-MP infected sample, and the results obtained from MP-RPA-CRISPR were consistent with microfluidic chip technology. In conclusion, our MP-RPA-CRISPR assay is a simple, rapid, portable and highly sensitive method to diagnose MP infection, which can be used as a promising tool in a variety of settings including clinical, field, and resource-limited aeras.

Loop-Mediated Isothermal Amplification Coupled With Nanoparticle-Based Biosensor: A Rapid and Sensitive Method to Detect Mycoplasma pneumoniae

Mycoplasma pneumoniae (MP), the causative agent of MP pneumonia (MPP), has posed a substantial burden to public health owing to a lack of rapid and effective diagnostic methods. Here, we designed a loop-mediated isothermal amplification (LAMP)-based assay, termed LAMP, combined with a nanoparticle-based lateral flow biosensor (LAMP-LFB) for rapid and sensitive diagnosis of MP.-LAMP-LFB included a set of six primers targeting the community-acquired respiratory distress syndrome (CARDS) toxin gene and was performed optimally at 63°C for only 30 min. The resulting LAMP products could be visually indicated by LFB within 2 min, thus the whole process could be accomplished within an hour. MP-LAMP-LFB's sensitivity was 50 fg per reaction, which was in complete accordance with these results obtained from real-time turbidity and visual detection reagent (VDR). MP-LAMP-LFB had no cross-reactivity with other pathogens that had similar clinical presentations. Our assay was further validated using 100 nasopharyngeal swab samples collected from children suspected of MPP, and the result was compared with the real-time PCR method. With a positive rate of 50%, the data indicated that MP-LAMP-LFB is a sensitive test for MP detection in clinical settings. Collectively, the MP-LAMP-LFB assay targeting the CARDS toxin gene was a rapid, highly sensitive, and specific test that could be widely applied in point-of-care settings and basic medical facilities in rural areas.

Performance Analysis of Novel Nucleic Acid Detection Kit for Mycoplasma pneumoniae

Respiratory tract infections caused by Mycoplasma pneumoniae is a serious risk for child health. It has been difficult to prevent and control for a variety of reasons; therefore, timely diagnosis is particularly important for treatment of patients. At present, the rapid M pneumoniae test kits based on nucleic acid amplification have been commercialized and used as primary diagnostic tools for M pneumoniae infection, but current kits are time-consuming, which is difficult to meet the requirement for accurate and rapid diagnosis of M pneumoniae during epidemics. Rapid and accurate test kits are urgently required to diagnose M pneumoniae infection. In this article, we evaluated the performance of a novel nucleic acid detection kit (A) for M pneumoniae from feasibility and sensitivity, and compared it with kit B. Results showed this kit has the advantage of being rapid, sensitive, and specific, which meets the demands for the diagnosis of M pneumoniae infection in clinical settings.

Mycoplasma pneumoniae infection prediction model for hospitalized community-acquired pneumonia children

OBJECTIVES

We sought to develop a nomogram to predict Mycoplasma pneumoniae (Mp) infection among hospitalized children with community-acquired pneumonia (CAP) and compare it with another model developed from age and duration of fever.

METHODS

Data on 5904 CAP children who were enrolled at Shanghai Children's Medical Center were retrospectively collected and divided into a training set (n = 4133) and a validation set (n = 1771). The model's performance was determined by concordance index (C-index), calibration curves, Brier scores, and decision curve analyses (DCAs). Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used for model comparisons.

RESULTS

Incorporating five factors (age, duration of fever, erythrocyte sedimentation rate, leukocyte count, and neutrophil proportion), the nomogram achieved good C-index values of 0.74 (95% confidence interval [CI]: 0.72-0.76) and 0.75 (95% CI: 0.73-0.78) and good Brier scores of 0.14 (95% CI: 0.13-0.15) and 0.17 (95% CI: 0.15-0.18) in predicting Mp infection in the training and validation cohorts, respectively, and had moderate fitted calibration plots. The DCAs showed good clinical usefulness of the nomogram. Patients were effectively divided into low, medium, and high risk groups by two cut-off score points of the nomogram, 210 and 300. With the lower AIC (3673.5) and BIC (3774.7) value, the model of five predictors is the better model.

CONCLUSIONS

By using five predictor variables, a simple nomogram of good predictive accuracy for Mp infection and moderate agreements between the actual outcome and the predicted probability was constructed. It could serve as a tool to aid physicians in clinical decision-making processes.

Mycoplasma pneumoniae infection and risk of childhood asthma: A systematic review and meta-analysis

The etiology of childhood asthma is multifactorial, atypical bacterial pathogens, including Mycoplasma pneumoniae, have been proposed as possible risk factors or contributors. This review aims to assess the possible association between M. pneumoniae infection and childhood asthma. We searched major international literature databases (up to January 10, 2021) to identify relevant studies. We used a random-effects meta-analysis (REM) model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Several subgroups analyses were performed concerning the IgG, IgM, and DNA detection of M. pneumoniae infection. We included 22 eligible studies; these studies involved a total of 5064 children. We found that there was a statistically significant association between M. pneumoniae infection, as determined by IgM serology (OR, 3.13; 95% CI, 1.78-5.48), and DNA detection (OR, 1.57; 95% CI, 1.25-1.97) with increased risk of any type of childhood asthma. Moreover, children with acute asthma had significantly higher seropositivity for anti- M. pneumoniae IgM antibodies (OR, 4.43; 95% CI, 2.80-7.02) than children with stable asthma. Although our findings indicate a positive association between M. pneumoniae infection and childhood asthma, well-designed and -controlled studies are need in the future to rigorously test this association and identify the underlying mechanisms.

A multisite SNP genotyping and macrolide susceptibility gene method for Mycoplasma pneumoniae based on MALDI-TOF MS

In this study, a multisite SNP genotyping and macrolide (ML) susceptibility gene test method for Mycoplasma pneumoniae (M. pneumoniae) was developed based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The detection limit of this method for nucleic acids was 10² -10³ copies/reaction. Six SNP site-based genotyping and 3 ML susceptibility sites could be detected simultaneously based on multiplex PCR and mass probe. Using the method constructed in this study, 141 Chinese clinical isolates were divided into 8 SNP types. All the SNP test results for the ML susceptibility gene were in line with those of the 23S rRNA sequencing results. With this method, the multisite SNP genotyping and ML susceptibility determination of M. pneumoniae can be completed simultaneously in one test, which greatly reduces the workload and cost, improves the genotyping ability of M. pneumoniae and deserves clinical application.

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An all-in-one genotyping and macrolide resistance testing method for M. pneumoniae

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Multisite SNP detection technology was used for genotyping and resistance testing

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The cost of M. pneumoniae genotyping and macrolide resistance detection was reduced

Vaccination using inactivated Mycoplasma pneumoniae induces detrimental infiltration of neutrophils after subsequent infection in mice

Mycoplasma pneumoniae (Mp) is one of the most common causes of community-acquired pneumonia. Given the emergence and high rates of antibiotic-resistant Mp strains, vaccines that prevent the pneumonia and secondary complications due to Mp infection are urgently needed. Although several studies have shown the protective efficacy of Mp vaccines in human clinical trials, some reports suggest that vaccination against Mp exacerbates disease upon subsequent Mp challenge. Therefore, to develop optimal vaccines against Mp, understanding the immune responses that contribute to post-vaccination exacerbation of inflammation is crucial. Here we examined whether Mp vaccination might exacerbate pneumonia after subsequent Mp infection in mice. We found that vaccination with inactivated Mp plus aluminum salts as an adjuvant induced Mp-specific IgG, Th1 cells, and Th17 cells. Toll-like receptor 2 signaling contributed to the induction of an Mp-specific IgG response and was necessary for Mp-specific Th17-cell-but not Th1-cell-responses in vaccinated mice. In addition, vaccination with inactivated Mp plus aluminum salts suppressed the number of Mp organisms in the bronchoalveolar lavage fluid, indicating that vaccination can reduce Mp infection. However, the numbers of total immune cells and neutrophils in bronchoalveolar lavage fluid after Mp challenge did not differ between vaccinated mice and non-vaccinated control mice. Furthermore, depletion of CD4⁺ T cells prior to Mp challenge decreased pulmonary neutrophil infiltration in vaccinated mice, suggesting that Th1 or Th17 cells (or both) are responsible for the vaccination-induced neutrophil infiltration. These results suggest that, despite reducing Mp infection, vaccination of mice by using inactivated Mp fails to suppress inflammation, such as neutrophil infiltration into the lung, after subsequent Mp infection.

Mycoplasma pneumoniae infection mimicking tuberculous pleurisy in a young woman: a case report and literature review

A 30-year-old woman was admitted to a different hospital with a 2-day history of fever, cough, and expectoration. She had a history of left pulmonary tuberculosis 8 years previously. Chest computed tomography showed an infiltrate in the inferior lobe of the left lung and spot-like calcifications in the anterior lobe of the upper left lobe and lower lobe of the left lung. After antibacterial treatment, the patient’s condition deteriorated and she developed significant pleural effusion on the left side. The pleural effusion assay showed a lymphocyte-predominant exudate with a significantly increased adenosine deaminase level. The patient was transferred to our hospital with a suspected diagnosis of tuberculous pleuritis. A serum test for Mycoplasma pneumoniae-specific immunoglobulin M was positive. Because of the limitations of this test in determining the occurrence of recent infection, a thoracoscopic pleural biopsy was performed, and M. pneumoniae DNA was detected in the biopsy tissue using M. pneumoniae-specific polymerase chain reaction. Thus, the patient was diagnosed with M. pneumoniae-related parapneumonic effusion. Clinicians must be aware of the usefulness and limitations of a high adenosine deaminase level and know that lymphocyte predominance in pleural effusion does not always indicate tuberculous pleurisy, especially in areas of high tuberculosis prevalence.

Immunochromatography for the diagnosis of Mycoplasma pneumoniae infection: A systematic review and meta-analysis

The aim of this study was to evaluate the diagnostic performance of immunochromatographic tests (ICTs) for the detection of Mycoplasma pneumoniae. Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science were searched through June 12, 2019 for relevant studies that used ICTs for the detection of M. pneumoniae infection with polymerase chain reaction (PCR) or microbial culturing as reference standards. Pooled diagnostic accuracy with 95% confidence interval (CI) was calculated using a bivariate random effects model. We also constructed summary receiver operating characteristic curves and calculated the area under the curve (AUC). Statistical heterogeneity was evaluated by χ² test or Cochrane’s Q test. Thirteen studies including 2,235 samples were included in the meta-analysis. The pooled sensitivity and specificity for diagnosing M. pneumoniae infection were 0.70 (95% CI: 0.59–0.79) and 0.92 (95% CI: 0.87–0.95), respectively. The positive likelihood ratio (LR) was 8.94 (95% CI: 4.90–14.80), negative LR 0.33 (95% CI: 0.22–0.46), diagnostic odds ratio 29.20 (95% CI: 10.70–64.20), and AUC 0.904. In subgroup analysis, ICTs demonstrated similar pooled sensitivities and specificities in populations of children only and mixed populations (children + adults). Specimens obtained from oropharyngeal swabs exhibited a higher sensitivity and specificity than those of nasopharyngeal swab. Moreover, pooled estimates of sensitivity and accuracy for studies using PCR as a reference standard were higher than those using culture. The pooled sensitivity and specificity of Ribotest Mycoplasma^®, the commercial kit most commonly used in the included studies, were 0.66 and 0.89, respectively. Overall, ICT is a rapid user-friendly method for diagnosing M. pneumoniae infection with moderate sensitivity, high specificity, and high accuracy. This suggests that ICT may be useful in the diagnostic workup of M. pneumoniae infection; however, additional studies are needed for evaluating the potential impact of ICT in clinical practice.

Use of a rapid recombinase-aided amplification assay for Mycoplasma pneumoniae detection

Background

Mycoplasma pneumoniae is one of the most common causative pathogens of community-acquired pneumonia (CAP), accounting for as many as 30–50% of CAP during peak years. An early and rapid diagnostic method is key for guiding clinicians in their choice of antibiotics.

Methods

The recombinase-aided amplification (RAA) assay is a recently developed, rapid detection method that has been used for the detection of several pathogens. The assays were performed in a one-step single tube reaction at 39° Celsius within 15–30 min. In this study, we established an RAA assay for M. pneumoniae using clinical specimens for validation and commercial real-time PCR as the reference method.

Results

The analytical sensitivity of the RAA assay was 2.23 copies per reaction, and no cross-reactions with any of the other 15 related respiratory bacterial pathogens were observed. Compared with the commercial real-time PCR assay used when testing 311 respiratory specimens, the RAA assay obtained 100% sensitivity and 100% specificity with a kappa value of 1.

Conclusions

These results demonstrate that the proposed RAA assay will be of benefit as a faster, sensitive, and specific alternative tool for the detection of M. pneumoniae.

Diagnostic value of quantitative MP-IgG for Mycoplasma pneumoniae pneumonia in adults

The passive particle agglutination (PA) test, once widely used for Mycoplasma pneumoniae (M. pneumoniae) antibody detection, has gradually been replaced by quantitative enzyme-linked immunosorbent assays (ELISA). However, the lack of diagnostic criteria for quantitative ELISA M. pneumoniae-IgG (MP-IgG) and the low positive rates of ELISA M. pneumoniae-IgM (MP-IgM) limit the diagnostic value of ELISA for M. pneumoniae infection in adults. Here, the diagnostic value of quantitative ELISA MP-IgG was evaluated in adults with Mycoplasma pneumoniae pneumonia (MPP). The serum M. pneumoniae antibodies were detected in 162 patients with MPP, 228 patients with community-acquired pneumonia (CAP) with non-Mycoplasma pneumoniae (NMP), and 162 healthy controls by ELISA, using the PA results as the reference standards. For the MP-IgM-/IgG+ subgroup, a single serum MP-IgG level of ≥92.67 RU/mL can be used as a reference criterion for the diagnosis of acute M. pneumoniae infection. At admission, for patients with CAP, the sensitivity and specificity of ELISA MP-IgM positivity for MPP were 18.51% and 99.56%, respectively. MP-IgM positivity combined with MP-IgG ≥ 92.67 RU/mL increased the sensitivity to 40.12% and decreased the specificity to 94.29%. For paired serum samples obtained within seven days, an ELISA MP-IgG concentration change of ≥1.48-fold and MP-IgG ≥ 92.67 RU/mL on day 7 were used as the diagnostic criteria for M. pneumoniae infection. Accordingly, the combination of qualitative MP-IgM detection and quantitative MP-IgG detection by ELISA is valuable for acute MPP diagnosis in adults.

Establishment and Application of a Multiple Cross Displacement Amplification Coupled With Nanoparticle-Based Lateral Flow Biosensor Assay for Detection of Mycoplasma pneumoniae

Mycoplasma pneumoniae (M. pneumoniae) is responsible for pneumonia, and is a causative agent of other respiratory tract infections (e.g., bronchiolitis and tracheobronchitis). Herein, we established and applied a multiple cross displacement amplification (MCDA) coupled with a nanoparticle-based lateral flow biosensor (LFB) assay (MCDA–LFB) for rapid, simple, and reliable detection of target pathogen. A set of 10 primers was designed based on M. pneumoniae-specific P1 gene, and optimal reaction conditions were found to be 30 min at 65°C. The detection results were visually reported using a biosensor within 2 min. The M. pneumoniae–MCDA–LFB method specifically detected only M. pneumoniae templates, and no cross-reactivity was generated from non-M. pneumoniae isolates. The analytical sensitivity for this assay was 50 fg of genomic templates in the pure cultures, as obtained from colorimetric indicator and real-time turbidimeter analysis. The assay was applied to 197 oropharyngeal swab samples collected from children highly suspected of M. pneumoniae infection, and compared to culture-based method and real-time PCR assay. The detection rates of M. pneumoniae using a culture-based method, real-time PCR assay, and MCDA–LFB assay were 8.1%, 33.0%, and 52.3%, respectively, which indicated that the MCDA–LFB assay was superior to the culture-based method and real-time PCR method for detection of target agent. Using this protocol, 25 min for rapid template extraction followed by MCDA reaction (30 min) combined with LFB detection (2 min) resulted in a total assay time of ~60 min. In conclusion, the MCDA–LFB assay established in this report was a simple, rapid, sensitive, and reliable assay to detect M. pneumoniae strains, and can be used as a potential diagnostic tool for M. pneumoniae in basic and clinical laboratories.

Detection of Mycoplasma pneumoniae in Mexican children with community-acquired pneumonia: experience in a tertiary care hospital

Purpose: Mycoplasma pneumoniae is an important cause of community-acquired pneumonia (CAP). Information on the prevalence of M. pneumoniae in pediatric patients with CAP in Mexico is limited. The aim of this study was to detect M. pneumoniae in hospitalized pediatric patients with CAP. Patients and methods: We performed a descriptive study in a tertiary-level pediatric reference center, obtaining 154 respiratory samples from patients under 18 years of age and diagnosed with CAP. M. pneumoniae was detected by real-time polymerase chain reaction (PCR) targeting the p1 and CARDS genes. Complete blood cell count, measurement of C-reactive protein and detection of IgM and IgG anti-P1 were performed. Clinical, epidemiological and radiological data of the patients were analyzed. Results: M. pneumoniae was detected by real-time PCR in 26.6% of the samples. 39% of the cases occurred during the spring season. A total of 83% of the patients with M. pneumoniae had some underlying disease; renal disease, autoimmune disease and primary immunodeficiencies had a significant association with M. pneumoniae CAP. Children under 6 years of age represented 53.7% of the cases. Fever and cough were the most frequent symptoms. IgM and IgG were positive in 1.9% and 14% of the patients, respectively. In the chest X-ray, 17.1% of the patients showed multifocal alveolar infiltrates pattern. The complications in this series were 26.8%. The mortality in this study was 4.9%. Conclusion: This is the first report in Mexico about M. pneumoniae as a causal agent of CAP in a tertiary care pediatric hospital using real-time PCR and serology. M. pneumoniae was responsible for 26.6% of the cases and was frequent in children under 6 years of age. In addition, we described the clinical presentation in patients with underlying diseases.

A Rare Case of Bartonella Encephalitis With Hemiplegia

The authors describe a 12-year-old girl with an atypical presentation of Bartonella encephalitis. She presented with fever and altered mental status and developed flaccid paralysis of her left upper extremity a day later. An electroencephalogram showed slowing over her right hemisphere. She had mild leukocytosis and bandemia, but her imaging and cerebrospinal studies were unrevealing. After five days, her symptoms resolved and she was discharged home on doxycycline due to suspicion for Bartonella encephalitis. The patient admitted to playing with a kitten two months prior, but she lacked the classic regional lymphadenopathy. Bartonella titers were sent during her hospitalization and returned positive after her discharge. Cat scratch disease neurologic manifestations are uncommon, with hemiplegia being exceedingly rare. This case illustrates that focal neurologic signs may develop during cat scratch disease infection and suggests that cat scratch disease encephalitis should be considered during evaluation of a pediatric patient with acute flaccid paralysis.

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.

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.

High flux isothermal assays on the pathogenic features of Mycoplasma pneumoniae

As one of the most important pathogens, M. pneumoniae is a causative agent responsible for atypical and other respiratory tract infections, even its extra-pulmonary complications. This study aims to use the high and rapid flux sequencing assays on the M. pneumoniae and further bioinformatic analysis, for the investigation of their clinical features and pathogenic characteristics. The results in this study on the clinical features and pathogenic characteristics of M. pneumoniae may further aid in the control and surveillance and better understanding of this pathogen.

Chemosynthetic homologues of Mycoplasma pneumoniae β-glycolipid antigens for the diagnosis of mycoplasma infectious diseases

Mycoplasma pneumoniae expresses β-glycolipids (β-GGLs) in cytoplasmic membranes, which possess a unique β(1 → 6)-linked disaccharide epitope, which has high potential in biochemical and medicinal applications. In the present study, a series of β-GGLs homologues with different acyl chains (C12, C14, C16, and C18) were prepared from a common precursor. An ELISA assay using an anti-(β-GGLs) monoclonal antibody indicated that the synthetic homologues with long acyl chains had greater diagnostic potential in the order C18 > C16 > C14 > C12. Toward a simultaneous detection of natural glycolipids by mass spectrometry (MS), a deuterium-labeled C16 homologue (β-GGL-C16-d₃) was prepared and applied as an internal standard for a high-resolution electrospray ionization MS (ESI-MS) analysis. The ESI-MS analysis was used to identify and quantify acyl homologues (C16/C16, C16/C18, and C18/C18) of β-GGL-C16 in cultured M. pneumoniae. A β-GGLs homologue with a 1,2-diacetyl group (C2) was also prepared as a "water soluble" glycolipid homologue and characterized by ¹H NMR spectroscopy. We envisage that each of these chemosynthetic homologues will provide promising approaches to solve medical and biological problems associated with mycoplasma infectious diseases (MIDs).

Diagnosis and treatment of community-acquired pneumonia in adults: 2016 clinical practice guidelines by the Chinese Thoracic Society, Chinese Medical Association

Community‐acquired pneumonia (CAP) in adults is an infectious disease with high morbidity in China and the rest of the world. With the changing pattern in the etiological profile of CAP and advances in medical techniques in diagnosis and treatment over time, Chinese Thoracic Society of Chinese Medical Association updated its CAP guideline in 2016 to address the standard management of CAP in Chinese adults. Extensive and comprehensive literature search was made to collect the data and evidence for experts to review and evaluate the level of evidence. Corresponding recommendations are provided appropriately based on the level of evidence. This updated guideline covers comprehensive topics on CAP, including aetiology, antimicrobial resistance profile, diagnosis, empirical and targeted treatments, adjunctive and supportive therapies, as well as prophylaxis. The recommendations may help clinicians manage CAP patients more effectively and efficiently. CAP in pediatric patients and immunocompromised adults is beyond the scope of this guideline. This guideline is only applicable for the immunocompetent CAP patients aged 18 years and older. The recommendations on selection of antimicrobial agents and the dosing regimens are not mandatory. The clinicians are recommended to prescribe and adjust antimicrobial therapies primarily based on their local etiological profile and results of susceptibility testing, with reference to this guideline.

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.

Evaluation of a real-time method of simultaneous amplification and testing in diagnosis of Mycoplasma pneumoniae infection in children with pneumonia

Mycoplasma pneumoniae (M. pneumoniae) infection can cause community acquired pneumonia in children. A real-time method of simultaneous amplification and testing of M. pneumoniae (SAT-MP) was developed to diagnose M. pneumoniae targeting a region of the ribosomal RNA. The SAT-MP assay can accurately identify M. pneumoniae with a detection range from 10¹ to 10⁷ CFU/ml. In this study, the specimens from 315 children with pneumonia were collected and analyzed by SAT-MP in parallel with real-time PCR method and IgM ELISA assay. The positive rates of these specimens examined by SAT-MP assay, real-time PCR method and IgM ELISA assay were 16.51%, 15.56% and 12.70% respectively. While there was statistical significance (p = 0.04) between SAT-MP assay and IgM ELISA assay, no statistical significance (p = 0.25) was found between SAT-MP assay and real-time PCR method and these two methods had high consistency (kappa value = 0.97). These findings indicate that the newly developed SAT-MP assay is a rapid, sensitive and specific method for identifying M. pneumoniae with potential clinical application in the early diagnosis of M. pneumoniae infection.

Multi-center evaluation of one commercial and 12 in-house real-time PCR assays for detection of Mycoplasma pneumoniae

Detection of Mycoplasma pneumoniae by real-time PCR is not yet standardized across laboratories. We have implemented a standardization protocol to compare the performance of thirteen commercial and in-house approaches. Despite differences on threshold values of samples, all assays were able to detect at least 20M. pneumoniae genomes per reaction.

Role of Atypical Bacteria in Hospitalized Patients With Nursing Home-Acquired Pneumonia

Background: Nursing home-acquired pneumonia (NHAP) has been identified as one of the leading causes of mortality and hospitalization for long-term care residents. However, current and previous pneumonia guidelines differ on the appropriate management of NHAP in hospitalized patients, specifically in regard to the role of atypical bacteria such as Chlamydiae pneumonia, Mycoplasma pneumoniae, and Legionella. Objectives: The purpose of this review is to evaluate clinical trials conducted in hospitalized patients with NHAP to determine the prevalence of atypical bacteria and thus the role for empiric antibiotic coverage of these pathogens in NHAP. Methods: Comprehensive MEDLINE (1966-April 2016) and Embase (1980-April 2016) searches were performed using the terms "atypical bacteria", "atypical pneumonia", "nursing-home acquired pneumonia", "pneumonia", "elderly", "nursing homes", and "long term care". Additional articles were retrieved from the review of references cited in the collected studies. Thirteen published clinical trials were identified. Results: In the majority of studies, atypical bacteria were infrequently identified in patients hospitalized with NHAP. However, when an active community-acquired pneumonia (CAP) cohort was available, the rate of atypical bacteria between NHAP and CAP study arms was similar. Only 3 studies in this review adhered to recommended strategies for investigating atypical bacteria; in 2 of these studies, C. pneumoniae was the most common pathogen identified in NHAP cohorts. Conclusion: Although atypical bacteria were uncommon in most NHAP studies in this review, suboptimal microbial investigations were commonly performed. To accurately describe the role of atypical bacteria in NHAP, more studies using validated diagnostic tests are needed.

Mycoplasma pneumoniae: Current Knowledge on Nucleic Acid Amplification Techniques and Serological Diagnostics

Mycoplasma pneumoniae (M. pneumoniae) belongs to the class Mollicutes and has been recognized as a common cause of respiratory tract infections (RTIs), including community-acquired pneumonia (CAP), that occur worldwide and in all age groups. In addition, M. pneumoniae can simultaneously or sequentially lead to damage in the nervous system and has been associated with a wide variety of other acute and chronic diseases. During the past 10 years, the proportion of LRTI in children and adults, associated with M. pneumoniae infection has ranged from 0 to more than 50%. This variation is due to the age and the geographic location of the population examined but also due to the diagnostic methods used. The true role of M. pneumoniae in RTIs remains a challenge given the many limitations and lack of standardization of the applied diagnostic tool in most cases, with resultant wide variations in data from different studies. Correct and rapid diagnosis and/or management of M. pneumoniae infections is, however, critical to initiate appropriate antibiotic treatment and is nowadays usually done by PCR and/or serology. Several recent reviews, have summarized current methods for the detection and identification of M. pneumoniae. This review will therefore provide a look at the general principles, advantages, diagnostic value, and limitations of the most currently used detection techniques for the etiological diagnosis of a M. pneumoniae infection as they evolve from research to daily practice.

Infection with and Carriage of Mycoplasma pneumoniae in Children

“Atypical” pneumonia was described as a distinct and mild form of community-acquired pneumonia (CAP) already before Mycoplasma pneumoniae had been discovered and recognized as its cause. M. pneumoniae is detected in CAP patients most frequently among school-aged children from 5 to 15 years of age, with a decline after adolescence and tapering off in adulthood. Detection rates by polymerase chain reaction (PCR) or serology in children with CAP admitted to the hospital amount 4–39%. Although the infection is generally mild and self-limiting, patients of every age can develop severe or extrapulmonary disease. Recent studies indicate that high rates of healthy children carry M. pneumoniae in the upper respiratory tract and that current diagnostic PCR or serology cannot discriminate between M. pneumoniae infection and carriage. Further, symptoms and radiologic features are not specific for M. pneumoniae infection. Thus, patients may be unnecessarily treated with antimicrobials against M. pneumoniae. Macrolides are the first-line antibiotics for this entity in children younger than 8 years of age. Overall macrolides are extensively used worldwide, and this has led to the emergence of macrolide-resistant M. pneumoniae, which may be associated with severe clinical features and more extrapulmonary complications. This review focuses on the characteristics of M. pneumoniae infections in children, and exemplifies that simple clinical decision rules may help identifying children at high risk for CAP due to M. pneumoniae. This may aid physicians in prescribing appropriate first-line antibiotics, since current diagnostic tests for M. pneumoniae infection are not reliably predictive.

How recent advances in molecular tests could impact the diagnosis of pneumonia

Molecular diagnostic tests have been the single major development in pneumonia diagnostics over recent years. Nucleic acid detection tests (NATs) have greatly improved the ability to detect respiratory viruses and bacterial pathogens that do not normally colonize the respiratory tract. In contrast, NATs do not yet have an established role for diagnosing pneumonia caused by bacteria that commonly colonize the nasopharynx due to difficulties discriminating between pathogens and coincidental carriage strains. New approaches are needed to distinguish infection from colonization, such as through use of quantitative methods and identification of discriminating cut-off levels. The recent realization that the lung microbiome exists has provided new insights into the pathogenesis of pneumonia involving the interaction between multiple microorganisms. New developments in molecular diagnostics must account for this new paradigm.

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.

Antibody Response to Mycoplasma pneumoniae: Protection of Host and Influence on Outbreaks?

In humans of all ages, the cell wall-less and genome-reduced species Mycoplasma pneumoniae can cause infections of the upper and lower respiratory tract. The well-documented occurrence of major peaks in the incidence of community-acquired pneumonia cases reported world-wide, the multifaceted clinical manifestations of infection and the increasing number of resistant strains provide reasons for ongoing interest in the pathogenesis of mycoplasmal disease. The results of recent studies have provided insights into the interaction of the limited virulence factors of the bacterium with its host. In addition, the availability of complete M. pneumoniae genomes from patient isolates and the development of proteomic methods for investigation of mycoplasmas have not only allowed characterization of sequence divergences between strains but have also shown the importance of proteins and protein parts for induction of the immune reaction after infection. This review focuses on selected aspects of the humoral host immune response as a factor that might influence the clinical course of infections, subsequent protection in cases of re-infections and changes of epidemiological pattern of infections. The characterization of antibodies directed to defined antigens and approaches to promote their induction in the respiratory mucosa are also preconditions for the development of a vaccine to protect risk populations from severe disease due to M. pneumoniae.

Respiratory Infections

The majority of respiratory tract infections (RTIs) are community acquired and are the single most common cause of physician office visits and among the most common causes of hospitalizations. The morbidity and mortality associated with RTIs are significant and the financial and social burden high due to lost time at work and school. The scope of clinical symptoms can significantly overlap among the respiratory pathogens, and the severity of disease can vary depending on patient age, underlying disease, and immune status, thereby leading to inaccurate presumptions about disease etiology. The rapid and accurate diagnosis of the causative agent of RTIs improves patient care, reduces morbidity and mortality, promotes effective hospital bed utilization and antibiotic stewardship, and reduces length of stay. This chapter focuses on the clinical utility, advantages, and disadvantages of viral and bacterial tests cleared by the Food and Drug Administration (FDA), and new promising technologies for the detection of bacterial agents of pneumonia currently in development or in US FDA clinical trials are briefly reviewed.

The multivariate detection limit for Mycoplasma pneumoniae as determined by nanorod array-surface enhanced Raman spectroscopy and comparison with limit of detection by qPCR

Mycoplasma pneumoniae is a cell wall-less bacterial pathogen of the human respiratory tract that accounts for up to 20% of community-acquired pneumonia. At present, the standard for detection and genotyping is quantitative polymerase chain reaction (qPCR), which can exhibit excellent sensitivity but lacks standardization and has limited practicality for widespread, point-of-care use. We previously described a Ag nanorod array-surface enhanced Raman spectroscopy (NA-SERS) biosensing platform capable of detecting M. pneumoniae in simulated and true clinical throat swab samples with statistically significant specificity and sensitivity. We report here that differences in sample preparation influence the integrity of mycoplasma cells for NA-SERS analysis, which in turn impacts the resulting spectra. We have established a multivariate detection limit (MDL) using NA-SERS for M. pneumoniae intact-cell sample preparations. Using an adaptation of International Union of Pure and Applied Chemistry (IUPAC)-recommended methods for analyzing multivariate data sets, we found that qPCR had roughly 10× better detection limits than NA-SERS when expressed in CFU ml(-1) and DNA concentration (fg). However, the NA-SERS MDL for intact M. pneumoniae was 5.3 ± 1.0 genome equivalents (cells per μl). By comparison, qPCR of a parallel set of samples yielded a limit of detection of 2.5 ± 0.25 cells per μl. Therefore, for certain standard metrics NA-SERS provides a multivariate detection limit for M. pneumoniae that is essentially identical to that determined via qPCR.

New insights in the outbreak pattern of Mycoplasma pneumoniae

Since a well-documented incidence peak in 2011/12 in European countries, infections due to the cell wall-less bacterium Mycoplasma pneumoniae have gained the increased attention of clinicians, microbiologists and health authorities. Despite the mild or asymptomatic clinical course of most M. pneumoniae infections, the microorganism is responsible for severe interstitial pneumonia and extra-pulmonary complications. Here, we report the time-dependence of 5545 notified cases of laboratory-confirmed M. pneumoniae disease in Saxony from 2001 until June 2014 as measured by serodiagnosis. In parallel, from 2003 until 2012 467 M. pneumoniae-positive respiratory samples or isolated strains were analysed by molecular typing based on sequence differences in the main P1 adhesin of M. pneumoniae. The epidemiological data showed a prolonged outbreak especially in the period 2011-2013. The typing of circulating strains during the outbreak did not support predominance of one of the two major P1 subtypes (mean proportion of subtype 1: 57%) or a change of one to the other subtype during the endemic situation before and during the outbreak period. From the last major outbreak in Europe, we conclude that the notification of M. pneumoniae-positive cases, which is legally required only in Saxony, should be expanded to the whole country, to optimise awareness of this human pathogen and to reflect upon antibiotic therapy.

Specificity and Strain-Typing Capabilities of Nanorod Array-Surface Enhanced Raman Spectroscopy for Mycoplasma pneumoniae Detection

Mycoplasma pneumoniae is a cell wall-less bacterial pathogen of the human respiratory tract that accounts for > 20% of all community-acquired pneumonia (CAP). At present the most effective means for detection and strain-typing is quantitative polymerase chain reaction (qPCR), which can exhibit excellent sensitivity and specificity but requires separate tests for detection and genotyping, lacks standardization between available tests and between labs, and has limited practicality for widespread, point-of-care use. We have developed and previously described a silver nanorod array-surface enhanced Raman Spectroscopy (NA-SERS) biosensing platform capable of detecting M. pneumoniae with statistically significant specificity and sensitivity in simulated and true clinical throat swab samples, and the ability to distinguish between reference strains of the two main genotypes of M. pneumoniae. Furthermore, we have established a qualitative lower endpoint of detection for NA-SERS of < 1 genome equivalent (cell/μl) and a quantitative multivariate detection limit of 5.3 ± 1 cells/μl. Here we demonstrate using partial least squares- discriminatory analysis (PLS-DA) of sample spectra that NA-SERS correctly identified M. pneumoniae clinical isolates from globally diverse origins and distinguished these from a panel of 12 other human commensal and pathogenic mycoplasma species with 100% cross-validated statistical accuracy. Furthermore, PLS-DA correctly classified by strain type all 30 clinical isolates with 96% cross-validated accuracy for type 1 strains, 98% cross-validated accuracy for type 2 strains, and 90% cross-validated accuracy for type 2V strains.

Evaluation of five real-time PCR assays for detection of Mycoplasma pneumoniae

Four commercial real-time PCR assays to detect Mycoplasma pneumoniae were tested, and the results were compared with the results for an in-house approach. Despite differences of crossing threshold values of up to 4, assays were able to detect at least 20 CFU/5 μl (52 fg DNA/5 μl) of sample with the Diagenode kit showing the best clinical sensitivity.

Comparison of Mycoplasma pneumoniae Infections in asthmatic children versus asthmatic adults

BACKGROUND

Mycoplasma pneumoniae has been implicated in asthma exacerbations and chronic asthma. A 2-year longitudinal study has been conducted to investigate the role of M. pneumoniae infections in 168 and 20 hospitalized children and adults, respectively, with asthma exacerbation compared with outpatients (88 children and 48 adults) with chronic asthma (without an exacerbation). The prevalence of Chlamydia pneumoniae and respiratory viruses was also assessed in these 2 populations.

METHODS

Lung function testing, blood sampling and microbiological testing (polymerase chain reaction, culture and serology) were performed for 256 children and 68 adults followed by a 7-week, follow-up visit with repeated blood sampling for serological testing and phone interviews at 6 and 12 months later.

RESULTS

M. pneumoniae infection was more prevalent in children with chronic asthma (13.6%) compared with children with exacerbation (7.1%), while the reverse was true in adults (6.3 vs. 10.0%, respectively). However, these differences were not statistically significant. Acute C. pneumoniae infection was identified in 3.9% of children and 7.4% adults. Children seen for chronic asthma were significantly more likely to be infected with C. pneumoniae than children hospitalized for an asthma exacerbation. Viruses were the most prevalent microorganisms detected in children with an asthma exacerbation. No differences in the outcome parameters were identified between M. pneumoniae-infected and noninfected patients.

CONCLUSIONS

The present study suggests that M. pneumoniae does not play a direct role in the pathogenicity of acute or chronic asthma in most children.

The emerging role of community sentinel surveillance in the understanding of the clinical features and epidemiology of acute Mycoplasma pneumoniae infection

Retrospective analysis of 3984 test results for the detection of Mycoplasma pneumoniae performed between 2009 and 2013 in Wales was undertaken. Analysis of the clinical presentation of positive cases suggested that mild respiratory infection was common in the community and appeared to coincide with increased hospitalizations. Symptomatic infection was more prevalent in men, with a median age of 22.6 years (range <1-88 years), and 40% of hospitalized cases presented with pneumonia. Inclusion of M. pneumonia nucleic acid amplification tests (NAATs) into routine respiratory NAAT screens will increase the understanding of the epidemiology and clinical spectrum of acute infections in the wider population.