Epidemiology, clinical manifestations, pathogenesis and laboratory detection of Mycoplasma pneumoniae infections

Development of machine learning-based differential diagnosis model and risk prediction model of organ damage for severe Mycoplasma pneumoniae pneumonia in children

Severe Mycoplasma pneumoniae pneumonia (SMPP) poses significant diagnostic challenges due to its clinical features overlapping with those of other common respiratory diseases. This study aims to develop and validate machine learning (ML) models for the early identification of SMPP and the risk prediction for liver and heart damage in SMPP using accessible laboratory indicators. Cohort 1 was divided into SMPP group and other respiratory diseases group. Cohort 2 was divided into myocardial damage, liver damage, and non-damage groups. The models built using five ML algorithms were compared to screen the best algorithm and model. Receiver Operating Characteristic (ROC) curves, accuracy, sensitivity, and other performance indicators were utilized to evaluate the performance of each model. Feature importance and Shapley Additive Explanation (SHAP) values were introduced to enhance the interpretability of models. Cohort 3 was used for external validation. In Cohort 1, the SMPP differential diagnostic model developed using the LightGBM algorithm achieved the highest performance with AUCROC = 0.975. In Cohort 2, the LightGBM model demonstrated superior performance in distinguishing myocardial damage, liver damage, and non-damage in SMPP patients (accuracy = 0.814). Feature importance and SHAP values indicated that ALT and CK-MB emerged as pivotal contributors significantly influencing Model 2's output magnitude. The diagnostic and predictive abilities of the ML models were validated in Cohort 3, demonstrating the models had some clinical generalizability. The Model 1 and Model 2 constructed by LightGBM algorithm showed excellent ability in differential diagnosis of SMPP and risk prediction of organ damage in children.

Rapid detection of Mycoplasma pneumoniae CARDS toxin in clinical respiratory specimens by a loop-mediated isothermal amplification assay

In light of the absence of rapid and precise diagnostic laboratory tests for the detection of Mycoplasma pneumoniae (MP), a prominent etiological agent implicated in a range of respiratory infections, we developed and evaluated a rapid and straightforward loop-mediated isothermal amplification (LAMP) assay targeting the MP community-acquired respiratory distress syndrome toxin (CARDS TX) gene. The LAMP assay was performed at 65°C for a duration of 60 min, yielding a minimum detection concentration of MP CARDS TX at 0.4986 pg/μl. The assay exhibited no cross-reactivity with 13 other prevalent pathogens associated with respiratory infections or with other common bacterial toxin genes. To further substantiate the validity of the LAMP assay, 200 pharyngeal swabs or bronchoalveolar lavage (BAL) samples were collected from inpatients diagnosed with community-acquired pneumonia (CAP) between June 2021 and July 2022. The results were compared with those obtained by the quantitative real-time polymerase chain reaction (qPCR) method for verification purposes. Of the 200 clinical specimens, 11 exhibited positive results for MP by LAMP and 10 displayed positive results for MP by qPCR (P = 1.000). In summary, a sensitive, specific, straightforward, and expeditious LAMP method for CARDS TX identification was developed to facilitate rapid detection of MP in point-of-care settings. This assay enables early and accurate diagnosis, even in resource-limited environments, which is important for proper antibiotic treatment and prognosis of MP infection.

Macrolide resistance in Mycoplasma pneumoniae in adult patients

Mycoplasma pneumoniae is one of the most significant pathogens responsible for respiratory infections in humans. Macrolides are recommended as the first-line treatment for M. pneumoniae infection. The prevalence of macrolide-resistant M. pneumoniae has increased significantly in recent decades, particularly in China. The mechanisms of resistance in M. pneumoniae to macrolides have been extensively studied in pediatric patients. However, a paucity reports regarding the resistance characteristics and mechanisms exhibited in adults. The aim of this study was to elucidate the resistance of M. pneumoniae to macrolides and the underlying mechanisms in adult patients. Pharyngeal swab specimens were collected from adult patients presenting with subacute cough or community-acquired pneumonia at our hospital from January 2011 to June 2017 to identify and isolate M. pneumoniae strains. The antimicrobial susceptibility of these isolates to 3 macrolide antibiotics was assessed using broth microdilution method. The 23S rRNA genes of macrolide-resistant M. pneumoniae strains were sequenced, and the presence of target methylation genes (ermA, ermB, and ermC), efflux pump genes (mefA, mefA/E, msrA, and msrA/B), and the macrolide resistance gene mphC was identified through polymerase chain reaction (PCR) testing. Additionally, MICs were determined with and without the efflux pump inhibitor reserpine. A total of 72 M. pneumoniae strains were isolated from adult patients, with 41.7% (30/72) exhibiting macrolide resistance. Among the 3 macrolides tested, the 16-membered-ring midecamycin exhibited the greatest activity (MIC90: 16 µg/ml) against M. pneumoniae. All macrolide-resistant M. pneumoniae strains harbored mutations at the 2063 site in domain V of the 23S rRNA gene. Two macrolide-resistant M. pneumoniae clinical isolates were found to harbor the efflux pump genes msrA/B and mefA. The efflux pump inhibitor reserpine reduced the MIC for azithromycin in these two strains to a quarter of their original values. In summary, macrolide-resistant M. pneumoniae is commonly observed among adults in Beijing. Point mutations are the primary mechanism responsible for macrolide resistance in adults with M. pneumoniae. Additionally, the efflux pump mechanism may contribute partially to this resistance. Midecamycin presents a promising alternative drug for treating M. pneumoniae infections, particularly in cases of azithromycin-resistant M. pneumoniae infection in young children.

Mycoplasma pneumoniae MPN606 induces inflammation by activating MAPK and NF-κB signaling pathways

Mycoplasma pneumoniae (M. pneumoniae) is one of the major pathogens causing community-acquired pneumonia (CAP), and its pathogenic mechanism is not fully understood. Inflammatory response is the most basic and common pathological phenomenon of CAP, but the specific mechanism needs further investigation. In this study, the inflammatory action of M. pneumoniae MPN606 protein was confirmed and its molecular mechanism was tentatively investigated. Compared with the control group treated with PBS, stimulation of RAW264.7 cells with rMPN606 can promote the release of NO, increase the expression level of TNF-α and IL⁃6 cytokines, and up-regulate the mRNA transcription levels of iNOS, IL-6 and TNF-α in RAW264.7 cells. In addition, rMPN606 also significantly induced the expression of iNOS protein in RAW264.7 cells, resulting in increased phosphorylation levels of p65, p38 and ERK proteins. The results of cellular immunofluorescence showed that NF-κB was transferred from cytoplasm to nucleus of RAW264.7 cells after stimulation with rMPN606, and nuclear translocation of NF-κB was significantly enhanced. These results indicate that Mycoplasma pneumoniae MPN606 induces M1-type activation of macrophages and secretes pro-inflammatory factors by activating NF-κB and MAPK pathways.

Detection of macrolide-resistant Mycoplasma pneumoniae using the Kogene Mp-DR real-time PCR assay: A clinical validation study

Macrolide-resistant Mycoplasma pneumoniae (MRMP) requires rapid diagnosis. The Kogene Mp-DR real-time PCR assay showed 100 % sensitivity and specificity for detecting A2063G mutations in the 23S rRNA gene. Although no samples were A2064G-positive, all wild-type cases were accurately classified, highlighting the rapid diagnostic capability of this method for MRMP detection.

P1 adhesin genotype characteristics of Mycoplasma pneumoniae in China from 2017 to 2019

Introduction

Mycoplasma pneumoniae is one of the important pathogens of community-acquired pneumonia (CAP), and P1 adhesin serves as a pathogenic protein and an immune protein involved in the pathogenesis of mycoplasma pneumoniae. The aim of this study was to investigate the P1 adhesin genotype in Mycoplasma pneumoniae and its association with disease severity in patients with CAP from 2017 to 2019.

Methods

M. pneumoniae was identified in patient samples by real-time quantitative polymerase chain reaction (qPCR). The P1 genotypes of samples were determined using a culture-independent P1 typing method.

Results

In total, 1,907 clinical samples were collected from 13 tertiary hospitals in Beijing, Shenyang, and Baotou, including 1488 samples from children and 419 from adults. Of these, 820 samples (43.00%), including 777 from children and 43 from adults, were positive for M. pneumoniae. 797 samples were successfully typed using the culture-independent P1 typing method (P1-1, 605; P1- 2, 192). The M. pneumoniae detection rate and P1-1 detection rate differed significantly between children and adults (both p < 0.01), with P1-1 remaining the dominant genotype. The proportion of P1-2 samples increased in children from 16.75% in 2017 to 28.76% in 2019.

Discussion

No relationship between the P1 genotype and disease severity was identified. Monitoring the genotype changes of P1 adhesin in local populations may positively impact the epidemiological prevention and control of M. pneumoniae infections.

Comparison of the epidemiological characteristics of mycoplasma pneumoniae infections among children during two epidemics in Wuhan from 2018 to 2024

BACKGROUND

Mycoplasma pneumoniae (M pneumoniae, MP) is a common pathogen causing respiratory tract infections, particularly in children. In 2023, a resurgence of MP epidemics was observed in Wuhan, Hubei Province, China. This study aims to examine the epidemiological trends and clinical characteristics of MP infections among children in Wuhan from 2018 to 2024, providing valuable scientific evidence to guide local prevention strategies.

METHODS

From January 1, 2018, to June 30, 2024, samples were collected from children under 14 years with Acute Respiratory Tract Infections (ARTI) at Renmin Hospital of Wuhan University. MP infections were diagnosed through MP-IgM antibody detection and MP-DNA detection. Results were analyzed and compared across distinct epidemic periods.

RESULTS

Of the 183 626 ARTI children, 57 393 (31.26%) tested positive for MP, with an average age of 4.87 ± 2.99 years and a male-to-female ratio of 1.12:1. The annual positive rates from 2018 to 2024 were 45.92%, 32.23%, 22.84%, 16.22%, 16.26%, and 42.93%, respectively. Across the study period, the highest positive rate was recored in autumn (35.13%, P < 0.05). Two distinct MP outbreaks were identified, in 2018-2019 and 2023. Significant differences were observed between the two outbreaks. The 2018-2019 epidemic peaked in summer, while the 2023 epidemic peaked in November and persisted into February 2024. By age, the 2018-2019 outbreaks predominantly affected pre-school children, whereas the 2023 outbreaks mainly involved school-aged children. In boths outbreaks, girls had higher positive rates. Antibody and DNA testing results followed similar trends.

CONCLUSION

This study highlights the epidemiological trends and clinical characteristics of MP infections in Wuhan from 2018 to 2024, including two distinct outbreaks with differing seasonal patterns. The MP strain in 2023 appeared to predominantly affect older children.The trends observed suggest that MP infections may persist into the winter of 2024. Enhanced surveillance of respiratory pathogens and early diagnosis and prevention of MP infections in children remain critical in this region.

A diagnostic host-specific transcriptome response for Mycoplasma pneumoniae pneumonia to guide pediatric patient treatment

Mycoplasma pneumoniae causes atypical pneumonia in children and young adults. Its lack of a cell wall makes it resistant to beta-lactams, which are the first-line treatment for typical pneumonia. Current diagnostic tests are time-consuming and have low specificity, leading clinicians to administer empirical antibiotics. Using a LASSO regression simulation approach and blood microarray data from 107 children with pneumonia (including 30 M. pneumoniae) we identify eight different transcriptomic signatures, ranging from 3-10 transcripts, that differentiate mycoplasma pneumonia from other bacterial/viral pneumonias with high accuracy (AUC: 0.84-0.95). Additionally, we demonstrate that existing signatures for broadly distinguishing viral/bacterial infections and viral/bacterial pneumonias are ineffective in distinguishing M. pneumoniae from viral pneumonia. The new signatures are successfully validated in an independent RNAseq cohort of children with pneumonia, demonstrating their robustness. The high sensibility of these signatures presents a valuable opportunity to guide the treatment and management of M. pneumoniae pneumonia patients.

Description of a Current Outbreak of Mycoplasma pneumoniae in the United States

During the COVID-19 pandemic, a significant decline in Mycoplasma pneumoniae was observed; however, M. pneumoniae re-emerged globally in 2023. Here, we describe a current outbreak of M. pneumoniae infections in the United States (US). More than 287 million patient records from all 50 states in the US were reviewed to identify patients with a M. pneumoniae diagnosis between 1 January 2017 and 30 September 2024. A c-chart was created by calculating the mean and standard error (SE) of cases during the pre-COVID-19 pandemic period, with the upper control limit (UCL) set at 3 SE above the mean. The presence of an outbreak was defined as counts above the UCL. Cumulative excess cases were used to estimate the magnitude of the outbreak, and the fold increase was calculated. A US outbreak of M. pneumoniae began at the end of 2023, resulting in 9708 excess cases corresponding to a 9.0-fold increase over the baseline UCL. The outbreak is ongoing, affects both children and adults, and includes patients with M. pneumoniae community-acquired pneumonia requiring hospitalization. This US outbreak of M. pneumoniae has significant implications for the management of patients with respiratory infections during the current pneumonia season.

Evaluating the effectiveness of different intervention measures for an outbreak of mycoplasma pneumoniae in hangzhou based on a dynamic model

For Mycoplasma pneumoniae (MP) infection in schools, the local Center for Disease Control and Prevention recommends nonpharmaceutical interventions, such as case isolation, school closures, suspension of group activities, reinforcement of ventilation and disinfection for influenza outbreaks. However, there is limited evidence supporting and evaluating the effectiveness of these interventions. On the basis of an outbreak of MP infection occurring in a primary school in Zhejiang Province, a susceptible-latent-overt infected-recessive infected-displaced (SEIAR) model was constructed to quantitatively evaluate the prevention and control effects by simulating the intervention measures mentioned above. With no intervention, the outbreak lasted 143 days, and the total attack rate (TAR) and total infection rate (TIR) reached 75.78% and 95.65%, respectively. The most effective single-intervention strategy was ventilation and disinfection (VD), with a TAR as low as 15.81% and a duration of outbreak (DO) of 61 days. The two- or three- combined intervention strategies, including all combinations with 90% VD, were more effective than the single-intervention strategy. In conclusion, the SEIAR model could effectively simulate the epidemic situation of MP and the intervention effect. For the outbreak of MP, the earlier comprehensive measures were taken, such as ventilation and disinfection, and case isolation, the better control effect would be.

Changes in the Levels of the Serum Markers Serum Amyloid A and Immunoglobulin M in Children with Mycoplasma pneumoniae Infection Complicated with Asthma and Their Clinical Significance

Asthma represents a chronic disorder with aberrant immunological and inflammatory responses. We analyzed the levels and clinical significance of serum markers serum amyloid A (SAA) and immunoglobulin M (IgM) in Mycoplasma pneumoniae (MP)-infected children with asthma. MP-infected children were allocated into the Asthma (n = 64) and N-Asthma (n = 104) groups, with baseline information collected. Levels of IgE, c-reactive protein, procalcitonin, lactate dehydrogenase, aspartate aminotransferase, interleukin-4/interferon-γ (IL-4/IFN-γ), transforming growth factor β1 (TGF-β1), SAA and IgM were determined by ELISA. Tidal breathing lung function [inspiratory time (TI), expiratory time (TE), inspiratory volume (V-TI), expiratory volume (V-TE), tidal volume (VT) and respiratory rate (RR)] was assessed using a pulmonary function instrument. The relationship of serum SAA and IgM with IgE, IL-4/IFN-γ, TGF-β1, and tidal breathing lung function in MP-infected asthmatic children, and their diagnostic value for asthma occurrence in MP-infected children were analyzed by Spearman analysis and receiver operating characteristic curve. IgE, V-TI, V-TE, VT, IL-4/IFN-γ, TGF-β1, SAA and IgM indexes in MP-infected asthmatic children surpassed those without asthma. Serum SAA and IgM significantly positively correlated with IgE, IL-4/IFN-γ, TGF-β1, V-TI, V-TE and VT, which had certain diagnostic value for asthma in MP-infected children. The incidence of asthma was higher in MP-infected children with high SAA and IgM expression levels. The diagnostic efficacy of SAA and IgM combined test surpassed single detection. Serum SAA and IgM were highly expressed in MP-infected asthmatic children, and their combined detection had high diagnostic value for asthma in MP-infected children.

Pulmonary thromboembolism due to Mycoplasma pneumoniae in children: a case report and literature review

BACKGROUND

Mycoplasma pneumoniae (MP) is a common respiratory pathogen in children that can sometimes lead to extrapulmonary manifestations. Among these, pediatric pulmonary thromboembolism (PE) is clinically rare but carries significant implications. However, it is often underrecognized, and its diagnosis and treatment are not well understood.

CASE PRESENTATION

We report a case of PE associated with MP pneumonia in a 6-year-old girl who presented with recurrent hyperpyrexia, cough, extensive consolidation in the upper lobe of the left lung, and pulmonary artery thrombi in the right lung. Following prompt diagnosis of PE and appropriate antibiotic therapy combined with anticoagulation treatment, the child recovered well and remained healthy at follow-up. The diagnostic and treatment processes were analyzed, and previously reported cases of pediatric MP-related PE were reviewed.

CONCLUSION

PE should be considered in pediatric patients with MP pneumonia who do not improve or whose condition worsens despite standard therapy. The outcomes of pediatric MP-related PE are generally favorable if prompt diagnosis and appropriate treatment are provided.

Reviewing advancement in Mycoplasma pneumoniae P30 adhesin protein provides insights for future diagnosis and treatment

Mycoplasma pneumoniae is a major pathogen that causes upper and lower respiratory tract infections in children, adolescents, and elderly individuals and can lead to pneumonia, intrapulmonary and extrapulmonary complications, and respiratory sequelae. M. pneumoniae must adhere to respiratory epithelial cells of a host for infection. The P1 and P30 proteins, as two adhesin proteins of M. pneumoniae, have attracted extensive attention from many researchers. In this paper, we present the latest research progress on the P30 protein in terms of structure and mutation typing, physiological function, clinical serological diagnosis and vaccine development in a literature review. This study deepens our knowledge on the pathogenesis of M. pneumoniae and is useful for diagnosing and preventing M. pneumoniae infection.

Understanding serum inflammatory markers in pediatric Mycoplasma pneumoniae pneumonia

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

Epidemic features and megagenomic analysis of childhood Mycoplasma pneumoniae post COVID-19 pandemic: a 6-year study in southern China

With the atypical rise of Mycoplasma pneumoniae infection (MPI) in 2023, prompt studies are needed to determine the current epidemic features and risk factors with emerging trends of MPI to furnish a framework for subsequent investigations. This multicentre, retrospective study was designed to analyse the epidemic patterns of MPI before and after the COVID-19 pandemic, as well as genotypes and the macrolide-resistance-associated mutations in MP sampled from paediatric patients in Southern China. Clinical data was collected from 1,33,674 patients admitted into investigational hospitals from 1 June 2017 to 30 November 2023. Metagenomic next-generation sequencing (mNGS) data were retrieved based on MP sequence positive samples from 299 paediatric patients for macrolide-resistance-associated mutations analysis. Pearson's chi-squared test was used to compare categorical variables between different time frames. The monthly average cases of paediatric common respiratory infection diseases increased without enhanced public health measures after the pandemic, especially for influenza, respiratory syncytial virus infection, and MPI. The contribution of MPI to pneumoniae was similar to that in the outbreak in 2019. Compared to mNGS data between 2019-2022 and 2023, the severity of MP did not grow stronger despite higher rates of macrolide-resistance hypervariable sites, including loci 2063 and 2064, were detected in childhood MP samples of 2023. Our findings indicated that ongoing surveillance is necessary to understand the impact of post pandemic on MP transmission disruption during epidemic season and the severity of clinical outcomes in different scenarios.

Mycoplasma pneumoniae at the rise not only in China: rapid increase of Mycoplasma pneumoniae cases also in Spain

After the use of facemasks, other isolation measures enacted during the SARS-CoV-2 pandemic were lifted, respiratory pathogens, such as RSV, reappeared, but until the November 2023 WHO alert for China, M. pneumoniae had virtually disappeared. After observing a similar reappearance in our hospital, a retrospective analysis of the number of positive M. pneumoniae tests. Between 2018 and December 2023, 1619 PCR tests were ordered and 43 (2.6%) of them were positive. Two outbreaks, one in 2018 and one in 2023, accounted for the majority of cases. Tests were usually ordered in an outpatient setting (53.54%, n = 23) and most of them were paediatric patients with a mean age (sd) of 10.2 (6.2) years. As for the severity of the cases, in the 2018 outbreak, of 15 children who tested positive, 53.3% (n = 8) were admitted to the ward and 6.7% (n = 1) at the intensive care unit. Whereas in 2023, 2 patients were tested in the ward (10.5%) and one in the intensive care unit (5.2%) from a total of 19 patients. The positive rate in 2023 was significantly higher in comparison with years 2020, 2021 and 2022 and significantly lower in comparison with 2018 (P-value=0.003). The outbreak in late 2023 can be explained by the seasonality of Mycoplasma pneumonia alone, which has shown outbreaks every 3-5 years, and it does not appear to be more severe than the previous one.

Hemolysis due to anti-IH in a patient with beta-thalassemia and Mycoplasma pneumoniae infection

Anti-IH is a common cold agglutinin that is typically clinically insignificant. We present a case that resulted in hemolysis. A 32-year-old male patient with transfusion-independent beta-thalassemia intermedia presented with symptomatic anemia. His blood sample typed as group B, D+ and demonstrated multiple alloantibodies and cold autoantibodies. He was transfused uneventfully, but re-presented 10 days later with recurrent, worsening anemia. At this time, transfusion of group O, phenotype-matched red blood cells (RBCs) resulted in an acute hemolytic reaction. While anemia was initially attributed to drug-mediated bone marrow toxicit y and subsequently to a delayed hemolytic reaction, further evaluation revealed Mycoplasma pneumoniae infection and a cold agglutinin (anti-IH specificity), indicating a likely autoimmune-mediated anemia due to an infectious etiology. Subsequent transfusion of 2 group B, phenotype-matched RBC units using a blood warmer was uneventful. Anti-IH is only rarely associated with hemolytic transfusion reactions, which may be exacerbated when transfusing group O RBC units to group B patients. M. pneumoniae infection likely led to cold agglutinin-mediated hemolysis of endogenous and transfused RBCs. The patient was successfully managed with intravenous immunoglobulin, steroids, rituximab, erythropoietin, hydroxyurea, and amoxicillin clavulanate/azithromycin. This case illustrates the importance of infectious disease evaluation in patients with unexplained anemia, the potential clinical significance of autoanti-IH, and the value of providing type-specific RBC units in these circumstances.

Integrated structural proteomics and machine learning-guided mapping of a highly protective precision vaccine against mycoplasma pulmonis

Mycoplasma pulmonis (M. pulmonis) is an emerging respiratory infection commonly linked to prostate cancer, and it is classified under the group of mycoplasmas. Improved management of mycoplasma infections is essential due to the frequent ineffectiveness of current antibiotic treatments in completely eliminating these pathogens from the host. The objective of this study is to design and construct effective and protective vaccines guided by structural proteomics and machine learning algorithms to provide protection against the M. pulmonis infection. Through a thorough examination of the entire proteome of M. pulmonis, four specific targets Membrane protein P80, Lipoprotein, Uncharacterized protein and GGDEF domain-containing protein have been identified as appropriate for designing a vaccine. The proteins underwent mapping of cytotoxic T lymphocyte (CTL), helper T lymphocyte (HTL) (IFN)-γ ±, and B-cell epitopes using artificial and recurrent neural networks. The design involved the creation of mRNA and peptide-based vaccine, which consisted of 8 CTL epitopes associated by GGS linkers, 7 HTL (IFN-positive) epitopes, and 8 B-cell epitopes joined by GPGPG linkers. The vaccine designed exhibit antigenic behavior, non-allergenic qualities, and exceptional physicochemical attributes. Structural modeling revealed that correct folding is crucial for optimal functioning. The coupling of the MEVC and Toll-like Receptors (TLR)1, TLR2, and TLR6 was examined through molecular docking experiments. This was followed by molecular simulation investigations, which included binding free energy estimations. The results indicated that the dynamics of the interaction were stable, and the binding was strong. In silico cloning and optimization analysis revealed an optimized sequence with a GC content of 49.776 % and a CAI of 0.982. The immunological simulation results showed strong immune responses, with elevated levels of active and plasma B-cells, regulatory T-cells, HTL, and CTL in both IgM+IgG and secondary immune responses. The antigen was completely cleared by the 50th day. This study lays the foundation for creating a potent and secure vaccine candidate to combat the newly identified M. pulmonis infection in people.

Molecular basis of bacterial lectin recognition of eukaryotic glycans: The case of Mycoplasma pneumoniae and Mycoplasma genitalium cytoadhesins

Mycoplasma pneumoniae and Mycoplasma genitalium are two emerging bacterial pathogens that colonize the human respiratory and urogenital epithelia, respectively. Both pathogens express cell surface cytoadhesins that play a crucial role in the interaction with the host, mediating the attachment to sialylated glycan receptors and triggering infection. The design of competitive binding inhibitors of Mycoplasma cytoadhesins has potential to disrupt these interactions and lessen bacterial pathogenesis. To this end, we report here molecular insights into the adhesion mechanisms of M. pneumoniae and M. genitalium, which are largely mediated by sialylated glycans on the host cell surface. In detail, a combination of Nuclear Magnetic Resonance (NMR) spectroscopy, fluorescence analysis and computational studies allowed us to explore the recognition by the cytoadhesins P40/P90 in M. pneumoniae and P110 in M. genitalium of sialylated N- and O-glycans. We reveal that, unlike other bacterial adhesins, which are characterized by a wide binding pocket, Mycoplasma cytoadhesins principally accommodate the sialic acid residue, in a similar manner to mammalian Siglecs. These findings represent crucial insight into the future development of novel compounds to counteract Mycoplasma infections by inhibiting bacterial adherence to host tissues.

New Insights into the Epidemiological Characteristics of Mycoplasma pneumoniae Infection before and after the COVID-19 Pandemic

Mycoplasma pneumoniae (M. pneumoniae), a prevalent respiratory pathogen affecting children and adolescents, is known to trigger periodic global epidemics. The most recent significant outbreak commenced in the first half of 2023 and reached its peak globally during the autumn and winter months. Considering the worldwide repercussions of the COVID-19 pandemic, it has become increasingly essential to delve into the epidemiological characteristics of M. pneumoniae both before and after the pandemic. This review aims to provide a comprehensive analysis of the key features of M. pneumoniae epidemics in the pre-and post-COVID-19 contexts, including but not limited to shifts in the susceptible population, the molecular genotypes of the pathogen, the clinical manifestations, and potential new trends in drug resistance. Additionally, we will introduce the latest advancements in the diagnosis of M. pneumoniae.

A comprehensive review of Mycoplasma pneumoniae infection in chronic lung diseases: recent advances in understanding asthma, COPD, and bronchiectasis

This review summarizes the research progress over the past 30 years on the relationship between Mycoplasma pneumoniae infection and chronic respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and bronchiectasis. Mycoplasma pneumoniae is a common cause of community-acquired pneumonia, particularly in children and young adults. Key findings from recent studies indicate that M. pneumoniae infection is associated with a higher risk of asthma exacerbations and may contribute to the development of bronchiectasis in susceptible individuals. Additionally, emerging evidence suggests that M. pneumoniae-induced immune dysregulation plays a crucial role in the pathogenesis of chronic lung diseases. This review aims to summarize the current understanding of the potential links between M. pneumoniae pneumonia and various chronic respiratory conditions, including asthma, chronic obstructive pulmonary disease (COPD), and bronchiectasis. We discuss the epidemiological data, pathogenic mechanisms, clinical manifestations, and long-term consequences of M. pneumoniae-related respiratory illnesses. Additionally, we highlight the challenges in diagnosis and treatment, as well as future research directions in this field.

Expert consensus on the diagnosis and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is a significant contributor to community-acquired pneumonia among children. Since 1968, when a strain of M. pneumoniae resistant to macrolide antibiotics was initially reported in Japan, macrolide-resistant M. pneumoniae (MRMP) has been documented in many countries worldwide, with varying incidence rates. MRMP infections lead to a poor response to macrolide antibiotics, frequently resulting in prolonged fever, extended antibiotic treatment, increased hospitalization, intensive care unit admissions, and a significantly higher proportion of patients receiving glucocorticoids or second-line antibiotics. Since 2000, the global incidence of MRMP has gradually increased, especially in East Asia, which has posed a serious challenge to the treatment of M. pneumoniae infections in children and attracted widespread attention from pediatricians. However, there is still no global consensus on the diagnosis and treatment of MRMP in children.

METHODS

We organized 29 Chinese experts majoring in pediatric pulmonology and epidemiology to write the world's first consensus on the diagnosis and treatment of pediatric MRMP pneumonia, based on evidence collection. The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, CNKI, Medline, and the Cochrane Library. We used variations in terms for "macrolide-resistant", "Mycoplasma pneumoniae", "MP", "M. pneumoniae", "pneumonia", "MRMP", "lower respiratory tract infection", "Mycoplasma pneumoniae infection", "children", and "pediatric".

RESULTS

Epidemiology, pathogenesis, clinical manifestations, early identification, laboratory examination, principles of antibiotic use, application of glucocorticoids and intravenous immunoglobulin, and precautions for bronchoscopy are highlighted. Early and rapid identification of gene mutations associated with MRMP is now available by polymerase chain reaction and fluorescent probe techniques in respiratory specimens. Although the resistance rate to macrolide remains high, it is fortunate that M. pneumoniae still maintains good in vitro sensitivity to second-line antibiotics such as tetracyclines and quinolones, making them an effective treatment option for patients with initial treatment failure caused by macrolide antibiotics.

CONCLUSIONS

This consensus, based on international and national scientific evidence, provides scientific guidance for the diagnosis and treatment of MRMP in children. Further studies on tetracycline and quinolone drugs in children are urgently needed to evaluate their effects on the growth and development. Additionally, developing an antibiotic rotation treatment strategy is necessary to reduce the prevalence of MRMP strains.

Yinqin Qingfei granules alleviate Mycoplasma pneumoniae pneumonia via inhibiting NLRP3 inflammasome-mediated macrophage pyroptosis

Background

Mycoplasma pneumoniae pneumonia (MPP) is a prevalent respiratory infectious disease in children. Given the increasing resistance of M. pneumoniae (MP) to macrolide antibiotics, the identification of new therapeutic agents is critical. Yinqin Qingfei granules (YQQFG), a Chinese patent medicine formulated specifically for pediatric MPP, lacks a clear explanation of its mechanism.

Methods

The primary components of YQQFG were identified using LC-MS/MS. In vitro, RAW264.7 cells infected with MP underwent morphological examination via scanning electron microscopy. Drug-containing serum was prepared, and its intervention concentration was determined using the CCK-8 assay. The active components of YQQFG were molecularly docked with NLRP3 protein using Autodock Vina software. A RAW264.7 cell line overexpressing NLRP3 was created using lentivirus to pinpoint the target of YQQFG. In vivo, MPP model mice were established via nasal instillation of MP. Lung damage was assessed by lung index and H&E staining. Pyroptosis-associated protein levels in cells and lung tissue were measured by western blot, while interleukin (IL)-1β and IL-18 levels in cell supernatants and mouse serum were quantified using ELISA. Immunofluorescence double staining of lung tissue sections was conducted to assess the correlation between NLRP3 protein expression and macrophages. The expression of the community-acquired respiratory distress syndrome toxin (CARDS TX) was evaluated by qPCR.

Results

25 effective components with favorable oral bioavailability were identified in YQQFG. Both in vitro and in vivo studies demonstrated that YQQFG substantially reduced the expression of the NLRP3/Caspase-1/GSDMD pathway, decreasing the release of IL-1β and IL-18, and inhibited MP exotoxin. Molecular docking indicated strong affinity between most YQQFG components and NLRP3 protein. Lentivirus transfection and immunofluorescence double staining confirmed that YQQFG significantly suppressed NLRP3 expression in macrophages, outperforming azithromycin (AZM). The combination of YQQFG and AZM yielded the optimal therapeutic effect for MPP.

Conclusion

YQQFG mitigates inflammatory responses by suppressing NLRP3 inflammasome-mediated macrophage pyroptosis, thereby ameliorating MP-induced acute lung injury. YQQFG serves as an effective adjunct and alternative medication for pediatric MPP treatment.

Mycoplasma pneumoniae infection outbreak in Guangzhou, China after COVID-19 pandemic

BACKGROUNDS

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen causing respiratory diseases in children. This study aimed to characterize epidemiological and disease severity shifts of M. pneumoniae: infections in Guangzhou, China during and after the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

Throat swab samples were obtained from 5405 hospitalized patients with symptoms of acute respiratory infections to detect M. pneumoniae. Differences in epidemiological and clinical characteristics of M. pneumoniae: infections were investigated during 2020-2022 and after COVID-19 pandemic (2023).

RESULTS

M. pneumoniae were detected in 849 (15.6%, 849/5405) patients. The highest annual positive rate was 29.4% (754/2570) in 2023, followed by 5.3% (72/1367) in 2022, 1.2% (12/1015) in 2021, and 2.0% (11/553) in 2020, with significantly increasing annual prevalence from 2020 to 2023. M. pneumoniae incidence peaked between July and December post-COVID-19 pandemic in 2023, with the highest monthly positive rate (56.4%, 165/293). Clinical characteristics and outcomes of patients with M. pneumoniae did not vary between periods during and after COVID-19 pandemic except that patients with M. pneumoniae post-COVID-19 pandemic were more likely to develop fever. Patients with severe M. pneumoniae pneumonia (SMPP) were more likely to develop respiratory complications, myocardial damage, and gastrointestinal dysfunction than those with non-SMPP. Patients with SMPP had lower lymphocytes, CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells, and higher IL-4, IL-6, IL-10 levels than those with non-SMPP. Bronchoalveolar lavage fluid specimens from infected patients were obtained to identify macrolide resistance mutations. Macrolide-resistant M. pneumoniae (MRMP) proportion in 2023 was 91.1% (215/236).

CONCLUSION

Outbreaks of M. pneumoniae: occurred in Guangzhou, China in 2023 upon Non-pharmaceutical interventions easing. Despite the increasing incidence of M. pneumoniae, the disease severity remained similar during and after the COVID-19 pandemic.

Application of LAMP coupled with NALF for precise detection of mycoplasma pneumoniae

Mycoplasma pneumoniae (MP),as the most commonly infected respiratory pathogen in community-acquired pneumonia in preschool children,has becoming a prominent factor affecting children's respiratory health.Currently, there is a lack of easy, rapid, and accurate laboratory testing program for MP infection, which causes comparatively difficulty for clinical diagnostic.Here,we utilize loop-mediated isothermal amplification (LAMP) to amplify and characterize the P1 gene of MP, combined with nucleic acid lateral flow (NALF) for fast and visuallized detection of MP.Furthermore, we evaluated and analyzed the sensitivity, specificity and methodological consistency of the method.The results showed that the limit of detection(LoD) of MP-LAMP-NALF assay was down to 100 copys per reaction and there was no cross-reactivity with other pathogens infected the respiratory system. The concordance rate between MP-LAMP-NALF assay with quantitative real-time PCR was 94.3 %,which exhibiting excellent testing performance.We make superior the turnaround time of the MP-LAMP-NALF assay, which takes only about 50 min. In addition, there is no need for precision instruments and no restriction on the laboratory site.Collectively, LAMP-NALF assay targeting the P1 gene for Mycoplasma pneumoniae detection was a easy, precise and visual test which could be widely applied in outpatient and emergency departments or primary hospitals.When further optimized, it could be used as "point-of-care testing" of pathogens or multiple testing for pathogens.

Age-related effects of Mycoplasma pneumoniae infection and subsequent asthma exacerbation in children

BACKGROUND

Mycoplasma pneumoniae causes community-acquired pneumonia in children and increases asthma risk, but large studies are lacking.

OBJECTIVE

To assess the link between M. pneumoniae infection and to asthma exacerbation, in children with allergies, and age of infection impact.

METHODS

This retrospective cohort study analyzed medical records of South Korean children between January 2002 and December 2017. The study's exposure was hospitalization with an M. pneumoniae-related diagnosis, and the outcome was defined as asthma exacerbation, confirmed by hospitalization at least 6 months after M. pneumoniae infection, with alternative validation using asthma diagnosis and systemic steroid prescription records. Hazard ratios (HRs) for asthma exacerbation risk were estimated for the matched cohort using a Cox proportional hazards model stratified by allergic comorbidities. Time-dependent covariates and age-stratified exposure groups were used to calculate odds ratios.

RESULTS

The study included 84,074 children with M. pneumoniae infection and 336,296 unexposed children. Follow-up for 12.2 ± 2.3 years found the exposed group had a significant risk of asthma exacerbation (HR 2.86, 95% confidence interval [CI] 2.67-3.06) regardless of allergic comorbidities. The risk was highest (over threefold) in children infected between 24 and 71 months. Sensitivity analysis using an alternative definition of the outcome showed an HR of 1.38 (95% CI 1.35-1.42), further supporting the association between M. pneumoniae infection and asthma exacerbation.

CONCLUSION

M. pneumoniae infection was significantly associated with an increased risk of subsequent asthma exacerbation regardless of allergic comorbidities. Further research needed for understanding and confirmation.

Macrolide resistance of Mycoplasma pneumoniae in several regions of China from 2013 to 2019

This paper retrospectively analysed the prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) in some parts of China. Between January 2013 and December 2019, we collected 4,145 respiratory samples, including pharyngeal swabs and alveolar lavage fluid. The highest PCR-positive rate of M. pneumoniae was 74.5% in Beijing, the highest resistance rate was 100% in Shanghai, and Gansu was the lowest with 20%. The highest PCR-positive rate of M. pneumoniae was 74.5% in 2013, and the highest MRMP was 97.4% in 2019; the PCR-positive rate of M. pneumoniae for adults in Beijing was 17.9% and the MRMP was 10.48%. Among the children diagnosed with community-acquired pneumonia (CAP), the PCR-positive and macrolide-resistant rates of M. pneumoniae were both higher in the severe ones. A2063G in domain V of 23S rRNA was the major macrolide-resistant mutation, accounting for more than 90%. The MIC values of all MRMP to erythromycin and azithromycin were ≥ 64 μg/ml, and the MICs of tetracycline and levofloxacin were ≤ 0.5 μg/ml and ≤ 1 μg/ml, respectively. The macrolide resistance varied in different regions and years. Among inpatients, the macrolide-resistant rate was higher in severe pneumonia. A2063G was the common mutation, and we found no resistance to tetracycline and levofloxacin.

Research on the metabolic regulation mechanism of Yangyin Qingfei decoction plus in severe pneumonia caused by Mycoplasma pneumoniae in mice

Introduction: With amazing clinical efficacy, Yangyin Qingfei Decoction Plus (YQDP), a well-known and age-old Chinese compound made of ten Chinese botanical drugs, is utilized in clinical settings to treat a range of respiratory conditions. This study examines the impact of Yangyin Qingfei Decoction (YQDP) on lung tissue metabolic products in severe Mycoplasma pneumoniae pneumonia (SMPP) model mice and examines the mechanism of YQDP in treating MP infection using UPLC-MS/MS technology. Methods: YQDP's chemical composition was ascertained by the use of Agilent 1260 Ⅱ high-performance liquid chromatography. By using a nasal drip of 1010 CCU/mL MP bacterial solution, an SMPP mouse model was created. The lung index, pathology and ultrastructural observation of lung tissue were utilized to assess the therapeutic effect of YQDP in SMPP mice. Lung tissue metabolites were found in the normal group, model group, and YQDP group using UPLC-MS/MS technology. Using an enzyme-linked immunosorbent test (ELISA), the amount of serum inflammatory factors, such as interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α), was found. Additionally, the protein expression of PI3K, P-PI3K, AKT, P-AKT, NF-κB, and P-NF-κB was found using Western blot. Results: The contents of chlorogenic acid, paeoniflorin, forsythrin A, forsythrin, and paeonol in YQDP were 3.480 ± 0.051, 3.255 ± 0.040, 3.612 ± 0.017, 1.757 ± 0.031, and 1.080 ± 0.007 mg/g respectively. YQDP can considerably lower the SMPP mice's lung index (p < 0.05). In the lung tissue of YQDP groups, there has been a decrease (p < 0.05) in the infiltration of inflammatory cells at varying concentrations in the alveoli compared with the model group. A total of 47 distinct metabolites, including choline phosphate, glutamyl lysine, L-tyrosine, 6-thioinosine, Glu Trp, 5-hydroxydecanoate, etc., were linked to the regulation of YQDP, according to metabolomics study. By controlling the metabolism of porphyrins, pyrimidines, cholines, fatty acids, sphingolipids, glycerophospholipids, ferroptosis, steroid hormone biosynthesis, and unsaturated fatty acid biosynthesis, enrichment analysis suggested that YQDP may be used to treat SMPP. YQDP can lower the amount of TNF-α and IL-6 in model group mice as well as downregulate P-PI3K, P-AKT, and P-NF-κB expression (p < 0.05). Conclusion: A specific intervention effect of YQDP is observed in SMPP model mice. Through the PI3K/Akt/NF-κB signaling pathways, YQDP may have therapeutic benefits by regulating the body's metabolism of α-Linoleic acid, sphingolipids, glycerophospholipids, arachidonic acid, and the production of unsaturated fatty acids.

Correlation of DNA load, genotyping, and clinical phenotype of Mycoplasma pneumoniae infection in children

Introduction

This study aimed to investigate the correlation between Mycoplasma pneumoniae (MP)-DNA load in the bronchoalveolar lavage fluid (BALF) of children with MP pneumonia (MPP) and its subtypes, relevant laboratory data, imaging, extrapulmonary complications in infected children, and its clinical significance in evaluating the disease.

Methods

Children hospitalized with MPP at Tianjin Children's Hospital between December 2017 and December 2020 were selected for the study, excluding those with mixed viral, bacterial, and fungal infections. Children were divided into low- and high-load groups according to the MP DNA load in BALF using real-time quantitative fluorescence polymerase chain reaction (PCR). After a successful MP culture, positive specimens were subjected to PCR-Restriction fragment length polymorphism and Multiple-locus variable number tandem repeat analysis typing. Basic data, clinical information, laboratory data, and radiological results were collected from all children included in the study.

Results

The PI-I type dominated the different load groups. Children in the low-load group had more wheezing and shortness of breath; however, children in the high-load group had a higher length of hospitalization, maximum fever temperature, higher chills/chilliness, incidence of abdominal pain, and higher C-reactive protein (CRP), procalcitonin (PCT) and aspartate aminotransferase (AST) levels. Children in the high-load group were more likely to have imaging changes such as pleural effusion, and the incidence of respiratory infections and extrapulmonary complications was higher than that of those in the low-load group. We applied Spearman's correlation analysis to clarify the relationship between MP DNA load and the clinical severity of MPP. We found that MP DNA load was positively correlated with length of hospitalization, maximum fever temperature, CRP, PCT, Interleukin-6 (IL-6), and AST levels, and negatively correlated with fever and cough durations, white blood cell count (WBC), and proportion of monocytes (MONO). The degree of correlation was as follows: length of hospitalization > IL-6 > cough duration > AST > fever duration > PCT > WBC > proportion of MONO > maximum fever temperature > CRP levels.

Conclusions

MP DNA load was not correlated with MP typing but was significantly correlated with the children's clinical phenotype. Therefore, the MP DNA load helps in the early diagnosis of infection and can better predict disease regression.

Observational retrospective clinical study on clinical features of macrolide-resistant Mycoplasma pneumoniae pneumonia in Chinese pediatric cases

This study aimed to investigate differences in clinical characteristics and laboratory findings between children infected with Macrolide-Sensitive Mycoplasma pneumoniae (MSMP) and Macrolide-Resistant Mycoplasma pneumoniae (MRMP). Additionally, the research sought to identify laboratory markers for rapidly distinguishing refractory Mycoplasma pneumoniae pneumonia (RMPP) from ordinary Mycoplasma pneumoniae pneumonia (OMPP). In total, 265 Mycoplasma pneumoniae (MP) patients were included, with MRMP identified by specific point mutations in domain V of the 23S rRNA gene. A retrospective analysis compared the clinical courses and laboratory data, revealing that MRMP patients experienced prolonged febrile days (P = 0.004), elevated CRP levels (P < 0.001), and higher MP DNA loads than MSMP patients (P = 0.037). Based on clinical symptoms, MRMP was divided into RMPP (n = 56) and OMPP (n = 70), with RMPP demonstrating significantly increased IL-18, community-acquired respiratory distress syndrome (CARDS) toxins in nasopharyngeal aspirate, and serum CRP levels (P < 0.001; P = 0.006; P < 0.001). In conclusion, timely recognition of RMPP is crucial for enhancing prognosis. The identification of MRMP, coupled with proinflammatory cytokines such as IL-18, CARDS toxins, and CRP, emerges as promising markers with the potential to contribute significantly to diagnostic accuracy and prognosis assessment.

Comparison of the clinical characteristics in parents and their children in a series of family clustered Mycoplasma pneumoniae infections

BACKGROUND

Mycoplasma pneumoniae infections have increased in China recently, causing some evidence of familial clustering. The purpose of this study was to compare the clinical features of parents and children in cases of familial clustering of Mycoplasma pneumoniae infection.

METHODS

A retrospective analysis was performed on the cases of familial clustering of Mycoplasma pneumoniae infection, and the clinical characteristics of parents and children were compared.

RESULTS

We identified 63 families, of these, 57 (65.5%) adults and 65 (94.2%) children required hospitalization. Fifty-seven adults (mean age 35.1 ± 4.6 years, 80.7% female) and 55 children (mean age 6.3 ± 3.9 years, 54.5% female) were included in the analysis. The incidence of mycoplasma infection in adults had increased gradually over the past year, while the rate in children had spiked sharply since June 2023. The clinical symptoms were similar in the two groups, mainly fever and cough. The peak temperature of children was higher than that of adults (39.1 ± 0.7℃ vs 38.6 ± 0.7℃, p = 0.004). Elevated lactate dehydrogenase was more common in children than in adults (77.8% vs 11.3%, p < 0.001). Bronchial pneumonia and bilateral involvement were more common in children, while adults usually had unilateral involvement. Three (60%) adults and 21 (52.5%) children were macrolide-resistant Mycoplasma pneumoniae infected. Children were more likely to be co-infected (65.5% vs 22.8%, p < .001). Macrolides were used in most children and quinolones were used in most adults. Ten (18.2%) children were diagnosed with severe Mycoplasma pneumoniae pneumonia, whereas all adults had mild disease. Children had a significantly longer fever duration than adults ((5.6 ± 2.2) days vs (4.1 ± 2.2) days, p = 0.002). No patient required mechanical ventilation or died.

CONCLUSIONS

Mycoplasma pneumoniae infection shows a familial clustering epidemic trend at the turn of summer and autumn, with different clinical characteristics between parents and children.

Association between Mycoplasma pneumoniae infection, high‑density lipoprotein metabolism and cardiovascular health (Review)

The association between Mycoplasma pneumoniae (M. pneumoniae) infection, high-density lipoprotein metabolism and cardiovascular disease is an emerging research area. The present review summarizes the basic characteristics of M. pneumoniae infection and its association with high-density lipoprotein and cardiovascular health. M. pneumoniae primarily invades the respiratory tract and damages the cardiovascular system through various mechanisms including adhesion, invasion, secretion of metabolites, production of autoantibodies and stimulation of cytokine production. Additionally, the present review highlights the potential role of high-density lipoprotein for the development of prevention and intervention of M. pneumoniae infection and cardiovascular disease, and provides suggestions for future research directions and clinical practice. It is urgent to explore the specific mechanisms underlying the association between M. pneumoniae infection, high-density lipoprotein metabolism, and cardiovascular disease and analyze the roles of the immune system and inflammatory response.

Aerobic glycolysis of bronchial epithelial cells rewires Mycoplasma pneumoniae pneumonia and promotes bacterial elimination

The immune response to Mycoplasma pneumoniae infection plays a key role in clinical symptoms. Previous investigations focused on the pro-inflammatory effects of leukocytes and the pivotal role of epithelial cell metabolic status in finely modulating the inflammatory response have been neglected. Herein, we examined how glycolysis in airway epithelial cells is affected by M. pneumoniae infection in an in vitro model. Additionally, we investigated the contribution of ATP to pulmonary inflammation. Metabolic analysis revealed a marked metabolic shift in bronchial epithelial cells during M. pneumoniae infection, characterized by increased glucose uptake, enhanced aerobic glycolysis, and augmented ATP synthesis. Notably, these metabolic alterations are orchestrated by adaptor proteins, MyD88 and TRAM. The resulting synthesized ATP is released into the extracellular milieu via vesicular exocytosis and pannexin protein channels, leading to a substantial increase in extracellular ATP levels. The conditioned medium supernatant from M. pneumoniae-infected epithelial cells enhances the secretion of both interleukin (IL)-1β and IL-18 by peripheral blood mononuclear cells, partially mediated by the P2X7 purine receptor (P2X7R). In vivo experiments confirm that addition of a conditioned medium exacerbates pulmonary inflammation, which can be attenuated by pre-treatment with a P2X7R inhibitor. Collectively, these findings highlight the significance of airway epithelial aerobic glycolysis in enhancing the pulmonary inflammatory response and aiding pathogen clearance.

The Impact of Respiratory Function Training and Rehabilitation Nursing on the Recovery of Patients With Mycoplasma Pneumoniae Pneumonia

Introduction The goal of this study was to see how people who had been diagnosed with Mycoplasma pneumoniae pneumonia (MPP) responded to respiratory function training and rehabilitation (RFTR) nursing. Methodology A total of 122 patients (five to 12 years of age) diagnosed with Mycoplasma pneumoniae pneumonia (MPP) and refractory Mycoplasma pneumoniae pneumonia (RMPP) using enzyme-linked immunoassay and PCR were included in this study. These patients were hospitalized at a tertiary care hospital from February 2022 to December 2022. Upon admission, they were assigned a numerical identifier based on the order of admission. Subsequently, they were randomly allocated into two equal groups: the observation (OG) and the control (CG), with each group consisting of 61 patients. Nano-acupoint sticking (NAS) therapy along with respiratory function training and rehabilitation (RFTR) nursing interventions were implemented for patients in the OG. Results The observed disparities in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and the ratio of FEV1 to FVC among the patients did not exhibit significant disparity prior to the commencement of treatment (p values of 0.700, 0.105, and 0.829, respectively). There was no significant difference observed in the range of inflammation in the right lung (p=0.523). Inflammation in the left lung and fluid volume in both lungs are statistically different in both groups (p values of 0.001 and 0.000, respectively). The patients in the observation group exhibited a shorter duration of cough and sputum, disappearance of lung sounds, and length of hospital stays (LOS) compared to the other groups, with statistical significance (p<0.05). Conclusion Nano-acupoint sticking (NAS) therapy with respiratory function training and rehabilitation (RFTR) in nursing practice has shown enhanced rehabilitation outcomes for individuals diagnosed with Mycoplasma pneumoniae pneumonia (MPP). The present study focuses on the application of NAS therapy in the context of RFTR for individuals diagnosed with MPP.

Molecular epidemiology of Mycoplasma pneumoniae pneumonia in children, Wuhan, 2020-2022

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is an important pathogen of community-acquired pneumonia in children. The factors contributing to the severity of illness caused by M. pneumoniae infection are still under investigation. We aimed to evaluate the sensitivity of common M. pneumoniae detection methods, as well as to analyze the clinical manifestations, genotypes, macrolide resistance, respiratory microenvironment, and their relationship with the severity of illness in children with M. pneumoniae pneumonia in Wuhan.

RESULTS

Among 1,259 clinical samples, 461 samples were positive for M. pneumoniae via quantitative polymerase chain reaction (qPCR). Furthermore, we found that while serological testing is not highly sensitive in detecting M. pneumoniae infection, but it may serve as an indicator for predicting severe cases. We successfully identified the adhesin P1 (P1) genotypes of 127 samples based on metagenomic and Sanger sequencing, with P1-type 1 (113/127, 88.98%) being the dominant genotype. No significant difference in pathogenicity was observed among different genotypes. The macrolide resistance rate of M. pneumoniae isolates was 96% (48/50) and all mutations were A2063G in domain V of 23S rRNA gene. There was no significant difference between the upper respiratory microbiome of patients with mild and severe symptoms.

CONCLUSIONS

During the period of this study, the main circulating M. pneumoniae was P1-type 1, with a resistance rate of 96%. Key findings include the efficacy of qPCR in detecting M. pneumoniae, the potential of IgM titers exceeding 1:160 as indicators for illness severity, and the lack of a direct correlation between disease severity and genotypic characteristics or respiratory microenvironment. This study is the first to characterize the epidemic and genomic features of M. pneumoniae in Wuhan after the COVID-19 outbreak in 2020, which provides a scientific data basis for monitoring and infection prevention and control of M. pneumoniae in the post-pandemic era.

Diagnostic significance of HRCT imaging features in adult mycoplasma pneumonia: a retrospective study

Mycoplasma pneumoniae pneumonia (MPP) often overlaps with the clinical manifestations and chest imaging manifestations of other types of community-acquired pneumonia (CAP). We retrospectively analyzed the clinical and imaging data of a group of patients with CAP, summarized their clinical and imaging characteristics, and discussed the diagnostic significance of their certain HRCT findings. The HRCT findings of CAP researched in our study included tree-in-bud sign (TIB), ground-glass opacity (GGO), tree fog sign (TIB + GGO), bronchial wall thickening, air-bronchogram, pleural effusion and cavity. The HRCT findings of all cases were analyzed. Among the 200 cases of MPP, 174 cases showed the TIB, 193 showed the GGO, 175 showed the tree fog sign, 181 lacked air-bronchogram. In case taking the tree fog sign and lack of air-bronchogram simultaneously as an index to distinguish MPP from OCAP, the sensitivity was 87.5%, the specificity was 97.5%, the accuracy was 92.5%. This study showed that that specific HRCT findings could be used to distinguish MPP from OCAP. The combined HRCT findings including the tree fog sign and lacked air-bronchogram simultaneously would contribute to a more accurate diagnosis of MPP.

Investigating the occurrence of autoimmune diseases among children and adolescents hospitalized for Mycoplasma pneumoniae infections

Background

Mycoplasma pneumoniae infection is common in the general population and may be followed by immune dysfunction, but links with subsequent autoimmune disease remain inconclusive.

Objective

To estimate the association of M. pneumoniae infection with the risk of subsequent autoimmune disease.

Methods

This retrospective cohort study examined the medical records of South Korean children from 01/01/2002 to 31/12/2017. The exposed cohort was identified as patients hospitalized for M. pneumoniae infection. Each exposed patient was matched with unexposed controls based on birth year and sex at a 1:10 ratio using incidence density sampling calculations. The outcome was subsequent diagnosis of autoimmune disease, and hazard ratios (HRs) were estimated with control for confounders. Further estimation was performed using hospital-based databases which were converted to a common data model (CDM) to allow comparisons of the different databases.

Results

The exposed cohort consisted of 49,937 children and the matched unexposed of 499,370 children. The median age at diagnosis of M. pneumoniae infection was 4 years (interquartile range, 2.5-6.5 years). During a mean follow-up time of 9.0 ± 3.8 years, the incidence rate of autoimmune diseases was 66.5 per 10,000 person-years (95% CI: 64.3-68.8) in the exposed cohort and 52.3 per 10,000 person-years (95% CI: 51.7-52.9) in the unexposed cohort, corresponding to an absolute rate of difference of 14.3 per 10,000 person-years (95% CI: 11.9-16.6). Children in the exposed cohort had an increased risk of autoimmune disease (HR: 1.26; 95% CI: 1.21-1.31), and this association was similar in the separate analysis of hospital databases (HR: 1.25; 95% CI 1.06-1.49).

Conclusion

M. pneumoniae infection requiring hospitalization may be associated with an increase in subsequent diagnoses of autoimmune diseases.

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.

Characteristics of the Mycoplasma pneumoniae Epidemic from 2019 to 2020 in Korea: Macrolide Resistance and Co-Infection Trends

Mycoplasma pneumoniae, a major etiological agent of community-acquired pneumonia, exhibits distinct cyclic epidemic patterns recurring every three to five years. Several cases of co-infection with severe acute respiratory syndrome coronavirus 2 have been reported globally, resulting in unfavorable clinical manifestations. This study investigated the epidemiological features of the recent M. pneumoniae outbreak (May 2019-April 2020) using retrospective data from the last five years. Molecular test data for macrolide resistance and co-infection were obtained from the Seegene Medical Foundation. National medical expenditure and hospitalization rates were analyzed using data from The Health Insurance Review and Assessment Service of Korea. The macrolide resistance rate was 69.67%, peaking at 71.30% during the epidemic period, which was considerably higher than the 60.89% rate during non-epidemic periods. The co-infection rate with other respiratory pathogens was 88.49%; macrolide-resistant M. pneumoniae strains showed a 2.33% higher co-infection rate than the susceptible strains. The epidemic period had 15.43% higher hospitalization and 78.27% higher medical budget expenditure per patient than non-epidemic periods. The increased rates of macrolide resistance and co-infection observed in macrolide-resistant M. pneumoniae during the epidemic period highlight the importance of monitoring future outbreaks, especially considering macrolide resistance and the risk of co-infection with other pathogens.

Identification of repurposable drug targets in Mycoplasma pneumoniae using subtractive genomics, molecular docking and dynamics simulation

Mycoplasma pneumoniae is a significant causative agent of community-acquired pneumonia, causing acute inflammation in the upper and lower respiratory tract as well as extrapulmonary syndromes. In particular, the elderly and infants are at greater risk of developing severe, life-threatening pneumonia caused by M. pneumoniae. Yet, the global increase in antimicrobial resistance against antibiotics for the treatment of M. pneumoniae infection highlights the urgent need to explore novel drug targets. To this end, bioinformatics approaches, such as subtractive genomics, can be employed to identify specific metabolic pathways and essential proteins unique to the pathogen that could be potential targets for new drugs. In this study, we implemented a subtractive genomics approach to identify 61 metabolic pathways and 42 essential proteins that are unique to M. pneumoniae. A subsequent screening in the DrugBank database revealed three druggable proteins with similarity to FDA-approved small-molecule drugs, and finally, the compound CHEBI:97093 was identified as a promising novel putative drug target. These findings can provide crucial insights for the development of highly effective drugs that selectively inhibit the pathogen-specific metabolic pathways, leading to better management and treatment of M. pneumoniae infections.

Unveiling the stealthy tactics: mycoplasma's immune evasion strategies

Mycoplasmas, the smallest known self-replicating organisms, possess a simple structure, lack a cell wall, and have limited metabolic pathways. They are responsible for causing acute or chronic infections in humans and animals, with a significant number of species exhibiting pathogenicity. Although the innate and adaptive immune responses can effectively combat this pathogen, mycoplasmas are capable of persisting in the host, indicating that the immune system fails to eliminate them completely. Recent studies have shed light on the intricate and sophisticated defense mechanisms developed by mycoplasmas during their long-term co-evolution with the host. These evasion strategies encompass various tactics, including invasion, biofilm formation, and modulation of immune responses, such as inhibition of immune cell activity, suppression of immune cell function, and resistance against immune molecules. Additionally, antigen variation and molecular mimicry are also crucial immune evasion strategies. This review comprehensively summarizes the evasion mechanisms employed by mycoplasmas, providing valuable insights into the pathogenesis of mycoplasma infections.

Absolute quantification of Mycoplasma pneumoniae in infected patients by droplet digital PCR to track disease severity and treatment efficacy

Mycoplasma pneumoniae is a common causative pathogen of community-acquired pneumonia. An accurate and sensitive detection method is important for evaluating disease severity and treatment efficacy. Digital droplet PCR (ddPCR) is a competent method enabling the absolute quantification of DNA copy number with high precision and sensitivity. We established ddPCR for M. pneumoniae detection, using clinical specimens for validation, and this showed excellent specificity for M. pneumoniae. The limit of detection of ddPCR was 2.9 copies/reaction, while that for real-time PCR was 10.8 copies/reaction. In total, 178 clinical samples were used to evaluate the ddPCR assay, which correctly identified and differentiated 80 positive samples, whereas the real-time PCR tested 79 samples as positive. One sample that tested negative in real-time PCR was positive in ddPCR, with a bacterial load of three copies/test. For samples that tested positive in both methods, the cycle threshold of real-time PCR was highly correlated with the copy number of ddPCR. Bacterial loads in patients with severe M. pneumoniae pneumonia were significantly higher than those in patients with general M. pneumoniae pneumonia. The ddPCR showed that bacterial loads were significantly decreased after macrolide treatment, which could have reflected the treatment efficacy. The proposed ddPCR assay was sensitive and specific for the detection of M. pneumoniae. Quantitative monitoring of bacterial load in clinical samples could help clinicians to evaluate treatment efficacy.

Novel mechanisms of macrolide resistance revealed by in vitro selection and genome analysis in Mycoplasma pneumoniae

Mycoplasma pneumoniae is an important pathogen causing upper and lower respiratory tract infections in children and other age groups. Macrolides are the recommended treatments of choice for M. pneumoniae infections. However, macrolide resistance in M. pneumoniae is increasing worldwide, which complicates the treatment strategies. The mechanisms of macrolide resistance have been extensively studied focusing on the mutations in 23S rRNA and ribosomal proteins. Since the secondary treatment choice for pediatric patients is very limited, we decided to look for potential new treatment strategies in macrolide drugs and investigate possible new mechanisms of resistance. We performed an in vitro selection of mutants resistant to five macrolides (erythromycin, roxithromycin, azithromycin, josamycin, and midecamycin) by inducing the parent M. pneumoniae strain M129 with increasing concentrations of the drugs. The evolving cultures in every passage were tested for their antimicrobial susceptibilities to eight drugs and mutations known to be associated with macrolide resistance by PCR and sequencing. The final selected mutants were also analyzed by whole-genome sequencing. Results showed that roxithromycin is the drug that most easily induces resistance (at 0.25 mg/L, with two passages, 23 days), while with midecamycin it is most difficult (at 5.12 mg/L, with seven passages, 87 days). Point mutations C2617A/T, A2063G, or A2064C in domain V of 23S rRNA were detected in mutants resistant to the 14- and 15-membered macrolides, while A2067G/C was selected for the 16-membered macrolides. Single amino acid changes (G72R, G72V) in ribosomal protein L4 emerged during the induction by midecamycin. Genome sequencing identified sequence variations in dnaK, rpoC, glpK, MPN449, and in one of the hsdS (MPN365) genes in the mutants. Mutants induced by the 14- or 15-membered macrolides were resistant to all macrolides, while those induced by the 16-membered macrolides (midecamycin and josamycin) remained susceptible to the 14- and 15-membered macrolides. In summary, these data demonstrated that midecamycin is less potent in inducing resistance than other macrolides, and the induced resistance is restrained to the 16-membered macrolides, suggesting a potential benefit of using midecamycin as a first treatment choice if the strain is susceptible.

Risk Prediction Model for Necrotizing Pneumonia in Children with Mycoplasma pneumoniae Pneumonia

Objective

To analyze the predictive factors for necrotizing pneumonia (NP) in children with Mycoplasma pneumoniae pneumonia (MPP) and construct a prediction model.

Methods

The clinical data with MPP at the Children's Hospital of Kunming Medical University from January 2014 to November 2022 were retrospectively analyzed. Eighty-four children with MPP who developed NP were divided into the necrotizing group, and 168 children who did not develop NP were divided into the non-necrotizing group by propensity-score matching. LASSO regression was used to select the optimal factors, and multivariate logistic regression analysis was used to establish a clinical prediction model. The receiver operating characteristic (ROC) curve and calibration curve were used to evaluate the discrimination and calibration of the nomogram. Clinical decision curve analysis was used to evaluate the clinical predictive value.

Results

LASSO regression analysis showed that bacterial co-infection, chest pain, LDH, CRP, duration of fever, and D-dimer were the influencing factors for NP in children with MPP (P < 0.05). The results of ROC analysis showed that the AUC of the prediction model established in this study for predicting necrotizing MPP was 0.870 (95% CI: 0.813-0.927, P < 0.001) in the training set and 0.843 (95% CI: 0.757-0.930, P < 0.001) in the validation set. The Bootstrap repeated sampling for 1000 times was used for internal validation, and the calibration curve showed that the model had good consistency. The Hosmer-Lemeshow test showed that the predicted probability of the model had a good fit with the actual probability in the training set and the validation set (P values of 0.366 and 0.667, respectively). The clinical decision curve showed that the model had good clinical application value.

Conclusion

The prediction model based on bacterial co-infection, chest pain, LDH, CRP, fever duration, and D-dimer has a good predictive value for necrotizing MPP.

Design and synthesis optimization of novel diimide indoles derivatives for ameliorating acute lung injury through modulation of NF-κB signaling pathway

Acute lung injury (ALI) is a common respiratory disease caused by local or systemic inflammatory reaction. Based on the natural 7-chain diaryl anti-inflammatory framework, a series of diimide indoles derivatives were designed by combining curcumin and indole in this study. The synthesis of diimide compounds was extended using dichloromethane (DCM) as solvent and 1,1'-carbonyldiimidazole (CDI) and sodium hydride (NaH) as double activators, and a total of 40 diimide-indole derivatives were obtained. The results of in vitro anti-inflammatory activity showed that most compounds could inhibit the production of interleukin-6 (IL-6) better than curcumin and indomethacin. Among the compounds, the IC₅₀ of compound 11f on IL-6 reached 1.05 μM with no obvious cytotoxic side effects. Mechanistically, compound 11f could block the expression of NF-κB P65 phosphorylation, and nuclear translocation of P65. The acute toxicity tests in-vivo also showed no obvious toxicity in mice after the intragastric administration of 1000 mg/kg. In addition, the compound 11f could significantly inhibit the LPS-induced inflammatory response in mice and reduce the number of neutrophils and wet/dry lung weight ratio, thereby alleviating ALI. These results indicated that the novel diimide indoles were promising anti-inflammatory agents for the treatment of ALI.

Potential of metagenomic next-generation sequencing in detecting infections of ICU patients

BACKGROUND

Due to the limitations of traditional microbiological detection techniques in evaluating complicated infections in ICU patients, it is necessary to explore novel and effective methods to improve the clinical detection of ICU patients' infections.

OBJECTIVE

This study aimed to evaluate the efficiency and specificity of mNGS in screening pathogens in the blood, deep phlegm, urine, and other sample types of ICU patients exploring an effective method for infection detection.

METHODS

A total of 56 ICU patients with 131 samples were included in this study. The sample types included blood, deep phlegm, urine, drainage, anal swabs, and other types. Samples were analyzed by both conventional detection method and mNGS tests. The diagnosis efficiency and consistency of the two methods were compared. The distribution of the identified pathogens was analyzed. Moreover, the clinical features of patients with mNGS-positive or mNGS-negative results were compared.

RESULTS

The positive rate of mNGS was 81.7% (107/131) including 3.1% (4/131) weakly positive, while the positive rate of traditional detection was only 30.5%, including 29 strong positive results and 11 weak positive results. Additionally, there were 41 patients chose to adjust anti-infection strategies according to the results of mNGS, which significantly saved treatment costs. The mNGS-positive patients showed a shorter ICU hospitalization and higher intention to adjust anti-infection strategies than the mNGS-negative patients.

CONCLUSION

mNGS is of great potential for the pathogen detection of ICU patients, and has a higher detection rate than traditional detection methods. Further clinical application investigations can be carried out to expand the application of mNGS.

Poor accuracy of single serological IgM tests in children with suspected acute Mycoplasma pneumoniae infection in Guangzhou, China

Introduction. Early and accurate diagnosis of Mycoplasma pneumoniae (MP) infection of children with pneumonia is at the core of treatment in clinical practice.Gap Statement. Serological immunoglobulin M (IgM) tests for MP infection of children in south China have been rarely described.Aim. To assess the diagnostic performance and clinical application of serodiagnosis of MP infection in paediatric pneumonia patients.Methodology. Serum samples from 144 children diagnosed with MP pneumonia were subjected to a particle agglutination (PA)-based IgM assay. Meanwhile, we used an established suspension array as the reference standard method for the detection of MP DNA in bronchoalveolar lavage fluid (BALF) from all patients to assess the reliability of serological assays.Results. When running immunological testing in single serum samples, 80.6 %(79/98) of cases were diagnosed with MP infection, whereas only 55 (56.1 %) cases were positive in MP DNA analysis. Furthermore, single serum tests for IgM during acute MP infection resulted in 85.5 % (47/55) sensitivity and 25.6 % (11/43) specificity. Nevertheless, immunological testing and MP DNA analysis yielded the same results when paired sera were available for MP IgM antibody testing.Conclusion. Paired serological IgM assays are necessary for the determination of an acute MP infection, whereas single serological IgM testing is unreliable. Moreover, even a short interval of two MP serological tests works well.

Amino-modified silica membrane capable of DNA extraction and enrichment for facilitated isothermal amplification detection of Mycoplasma pneumoniae

Herein, we developed a facile integrated Mycoplasma pneumoniae diagnosis platform by combining amino-modified silica membrane (AMSM)-based nucleic acids fast extraction and enrichment with colorimetric isothermal amplification detection. AMSM demonstrates a strong ability to capture and enrich nucleic acids in complicated biological matrices, and the purified AMSM/nucleic acids composite could be directly used to perform isothermal amplification including denaturation bubble-mediated strand exchange amplification (SEA) and loop-mediated isothermal amplification (LAMP) reactions. Through comparing clinical specimens, excellent performance of AMSM-based SEA assay with 93.33% sensitivity and 100% specificity relative to real-time PCR was observed, and for AMSM-based LAMP was 96.67% and 100%, respectively. The diagnostic procedure could be completed within 55 min, and the colorimetric-based visual result further alleviates the use of sophisticated equipment. The proposed approach possesses great potential as a simple and time-saving alternative for point-of-care testing (POCT) of M. pneumoniae in resource-limited regions.