To unravel distinct patterns of metagenomic surveillance and respiratory microbiota between Mycoplasma pneumoniae (M. pneumoniae) P1-1 and P1-2 and to explore the impact of the COVID-19 pandemic on epidemiological features, we conducted a multicentre retrospective study which spanned 90,886 pneumonia patients, among which 3164 cases M. pneumoniae were identified. Our findings revealed a concurrent outbreak of M. pneumoniae, with the positivity rate rising sharply to 9.62% from July 2023, compared to the 0.16% to 4.06% positivity rate observed during the 2020-2022 COVID-19 pandemic. P1-1 had a higher odds ratio of co-detecting opportunistic pathogens. However, no significant differences were observed in the co-detection odds ratio between children and other age groups in P1-2. This study is the first to demonstrate differences in relative abundance, diversity of respiratory microbiota and co-detection rate of opportunistic pathogen between M. pneumoniae P1-1 and P1-2. Through bronchoalveolar lavage (BAL) metagenomic and host transcriptomic analyses, we identified variations in co-detection rates of M. pneumoniae P1-1 genotype with opportunistic pathogens like S. pneumoniae, alterations in respiratory microbiota composition, lung inflammation, and disruption of ciliary function. Consistent with the results of host transcriptome, we found that P1-1 infections were associated with significantly higher rates of requiring respiratory support and mechanical ventilation compared to P1-2 infections (Fisher's exact test, p-value = 0.035/0.004). Our study provides preliminary evidence of clinical severity between M. pneumoniae strains, underscoring the need for ongoing research and development of targeted therapeutic strategies.

Mycoplasma pneumoniae causes community-acquired pneumonia and extrapulmonary manifestations. It is an important cause of atypical pneumonia in children and can be associated with cyclical epidemics. This manuscript reviews the performance of current M. pneumoniae diagnostic methods, including culture-based, serological and nucleic acid amplification testing. The added value of molecular typing and genome sequencing in controlling M. pneumoniae epidemics is also considered, especially in characterising the evolving epidemiology and detecting genes and mutations associated with antimicrobial resistance, studies of which are lacking in Australia at present.

The isolation and culture of Mycoplasma pneumoniae (MP) is time-consuming and has a low success rate. On the basis of the fact that cell lines are susceptible to MP contamination, we explored the possibility of using Hep-2 cell culture for the isolation and culture of MP, to overcome this long-standing technical problem.

Quantitative Real-time PCR (qPCR) was used to detect MP in the nucleic acid samples of clinically suspected mycoplasma-infected patients. Positive samples were cultured in Hep-2 cells, with the classical commercial MP liquid culture medium serving as a control. For successful isolation of MP, the broth culture medium was used for subculture, then transferred to solid agar medium for isolation. The isolated strains were identified by nucleic acid and whole-genome sequencing.

Among the 20 throat swab samples collected from individuals with influenza-like illness, 10 MP-positive samples were detected by qPCR. Five strains of Mycoplasma were successfully cultured in Hep-2 cells within 7-10 days, while one strain was cultured in commercial MP broth after 21 days, with isolation rates of 50% and 10%, respectively. After repeated subculturing in liquid medium and inoculation onto solid medium, "fried-egg"-like colonies emerged. The isolated strains were identified by nucleic acid and whole-genome sequencing.

The use of cell culture enables the rapid and effective isolation and culture of MP, addressing the long-standing challenge of MP cultivation. This advancement may contribute to improved antibiotic development, vaccine research, and the maintenance of global public health security.

Pneumonia constitutes a major health challenge in sheep, severely compromising growth rates and overall productivity, and resulting in considerable economic losses to the sheep industry. To address this issue, the development of disease-resistant breeding programs based on the identification of genetic markers associated with pneumonia susceptibility is of critical importance. This study investigated a sheep population on a farm where pneumonia was endemic. The purpose was to use multi-omics methods to rapidly identify the principal pathogens responsible for pneumonia outbreaks, and to screen for genetic loci and key genes related to pneumonia resistance, thereby providing a scientific basis for the implementation of targeted breeding strategies for pneumonia resistance.

Here, we assessed the impact of pneumonia on sheep growth by evaluating the pneumonia phenotypes of 912 sheep. High-throughput transcriptome sequencing of 40 lungs was conducted to obtain exogenous RNA fragments for microbial sequence alignment. Additionally, 16S rRNA sequencing was performed on lung tissues from 10 healthy and 10 diseased sheep to identify biomarkers associated with phenotypic differences. Mycoplasma ovipneumoniae was identified as the primary pneumonia pathogen, and its presence was further validated by load quantification and immunohistochemical analysis. Integration of genome-wide association study (GWAS) data from 266 lung pathological scores with transcriptome-based differentially expressed genes analysis enabled the identification of five single nucleotide polymorphisms (SNPs) and three potential candidate genes associated with Mycoplasma pneumonia. Subsequent genotyping and phenotype association analyses confirmed the significance of two SNPs and established a strong association between the FOXF1 gene and resistance to Mycoplasma pneumonia.

High-throughput sequencing technologies have enabled the rapid and accurate identification of the causative pathogen of sheep pneumonia. By integrating multi-omics data, two genomic loci significantly associated with Mycoplasma pneumonia were screened, as well as an anti-Mycoplasma pneumonia key gene, FOXF1.

Although lung transplant recipients who develop Ureaplasma-associated hyperammonemia syndrome are treated with Ureaplasma-targeted antibiotics, optimal therapy is incompletely defined, and typically not based on real-time antimicrobial susceptibility testing results. This study compared levofloxacin, azithromycin, and doxycycline prevention and treatment of Ureaplasma urealyticum (UU) and Ureaplasma parvum (UP) infections in an immunosuppressed murine lung infection model. For prophylaxis, mice received antibiotics before infection with UP-FS (susceptible to all study antibiotics), UP-AzmR (azithromycin-resistant), UP-LevR (levofloxacin-resistant), or UU-DoxR (doxycycline-resistant), with lung bacterial loads (color changing units [CCUs]) measured 18 hours following infection. For UP-FS, doxycycline was most active (Δ4.84 log10 CCU/g; P = 0.0006), followed by levofloxacin (Δ2.45 log10 CCU/g; P = 0.018), with azithromycin yielding a nonsignificant CCU reduction. Doxycycline (Δ1.9 log10 CCU/g; P = 0.0025) and levofloxacin (Δ1.3 log10 CCU/g; P = 0.004) showed activity against UP-AzmR. Only doxycycline showed activity against UP-LevR (Δ2.28 log10 CCU/g; P = 0.0002), and only azithromycin showed activity against UU-DoxR (Δ0.67 log10 CCU/g; P = 0.0175). For treatment, antibiotics were administered 24 hours following infection; doxycycline significantly reduced bacterial loads of all study isolates, except UU-DoxR. In addition, azithromycin was active against UP-LevR (Δ1.21 log10 CCU/g reduction; P = 0.0003). In summary, except for doxycycline-resistant UU, doxycycline was active in preventing and treating Ureaplasma lung infection in immunosuppressed mice.

Mycoplasma pneumoniae is a major cause of respiratory tract infections. We aimed to investigate the spatiotemporal dynamics, antimicrobial resistance, and severity of the delayed re-emergence of infections with M pneumoniae after the implementation of non-pharmaceutical interventions (NPIs) against COVID-19.

Epidemiological data (positive and total test numbers, and macrolide-resistant M pneumoniae detections) and clinical data (hospitalisations, intensive care unit [ICU] admissions, and deaths) were collected through our global surveillance from April 1, 2017 to March 31, 2024. The moving epidemic method (MEM) was used to establish epidemic periods, and the time-series susceptible-infected-recovered (TSIR) model to investigate the delayed re-emergence.

The dataset included 65 sites in 29 countries from four UN regions: Europe, Asia, the Americas, and Oceania. A global re-emergence of M pneumoniae cases by PCR detection was noted from the second half of 2023. The mean global detection rate was 11·47% (SD 15·82) during the re-emergence (April, 2023-March, 2024). By use of MEM, the re-emergence was identified as epidemic in all four UN regions, simultaneously in ten countries at calendar week 40 (early October, 2023). Macrolide-resistant M pneumoniae rates from Europe and Asia were 2·02% and 71·22%, respectively, and did not differ between the re-emergence and pre-COVID-19 pandemic periods. During the re-emergence, some countries reported increased hospitalisations (in adults, two of ten countries; and in children, two of 14 countries) and ICU admissions (in adults, one of nine countries; and in children, two of 14 countries). Overall, 65 (0·11%) deaths were reported, without statistical difference between pre-COVID-19 pandemic and re-emergence. The TSIR model accurately predicted, considering a 3-week generation time of M pneumoniae and a 90% reduction in transmission through NPIs, the observed delayed re-emergence.

This large global dataset for M pneumoniae detections shows that although there was an unprecedented high number of detections across many countries in late 2023, the severity and number of deaths remained low. Our results suggest that the delayed re-emergence was related to the long incubation period of M pneumoniae infection.

None.

Mycoplasma pneumoniae (MP) is a significant pathogen associated with community-acquired pneumonia, with considerable infectious risks posed, particularly to children and immunocompromised individuals. The current methods for detecting MP in research and clinical settings are recognized as time-consuming, instrument-dependent, and prone to non-specific cross-reactivity. Therefore, the creation of a rapid and sensitive detection method is urgently required. In this study, the MP-ERA-Cas12a system, integrating enzyme restriction amplification (ERA) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a technology, was introduced. Three detection methods were evaluated: the two-pot system, a modified one-pot system, and a lateral flow assay (LFA) strip-based system. In the one-pot system, the amplification and detection steps were consolidated within a single reaction vessel, effectively minimizing the risk of contamination and false positives that may arise from the handling of multiple tubes. It was observed that the one-pot system generated a fluorescent signal within 1 h and produced 1.6 times higher fluorescence signal intensity compared to the two-pot system, achieving a detection limit of 1 copy/μL. In contrast, the LFA system facilitated rapid on-site screening, with visible band results appearing on the strip within 5 min of the reaction, and a detection limit of 102 copies/μL was achieved. High specificity for MP was demonstrated by all methods. Significant advantages, including rapid processing, the absence of complex instrumentation, and ease of use are offered by this detection system, making it particularly suitable for resource-limited clinical settings. The system is seen as an efficient tool for the early diagnosis of MP, with substantial public health and clinical relevance.

This study successfully combined enzyme restriction amplification (ERA) with the specific detection capabilities of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a. Based on the two-pot system established before, the one-pot system and lateral flow assay (LFA) system were developed for Mycoplasma pneumoniae (MP) detection. The MP-ERA-Cas12a system eliminates the need to open the lid during the reaction, reducing aerosol contamination, and minimizing the risk of false positives. The method does not require the use of advanced instruments or equipment and shows strong specificity while not being affected by other pathogens. As a new method of MP detection, the MP-ERA-Cas12a system has an important practical application prospect.

Mycoplasmas are the smallest cell-wall-less self-replicating prokaryotes. Mycoplasma species can be found within and outside cells as "silent parasites" that live intracellularly and as membrane surface parasites. The pathogen's impact on respiratory health seems primarily caused by its capacity to alter immune responses, cause airway inflammation, and damage epithelial barriers. Much progress has been made in understanding Mycoplasma-induced inflammation and oxidative stress. However, there are still issues in therapeutic management, such as the development of strains that are resistant to antibiotics, the shortcomings of the available diagnostic techniques, and possible long-term respiratory consequences. On the other hand, to combat oxidative stress, inflammation, and metabolic abnormalities, activation of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is becoming a more appealing therapeutic strategy. Nrf2 activation coordinates a thorough defense through its transcriptional targets, enabling adaptability and survival under a variety of cellular stressors. Nrf2 is regarded as a therapeutic target, and pharmacological Nrf2 activators have demonstrated protective effects in multiple pathological consequences and advantages in clinical trials. In this review, we discussed the rationale for targeting Nrf2 in a series of inflammatory responses caused by Mycoplasma species.

This study aimed to explore the characteristics of bronchial mucus plug formation and its risk factors. A total of 578 children who underwent bronchoalveolar lavage treatment between January 2022 and June 2024 at the Department of Pediatric, Women and Children's Hospital of Ganzhou were assessed in this study.The bronchoalveolar lavage fluid was tested by next-generation sequencing. The resistance genes of macrolides in Mycoplasma pneumoniae (MP) were detected by polymerase chain reaction. Data related to the basic information, clinical characteristics, and etiology were statistically analyzed. Logistic regression analysis was performed to identify the independent risk factors for bronchial mucus plug formation. There were 312 cases in the mucus plug group and 266 in the non-mucus plug group. The mucus plug group children were older, had longer hospital stays, exhibited a higher incidence of fever, experienced more complications, and had higher rates of hormone use when compared to those in the non-mucus plug group (P < 0.05). The detection rate of MP and macrolide resistance was significantly higher in the mucus plug group than in the non-mucus plug group (P < 0.05). According to the logistic regression analysis, macrolide-resistant MP (MRMP) acted as an independent risk factor for the formation of bronchial mucus plugs in children.

Bronchial mucus plugs were common in children with MP infection, often accompanied by fever and prolonged hospitalization. MRMP was thus identified as an independent risk factor for bronchial mucus plug formation.

• MP can lead to bronchial mucus plugs.

• MRMP is an independent risk factor for the formation of bronchial mucus plugs.

Mycoplasma pneumoniae (MP) is a common bacterial respiratory infection that can cause pneumonia, particularly in children. Previously published data have highlighted the high incidence of viral co-infections and the problem of increasing macrolide resistance in MP worldwide.

(1) to estimate the impact of viral infections circulating in a local population on the spectrum of co-infection in hospitalized children with Mycoplasma pneumoniae pneumonia (MPP), (2) to determine if there are differences in resistance mutation rate for samples from hospitals of Russia located in the European and Far East, (3) to describe genomic characteristics of MP from Russian patients during the MPP outbreaks in the fall-winter of 2023-2024.

The carriage of viral pathogens was analyzed by real-time PCR in children with MPP from the European Part and Far East of Russian Federation and compared with the infections from two control groups. The V region of the 23S gene and the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes were sequenced to detect resistance-associated mutations in MP. Whole-genome sequencing method was used to determine the genetic relationship of a Russian MP isolate with known MP isolates.

The 62% of patients with MPP had a viral co-infection, with HPIV and SARS-CoV-2 predominating at 47% and 12.4%, respectively. The 15% of patients were infected with two or more viruses. In the control groups, 21% of healthy children and 43% of healthy adults were infected with Coronaviruses and Human Parainfluenza Viruses (HPIV-3 and -4), respectively. The 2063 A/G mutation of the 23S gene was found in 40.8% of patients from European Russia and in 35.7% of patients from the Far East. The result of core genes demonstrates that the sequence obtained from Russia clusters with sequences from clade 1.

Both HPIV and SARS-CoV-2 circulated in the population among healthy children and adults in December 2023 and they also were predominated in children with MPP. The rate of macrolide resistance was ⁓40%, which is higher than in European countries and significantly lower than in patients from Asian countries. Phylogenetic analysis showed the MP genome form Russia related to P1 type 1 (clade 1).

Serious respiratory infections can occur in both in-hospital and out-of-hospital settings. These infections are known as community-acquired pneumonias (CAPs). Streptococcus pneumoniae and other microorganisms commonly cause atypical pneumonia. This study examined the clinical features, medication therapy, and prognosis of 85 cases of community-acquired pneumonia (CAP) caused by Mycoplasma pneumoniae (MPP) and Chlamydia psittaci(C. psittaci)neumoniae (CPP).

A retrospective analysis was conducted at Shaoxing People's Hospital from July 2021 to August 2024, using targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid (BALF). Patients were classified into the MPP group (54 patients) and the CPP group (31 patients). Compared with the control group, the CPP group had a significantly lower proportion of patients with a contact history of poultry and birds, a shorter length of hospital stay, and a lower percentage of severe pneumonia cases.

The MPP group demonstrated higher incidences of cough and sputum production; conversely, the occurrences of fever, fatigue, diminished appetite, and generalised myalgia were comparatively lower. The MPP group exhibited markedly diminished levels of neutrophils, C-reactive protein, procalcitonin, erythrocyte sedimentation rate, heparin-binding protein, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, direct bilirubin, pH, lactic acid, and D-dimer compared with the CPP group. In contrast, the MPP group had a markedly higher lymphocyte count, platelet count, albumin levels, as well as higher concentrations of blood sodium and blood chloride. The drug treatment regimens differed between the two groups, resulting in one unfavourable outcome within the MPP group.

In summary, fatigue, fever, and reduced appetite are more prominent symptoms in patients with CPP, whereas cough and sputum production are the primary manifestations of MPP. Pleural effusion is more prevalent in patients with CPP, Additionally, these patients also have increased inflammatory responses and decreased immune function.

The outsourcing of amino acid (AA) production to the environment is relatively common across the tree of life. We recently showed that the massive loss of AA synthesis capabilities in animals is governed by selective pressure linked to the energy costs of AA production. Paradoxically, these AA auxotrophies facilitated the evolution of costlier proteomes in animals by enabling the increased use of energetically expensive AAs. Experiments in bacteria have shown that AA auxotrophies can provide a fitness advantage in competition with prototrophic strains. However, it remains unclear whether energy-related selection also drives the evolution of bacterial AA auxotrophies and whether this affects the usage of expensive AAs in bacterial proteomes. To investigate these questions, we computationally determined AA auxotrophy odds across 980 bacterial genomes representing diverse taxa and calculated the energy costs of all their proteins. Here, we show that auxotrophic AAs are generally more expensive to synthesize than prototrophic AAs in bacteria. Moreover, we found that the cost of auxotrophic AAs significantly correlates with the cost of their respective proteomes. Interestingly, out of all considered taxa, Mollicutes and Borreliaceae-chronic pathogens highly successful in immune evasion-have the most AA auxotrophies and code for the most expensive proteomes. These findings indicate that AA auxotrophies in bacteria, similar to those in animals, are shaped by selective pressures related to energy management. Our study reveals that bacterial AA auxotrophies act as costly outsourced functions, enabling bacteria to explore protein sequence space more freely. It remains to be investigated whether this relaxed use of expensive AAs also enabled auxotrophic bacteria to evolve proteins with improved or novel functionality.

Mycoplasma pneumoniae (Mp), a unique pathogen devoid of a cell wall, is naturally impervious to penicillin antibiotics. This bacterium is the causative agent of M. pneumoniae pneumonia, an acute pulmonary affliction marked by interstitial lung damage. Non-macrolide medications may have potential adverse effects on the developmental trajectory of children, thereby establishing macrolides as the preferred treatment for M. pneumoniae in pediatric patients. However, the emergence of macrolide-resistant and multidrug-resistant strains of M. pneumoniae presents significant challenges to clinical management and public health. Vaccines, particularly those based on mRNA technology, are regarded as a promising avenue for preventing and controlling M. pneumoniae infections due to their inherent safety, immunogenicity, and adaptability. Our research delves into the P1 adhesin of M. pneumoniae, a protein that binds to host cell receptors with its immunodominant epitopes located at the carboxyl terminus, known to provoke robust immune responses and pulmonary inflammation. We have developed an mRNA vaccine harnessing this dominant antigenic epitope and assessed its protective immunity in BALB/c mice against M. pneumoniae infection. The vaccine elicited potent humoral and cellular immune responses, effectively diminishing inflammation. It notably decreased IL-6 levels in the lungs of infected mice and concurrently elevated IL-4, IL-10, and IFN-γ levels post-immunization. The vaccine also reduced pathological changes in the lungs and the M. pneumoniae DNA copy numbers in the infected animals. Collectively, these findings underscore the mRNA vaccine's remarkable immunogenicity and protective potential against M. pneumoniae infections, offering valuable insights for the development of mRNA vaccines targeting mycoplasma infections.IMPORTANCEM. pneumoniae, a bacteria without a cell wall, is known for causing pneumonia and is resistant to penicillin. The increasing prevalence of macrolide-resistant strains has complicated treatment options, emphasizing the need for new strategies. Our research explores an mRNA vaccine candidate that targets the P1 adhesin of M. pneumoniae, a protein critical for the bacteria's interaction with host cells. In a mouse model, this vaccine has shown potential by inducing immune responses and suggesting a possible reduction in inflammation, as indicated by changes in cytokine levels and lung pathology. While further research is required, the vaccine's preliminary results hint at a potential new direction in managing mycoplasma infections, offering a promising avenue for future therapeutic development. This study contributes to the ongoing search for effective preventive measures against M. pneumoniae.

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

Analysis of current 2023-2024 Mycoplasma pneumoniae (Mp) infection characteristics in adults.

A retrospective case series analysis was performed on Mp polymerase chain reaction-positive adult patients admitted to the University Hospital of Marseille from April 2017 to June 2024. Clinical presentations, treatments, and outcomes were assessed. We compared the epidemiological and clinical characteristics of Mp infections between 2017 and 2022 with the current epidemic.

Clinical and radiological characteristics and outcomes of patients with Mp infection did not differ significantly between the current epidemic (N = 108) and the 5 previous years (N = 94), except that patients in the current epidemic required less supplemental oxygen (odds ratio [95% confidence interval] = 0.48 [0.29-0.78]) and were less likely to present with fever on admission (odds ratio [95% confidence interval] = 0.22 [0.10-0.47]). In both periods, more than half of the patients hospitalized with Mp infection required supportive oxygen therapy.

During the current 2023-2024 epidemic, more hospital admissions for Mp infection in adults were observed at the University Hospital of Marseille than in the previous 5 years. The clinical characteristics and outcomes of patients with Mp infection did not differ significantly. In our cohort, Mp infection was often severe, regardless of the study period.

The global prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) pneumonia infections, particularly in children, is on the rise. It is imperative to assess the clinical efficacies of alternative antibiotics such as tetracyclines to ensure effective treatment, mitigate antibiotic resistance, enhance clinical outcomes, and minimize the spread of resistant strains among MRMP-infected children. The objective of this study was to compare the therapeutic efficacies of macrolides and tetracyclines in treating MRMP pneumonia in children.

We systematically searched the literature to identify comparative studies that examined the clinical outcomes of macrolide and tetracycline antibiotics in children with MRMP pneumonia. We conducted a meta-analysis of the mean duration of fever, hospital stay duration, therapeutic efficacies, and time to defervescence to compare macrolides and tetracyclines.

Eleven studies involving 1143 patients compared the clinical efficacies of macrolides and tetracyclines in children with MRMP pneumonia. The studies were conducted in China, Japan, and Korea, and the outcomes of febrile days, hospital stay duration, therapeutic efficacy, and time to defervescence were analyzed. The macrolides studied were azithromycin and clarithromycin, whereas the tetracyclines included minocycline and doxycycline. The pooled estimate of 5 studies showed that the mean duration of febrile days and hospital stay was longer in the macrolides group than tetracycline group [weighted mean difference = 1.64 days, 95% confidence interval (CI): 0.68-2.59, weighted mean difference = 1.22 days, 95% CI: 0.82-1.62, respectively]. The therapeutic efficacy was significantly lower in the macrolide group than in the tetracycline group (odds ratio: 0.33, 95% CI: 0.20-0.57).

The clinical efficacy of tetracycline treatment was superior to that of macrolide treatment in children with MRMP pneumonia. However, further research is required to validate these findings and inform evidence-based clinical practice guidelines.

We aimed to systematically review and analyze the prevalence and pattern of resistance in Mycoplasma pneumoniae.

We searched authentic scientific sources and databases, and reference lists of relevant articles from Jan 1, 2017, to Jun 1, 2023.

Most of the included studies were conducted in Asia (11470 patients). The overall pooled prevalence was 53% (41%-65%), I2=99.69%; P <0.001. While subgroups analyses revealed that the pooled prevalence for America (3 studies), Asia (29 studies), and Europe (3 studies) was 9% (5%-12%), 62% (52%-73%), and 6% (1%-12%), respectively. Twenty-one eligible studies for determining of A2063G and 16 for A2064G were analyzed. Global pooled prevalence was 67% (58%-76%), I2=99.65%; P<0.001, and 3% (2%-4%), I2=87.44%; P<0.001 for A2063G and A2064G, respectively. Pooled prevalence of A2063G for America, Asia and Europe was 10% (5%-16%), 77% (71%-83%) and 5% (2%-9%), respectively.

While the prevalence of macrolide-resistant M. pneumonia is quite low in America, it is a great dilemma in East Asia and the low prevalence in most countries could be underestimated. This study revealed an increasing trend in macrolide resistance. Indiscriminate and improper use of macrolides may be a warning in this regard.

During the winter 2023-2024, an upsurge of Mycoplasma pneumoniae (M.pneumoniae) was noted in the Netherlands. To investigate the distribution of M.pneumoniae sequence types from different patient populations and to explore genotypic macrolide resistance which is common in East Asia but not (yet) in Europe. M.pneumoniae positive throat/nasal samples from participatory respiratory surveillance, patients visiting general practitioners with an acute respiratory infection including community acquired pneumonia (CAP) and hospitalised patients with CAP were included, representing different disease severity. The M.pneumoniae were typed with multilocus sequence typing and the 23 S rRNA region was sequenced to determine macrolide resistance markers. In total, 153 M.pneumoniae were sequenced, six sequence types (STs) and only one bacterium with macrolide resistance marker were detected. No link between STs or bacterial load (PCR cycle threshold) and source population of M.pneumoniae was detected. In the Netherlands, the M.pneumoniae upsurge in 2023-2024 existed of multiple commonly found STs. No link between ST and severity of illness was detected. Macrolide resistance remained sporadic.

An epidemic of Mycoplasma pneumoniae infection has been observed in France since September, 2023. We aimed to describe the characteristics of adults hospitalised for M pneumoniae infection and identify factors associated with severe outcomes of infection.

MYCADO is a retrospective observational study including adults hospitalised for 24 h or more in 76 hospitals in France for a M pneumoniae infection between Sept 1, 2023, and Feb 29, 2024. Clinical, laboratory, and imaging data were collected from medical records. We identified factors associated with severe outcomes of infection, defined as a composite of intensive care unit (ICU) admission or in-hospital death, using multivariable logistic regression.

1309 patients with M pneumoniae infection were included: 718 (54·9%) were men and 591 (45·1%) were women; median age was 43 years (IQR 31-63); 288 (22·0%) had chronic respiratory failure; 423 (32·3%) had cardiovascular comorbidities; and 105 (8·0%) had immunosuppression. The most common symptoms were cough (1098 [83·9%]), fever (1023 [78·2%]), dyspnoea (948 [72·4%]), fatigue (550 [42·0%]), expectorations (473 [36·1%]), headache (211 [16·1%]), arthromyalgia (253 [19·3%]), ear, nose, and throat symptoms (202 [15·4%]), diarrhoea (138 [10·5%]), and vomiting (132 [10·1%]). 156 (11·9%) of 1309 patients had extra-respiratory manifestations, including 36 (2·8%) with erythema multiforme, 19 (1·5%) with meningoencephalitis, 44 (3·4%) with autoimmune haemolytic anaemia, and 17 (1·3%) with myocarditis. The median hospital stay was 8 days (IQR 6-11). 424 (32·4%) patients had a severe outcome of infection, including 415 (31·7%) who were admitted to the ICU and 28 (2·1%) who died in hospital. Those more likely to present with severe outcomes of infection were patients with hypertension, obesity, chronic liver failure, extra-respiratory manifestations, pulmonary alveolar consolidation or bilateral involvement on CT scan, as well as elevated inflammatory markers, lymphopenia or neutrophilic polynucleosis, and those who did not versus did receive any antibiotic active against M pneumoniae before admission.

This national, observational study highlighted unexpected, atypical radiological presentations, a high proportion of transfers to the ICU, and an association between severity and delayed administration of effective antibiotics. This should remind clinicians that no radiological presentation can rule out M pneumoniae infection, and encourage them to reassess patients early after prescribing a β-lactam, or even to discuss prescribing macrolides as first-line treatment in the context of an epidemic.

None.

For the French translation of the abstract see Supplementary Materials section.

Mycoplasma pneumoniae (MP) is a major a rapid, sensitive and reliable method for the detection of 16S ribosomal RNA (16S rRNA) was developed based on catalytic hairpin assembly (CHA) technology and digoxine-biotin double-labeled fluorescence immunochromatography (FICA) strip. The signal amplification achieved by CHA avoids the dependence on expensive thermal cycling equipment. The method can obtain the results within 1 h in the absence of an enzyme, and the minimum detection limit can reach 1 pM. It has good specificity and can effectively distinguish target sequences from non-target sequences. After verification with adult samples and pediatric samples, it was found that CHA-FICA detection was highly consistent with those of PCR detection, indicating that it has clinical application potential and is expected to be used in clinical screening and treatment detection of mycoplasma pneumoniae (MP) infection.

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

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

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

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

This study aimed to describe the epidemiological trends of Mycoplasma pneumoniae (MP) infection among children with acute respiratory tract infections (ARTIs) before, during and after the COVID-19 pandemic, and evaluating the impact of non-pharmaceutical interventions (NPIs) on the epidemiology of MP infection.

Children with ARTIs admitted to the Children's Hospital of Soochow University (SCH) from January 2010 to December 2023 and underwent MP nucleic acid PCR assay were included. Clinical data on age, sex, onset time and detection result were collected and analyzed.

All of the 122,984 inpatients were enrolled, in which 20.8% (25659/122984) of the children with MP tested positive, including 19.4% (14139/72662) for male and 22.9% (11520/50322) for female. It was a statistically significant difference between the two genders (p < 0.05). In addition, the positive rate of MP was the highest in the age group > 6 years old each year (p < 0.05). During 14-year period, the detection rate of MP has experienced four peaks in 2012, 2013, 2019, and 2023. Before the NPIs the prevalence of MP showed seasonality, and the number and rate of MP positivity reached their peak in August. However, the rate of MP positivity remained at a low level during the NPIs. After the abolition of NPIs, the MP positivity rate obviously increased and remained at a high level.

The NPIs could reduce the spread of MP infection and change its epidemic season, but it has not changed the susceptible population of MP infection.

Antimicrobial drug resistance (AMR) is a pressing global human health challenge. Humans face one of their grandest challenges as climate change expands the habitat of vectors that bear human pathogens, incidences of nosocomial infections rise, and new antibiotics discovery lags. AMR is a multifaceted problem that requires a multidisciplinary and an "all-hands-on-deck" approach. As chemical microbiologists, we are well positioned to understand the complexities of AMR while seeing opportunities for tackling the challenge. In this Outlook, we focus on vulnerabilities of human pathogens and posit that they represent "opportunity targets" for which few modulatory ligands exist. We center our attention on proteins in Gram-negative organisms, which are recalcitrant to many antibiotics because of their external membrane barrier. Our hope is to highlight such targets and explore their potential as "druggable" proteins for infectious disease mitigation. We posit that success in this endeavor will introduce new classes of antibiotics that might alleviate some of the current pressing AMR concerns.

Mycoplasma pneumoniae caused lower respiratory tract infection in children and can exacerbate these infections through the production of various inflammatory factors, with chemokines playing a key role. However, the pathogenesis of this infection is complicated and thus has not been thoroughly studied. We clarified that cytokine expression levels were analyzed in both peripheral blood and bronchoalveolar lavage fluid (BALF), and in vitro assays were conducted using THP-1 macrophages. We discovered that, compared to control children, M. pneumoniae pneumonia (MPP) patients expressed significantly higher levels of CXCL10 both in the peripheral blood and BALF. Moreover, numbers of macrophages, predominantly with a M1 phenotype, were significantly increased in BALFs of children of MPP. In vitro, coculture with IFN-γ or activated CD4+ Th1 cells significantly promoted CXCL10 expressions in THP-1 derived macrophages, which was largely reversed by siRNA-mediated down regulation of STAT1. In addition, IFN-γ-stimulated macrophages greatly promoted the trans-migration of Th1 cells. our data show that Th1 cells-derived IFN-γ augments CXCL10 production in macrophages via the JAK-STAT1 pathway, which subsequently recruits more immune cells like Th1 cells into the infection sites, thereby constituting a positive feedback loop and aggravating the type I inflammatory responses in MPP patients.

Although infection with Mycoplasma pneumoniae is generally self-limited, it may cause refractory or life-threatening pneumonia with pulmonary or extrapulmonary complications. Necrotizing bronchitis is a rare condition with a high mortality rate. The present report describes a patient with mycoplasma pneumonia and necrotizing bronchitis that caused airway obstruction. A 7-year-old girl presented with fever and cough and was hospitalized. Her symptoms did not improve, and mild hypoxemia was observed. Fiberoptic bronchoscopy revealed diffuse bronchitis with necrotic and hemorrhagic material obstructing the bronchus. The necrotic tissue was removed directly, unblocking the airways. This case underscores the importance of fiberoptic bronchoscopy for early diagnosis and treatment of severe respiratory complications associated with Mycoplasma pneumoniae infection, such as necrotizing bronchitis. Early recognition and timely intervention are critical to improving patient outcomes in such cases.

In this prospective study incidence of Mycoplasma pneumoniae (M. pneumoniae) infection was investigated in children with community-aquired lower respiratory tract infections (LRTIs) using methods such as serology, nested PCR (polymerase chain reaction), and multiplex PCR analysis.

M. pneumoniae infection was investigated among 200 children with LRTIs, ages 2 months to 12 years,. Blood samples were taken for M. pneumoniae antibodies both during admission and four to six weeks following enrollment. Nested and multiplex PCR analysis was performed to identify M. pneumoniae from nasopharyngeal aspirates (NPAs).

Infection due to M. pneumoniae was noted in 29 children (74.35 %) < 5 years of age and in 10 children (25.65 %) aged ≥5 years. The relationship between M. pneumoniae and age was statistically significant in the age group of children under five years [P = 0.004]. No statistically significant difference was seen between male and female children [P = 0.91]. Clinical and radiological results and M pneumoniae infection did not demonstrate any statistically significant correlation with the exception of the presence of statistically significant infiltrates (P = 0.04). In 39 (19.5 %) children, M. pneumoniae was found using a combination of multiplex PCR, nested PCR, and serology. Serology sensitivity was 66.67 %, specificity was 88.56 %, positive and negative predictive values were 36.36 % and 96.41 %, respectively, when using nested PCR as the diagnostic criteria.

In summary, our research established the critical role of M. pneumoniae infection in community-acquired LRTIs in children particularly in children under five years. There was an association between wheezing and acute M. pneumoniae infection. Multiplex PCR, nested PCR, and serology are used in conjunction to help diagnose M. pneumoniae infection in children with community-acquired LRTIs.

After ending the three-year zero COVID policy in China, the epidemiology of other respiratory pathogens has been affected. This study aimed to characterize of common respiratory pathogen infections in pediatric patients hospitalized for acute respiratory tract infections (ARTIs) in Suzhou before and after ending the zero COVID policy. Nasopharyngeal aspirates (NPAs) were obtained from children with ARTIs (aged ≤ 16 years) at the Children's Hospital of Soochow University for the detection of respiratory syncytial virus (RSV), influenza A (FluA), FluB, human parainfluenza virus (HPIV), adenovirus (ADV), human rhinovirus (HRV), bocavirus (BoV), human metapneumovirus (HMPV), and mycoplasma pneumoniae (MP). The data were compared between two periods: January 2020 to December 2022 (before ending the zero COVID policy) and January 2023 to May 2024 (after ending the zero COVID policy). Patients were divided into four groups: 0-2, ≥ 3-5, ≥ 6-10, and ≥ 11-16 years. A total of 42,379 patients were enrolled and the top four pathogens identified were MP, HRV, RSV and HPIV with positive rates of 20.2%, 19.5%, 15.1%, and 6.9%, respectively. A total of 28,352 positive cases were detected, with positive rates of 54.0% (n = 11,850/21,941) and 80.7% (n = 16,502/20,438) before and after ending the zero COVID policy, respectively. Total RSV, HRV, HPIV, and MP positivity increased by 27.8%, 39.0%, 12.3%, and 322.7%, respectively, after ending the zero COVID policy compared to positivity before the policy. After ending the zero COVID policy, the positive rates of RSV, HRV, and HPIV increased most in children aged 0-2 years, with increases by 88.8% (OR: 2.3, 95% CI: 2.2-2.5), 50.0% (OR: 1.6, 95% CI: 1.5-1.7), and 69.6% (OR: 1.8, 95% CI: 1.6-2.0), respectively. The greatest increase in MP positivity was 316.9% in the 3-5 years (OR: 5.5, 95% CI: 4.9-6.1). After ending the zero COVID policy, the RSV-positive rate increased most in summer, while HRV was predominantly circulated in spring and the MP-positive rate peaked in autumn. Ending the zero COVID policy facilitated the transmission of common respiratory pathogens in children. Post-pandemic surveillance and control of respiratory pathogens must be strengthened to reduce health risks.

Mycoplasmas are structurally simple pathogenic microorganisms that can cause a wide range of diseases in humans and animals and conventional antibiotic therapies of fluoroquinolones and tetracyclines are toxic to young children and young animals and macrolide resistance is increasing. In this context, new anti-mycoplasma antimicrobial agents need to be developed. 22-((4-((4-nitrophenyl)acetamido)phenyl)thio)deoxypleuromutilin (compound 16C) is a novel acetamine phenyl pleuromutilin derivative. This study aimed to evaluate its acute toxicity in mice and generate pharmacokinetic and anti-mycoplasma profiles.

The safety of compound 16C was preliminarily evaluated by oral and intramuscular acute toxicity tests and single intravenous and intramuscular pharmacokinetic experiments were performed to obtain its pharmacokinetic profile. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-killing curves reflected the in vitro effects of the compounds against Mycoplasma pneumoniae. Five groups consisted of three treatments for compound 16C (20, 40, and 80 mg/kg), and two treatments for tiamulin (oral and intramuscular 40 mg/kg) were continued for 4 d. Bronchoalveolar lavage fluid (BALF) and lung tissues were collected at the end of treatment (96 h) and 4 days later (192 h) to assess the in vivo anti-mycoplasma and anti-pneumonia effects. ELISA assays were performed to detect IFN-γ, TNF-α, and IL-8 (CXCL1) in BALF. Lung tissues were fixed with 4% paraformaldehyde and sectioned for histopathological assessment.

The results show that compound 16C has low toxicity (LD50 > 5,000 mg/kg). Its pharmacokinetic profile is characterized by a short time to maximum concentration (Tmax = 0.24 h), high bioavailability (F = 71.29%), and short elimination half-life (T1/2kel) (intramuscular and intravenous administration was 2.20 and 1.89 h, respectively). Treatment with compound 16C and intramuscular tiamulin reduced the mycoplasma load in mice. Intramuscular compound 16C and tiamulin also inhibited the release of IFN-γ, TNF-α, and CXCL1, decreasing the accumulation of inflammatory cells in the lungs, thereby mitigating lung damage.

This study proved that compound 16C has a strong antimicrobial effect against M. pneumoniae, can be rapidly absorbed and has therapeutic efficacy that provides a basis for developing new anti-mycoplasma drugs.

Mycoplasma pneumoniae (M. pneumoniae), a common pathogen of community-acquired pneumonia in school-age children and adolescents, can cause epidemics worldwide. In late 2023, the incidence of M. pneumoniae infection among children reached a high level.

We investigated the in vitro antimicrobial susceptibility of 62 M. pneumoniae isolates obtained from children with pneumonia in Beijing between 2021 and 2023, and analyzed the correlation of antimicrobial susceptibility with molecular characteristics of isolates and clinical manifestations of patients.

The resistance rates of M. pneumoniae isolates against erythromycin and azithromycin were both 100% (62/62). The minimum inhibitory concentration (MIC) of acetylspiramycin (16-membered macrolides) was lower than that of erythromycin and azithromycin. The MIC of azithromycin in 2023 was notably higher compared to 2021 and 2022. No resistance to tetracycline and levofloxacin was observed. Genotypes P1 type 1 and P1 type 2 were identified in 74.2% and 25.8% of isolates, and M4-5-7-2 (61.3%) and M3-5-6-2 (22.6%) were predominant multi-locus variable-number tandem-repeat analysis (MLVA) types. The A2063G mutation was present in all isolates (100%). Among the patients, 45/59 cases (76.3%) had severe M. pneumoniae pneumonia, and 14/59 cases (23.7%) presented co-infection. The duration of fever was 12 days (1-30 days) and the fever duration after initiation of macrolide antibiotics treatment was 8 days (1-22 days).

Our study showed that macrolide-resistant M. pneumoniae (MRMP) with high in vitro antimicrobial resistance level may be the causative factor of the M. pneumoniae epidemic in late 2023 in Beijing, China. It is urgent to pay more attention to MRMP and the antibiotics choose.

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

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

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

Respiratory infection caused by pathogens is among the most prevalent health issues affecting people worldwide. Accurate and rapid screening of respiratory pathogens is crucial for selecting appropriate treatments to control epidemics. However, it is often challenged by two aspects: first, the low concentration of pathogens in the early stages of infection; second, the difficulty of analyzing multiple pathogens. Herein, we report a mass spectrometry strategy combining the CRISPR/Cas12a system with DNA nanomachines for respiratory pathogens detection. Thanks to the high sensitivity of the CRISPR/Cas12a-enhanced DNA nanomachine and the multiple analysis of elemental mass spectrometry, the proposed method was successfully applied for clinical sample analysis with a low detection limit of 28 amol, 30 amol, and 38 amol for SARS-CoV-2, influenza A virus subtype H1N1, and Mycoplasma pneumoniae, respectively.

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

Macrolide-unresponsive Mycoplasma pneumoniae pneumonia (MUMPP) cases have been rapidly increasing. The primary reason for this increased incidence is the pathogen's acquisition of resistance through mutations in 23S rRNA genes. Due to the unfeasibility of testing for macrolide susceptibility at the time of admission, this study aimed to assess the clinical features of pediatric MUMPP, using insights from laboratory tests and patterns of chest radiographic resolution.

We conducted a retrospective review of 161 patients with M. pneumoniae pneumonia (MPP) between January 2023 and December 2023. These patients were categorized into two groups based on their responsiveness to macrolides: 72 patients were in the MUMPP group, and 89 patients were in the macrolide-sensitive Mycoplasma pneumoniae pneumonia (MSMP) group.

MUMPP patients experienced a longer duration of fever and hospital stay. A higher proportion of MUMPP patients had shortness of breath, transcutaneous blood oxygen saturation (SpO2) lower than 94%, bilateral lobar infiltrates, lobar pneumonia and pleural effusion. The serum level of serum ferritin (SF), interleukin-6(IL-6), D-dimer, lactate dehydrogenase to albumin rate (LAR), and neutrophil to lymphocyte rate (NLR) were higher in MUMPP group.

Our findings revealed that patients with MUMPP exhibit more severe initial radiographic indicators and clinical course compared to those with MSMP. Therefore, it is crucial to promptly administer alternative therapeutic agents besides macrolides for the management of MUMPP.

Mycoplasma pneumoniae (MP) is the cause of Mycoplasma pneumoniae pneumonia (MPP) in children and adolescents, with the clinical manifestations highlighted by intermittent irritating cough, accompanied by headache, fever and muscle pain. This paper aimed to study the research status and focal points in MP infection, especially the common laboratory diagnostic methods and clinical treatment of Mycoplasma pneumoniae. Laboratory diagnostic methods include molecular assay, serological antibody detection, rapid antigen detection and isolation and culture. Polymerase chain reaction (PCR) is the gold standard with high sensitivity and specificity. The serological antibody can detect various immune antibodies qualitatively or quantitatively in serum. Rapid antigen can be detected faster, with no equipment environment requirements, which can be used for the early diagnosis of MP infection. While the culture growth cycle is long and insensitive, not recommended for routine diagnosis. Macrolides were the preferred drug for children with MPP, while the drug resistance rate was rising in China. Tetracycline can be substituted but was not recommended for children under 8 years of age, quinolone drugs are not necessary, severe MPP can be combined with glucocorticoids, involving the nervous or immune system can choose gamma globulin. Other treatments for MPP including symptomatic treatment which can alleviate symptoms, improve lung function and improve prognosis. A safe and effective vaccine needed to be developed which can provide protective immunity to children and will reduce the incidence of MPP.

Since the onset of COVID-19, respiratory diseases have emerged as a focal concern within the field of public health. This study aims to reveal the prevalence of acute respiratory infectious diseases by screening antipyretic, antiviral, and antibiotic biomarkers through wastewater analysis. Samples were collected over a seven-day period each year in 2022, 2023, and 2024 from a northern city in China, assessing the concentrations of two antipyretics (paracetamol and ibuprofen), one antiviral drug (oseltamivir), eleven antibiotics, and three pathogens (influenza A, influenza B, and Mycoplasma pneumoniae). The usage of most antipyretics and antibiotics was higher in 2023 and 2024, primarily due to the outbreak of COVID-19 in 2023 and the prevalence of influenza A, influenza B, and Mycoplasma pneumoniae in 2024. The prevalence assessed using antipyretics (2.68 %) and pathogens (2.70 %) demonstrated a high degree of consistency, whereas the prevalence estimated using antibiotics and antiviral drugs was only 0.53 % and 0.36 %, respectively. Antibiotics are generally used to treat a broad spectrum of bacterial infections rather than targeting a specific pathogen, so their presence in wastewater may not directly reflect the prevalence of a particular disease. In contrast, antipyretics and specific pathogens exhibit a stronger correlation, suggesting that they may serve as more reliable biomarkers than antiviral and antibiotic drugs. The research findings offer alternative biomarkers, such as antipyretics, aside from pathogens, for the assessment of acute respiratory infectious diseases.

The introduction of non-pharmaceutical interventions (NPIs) against COVID-19 disrupted circulation of many respiratory pathogens and eventually caused large, delayed outbreaks, owing to the build up of the susceptible pool during the intervention period. In contrast to other common respiratory pathogens that re-emerged soon after the NPIs were lifted, longer delays (> 3 years) in the outbreaks of Mycoplasma pneumoniae (Mp), a bacterium commonly responsible for respiratory infections and pneumonia, have been reported in Europe and Asia. As Mp cases are continuing to increase in the US, predicting the size of an imminent outbreak is timely for public health agencies and decision makers. Here, we use simple mathematical models to provide robust predictions about a large Mp outbreak ongoing in the US. Our model further illustrates that NPIs and waning immunity are important factors in driving long delays in epidemic resurgence.

Acute respiratory infections (ARIs) can cause morbidity and mortality in children. This study was to determine the characteristics of pathogens in hospitalized children with ARIs after the relaxation of COVID-19 non-pharmacological interventions (NPIs) in Quzhou, China.

Hospitalized children with ARIs were enrolled between May and October 2023, and thirteen common respiratory pathogens were tested by fluorescent quantitative polymerase chain reaction. Mono- and co-infections were assessed, and the association between pathogens and age was explored using restricted cubic spline analysis.

A total of 1225 children were included, 820 of them detected one pathogen and 238 of them detected two or more pathogens. The dominant pathogen varies monthly. Mycoplasma pneumoniae (Mp) was the most common pathogen in monoinfection, followed by respiratory syncytial virus (RSV) and human rhinovirus (HRV), while influenza virus was detected at a lower rate. Mp + HRV was the most common combination of coinfections. The detection rates of Mp and HRV were higher in coinfections than in monoinfection, but there was no difference in the detection rate of RSV. Children aged 1-3 years had the highest positive detection rates and were more likely to be infected with multiple pathogens, with 40% of respiratory pathogen monoinfection and 47.48% of coinfections (χ2 = 4.245, P = 0.039). In the restricted cubic spline models, a J-shaped association was consistently observed between age and Mp infection, the risk of HRV first increased and then decreased, the risk of RSV was relatively flat until 1.5 years and then decreased rapidly.

Our study revealed the epidemiological characteristics of ARIs pathogens after the relaxation of NPIs. The positivity rates of Mp, RSV, and HRV are the highest, while those of influenza virus are still low. Additionally, age and season affect the distribution of respiratory pathogens. These findings underscore the importance of ongoing regional pathogen surveillance to guide local public health responses.