Mycoplasma pneumoniae in pediatric patients: Do macrolide-resistance and/or delayed treatment matter?

Serum IL-17A and IL-6 in paediatric Mycoplasma pneumoniae pneumonia: implications for different endotypes

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a heterogeneous disease with a diverse spectrum of clinical phenotypes. No studies have demonstrated the relationship between underlying endotypes and clinical phenotypes as well as prognosis about this disease. Thus, we conducted a multicentre prospective longitudinal study on children hospitalized for MPP between June 2021 and March 2023, with the end of follow-up in August 2023. Blood samples were collected and processed at multiple time points. Multiplex cytokine assay was performed to characterize serum cytokine profiles and their dynamic changes after admission. Cluster analysis based on different clinical phenotypes was conducted. Among the included 196 patients, the levels of serum IL-17A and IL-6 showed remarkable variabilities. Four cytokine clusters based on the two cytokines and four clinical groups were identified. Significant elevation of IL-17A mainly correlated with diffuse bronchiolitis and lobar lesion by airway mucus hypersecretions, while that of IL-6 was largely associated with lobar lesion which later developed into lung necrosis. Besides, glucocorticoid therapy failed to inhibit IL-17A, and markedly elevated IL-17A and IL-6 levels may correlate with lower airway obliterans. Our study provides critical relationship between molecular signatures (endotypes) and clustered clinical phenotypes in paediatric patients with MPP.

A Case Report of Mycoplasma pneumoniae-induced fulminant myocarditis in a 15-year-old male leading to cardiogenic shock and electrical storm

Mycoplasma pneumoniae (M. pneumoniae) is a well-recognized pathogen primarily associated with respiratory tract infections. However, in rare instances, it can lead to extrapulmonary manifestations, including myocarditis. We present a case of a 15-year-old male who developed fulminant myocarditis, cardiogenic shock, and cardiac electrical storm attributed to M. pneumoniae infection. He underwent a combination of intra-aortic balloon pump (IABP) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for cardiac support, ultimately surviving despite the intracardiac thrombus formation and embolic stroke. Following comprehensive treatment and rehabilitation, he was discharged in stable condition. This case underscores the importance of considering atypical pathogens as potential etiological factors in patients presenting with cardiac complications, especially in the adolescents. It also emphasizes the need for clinical vigilance and effective support for potential cardiac complications arising from M. pneumoniae infection.

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.

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.

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.

Integrative study of pulmonary microbiome, transcriptome and clinical outcomes in Mycoplasma pneumoniae pneumonia

BACKGROUND

This study aimed to investigate the interactions among three core elements of respiratory infection-pathogen, lung microbiome, and host response-and their avocation with the severity and outcomes of Mycoplasma pneumoniae pneumonia (MPP) in children.

METHODS

We prospectively collected bronchoalveolar lavage fluid from a cohort of 41 children with MPP, including general MPP (GMPP) and complicated MPP (CMPP), followed by microbiome and transcriptomic analyses to characterize the association among pathogen, lung microbiome, and host response and correlate it with the clinical features and outcomes.

RESULTS

The lung microbiome of patients with CMPP had an increased relative abundance of Mycoplasma pneumoniae (MP) and reduced alpha diversity, with 76 differentially expressed species. Host gene analysis revealed a key module associated with neutrophil function and several inflammatory response pathways. Patients with a high relative abundance of MP, manifested by a specific lung microbiome and host response type, were more prone to CMPP and had a long imaging recovery time.

CONCLUSION

Patients with CMPP have a more disrupted lung microbiome than those with GMPP. MP, lung microbiome, and host response interacts with each other and are closely related to disease severity and outcomes in children with 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.

The clinical significance of macrolide resistance in pediatric Mycoplasma pneumoniae infection during COVID-19 pandemic

Background

Mycoplasma pneumoniae (MP) is a commonly occurring pathogen causing community-acquired pneumonia (CAP) in children. The global prevalence of macrolide-resistant MP (MRMP) infection, especially in Asian regions, is increasing rapidly. However, the prevalence of MRMP and its clinical significance during the COVID-19 pandemic is not clear.

Methods

This study enrolled children with molecularly confirmed macrolide-susceptible MP (MSMP) and MRMP CAP from Beijing Children's Hospital Baoding Hospital, Capital Medical University between August 2021 and July 2022. The clinical characteristics, laboratory findings, chest imaging presentations, and strain genotypes were compared between patients with MSMP and MRMP CAP.

Results

A total of 520 hospitalized children with MP-CAP were enrolled in the study, with a macrolide resistance rate of 92.7%. Patients with MRMP infection exhibited more severe clinical manifestations (such as dyspnea and pleural effusion) and had a longer hospital stay than the MSMP group. Furthermore, abnormal blood test results (including increased LDH and D-dimer) were more common in the MRMP group (P<0.05). Multilocus variable-number tandem-repeat analysis (MLVA) was performed on 304 samples based on four loci (Mpn13-16), and M3562 and M4572 were the major types, accounting for 74.0% and 16.8% of the strains, respectively. The macrolide resistance rate of M3562 strains was up to 95.1%.

Conclusion

The prevalence of MRMP strains in hospitalized CAP patients was extremely high in the Baoding area, and patients infected with MRMP strains exhibited more severe clinical features and increased LDH and D-dimer. M3562 was the predominant resistant clone.

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

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

The clinical significance of and the factors associated with macrolide resistance and poor macrolide response in pediatric Mycoplasma pneumoniae infection: A retrospective study

BACKGROUND

Macrolide-resistant Mycoplasma pneumoniae (MRMP) infection is increasing worldwide. However, its clinical significance is still uncertain.

METHODS

The data of the Laboratory Medicine Department of Chang Gung Memorial Hospital in northern Taiwan was searched for children with molecular confirmed macrolide-susceptible Mycoplasma pneumoniae (MSMP) and MRMP infections between January 2011 and December 2018. The clinical features, laboratory data, and chest image presentations were compared between patients with MRMP and MSMP infections and between patients with good and poor macrolide response, respectively.

RESULTS

Records from 158 patients were recovered. Of the enrolled patients 34 (22%) suffered MRMP infection, 27 (17%) had pleural effusions, and 47 (32%) had poor macrolide response. The macrolide resistance rate was 12% in 2011, 20% between 2015 and 2016, and 50% between 2017 and 2018, respectively. Other than a poor macrolide response, the MRMP and MSMP infections are clinically indistinguishable. The presence of pleural effusion and MRMP infections were found to be independently associated with a poor macrolide response, with odds ratios (95% confidence interval) of 14.3 (4.9-42.0) and 14.6 (5.4-40), respectively. The macrolide resistance rate of the patients with a poor macrolide response was 49% and 18% among all the patients enrolled and the patients with a pleural effusion, respectively.

CONCLUSION

The macrolide resistance rate had possibly increased in recent years in Taiwan and should be continuously monitored. In addition, the macrolide response could be misleading in predicting a macrolide resistance especially for the patients with a pleural effusion.

Circulating pediatric respiratory pathogens in Taiwan during 2020: Dynamic change under low COVID-19 incidence

BACKGROUND

In Taiwan, there were only 799 confirmed COVID-19 cases in 2020. The unique backdrop amidst a pandemic and promotion of nonpharmaceutical interventions generated some distinct changes in the epidemiology of common respiratory pathogens. In this study, we aimed to investigate the dynamic changes in respiratory pathogens in children during 2020.

METHODS

We performed a retrospective cohort study at a tertiary hospital in southern Taiwan during 2020. Patients aged 0-18 years who visited the pediatric emergency department were enrolled. Children who presented with clinical symptoms (fever or respiratory illness) and received nasopharyngeal swabs for multiplex polymerase chain reaction (PCR) were included in our analysis. We also compared respiratory syncytial virus (RSV) trends from previous years by PCR and lateral flow immunochromatographic assays from 2017 to 2020.

RESULTS

A total of 120 children were tested. The overall detection rate was 55%. With strengthened restrictions, the detection rate dropped from 70% to 30%. However, non-enveloped viruses (rhinovirus/enterovirus and adenovirus) were in constant circulation. Upon easing prevention measures, the detection rate remained above 60%, and an outbreak of an enveloped virus (RSV and parainfluenza virus) was noted. Compared with 2017-2019, the cyclical RSV epidemic was delayed, with a large surge in late 2020.

CONCLUSIONS

We observed a constant circulation of non-enveloped viruses when strict nonpharmaceutical interventions were employed and a delayed surge of enveloped viruses during the easing of restrictions. Continuous surveillance and monitoring of the evolutionary dynamics of respiratory viruses is important, while easing restrictions requires balanced judgment.

Global prevalence of resistance to macrolides in Mycoplasma pneumoniae: a systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of resistance to macrolides in Mycoplasma pneumoniae worldwide.

METHODS

Prior to 12 December 2020, PubMed, Web of Science, Scopus and Embase databases were searched for epidemiological studies of M. pneumoniae resistance. Two reviewers independently extracted data from included studies. The extracted data include sampling population, total sampling number, the number of resistant strains and the molecular subtype of resistant strains. The estimate of resistance prevalence was calculated using the random-effects model.

RESULTS

A total of 17 873 strains were obtained from five continents and reported in 98 investigations between 2000 and 2020, with 8836 strains characterized as macrolide resistant. In summary, macrolide-resistant M. pneumoniae was most common in Asia (63% [95% CI 56, 69]). In Europe, North America, South America and Oceania, the prevalence was 3% [2, 7], 8.6% [6, 11], 0% and 3.3%, respectively. Over the last 20 years, the prevalence of macrolide-resistant M. pneumoniae has remained high in China (81% [73, 87]), with a significant increasing trend in South Korea (4% [1, 9] to 78% [49, 93], P < 0.0001). Furthermore, a point mutation at 2063 from A to G was mostly related to M. pneumoniae macrolide resistance. In terms of clinical outcomes, longer cough (mean difference [MD]: 2.93 [0.26, 5.60]) and febrile days (MD: 1.52 [1.12, 1.92]), and prolonged hospital stays (MD: 0.76 [0.05, 1.46]) might be induced by macrolide-resistant M. pneumoniae pneumonia.

CONCLUSIONS

The incidence of macrolide-resistant M. pneumoniae varies globally, with eastern Asia having a greater degree of resistance. However, attention is also required in other areas, and antibiotic alternatives should be considered for treatment in high-prevalence countries.

Prediction Model for Severe Mycoplasma pneumoniae Pneumonia in Pediatric Patients by Admission Laboratory Indicators

OBJECTIVE

The purpose of this study was to develop a model for predicting severe Mycoplasma pneumoniae pneumonia (SMPP) in pediatric patients with Mycoplasma pneumoniae pneumonia (MPP) on admission by laboratory indicators.

METHODS

Pediatric patients with MPP from January 2019 to December 2020 in our hospital were enrolled in this study. SMPP was diagnosed according to guideline for diagnosis and treatment of community-acquired pneumonia in children (2019 version). Prediction model was developed according to the admission laboratory indicators. Receiver operating characteristic curve and Goodness-of-fit test were analyzed for the predictive value.

RESULTS

A total of 233 MPP patients were included in the study, with 121 males and 112 females, aged 4.541 (1-14) years. Among them, 84 (36.1%, 95% CI 29.9-42.6%) pediatric patients were diagnosed as SMPP. Some admission laboratory indicators (immunoglobulins M (IgM), eosinophil proportion, eosinophil count, hemoglobin, erythrocyte sedimentation rate (ESR), total protein, albumin and prealbumin) were found statistically different (p < 0.05) between non-SMPP group and SMPP group. Logistic regress analysis showed IgM, eosinophil proportion, eosinophil count, ESR and prealbumin were independent risk factors for SMPP. According to these five admission laboratory indicators, the prediction model for SMPP in pediatric patients was developed. The area under curve of the prediction model was 0.777, and the goodness-of-fit test showed that the predicted SMPP incidence by the model was consistent with the actual incidence (χ2 = 244.51, p = 0.203).

CONCLUSION

We developed a model for predicting SMPP in pediatric patients by admission laboratory indicators. This model has good discrimination and calibration, which provides a basis for the early identification SMPP on admission. However, this model should be validated by multicenter studies with large sample.

Refractory Mycoplasma pneumoniae Pneumonia in Children: Early Recognition and Management

Refractory Mycoplasma pneumoniae pneumonia (RMPP) is a severe state of M. pneumoniae infection that has attracted increasing universal attention in recent years. The pathogenesis of RMPP remains unknown, but the excessive host immune responses as well as macrolide resistance of M. pneumoniae might play important roles in the development of RMPP. To improve the prognosis of RMPP, it is mandatory to recognize RMPP in the early stages, and the detection of macrolide-resistant MP, clinical unresponsiveness to macrolides and elevated proinflammatory cytokines might be clues. Timely and effective anti-mycoplasmal therapy and immunomodulating therapy are the main strategies for RMPP.

Ultrasensitive, Specific, and Rapid Detection of Mycoplasma pneumoniae Using the ERA/CRISPR–Cas12a Dual System

Mycoplasma pneumoniae can cause severe respiratory tract infections and extrapulmonary diseases, which pose a significant threat to the health of children. Diagnostic methods for M. pneumoniae include isolation and culture, antibody detection, fluorescence quantitative PCR, and so on, but there are various shortcomings in time, cost, convenience, and sensitivity. In this study, we developed a rapid, sensitive, specific, and economical method for the detection of M. pneumoniae, termed the ERA/CRISPR–Cas12a dual system. The system used the high specificity and collateral cleavage activity of the LbCas12a protein, combined with enzymatic recombination amplification (ERA) technology with strong amplification ability, allowing the results to be observed by a portable fluorometer or visualized by the naked eye with a dipstick, which could be obtained in approximately 30 min. The ERA/CRISPR–Cas12a fluorescence and dipstick system were able to detect M. pneumoniae at titers as low as 1 and 100 copies/μL, respectively. The specificity of the two interpretation methods was 100%, and no cross-reaction with other pathogens was observed. In the evaluation of 92 clinical samples, the positive predictive agreements of the ERA/CRISPR–Cas12a fluorescence and dipstick systems with qPCR detection were 100% and 92.86%, respectively. The negative predictive agreements of both methods were 100%. In conclusion, this study established a portable, rapid, low-cost, ultrasensitive, and specific method for the early and rapid diagnosis of M. pneumoniae to meet the needs of on-site rapid detection in primary health institutions.

Mycoplasmas as Host Pantropic and Specific Pathogens: Clinical Implications, Gene Transfer, Virulence Factors, and Future Perspectives

Mycoplasmas as economically important and pantropic pathogens can cause similar clinical diseases in different hosts by eluding host defense and establishing their niches despite their limited metabolic capacities. Besides, enormous undiscovered virulence has a fundamental role in the pathogenesis of pathogenic mycoplasmas. On the other hand, they are host-specific pathogens with some highly pathogenic members that can colonize a vast number of habitats. Reshuffling mycoplasmas genetic information and evolving rapidly is a way to avoid their host's immune system. However, currently, only a few control measures exist against some mycoplasmosis which are far from satisfaction. This review aimed to provide an updated insight into the state of mycoplasmas as pathogens by summarizing and analyzing the comprehensive progress, current challenge, and future perspectives of mycoplasmas. It covers clinical implications of mycoplasmas in humans and domestic and wild animals, virulence-related factors, the process of gene transfer and its crucial prospects, the current application and future perspectives of nanotechnology for diagnosing and curing mycoplasmosis, Mycoplasma vaccination, and protective immunity. Several questions remain unanswered and are recommended to pay close attention to. The findings would be helpful to develop new strategies for basic and applied research on mycoplasmas and facilitate the control of mycoplasmosis for humans and various species of animals.

Recent Trends in the Epidemiology, Diagnosis, and Treatment of Macrolide-Resistant Mycoplasma pneumoniae

Among Mycoplasma pneumoniae (MP) is one of the major pathogens causing lower respiratory tract infection. Macrolide-resistant Mycoplasma pneumoniae (MRMP) isolates have been increasing and has become a global concern, especially in East Asian countries. This affects the treatment of MP infection; that is, some patients with MRMP infections fever cannot be controlled despite macrolide therapy. Therefore, alternative therapies, including secondary antimicrobials, including tetracyclines, fluoroquinolones, or systemic corticosteroids, were introduced. However, there are insufficient data on these alternative therapies. Thus, this article provides reviews of the recent trends in the epidemiology, diagnosis, and treatment of MRMP.

Analysis of Clinical Related Factors of Severe Mycoplasma pneumoniae Pneumonia in Children Based on Imaging Diagnosis

Severe pneumonia is a common acute respiratory disease in children, and it has a rapid onset and violent onset, which often affects the whole body. Moreover, typical clinical manifestations and signs often cannot be taken seriously or covered up in clinical work. Due to the short time for treatment, it is easy to cause improper diagnosis and treatment, aggravate the disease and further deteriorate, and even threaten the life of the child. In order to achieve early intervention and treatment of severe Mycoplasma pneumoniae pneumonia in children, reduce or shorten the course of the disease, and improve the cure rate, this paper combines the imaging diagnosis to study the analysis of clinical related factors of severe Mycoplasma pneumoniae pneumonia in children. In addition, this paper analyzes the experimental data with hospital case samples, conducts statistical research on the analysis of clinical related factors of severe Mycoplasma pneumoniae pneumonia in children, and proposes effective coping strategies.

Comparative Metabolic Pathways Analysis and Subtractive Genomics Profiling to Prioritize Potential Drug Targets Against Streptococcus pneumoniae

Streptococcus pneumoniae is a notorious pathogen that affects ∼450 million people worldwide and causes up to four million deaths per annum. Despite availability of antibiotics (i.e., penicillin, doxycycline, or clarithromycin) and conjugate vaccines (e.g., PCVs), it is still challenging to treat because of its drug resistance ability. The rise of antibiotic resistance in S. pneumoniae is a major source of concern across the world. Computational subtractive genomics is one of the most applied techniques in which the whole proteome of the bacterial pathogen is gradually reduced to a limited number of potential therapeutic targets. Whole-genome sequencing has greatly reduced the time required and provides more opportunities for drug target identification. The goal of this work is to evaluate and analyze metabolic pathways in serotype 14 of S. pneumonia to identify potential drug targets. In the present study, 47 potent drug targets were identified against S. pneumonia by employing the computational subtractive genomics approach. Among these, two proteins are prioritized (i.e., 4-oxalocrotonate tautomerase and Sensor histidine kinase uniquely present in S. pneumonia) as novel drug targets and selected for further structure-based studies. The identified proteins may provide a platform for the discovery of a lead drug candidate that may be capable of inhibiting these proteins and, therefore, could be helpful in minimizing the associated risk related to the drug-resistant S. pneumoniae. Finally, these enzymatic proteins could be of prime interest against S. pneumoniae to design rational targeted therapy.

Analysis of the Nursing Effect of Respiratory Critical Illness Based on Refined Nursing Management

In order to improve the nursing effect of respiratory critical illness, this paper combines the refined nursing method to explore the nursing plan of respiratory critical illness. Moreover, this paper uses the variable control method to explore the effects of nursing management, combines the hospital patient samples to conduct a controlled trial analysis, and conducts sample grouping according to the random grouping method. The patients in the control group are managed by traditional nursing management methods, the patients in the test group are managed by refined nursing management methods, and other conditions are basically the same. In addition, the experiment process variable control is carried out according to the mathematical statistics method, and the reasonable statistics and data processing are carried out. Through the comparison method, we can see that the refined management method proposed in this paper has a good effect in the nursing of respiratory critical illness.

Combined therapy of Xiaoer Feire Kechuan oral liquid and azithromycin for mycoplasma Pneumoniae pneumonia in children: A systematic review & meta-analysis

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP) has high morbidity with an increased global burden. Xiaoer Feire Kechuan (XEFRKC) oral liquid comprises multiple herbal medicines and possesses numerous broad-spectrum antibacterial activities for MPP. Therefore, treatment options with XEFRKC to provide new clinical evidence for children with MPP needs to be explored.

PURPOSE

This study aimed to evaluate the clinical efficacy and safety of combined treatment of XEFRKC with azithromycin (XEFRKC + azithromycin) for treating the MPP in children.

METHODS

We conducted a comprehensive search in 7 databases to find the randomized controlled trials (RCTs) of XEFRKC + azithromycin treatment. Two researchers independently review the retrieval, extraction, and quality assessment of the dataset. In addition, we conducted the effect model to analyze the data and performed the meta-regression with sensitivity analysis to assess the heterogeneity and stability.

RESULTS

A total of 30 RCTs with 2997 participants were included in this review. The results of primary outcomes showed that the XEFRKC + azithromycin therapy was significantly different with the azithromycin in response rate (RR = 1.18, 95% CI: 1.13 to 1.22), fever disappearance time (MD = -1.01, 95% CI: -1.18 to -0.84), cough disappearance time (MD = -2.18, 95% CI: -2.69 to -1.67), and pulmonary rales disappearance time (MD = -1.3, 95% CI: -1.71 to -0.88). For secondary outcomes and safety as well, XEFRKC + azithromycin had a significant difference compared with azithromycin. Meta-regression results showed that multiple covariables were not the source of heterogeneity. Moreover, sensitivity analysis showed that the stability of the meta-analysis results remained robust.

CONCLUSIONS

For MPP in children, the XEFRKC + azithromycin therapy may be the better option compared with azithromycin alone. However, the accuracy of safety needs to be confirmed and verified with more high-quality RCTs.

Association of Tandem Repeat Number Variabilities in Subunit S of the Type I Restriction-Modification System with Macrolide Resistance in Mycoplasma pneumoniae

Mycoplasma pneumoniae is one of the major pathogens responsible for pneumonia in children. Modern molecular genetics has advanced both the management and the epidemiologic study of this disease. Despite these advancements, macrolide resistance remains a global threat in the management of M. pneumoniae infection, for which the genetic background remains unrevealed. In this study, the result of whole genome analysis of 20 sequence type 3 (ST3) M. pneumoniae strains were examined to investigate the gene(s) associated with macrolide resistance. Overall, genetic similarities within M. pneumoniae, and especially ST3, were very high (over 99.99 %). Macrolide resistant ST3 strains shared 20 single nucleotide polymorphisms, of which one gene (mpn085) was found to be associated with resistance. BLAST comparison of M. pneumoniae revealed regular tandem repeat number variabilities between macrolide-susceptible and resistant strains for genes coding the Type I restriction-modification (R-M) system of subunit S (HsdS). Of the ten known HsdS genes, macrolide resistance was determined by the unique tandem repeat of mpn085 and mpn285. In conclusion, the use of whole genome sequencing (WGS) to target macrolide resistance in M. pneumoniae indicates that the determinant of macrolide resistance is variabilities in the tandem repeat numbers of the type I R-M system in subunit S.

Mycoplasma pneumoniae Infections and Primary Immune Deficiencies

Mycoplasma pneumoniae (M. pneumoniae) is one of the leading causes of community-acquired pneumonia in children and is also implicated in a variety of reactive extrapulmonary diseases. Recurrent and/or severe respiratory infections are one of the most frequent manifestations of several types of primary immunodeficiency. Here, we reviewed the medical literature to assess the potential relevance of M. pneumoniae in the infections observed in children affected with combined, humoral, and innate primary immune deficiencies. M. pneumoniae does not result to be epidemiologically prevalent as a cause of pneumonia in children affected by primary immunodeficiencies, but this infection can have a persistent or severe course in this category of patients. Indeed, the active search of M. pneumoniae could be useful and appropriate especially in children with humoral immune deficiencies. Indeed, most cases of M. pneumoniae infection in primary immunodeficiencies are described in patients affected by a/hypo-gammaglobulinemia.

The epidemiology, clinical characteristics, and macrolide susceptibility of Mycoplasma pneumoniae pneumonia in children in Southern Taiwan, 2019-2020

BACKGROUND

Since the global use of the pneumococcal conjugate vaccine, Mycoplasma pneumoniae (MP) has become the most common bacterial cause of lower respiratory tract infections among children. Monitoring the changing epidemiology and antimicrobial resistance rates of this organism is important for MP clinical management.

METHODS

This study characterizes key features of MP during the 2019-2020 epidemic in children in Taiwan. The cohort included all hospitalized children under 18 years of age with polymerase chain reaction (PCR)-confirmed community-acquired mycoplasma pneumonia (CAMP) in southern Taiwan. Macrolide resistance was identified by mutations in domain V of MP 23S rRNA. Severe disease referred to symptoms warranting oxygen therapy, septic shock, or intensive care unit admission.

RESULTS

Among 495 LRTI patients, 195 (39.4%) had CAMP, of which 106 (54.4%) had concurrent serological evidence of MP infection. The diagnostic sensitivity of IgM in the acute phase was 65.6%. CAMP case numbers were highest from July 2019 to January 2020. The most common clinical presentations of CAMP were fever (99.0%), cough (99.0%), and coryza (31.8%). Despite a high rate of macrolide resistance (88.1%), macrolide-resistant MP (MRMP) did not differ from macrolide-sensitive MP (MSMP) in clinical course or severity. Delayed administration of effective antimicrobial treatment was also associated with severe disease (p < 0.05).

CONCLUSION

Early diagnosis and determination of MRMP are needed for effective management of MP infection.

Consideration in treatment decisions for refractory Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is the most common cause of childhood bacterial pneumonia. Although macrolide is known to be effective as a first-line therapy, the proportion of macrolide resistance in MP pneumonia has strikingly increased during recent 2 decades in East Asia. This is challenging to physicians since they have to decide more often whether to use secondary treatment. Diagnostic methods to detect macrolide-resistance of MP are currently not available in Korean hospitals. Even in the diagnosis of MP infection, both serologic and molecular test have limitation: inability to differentiate current illness from carriage or asymptomatic infection. Combining these 2 diagnostic methods and excluding infection caused by other respiratory pathogens allow a more reliable diagnosis. This effort is even more demanding in recent years to keep children from unnecessary exposure to secondary antibiotics. Although several observational studies have reported that tetracycline and fluoroquinolone, which are considered in the treatment of refractory MP pneumonia, have efficacy of shortening the duration of fever and respiratory symptoms, those findings need to be proven by well-designed prospective studies. The use of tetracycline and fluoroquinolone in children is generally tolerable, as supported by many observational data. However, since concerns about side effects still remain, careful consideration about benefits and risks is needed to decide their use.

Epidemiology and clinical manifestations of children with macrolide-resistant Mycoplasma pneumoniae pneumonia in Southern Taiwan

BACKGROUND

Mycoplasma pneumoniae is a pneumonia-causing pathogen commonly found in pediatric patients in Taiwan. Recently, macrolide-resistant (MR) strains have been emerging globally. The prevalence of pneumonia due to MR-M. pneumoniae (hereafter, MPP) in northern Taiwan before 2017 has been reported to be 12.3-24%. The prevalence of MR-MPP within a specific location can vary. Hence, we investigated the prevalence of MR-MPP in southern Taiwan.

METHODS

Eighty-one children with PCR-confirmed MPP were enrolled between July 2016 and June 2019. They were assigned to macrolide-sensitive (MS) and MR groups based on their PCR results, and their clinical manifestations and laboratory data were compared.

RESULTS

The proportions of patients with MS-MPP and MR-MPP varied with time. The average ratio of the proportion of MR-MPP was 54.3% in this study. Patients with MR-MPP had lower neutrophil counts, higher lymphocyte counts, and higher platelet counts than those with MS-MPP. In contrast with the 40% of the MR-MPP group that still had a fever after three days of azithromycin treatment, only 11.8% of the MS-MPP group still had a fever.

CONCLUSION

Our study provided valuable epidemiological survey information for children with MR-MPP in southern Taiwan. The prevalence of MR-MPP was different from that reported in previous studies in northern Taiwan. Specific MR strains should be considered in children with MPP if they still have a fever after three days of macrolide treatment.

Persistent high macrolide resistance rate and increase of macrolide-resistant ST14 strains among Mycoplasma pneumoniae in South Korea, 2019-2020

BACKGROUND

Expansion of the single sequence type 3 (ST3) was associated with a high macrolide resistance rate among Mycoplasma pneumoniae in Korea during the 2014-2016 epidemic. This study investigates the macrolide resistance rate and genetic diversity of the subsequent epidemic of M. pneumoniae pneumonia in 2019-2020.

METHODS

The culture for M. pneumoniae was developed from 1228 respiratory samples collected from children with pneumonia in four hospitals in Korea between January 2019 and January 2020. Determination of macrolide resistance and multilocus sequence typing analysis were performed on M. pneumoniae isolates. eBURST analysis was applied to estimate the relationships among strains and to assign strains to a clonal complex.

RESULTS

M. pneumoniae was cultured in 93 (7.6%) of 1228 clinical samples. The overall macrolide resistance rate of M. pneumoniae strains was 78.5% (73/93). Of the nine STs identified, three were novel. The most common ST was ST3 (66 [71.0%]) followed by ST14 (18 [19.4%]) and ST7/ST15 (2 [2.2%] each). Three STs (ST3, ST14, and ST17) exhibited macrolide resistance. The macrolide resistance rates of ST3 and ST14 were 98.5% (65 of 66) and 38.9% (7 of 18), respectively.

CONCLUSION

Compared to the previous outbreak in 2014-2016, the overall macrolide resistance remained high; however, an increasing proportion of macrolide resistance was observed within ST14 strains in 2019-2020.

Thrombosis associated with mycoplasma pneumoniae infection (Review)

Mycoplasma pneumoniae is a common pathogen causing respiratory infections in children and adults. In addition to respiratory diseases, Mycoplasma pneumoniae is also involved in numerous extrapulmonary diseases. Thrombosis is an extrapulmonary manifestation associated with Mycoplasma pneumoniae infection. In recent years, an increasing number of case reports have been published identifying thrombosis secondary to Mycoplasma pneumoniae infection. In the present study, the available relevant literature in English available on PubMed, Medline and Web of Science was consulted. The results of the present study demonstrated that in patients with thrombosis caused by Mycoplasma pneumoniae infection, some of the factors causing thrombosis are transient and some are due to hereditary thrombophilia. Following timely treatment, the majority of patients recovered completely but some patients had a poor prognosis. The present review focuses on the pathogenesis, clinical features, treatment and prognosis of this crucial issue, which contributes toward the understanding of the disease.

Mechanism of Shuang-Huang-Lian Oral Liquid for Treatment of Mycoplasmal Pneumonia in Children on Network Pharmacology

BACKGROUND AND OBJECTIVE

Mycoplasmal pneumonia (MP) can lead to inflammation, multiple system immune damage, and mixed infection in children. The pathogenesis is still unclear. Shuang-Huang-Lian (SHL) oral liquid can treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. However, our current understanding of the molecular mechanisms supporting its clinical application still lags behind due to the lack of researches. It is difficult to understand the overall sensitization mechanism of SHL oral liquid. The purpose is to explain the mechanism of action of drugs in this study, which is useful to ensure the safety of medication for children.

METHODS

The therapeutic mechanism of SHL oral liquid was investigated by a system pharmacology approach integrating drug-likeness evaluation, oral bioavailability prediction, ADMET, protein-protein interaction worknet, Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes database pathway performance, C-T-P network construction and molecular docking.

RESULTS

A total of 18 active ingredients contained in SHL oral liquid and 53 major proteins were screened out as effective players in the treatment of M. pneumoniae disease through some related pathways and molecular docking. The majority of targets, hubs and pathways were highly related to anti-mycoplasma therapy, immunity and inflammation process.

CONCLUSION

This study shows that the anti-bacterial effect of SHL oral liquid has multicomponent, multi-target and multi-pathway phenomena. The proposed approach may provide a feasible tool to clarify the mechanism of traditional Chinese medicines and further develop their therapeutic potentials.

Macrolide-Resistant Mycoplasma pneumoniae Infections in Pediatric Community-Acquired Pneumonia

A high prevalence rate of macrolide-resistant Mycoplasma pneumoniae (MRMP) has been reported in Asia. We performed a systematic review and meta-analysis to investigate the effect of macrolide resistance on the manifestations and clinical judgment during M. pneumoniae infections. We found no difference in clinical severity between MRMP and macrolide-sensitive Mycoplasma pneumoniae (MSMP) infections. However, in the pooled data, patients infected with MRMP had a longer febrile period (1.71 days), length of hospital stay (1.61 day), antibiotic drug courses (2.93 days), and defervescence time after macrolide treatment (2.04 days) compared with patients infected with MSMP. The risk of fever lasting for >48 hours after macrolide treatment was also significantly increased (OR 21.24), and an increased proportion of patients was changed to second-line treatment (OR 4.42). Our findings indicate diagnostic and therapeutic challenges after the emergence of MRMP. More precise diagnostic tools and clearly defined treatment should be appraised in the future.

Increased Macrolide Resistance Rate of M3562 Mycoplasma pneumoniae Correlated With Macrolide Usage and Genotype Shifting

To characterize Mycoplasma pneumoniae (MP) strains and to clarify the continuous high rates of macrolide resistance, 1,524 oropharyngeal swabs collected from children in Beijing Children’s Hospital infected with MP during 2016-2019 were analyzed. Among the 1,524 samples, 1,386 harbored mutations associated with macrolide resistance; 1,049 samples were successfully classified into 11 genotypes using multiple locus variable-number tandem-repeat analysis (MLVA). The proportion of the predominant type, M4572, decreased from 84.49 to 70.77% over the time period examined, while that of M3562 increased from 11.63 to 24.67%. Notably, we also found that the frequency of macrolide resistance in M3562 drastically increased, from 60% in 2016 to 93.48% in 2019. Clinical data suggested that the frequency of resistant M3562 was higher in the macrolide usage group than in the nondrug usage group (90.73 vs 53.57%, P<0.0001), while the resistance rate of M4572 was not substantially affected by previous macrolide exposure. These findings validated that antimicrobial application and clonal expansion of resistant MP strains play important roles in the high rates of macrolide resistance.

Predictive Factors of the Responses to Treatment of Mycoplasma pneumoniae Pneumonia

The prevalence of refractory Mycoplasma pneumoniae (MP) pneumonia is increasing. The present study aimed to identify the predictive factors of responses to treatment of MP pneumonia in children. A total of 149 children were diagnosed with MP pneumonia, of whom 56 were included in the good response group, 75 children in the slow response group, and 18 children in no response or progression group. Data on the clinical, laboratory, and radiologic features were retrospectively obtained through medical chart reviews. The severity of pneumonia, based on the extent of pneumonic lesions on chest x-ray (adjusted odds ratio (aOR), 10.573; 95% confidence intervals (CIs), 2.303-48.543), and lactate dehydrogenase (LDH) levels (aOR, 1.002; 95% CIs, 1.000-1.004) at the time of admission were associated with slow response to treatment of MP pneumonia. Pleural effusion (aOR, 5.127; 95% CIs, 1.404-18.727), respiratory virus co-infection (aOR, 4.354; 95% CIs, 1.374-13.800), and higher LDH levels (aOR, 1.005; 95% CIs, 1.002-1.007) as well as MP-specific IgM titer (aOR, 1.309; 95% CIs, 1.095-1.564) were associated with no response or progression of MP pneumonia. The area under the curve for the prediction of no or poor response in MP pneumonia using pleural effusion, respiratory virus co-infection, LDH levels, and MP-specific IgM titer at the time of admission was 0.8547. This study identified the predictive factors of responses to treatment of MP pneumonia in children, which would be helpful in establishing a therapeutic plan and predicting the clinical course of MP pneumonia in children.

Highly homogeneous microbial communities dominated by Mycoplasma pneumoniae instead of increased resistance to macrolide antibiotics is the characteristic of lower respiratory tract microbiome of children with refractory Mycoplasma pneumoniae pneumonia

BACKGROUND

Although researchers have found that the microbiota changed during the lower respiratory tract (LRT) infection, little was known about the association between LRT microbiome and refractory M. pneumoniae pneumonia (RMPP).

METHODS

From June 28th, 2019 to March 23rd, 2020, we enrolled fifty-two children diagnosed with RMPP or non-refractory M. pneumoniae pneumonia (NRMPP), and characterized the structure and function of microbiota in the bronchoalveolar lavage fluid (BALF) by metagenomic next generation sequencing (mNGS).

RESULTS

Based on Bray-Curtis distance between samples, samples in RMPP group were highly homogeneous, and Shannon index in the RMPP group was much lower than NRMPP group while Simpson index, which presents the degree of dominance, was higher in RMPP group. The dominant taxon with relative abundance greater than 50% was merely Mycoplasma among RMPP and NRMPP patients, but the proportions of other taxonomic distribution were different. M. pneumoniae was the dominant species and occupied almost all niches in the vast majority of RMPP patients, whereas the other genera were dramatically lower. The NRMPP group was more enriched in antibiotic resistance genes (ARGs) than the RMPP group, and also exhibited a greater relative abundance of macrolide antibiotics resistance gene (macB) and fluoroquinolone antibiotic resistance genes (patA-B) in M. pneumoniae genome. In RMPP patients, higher relative abundance of Streptococcus pneumoniae had a strong correlation with increased hospitalization days while higher relative abundance of Streptococcus pneumoniae had a negative correlation with hospitalization days among NRMPP patients.

CONCLUSIONS

The microbiota of LRT in children with RMPP was much more homogeneous and simpler than that of the NRMPP group and with lower relative abundance of macrolide antibiotics resistance gene in M. pneumoniae genome. M. pneumoniae was absolutely dominant in the vast majority of RMPP patients. Prolonged hospitalization days was associated with relative abundance of M. pneumoniae in NRMPP patients while it was related with other pathogens' relative abundance (e.g., Streptococcus pneumoniae) in RMPP patients.

Mycoplasma pneumoniae: a pathogen with unsolved therapeutic problems

INTRODUCTION

Despite the amount of new information, the most effective approach for the diagnosis and treatment of Mycoplasma pneumoniae infections is not established. In this narrative review the pharmacological options for macrolide-resistant (ML) M. pneumoniae infections in children are discussed.

AREAS COVERED

Despite significant improvement in the diagnosis and in the definition of diseases potentially associated with this pathogen, not all the problems related to M. pneumoniae infection are solved. True epidemiology of M. pneumoniae diseases and the real role of this pathogen in extra-respiratory manifestations is still unestablished. This reflects on therapy. It is not known whether antibiotics are really needed in all the cases, independently of severity and localization. The choice of antibiotic therapy is debated as it is not known whether ML resistance has clinical relevance. Moreover, not precisely defined is the clinical importance of corticosteroids for improvement of severe cases, including those associated with ML-resistant strains.

EXPERT OPINION

Improvement in M. pneumoniae identification is mandatory to reduce antibiotics overuse , especially in the presence of ML-resistant strains. Priority for future studies includes the evaluation of the true benefit of therapeutic approaches including corticosteroids in patients with severe CAP and in those with extra-respiratory M. pneumoniae diseases.

Mycoplasma pneumoniae: Atypical Pathogen in Community Acquired Pneumonia

Mycoplasma pneumoniae is a one of most common reasons of respiratory tract infections in both adolescents and children with severity ranged from moderate to high. Many facts in the previous years regarding infections were induced via this organism having extra pathogenic mechanisms. Clinically, resistance to macrolide has produced internationally and represents a treatment trouble. Antimicrobial sensitivity checking out techniques have been applied, and novel antibiotics which are effective towards M. pneumoniae are present processing development. That evaluate concentrates on the several trends occurring in the previous quite a few years which beautify the grasp of that microorganism, which is one of the smallest pathogenic bacteria; however, is of extreme medical significance.

Rational stepwise approach for Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae is a common pathogen that causes community-acquired pneumonia. In the past, M. pneumoniae was sensitive to macrolide antibiotics, and M. pneumoniae pneumonia (MPP) was usually a benign and self-limiting disease. However, despite use of the appropriate antibiotics, persistent fever and clinical deterioration may occur, leading to severe disease. Two major complicated conditions that may be clinically encountered are macrolide-resistant MPP and refractory MPP. Regarding the epidemics in Taiwan, before 2017, the mean rate of macrolide resistance was below 30%. Notably, since 2018, the prevalence of macrolide-resistant MPP in Taiwan has increased rapidly. Macrolide-resistant MPP shows persistent fever and/or no radiological regression to macrolide antibiotics and may even progress to severe and complicated pneumonia. Tetracyclines (doxycycline or minocycline) or fluoroquinolones are alternative treatments for macrolide-resistant MPP. Refractory MPP is characterized by an excessive immune response against the pathogen. In this context, corticosteroids have been suggested as an immunomodulator for downregulating the overactive host immune reaction. Overuse of macrolides may contribute to macrolide resistance, and thereafter, an increase in macrolide-resistant MPP. Delayed effective antimicrobial treatment is associated with prolonged and/or more severe disease. Thus, the appropriate prescription of antibiotics, as well as the rapid and accurate diagnosis of MPP, is important. The exact starting point, dose, and duration of the immunomodulator are yet to be established. We discuss these important issues in this review.

Clonal spread of macrolide-resistant Mycoplasma pneumoniae sequence type-3 and type-17 with recombination on non-P1 adhesin among children in Taiwan

OBJECTIVES

Mycoplasma pneumoniae is currently the most commonly detected bacterial cause of childhood community-acquired pneumonia in several countries. Of note, clonal expansion of macrolide-resistant ST3 occurred in Japan and South Korea. An alarming surge in macrolide resistance complicates the treatment of pneumonia. We aimed to evaluate the clinical manifestation and clonal relatedness of M. pneumoniae circulating among children in Taiwan.

METHODS

We prospectively enrolled 626 children with radiologically confirmed pneumonia between 2017 and 2019. An M. pneumoniae infection was suspected on clinical grounds, and tested by real-time PCR and oropharyngeal swab cultures. We used multilocus sequence typing and whole-genome sequencing to characterize the genetic features of M. pneumoniae.

RESULTS

A total of 226 children with M. pneumoniae pneumonia were enrolled. Macrolide resistance was found in 77% (174/226) of patients. Multi-locus sequence typing revealed that ST3 (n = 93) and its single-locus variant ST17 (n = 84) were the predominant clones among macrolide-resistant strains. ST17 presented clinical characteristics comparable to its ancestor ST3. On multivariate analysis, macrolide resistance (OR 3.5; 95% CI 1.4-8.5; p 0.007) was independently associated with fever >72 hours after macrolide treatment. By whole-genome sequencing, prediction analysis of recombination sites revealed one recombination site in ST3 and ST17 compared with M29 (a macrolide-sensitive ST3 strain isolated from China in 2005) containing cytadhesin MgpC-like protein, RepMP4 and RepMP5. ST17 had another recombination site containing an adhesin and RepMP2/3.

CONCLUSIONS

In addition to macrolide resistance, ST3 and its ST17 variant might evolve through recombination between repetitive sequences and non-P1 cytadhesins for persistent circulation in Taiwan.

Severe Mycoplasma pneumoniae pneumonia requiring intensive care in children, 2010-2019

BACKGROUND/PURPOSE

Despite the high prevalence of Mycoplasma pneumoniae infections, reports on severe life-threatening M. pneumoniae pneumonia (MPP) in children are limited.

METHODS

We retrospectively enrolled pediatric patients with PCR-positive MPP requiring ICU admission in a children's hospital in Taipei, Taiwan from Jun 2010 to October 2019. Clinical manifestations and laboratory data of severe MPP were analyzed. Macrolide susceptibility was determined by genotyping, and its relationship with clinical manifestations was also analyzed.

RESULTS

Approximately 5% (34/658) children hospitalized for MPP required ICU admission. Compared with non-ICU cases (n = 291), ICU cases (n = 34) were associated with more underlying conditions, more pleural effusion, longer fever duration, longer hospital stay, the requirement of second-line antibiotic treatment, and delayed effective and second-line antibiotic treatment. Macrolide resistance was similar in ICU and non-ICU groups (53% vs 53%; p = 0.986). In severe MPP, patients requiring endotracheal intubation were associated with more septic shock, empyema, ARDS, prolonged fever after effective antibiotic treatment, delayed second-line and effective antibiotic treatment. In 18 of the 22 patients with pleural fluid analysis, the pleural effusion was alkaline (pH > 7.7) and lymphocyte-predominant.

CONCLUSION

M. pneumoniae infection can cause severe life-threatening pneumonia in children. Delayed effective and second-line antibiotic treatments are associated with severe life-threatening MPP.

Pediatric parapneumonic effusion before and after national pneumococcal vaccination programs in Taiwan

BACKGROUND

Reports on the effectiveness of pneumococcal conjugate vaccines (PCVs) on pediatric parapneumonic effusion are limited. We report the changes in cases and etiologies of pediatric parapneumonic effusion in a children's hospital before and after national PCV13 vaccination programs.

METHODS

We screened medical records of children 0-18 years admitted to the National Taiwan University Hospital with diagnoses of lobar pneumonia and parapneumonic effusion between 2008 and 2017. Patients with effusion analyses were included. Results of blood, pleural fluid, and respiratory specimens surveyed as standard care were analyzed.

RESULTS

Diagnostic testing revealed at least a pathogen in 85% of 202 children with lobar pneumonia and parapneumonic effusion. After national PCV13 immunization, pneumococcal empyema decreased by 72% among 2- to 5-year olds. Mycoplasma pneumoniae was the second most common etiology. There were marked differences in effusion characteristics, metabolic, and respiratory parameters between children infected with pneumococcus and M. pneumoniae.

CONCLUSION

The effectiveness of the national PCV13 immunization programs on pneumococcal empyema was evident and remained substantial after 4 years in Taiwan. Continuous surveillance is important to monitor the emergence of other pathogens including non-PCV serotypes and M. pneumoniae.

Early diagnosis and appropriate respiratory support for Mycoplasma pneumoniae pneumonia associated acute respiratory distress syndrome in young and adult patients: a case series from two centers

BACKGROUND

Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community acquired pneumonia (CAP). Establishing an early diagnosis of M. pneumoniae pneumonia in patients with acute respiratory distress syndrome (ARDS) may have important therapeutic implications.

METHODS

We describe diagnosis and management of M. pneumoniae pneumonia induced ARDS in a case series of adults and youth hospitalized with radiographically confirmed CAP prospectively enrolled in an observational cohort study in two university teaching hospitals, from November 2017 to October 2019.

RESULTS

In all 10 patients, early and rapid diagnosis for severe M. pneumoniae pneumonia with ARDS was achieved with polymerase chain reaction (PCR) or metagenomic next-generation sequencing (mNGS) testing of samples from the lower respiratory tract or pleural effusion. The average PaO₂/FiO₂ of all patients was 180 mmHg. Of the 10 cases, 4 cases had moderate ARDS (100 mmHg ≤ PaO₂/FiO₂ < 200 mmHg) and 3 cases had severe ARDS (PaO₂/FiO₂ < 100 mmHg). High flow nasal cannula (HFNC) was applied in all patients, though only two patients were sufficiently supported with HFNC. Invasive mechanical ventilation (IMV) was required in 5 patients. High resistance (median 15 L/cmH₂O/s) and low compliance (median 38 ml/cmH₂O) was observed in 4 cases. In these 4 cases, recruitment maneuvers (RM) were applied, with 1 patient demonstrating no response to RM. Prone positioning were applied in 4 cases. Two cases needed ECMO support with median support duration of 5.5 days. No patient in our case series received corticosteroid therapy. All patients were survived and were discharged from hospital.

CONCLUSIONS

Early and rapid diagnosis of severe M. pneumoniae pneumonia with ARDS can be achieved with PCR/mNGS tests in samples from the lower respiratory tract or pleural effusion. In our case series, half of M. pneumoniae pneumonia induced ARDS cases were adequately supported with HFNC or NIV, while half of cases required intubation. RM and prone position were effective in 30% of intubated cases, and 20% needed ECMO support. When early anti-mycoplasmal antibiotics were given together with sufficient respiratory support, the survival rate was high with no need for corticosteroid use.

Altered chemokine profile in Refractory Mycoplasma pneumoniae pneumonia infected children

BACKGROUND

Mycoplasma pneumoniae is one of the major pathogens causing community-acquired pneumonia in children. Although usually self-limited, Mycoplasma pneumoniae pneumonia (MPP) may lead to complicated morbidity that can even be life-threatening. Upon MPP infection, alveolar macrophage becomes attracted and activated and will induce subsequent cytokine and chemokine reaction. Refractory Mycoplasma pneumoniae pneumonia (RMPP) is manifested by clinical or radiological deterioration despite proper antibiotic therapy. RMPP is characterized with excessive inflammation and may need subsequent glucocorticoid treatment.

AIM

The aim of this study was to investigate the change of plasma chemokines in non-refractory Mycoplasma pneumoniae pneumonia (NRMPP) and RMPP before and after antibiotic or methylprednisolone treatment.

METHOD

A total of 42 children with MPP were enrolled in this study. Plasma specimens were collected at admission and one to two weeks after antibiotic or methylprednisolone treatment with declined fever. Plasma specimens were then indicated to chemokines detection.

RESULTS

Mycoplasma pneumoniae pneumonia altered the chemokine profile through the observation of decreased plasma M1 related chemokines (CCL2, CCL8 and CXCL10) and increased M2 related chemokines (CCL17 and CCL22) after treatment.When the patients were divided into RMPP and NRMPP groups and the chemokines before treatment were compared, the RMPP group showed higher CXCL10 but lower CCL3 and CCL11 than the NRMPP group.

CONCLUSION

Unique changes in macrophage related chemokines is observed in the course of MPP infection. NRMPP and RMPP infection in children showed distinct manifestation in chemokine profiles.

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.

Azithromycin suppresses Th1- and Th2-related chemokines IP-10/MDC in human monocytic cell line

BACKGROUND

Cytokines and chemokines play critical roles in the pathogenesis of asthma. Azithromycin, a macrolides, is frequently used in asthmatic children with lower respiratory tract infection and is reported having anti-inflammatory and immunomodulatory effects. However, the effects of azithromycin on the expression of TNF-α, Th1- and Th2-related chemokines, and neutrophil chemoattractant are unknown. We investigated the in vitro effects of azithromycin on the expression of TNF-α, Th1-related chemokine interferon-γ-inducible protein-10 (IP-10/CXCL10), Th2-related chemokine macrophage-derived chemokine (MDC/CCL22) and neutrophil chemoattractant growth-related oncogene-α (GRO-α/CXCL1) in THP-1 cells as a model for human monocytes.

METHODS

THP-1 cells were pretreated with various concentrations of azithromycin before Toll-like receptor 4 (TLR4) agonist lipopolysaccharide (LPS) stimulation. TNF-α, IP-10, MDC and GRO-α were measured by ELISA. Intracellular signaling was investigated by pathway inhibitors and Western blot.

RESULT

Azithromycin suppressed MDC and IP-10 expression in LPS-stimulated THP-1 cells. However, azithromycin had no effect LPS-induced TNF-α and GRO-α expression. Western blotting revealed that azithromycin suppressed LPS-induced phosphorylation of mitogen-activated protein kinase (MAPK)-JNK and ERK expression, and also suppressed LPS-induced phosphorylation of nuclear factor (NF) κB-p65 expression.

CONCLUSION

Azithromycin suppressed LPS-induced MDC expression via the MAPK-JNK and the NFκB-p65 pathway. Azithromycin also suppressed LPS-induced IP-10 via the MAPK-JNK/ERK and the NFκB-p65 pathway. Azithromycin may benefit asthmatic patients by suppressing chemokines expression.

Reverse vaccinology and subtractive genomics reveal new therapeutic targets against Mycoplasma pneumoniae: a causative agent of pneumonia

Pneumonia is an infectious disease caused by bacteria, viruses or fungi that results in millions of deaths globally. Despite the existence of prophylactic methods against some of the major pathogens of the disease, there is no efficient prophylaxis against atypical agents such as Mycoplasma pneumoniae, a bacterium associated with cases of community-acquired pneumonia. Because of the morphological peculiarity of M. pneumoniae, which leads to an increased resistance to antibiotics, studies that prospectively investigate the development of vaccines and drug targets appear to be one of the best ways forward. Hence, in this paper, bioinformatics tools were used for vaccine and pharmacological prediction. We conducted comparative genomic analysis on the genomes of 88 M. pneumoniae strains, as opposed to a reverse vaccinology analysis, in relation to the capacity of M. pneumoniae proteins to bind to the major histocompatibility complex, revealing seven targets with immunogenic potential. Predictive cytoplasmic proteins were tested as potential drug targets by studying their structures in relation to other proteins, metabolic pathways and molecular anchorage, which identified five possible drug targets. These findings are a valuable addition to the development of vaccines and the selection of new in vivo drug targets that may contribute to further elucidating the molecular basis of M. pneumoniae-host interactions.

Mycoplasma pneumoniae-related extra-pulmonary diseases and antimicrobial therapy

The findings by Yang-TI et al. suggested that macrolide-resistance and/or delayed appropriate antimicrobial treatment may contribute to the development of Mycoplasma pneumoniae-related extra-pulmonary diseases in children. Indeed, these conditions can have variable clinical expression and severity, and may arise in immunologically predisposed children after recurrent/persistent exposure to Mycoplasma pneumoniae.