Molecular beacon based real-time PCR p1 gene genotyping, macrolide resistance mutation detection and clinical characteristics analysis of Mycoplasma pneumoniae infections in children

Navigating the outbreak: a comprehensive analysis of pediatric Mycoplasma pneumoniae pneumonia via targeted next-generation sequencing in Wuhan, 2022-2023

This study aims to delineate the epidemiological characteristics and impacts of the Mycoplasma pneumoniae (MP) outbreak, utilizing targeted next-generation sequencing (tNGS) to assess pathogen prevalence and co-infections in pediatric pneumonia cases. Pediatric patients admitted to Wuhan Children's Hospital with pneumonia from 1 October 2022 to 31 October 2023 were included. tNGS was used for comprehensive pathogen detection, including MP and other respiratory pathogens, with additional sequencing of the 23S rRNA gene V region to identify macrolide resistance mutations. This study enrolled 10,223 patients with pneumonia with a positivity rate of 98.4% by targeted next-generation sequencing. Fever (86.4%) and cough (79.3%) were the most common symptoms of Mycoplasma pneumoniae pneumonia (MPP). Lung consolidation (25.8%) was a common imaging feature, and corticosteroid use was noted in 22.5% of MPP patients. MP proved to be the primary pathogen, particularly evident during the MP pandemic, which began in March 2023 and peaked in October with a detection rate of 63.2%. Of the 4,397 MPP cases, 34.5% were sole infections, while 65.6% were co-infections, mostly with viruses. The main causative agents of co-infections were Haemophilus influenzae and Rhinovirus. The macrolide resistance rate was 79.03%. The A2063G mutation in the 23S rRNA V region is the dominant mutation. High-sensitivity C-reactive protein and serum amyloid A were significantly elevated in MPP, while the absolute counts of CD3+T, CD4+T, CD8+T, CD19+B, and NK cells were significantly reduced. This study demonstrates the utility of tNGS in identifying MP co-infections and macrolide resistance and highlights the role of inflammatory markers and lymphocyte subpopulations in differentiating MPP from non-Mycoplasma pneumoniae pneumonia for clinical management.IMPORTANCEOur study is of great scientific value as it provides practical solutions to clinical challenges and supports both clinical decision-making and public health policy. First, it presents new and important insights into the application of targeted next-generation sequencing (tNGS) technology, which enables rapid and accurate pathogen detection and overcomes the limitations of conventional diagnostic methods. Second, the large sample size, focusing specifically on children during a Mycoplasma pneumoniae epidemic, provides valuable epidemiologic data specifically for the Wuhan region. Finally, by integrating rapid tNGS detection with inflammatory markers and lymphocyte subsets, our study demonstrates direct clinical applications that have the potential to improve patient outcomes. This approach highlights the practical utility of our research in enhancing clinical decision-making and contributes important knowledge to the field.

C-reactive protein-induced injury in Mycoplasma pneumoniae-infected lung epithelial cells is mediated by the P38 MAPK/mitochondrial apoptosis pathway

Patients with Mycoplasma pneumoniae (MP) infections have markedly higher C-reactive protein (CRP). We investigated how CRP contributes to lung epithelial cell death following MP infection. CRP levels were assessed in children diagnosed with Mycoplasma pneumoniae pneumonia (MPP) and A549 lung epithelial cells infected with MP. A549 cells were genetically modified to overexpress CRP. Effects on cell viability, apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm) were evaluated. The expression of proteins implicated in the p38 MAPK/mitochondrial apoptotic pathway was analyzed. The protective effects of the p38 MAPK inhibitor SB203580 and the mitochondrial protector cyclosporin A (CsA) were assessed. CRP levels were elevated in both MPP patients and MP-infected A549 cells compared to controls. Increased apoptosis and reduced cell viability were observed in MP-infected cells. CRP overexpression led to upregulation of proteins in the p38 MAPK/mitochondrial apoptosis pathway, increased cytoplasmic Cyt C, decreased Tom 20 and ΔΨm, and elevated ROS. Pretreatment with SB203580 or posttreatment with CsA reduced apoptosis and mitochondrial damage and enhanced cell survival. Increased CRP levels during MP infection promote lung epithelial cell death by activating the p38 MAPK/mitochondrial apoptosis pathway. Targeting this pathway could offer therapeutic potential to reduce lung damage in MPP patients.IMPORTANCEThis study provides critical information in understanding the pathophysiological mechanisms for MP infections concerning CRP in mediating lung epithelial cell injury. This study outlines the significant increase in MP-infected patients and shows its direct involvement in cell apoptosis through the p38 MAPK/mitochondrial apoptosis pathway. By explaining this pathway, the possibility of targeting CRP and its connected signaling mechanisms to devise therapeutic interventions for the amelioration of lung damage in MP-infected patients is brought to light. The implications of such data are not merely in the added knowledge for disease pathobiology but also it brings new promise for novel intervention strategies to result in improved clinical outcomes. The elucidation of specific molecular targets inside the apoptosis pathway heralds a new area regarding the direction of future research and clinical application for humanity in general and concerning the broader relevance and impact of this study on respiratory diseases.

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.

Trends in Mycoplasma pneumoniae infections in pediatric patient preceding, during, and following the COVID-19 pandemic: a comprehensive longitudinal analysis

This study investigated the impact of the coronavirus disease 2019 (COVID-19) pandemic and its associated restrictive measures on Mycoplasma pneumoniae infections in children with acute respiratory tract infection. The study aimed to elucidate the epidemiological characteristics of M. pneumoniae infections before and during the pandemic and following the easing of restrictive measures. Pharyngeal secretions were collected from 1,0174 pediatric patients with acute respiratory infection (ARI) who were admitted to Shaoxing Maternity and Child Health Care Hospital (Shaoxing, China) between May 2018 and December 2023. The analysis concentrated on M. pneumoniae detection rates, epidemiological features, and clinical characteristics. Among 10,174 samples collected from 2018 to 2023, 1,060 strains of M. pneumoniae were detected, resulting in an overall positive rate of 10.42% (n = 1,060 out of 1,0176). Further breakdown revealed positive rates of 8.25% (n = 279 out of 3,381) in phase I (May 2018-December 2019), 2.40% (n = 87 out of 3,623) in phase II (January 2020-November 2022), and 21.89% (n = 694 out of 3,170) in phase III (December 2022-December 2023). In comparison to phase I, a noteworthy decline in the positive rate of M. pneumoniae was found during phase II, followed by a substantial increase during phase III (P < 0.05). Furthermore, the positive rate of M. pneumoniae exhibited a significantly greater surge during the summer-autumn period in contrast to the winter-spring (P < 0.05). Additionally, the risk of M. pneumoniae infection in children who aged 7 years surpassed that of the age group of 0-3 years. Throughout the phases preceding, during, and after the COVID-19 pandemic, discernible fluctuations in both age distribution and seasonality of M. pneumoniae infections were identified among hospitalized children with ARI in the East China.

IMPORTANCE

The resemblance between the transmission pathways of M. pneumoniae and those of COVID-19 suggests that non-pharmaceutical interventions may have comparable effects on both. This study aimed to analyze the epidemiological characteristics of children with M. pneumoniae infections in Shaoxing, China, from 2018 to 2023. This study explored how the COVID-19 pandemic has influenced the prevalence of M. pneumoniae and provided guidance for disease treatment and infection prevention.

Epidemiological and clinical characteristics of hospitalized pediatric patients with Mycoplasma pneumoniae pneumonia before and after the COVID-19 pandemic in China: a retrospective multicenter study

BACKGROUND

In China many respiratory pathogens stayed low activities amid the COVID-19 pandemic due to strict measures and controls. We here aimed to study the epidemiological and clinical characteristics of pediatric inpatients with Mycoplasma pneumoniae pneumonia (MPP) after the mandatory COVID-19 restrictions were lifted, in comparison to those before the COVID-19 pandemic.

METHODS

We here included 4,296 pediatric patients with MPP, hospitalized by two medical centers in Jiangsu Province, China, from January 2015 to March 2024. Patients were divided into the pre-COVID (n = 1,662) and post-COVID (n = 2,634) groups. Their baseline characteristics, laboratory test results and radiological patterns were separately assessed and compared between the two groups to determine the substantial changes in the disease profile of MPP after the COVID-19 pandemic.

RESULTS

Epidemiological results suggested a higher annual incidence of MPP after the COVID-19 pandemic when the outbreak reached a peak in October, two months delayed in seasonality compared to that in the pre-COVID era. For pediatric patients with MPP, there was no difference in their median ages, gender ratios, and severe case percentages between the two groups, where most patients were younger than 14 years old. With significance, the post-COVID group had more occurrences of cough and expectoration and higher incidences of influenza A/B virus (IAV/IBV) co-infection than the pre-COVID group. Many hematological parameters and radiological features between the two groups displayed alteration, but comparatively there demonstrated no worsened severity in hospitalized children with MPP after COVID-19 pandemic. Concurrently, the post-COVID group was administered with fewer antibiotics but more corticosteroids for effective treatment than the pre-COVID group.

CONCLUSION

Through the COVID-19 pandemic, the epidemiological and clinical characteristics of pediatric patients with MPP differed, but there was no evident change in the disease severity. After the COVID-19 pandemic, the increased incidence of IAV/IBV co-infection may contribute to the differences in clinical symptoms and hematological profiles, while the adding usage of corticosteroids might treat more effectively.

Epidemiological characteristics of mycoplasma pneumoniae in hospitalized children before, during, and after COVID-19 pandemic restrictions in Chongqing, China

Background

Mycoplasma pneumoniae (MP) is a significant cause of community-acquired pneumonia with high macrolide resistance rates. Various COVID-19 pandemic restrictions have impacted the prevalence of MP.

Objective

To assess the changes in the pattern of MP infections among children before, during, and after the COVID-19 pandemic.

Methods

A total of 36685 enrolled patients, aged 0-18 years, diagnosed with pneumonia and admitted to Children's Hospital of Chongqing Medical University from January 2019 to December 2023, were retrospectively reviewed in this study. The epidemiological characteristics of pediatric MP infection were analyzed.

Results

Among 36685 patients, 7610 (20.74%) tested positive for MP. The highest positive rate was observed among children aged over 6 years (55.06%). There was no gender disparity in MP infection across the three phases of the COVID-19 pandemic. Hospital stays were longest for children during the COVID-19 pandemic (P <0.001). MP infection was most prevalent in the summer (29.64%). The lowest positive rate was observed during the pandemic, with the highest rate found after easing the measures across all age groups (P <0.001). There was a surge in the positive rate of MP in the third year after the COVID-19 pandemic. Regression analyses demonstrated a shift in the age range susceptible to MP infection, with children aged 3.8 to 13.5 years post-pandemic compared to the pre-pandemic range of 5.3 to 15.5 years old. Additionally, the average macrolide resistance rate was 79.84%. We observed a higher resistance rate during the pandemic than in the pre- and post-pandemic phases (P <0.001).

Conclusion

The restrictive measures implemented during the COVID-19 pandemic have influenced the spread of MP to some extent and altered demographic and clinical characteristics, such as age, age group, season, length of stay, and macrolide resistance. We recommend continuous surveillance of the evolving epidemiological characteristics of MP infection in the post-pandemic period when restrictions are no longer necessary.

Increased macrolide resistance rate of Mycoplasma pneumoniae correlated with epidemic in Beijing, China in 2023

We collected respiratory specimens from 128 pediatric patients diagnosed with pneumonia in Beijing in late 2023. Mycoplasma pneumoniae was detected in 77.3% (99/128) patients, with 36.4% (4/11), 82.9% (34/41), 80.3% (61/76) in children aged less than 3 years, 3-6 years, over 7 years, respectively. Mycoplasma pneumoniae (M. pneumoniae) was characterized using P1 gene typing, MLVA typing and sequencing of domain V of the 23S rRNA gene. P1 gene type 1 (P1-1; 76.1%, 54/71) and MLVA type 4-5-7-2 (73.7%, 73/99) were predominant. MLVA identified a new genotype: 3-4-6-2. Macrolide resistance-associated mutations were detected in 100% of samples, with A2063G accounting for 99% and A2064G for 1%. The positive rate of M. pneumoniae was higher compared to previous reports, especially in children less than 3 years, suggesting a M. pneumoniae epidemic showing a younger age trend occurred in late 2023 in Beijing, China. Higher proportions of macrolide-resistant M. pneumoniae, P1-1 and 4-5-7-2 genotype M. pneumoniae indicated increased macrolide resistance rate and genotyping shift phenomenon, which might be attributable to this epidemic. Additionally, complete clinical information from 73 M. pneumoniae pneumonia inpatients were analyzed. The incidence of severe M. pneumoniae pneumonia was 56.2% (41/73). Mycoplasma pneumoniae pneumonia patients exhibited longer duration of fever, with a median value of 10.0 days (IQR, 8.0-13.0), and higher incidence of complications (74.0%, 54/73). However, in this cohort, we found that the severity of M. pneumoniae pneumonia, co-infection, or complications were not associated with M. pneumoniae P1 gene or MLVA types. Clinicians should be aware that patients infected with macrolide-resistant M. pneumoniae exhibited more severe clinical presentations.

Predominance of A2063G mutant strains in the Mycoplasma pneumoniae epidemic in children: A clinical and epidemiological study in 2023 in Wuhan, China

OBJECTIVES

The prevalence of respiratory infectious diseases has changed in the post-COVID-19 epidemic era, and mycoplasma pneumoniae (MP) infection in children has attracted wide attention.

METHODS

Children hospitalized for pneumonia in Wuhan, China, in 2023 were enrolled. Respiratory secretions were obtained for the targeted next-generation sequencing (tNGS) including mutation of MP. Pulmonary inflammation was divided into bronchopneumonia and pulmonary consolidation/atelectasis according to lung computed tomography imaging.

RESULTS

Of the 667 pediatric pneumonia, 478 were MP positive (72%). The positive rate of MP detected by tNGS increased from April, and MP had become the primary pathogen of pneumonia in children in 2023. The 23S rRNA mutations were all A2063G, accounting for 85% of detected MP. The clinical symptoms of the mutant and wild-type strains were similar, with half of them experiencing atelectasis and lung consolidation. Early bronchoscopic lavage combined with azithromycin in pediatric pulmonary consolidation was an effective therapy strategy, which could be an alternative selection to MP pneumonia treatment.

CONCLUSIONS

A2063G mutant strain MP was the primary pathogen of mycoplasma pneumoniae in children recently, which was often complicated by extra-pulmonary symptoms and complications.

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.

Influence of COVID-19 pandemic on the epidemiology of Mycoplasma pneumoniae infections among hospitalized children in Henan, China

Background

Increasing reports have indicated that non-pharmaceutical interventions to control the COVID-19 pandemic may also have an effect on the prevalence of other pathogens. Mycoplasma pneumoniae is an important atypical pathogen prevalent in children with high rates of macrolide resistance. The aim of this study was to investigate the epidemiological characteristics of M. pneumoniae infection in children before and during the COVID-19 pandemic.

Methods

In this study, M. pneumoniae detection results were extracted from Henan Children's Hospital from 2018 to 2021. The epidemiological characteristics of pediatric M. pneumoniae infection were analyzed.

Results

We found that the highest positive rate of M. pneumoniae infection was 11.00 % in 2018, 14.01 % in 2019, followed by 11.24 % in 2021 and 8.75 % in 2020 (p < 0.001). Most tested children had respiratory system manifestations, and pneumoniae was the most common diagnosis (53.23 %). An increase in the number of positive cases was observed with an increase in age, with a higher number of cases among children over 6 years old. No positive cases were identified among children aged 1-28 days. The decrease in the positive rate among children aged between1-6 years old in 2020 and 2021 was found to be statistically significant (p < 0.001). The pre-pandemic period demonstrated a higher incidence rate in the fall, whereas the summers and winters exhibited a significantly higher positive rate during the pandemic period (p < 0.001). Different regions in Henan also showed different epidemic patterns.

Conclusions

In summary, strict pandemic measures influenced the spread of M. pneumoniae to some extent and changed demographic characteristics, including age, season and regional distribution. Continuous monitoring is required for the control and prevention of related diseases.

Droplet magnetic-controlled microfluidic chip integrated nucleic acid extraction and amplification for the detection of pathogens and tumor mutation sites

Traditional nucleic acid extraction and detection is based on open operation, which may cause cross-contamination and aerosol formation. This study developed a droplet magnetic-controlled microfluidic chip integrated nucleic acid extraction, purification and amplification. The reagent is sealed in oil to form a droplet, and the nucleic acid is extracted and purified by controlling the movement of the magnetic beads (MBs) through a permanent magnet, ensuring a closed environment. This chip can automatically extract nucleic acid from multiple samples within 20 min, and can be directly placed in the in situ amplification instrument for amplification without further transfer of nucleic acid, characterized by simple, fast, time-saving and labor-saving. The results showed that the chip was able to detect <10 copies/test SARS-CoV-2 RNA, and EGFR exon 21 L858R mutations were detected in H1975 cells as low as 4 cells. In addition, on the basis of the droplet magnetic-controlled microfluidic chip, we further developed a multi-target detection chip, which used MBs to divide the nucleic acid of the sample into three parts. And the macrolides resistance mutations A2063G and A2064G, and the P1 gene of mycoplasma pneumoniae (MP) were successfully detected in clinical samples by the multi-target detection chip, providing the possibility for future application in the detection of multiple pathogens.