Antimicrobial therapy of macrolide-resistantMycoplasma pneumoniaepneumonia in children

Challenges in the treatment of pediatric Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a first-line therapy, persistence of fever and/or clinical deterioration sometimes may complicate treatment and may even lead to severe systemic disease. To date, there is no consensus on alternative treatment options, optimal dosage, and duration for treating severe, progressive, and systemic MP pneumonia after macrolide treatment failure. Macrolide-resistant MP pneumonia and refractory MP pneumonia are the two major complex conditions that are clinically encountered. Currently, the vast majority of MP isolates are resistant to macrolides in East Asia, especially China, whereas in Europe and North America, whereas in Europe and North America prevalence is substantially lower than in Asia, varying across countries. The severity of pneumonia and extrapulmonary presentations may reflect the intensity of the host's immune reaction or the dissemination of bacterial infection. Children infected with macrolide-resistant MP strains who receive macrolide treatment experience persistent fever with extended antibiotic therapy and minimal decrease in MP-DNA load. Alternative second-line agents such as tetracyclines (doxycycline or minocycline) and fluoroquinolones (ciprofloxacin or levofloxacin) may lead to clinical improvement after macrolide treatment failure in children. Refractory MP pneumonia reflects a deterioration of clinical and radiological findings due to excessive immune response against the infection. Immunomodulators such as corticosteroids and intravenous immunoglobulin (IVIG) have shown promising results in treatment of refractory MP pneumonia, particularly when combined with appropriate antimicrobials. Corticosteroid-resistant hyperinflammatory MP pneumonia represents a persistent or recrudescent fever despite corticosteroid therapy with intravenous methylprednisolone at standard dosage.

CONCLUSION

 This report summarizes the clinical significance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drugs, with a stepwise approach to the management of MP pneumonia recommended from the viewpoint of clinical practice.

WHAT IS KNOWN

• Although MP pneumonia is usually a benign self-limited infection with response macrolides as first line therapy, severe life-threatening cases may develop if additional treatment strategies are not effectively implemented. • Macrolide-resistant and refractory MP pneumonia are two conditions that may complicate the clinical course of MP pneumonia, increasing the risk for exacerbation and even death.

WHAT IS NEW

• This report summarizes the clinical relevance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drug therapies. • A practical stepwise approach to the management of MP pneumonia is developed based on a comprehensive analysis of existing evidence and expert opinion.

Comparative genomic sequencing to characterize Mycoplasma pneumoniae genome, typing, and drug resistance

To analyze the characteristics of Mycoplasma pneumoniae as well as macrolide antibiotic resistance through whole-genome sequencing and comparative genomics. Thirteen clinical strains isolated from 2003 to 2019 were selected, 10 of which were resistant to erythromycin (MIC >64 µg/mL), including 8 P1-type I and 2 P1-type II. Three were sensitive (<1 µg/mL) and P1-type II. One resistant strain had an A→G point mutation at position 2064 in region V of the 23S rRNA, the others had it at position 2063, while the three sensitive strains had no mutation here. Genome assembly and comparative genome analysis revealed a high level of genome consistency within the P1 type, and the primary differences in genome sequences concentrated in the region encoding the P1 protein. In P1-type II strains, three specific gene mutations were identified: C162A and A430G in L4 gene and T1112G mutation in the CARDS gene. Clinical information showed seven cases were diagnosed with severe pneumonia, all of which were infected with drug-resistant strains. Notably, BS610A4 and CYM219A1 exhibited a gene multi-copy phenomenon and shared a conserved functional domain with the DUF31 protein family. Clinically, the patients had severe refractory pneumonia, with pleural effusion, necessitating treatment with glucocorticoids and bronchoalveolar lavage. The primary variations between strains occur among different P1-types, while there is a high level of genomic consistency within P1-types. Three mutation loci associated with specific types were identified, and no specific genetic alterations directly related to clinical presentation were observed.IMPORTANCEMycoplasma pneumoniae is an important pathogen of community-acquired pneumonia, and macrolide resistance brings difficulties to clinical treatment. We analyzed the characteristics of M. pneumoniae as well as macrolide antibiotic resistance through whole-genome sequencing and comparative genomics. The work addressed primary variations between strains that occur among different P1-types, while there is a high level of genomic consistency within P1-types. In P1-type II strains, three specific gene mutations were identified: C162A and A430G in L4 gene and T1112G mutation in the CARDS gene. All the strains isolated from severe pneumonia cases were drug-resistant, two of which exhibited a gene multi-copy phenomenon, sharing a conserved functional domain with the DUF31 protein family. Three mutation loci associated with specific types were identified, and no specific genetic alterations directly related to clinical presentation were observed.

Identification of Mycoplasma pneumoniae proteins interacting with NOD2 and their role in macrophage inflammatory response

Mycoplasma pneumoniae (M. pneumoniae, Mp) is a cell wall-deficient microorganism known to cause chronic respiratory infections in both children and adults. Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) is an intracellular pattern recognition receptor primarily responsible for identifying muramyl dipeptide (MDP) found in bacterial cell walls. Previous experiments have demonstrated that Mycoplasma ovipneumoniae induces macrophage autophagy through NOD2. In this study, we conducted RNA-seq analysis on macrophages infected with M. pneumoniae and observed an up-regulation in the expression of genes associated with the NOD2 signaling pathway. Mechanistic investigations further revealed the involvement of the NOD2 signaling pathway in the inflammatory response of macrophages activated by M. pneumoniae. We utilized GST pull-down technology in conjunction with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to pinpoint the M. pneumoniae proteins that interact with NOD2. Additionally, co-immunoprecipitation (Co-IP) and immunofluorescence co-localization techniques were used to confirm the interaction between DUF16 protein and NOD2. We found that DUF16 protein can enter macrophages and induce macrophage inflammatory response through the NOD2/RIP2/NF-κB pathway. Notably, the region spanning amino acids 13-90 was identified as a critical region necessary for DUF16-induced inflammation. This research not only broadens our comprehension of the recognition process of the intracellular receptor NOD2, but also deepens our understanding of the development of M. pneumoniae infection.

Diagnostic value of cytokines in severe childhood Mycoplasma pneumoniae pneumonia combined with Adenovirus infection

BACKGROUND

To explore the alterations of inflammatory markers and immune-related cytokines in children infected with Mycoplasma pneumoniae (MP) combined with Adenovirus (ADV).

METHODS

The study population consisted of 201 children with MPP, and they were grouped according to whether they were coinfected with ADV infection and critically ill. Additionally, comparative analyses were performed. The diagnostic value of different indicators and combined indicators for SMPP combined with ADV was assessed using ROC curves.

RESULTS

There was no difference between group A1 and group A2, group B1 and group B2 in terms of age, gender, duration of hospitalisation and fever. The levels of calcitoninogen(PCT), lactate dehydrogenase concentration(LDH), interleukin(IL)-6, IL-8, IL-10, IL-4, IL-12P70, and IFN-γ in group A were higher than group B. The severe group (A1, B1) was significantly higher than the mild group (A2, B2) in terms of D-dimer, CRP, PCT, LDH, IL-6, IL-8, IL-10, IL-17a and number of patients with pleural effusion, solid lung changes. Among the individual indexes of D-dimer, CRP, N%,LDH, and PCT, the AUC of the combined test was 0.977, which was higher than that of the individual indicators. Among IL-6, IL-8, IL-10, and IL-17a, the AUC of the combined assay was 0.802, which was higher than that of the individual indicators.

CONCLUSION

MP combined with ADV infection was associated with increased expression levels of IL-6, IL-8, IL-10, IL-4, IL-12P70, IFN-γ, and LDH. IL-6, IL-8, IL-10, IL-17a, LDH, PCT, CRP, and D-dimer could be used as predictors of SMPP and the combined test can improve the diagnostic value.

Peptide Dendrimer-Based Antibacterial Agents: Synthesis and Applications

Pathogenic bacteria cause the deaths of millions of people every year. With the development of antibiotics, hundreds and thousands of people's lives have been saved. Nevertheless, bacteria can develop resistance to antibiotics, rendering them insensitive to antibiotics over time. Peptides containing specific amino acids can be used as antibacterial agents; however, they can be easily degraded by proteases in vivo. To address these issues, branched peptide dendrimers are now being considered as good antibacterial agents due to their high efficacy, resistance to protease degradation, and low cytotoxicity. The ease with which peptide dendrimers can be synthesized and modified makes them accessible for use in various biological and nonbiological fields. That is, peptide dendrimers hold a promising future as antibacterial agents with prolonged efficacy without bacterial resistance development. Their in vivo stability and multivalence allow them to effectively target multi-drug-resistant strains and prevent biofilm formation. Thus, it is interesting to have an overview of the development and applications of peptide dendrimers in antibacterial research, including the possibility of employing machine learning approaches for the design of AMPs and dendrimers. This review summarizes the synthesis and applications of peptide dendrimers as antibacterial agents. The challenges and perspectives of using peptide dendrimers as the antibacterial agents are also discussed.

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.

Efficacy of doxycycline therapy for macrolide-resistant Mycoplasma pneumoniae pneumonia in children at different periods

BACKGROUND

The prevalence of macrolide-resistant Mycoplasma pneumoniae has increased considerably. Treatment in children has become challenging. This study aimed to evaluate the efficacy of doxycycline therapy for macrolide-resistant Mycoplasma pneumoniae pneumonia in children at different periods.

METHODS

We retrospectively analyzed the data of patients with macrolide-resistant Mycoplasma pneumoniae pneumonia hospitalized between May 2019 to August 2022. According to treatment, patients were divided into three groups: oral doxycycline treatment alone (DOX group), changed from intravenous azithromycin to oral doxycycline (ATD group), and intravenous azithromycin treatment alone (AZI group). ATD group cases were separated into two sub-groups: intravenous azithromycin treatment<3 days (ATD1 group) and ≥ 3 days (ATD2 group). Clinical symptoms were compared in each group and adjusted by Propensity score matching (PSM) analysis.

RESULTS

A total of 106 were recruited in this study. 17 (16%) were in DOX group, 58 (55%) in ATD group, and 31(29%) in AZI group. Compared with ATD group and AZI group, the DOX group showed shorter hospitalization duration and fever duration after treatment, while higher rate of chest radiographic improvement. After using PSM analysis, shorter days to hospitalization duration (P = 0.037) and to fever duration after treatment (P = 0.027) in DOX + ATD1 group than in ATD2 group was observed. A higher number of patients in the DOX + ATD1 group achieved defervescence within 72 h (P = 0.031), and fewer children received glucocorticoid adjuvant therapy (P = 0.002). No adverse reactions associated with doxycycline was observed during treatment.

CONCLUSIONS

Children receiving early oral doxycycline had a shorter duration of fever and hospitalization in macrolide-resistant Mycoplasma pneumoniae patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Community-acquired pneumonia in children: updated perspectives on its etiology, diagnosis, and treatment

Pneumonia is a common pediatric infectious disease that is familiar to pediatricians and a major cause of hospitalization worldwide. Recent well-designed epidemiologic studies in developed countries indicated that respiratory viruses are detected in 30%-70%, atypical bacteria in 7%-17%, and pyogenic bacteria in 2%-8% of children hospitalized with community-acquired pneumonia (CAP). The etiological distribution of CAP varies widely by child age and the epidemiological season of the respiratory pathogen. Moreover, diagnostic tests, particularly for the detection of Streptococcus pneumoniae and Mycoplasma pneumoniae, the 2 major bacterial pathogens involved in pediatric CAP, have several limitations. Therefore, management and empirical antimicrobial therapy for children with CAP should be applied in a stepwise manner based on recent epidemiological, etiological, and microbiological evidence.

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.

Peripheral blood microR-146a and microR-29c expression in children with Mycoplasma pneumoniae pneumonia and its clinical value

BACKGROUND

We investigated changes in microR-29c and microR-146a expression in the serum of children with Mycoplasma pneumoniae pneumonia, analysed their relationship with inflammatory factors and disease severity, and evaluated their diagnostic significance.

METHODS

Fifty-six children with Mycoplasma pneumoniae pneumonia were enrolled as the Mycoplasma pneumoniae pneumonia group; 37 healthy children were enrolled as the control group. The microR-29c or microR-146a serum expression levels were determined using real-time quantitative reverse transcription polymerase chain reaction. Interleukin-17, tumour necrosis factor-alpha, and interleukin-1 beta levels were detected using enzyme-linked immunosorbent assay. The correlation between serum microR-29c or microR-146a expression and inflammatory factors was analysed using the Pearson's method. Receiver operating characteristic curves were used to evaluate the diagnostic value of serum microR-29c, microR-146a, and their combined detection in Mycoplasma pneumoniae pneumonia.

RESULTS

Compared with that in healthy children, the microR-29c and microR-146a serum levels were significantly downregulated in children with Mycoplasma pneumoniae pneumonia; the decrease was more obvious in children with severe cases than that in those with mild cases. In addition, microR-29c and microR-146a were negatively correlated with increased expression of interleukin-17, tumour necrosis factor-alpha, and interleukin-1 beta. Receiver operating characteristic curves showed that a combination of microR-29c and microR-146a was highly suitable for diagnosing Mycoplasma pneumoniae pneumonia.

CONCLUSION

Serum microR-29c and microR-146a were underexpressed in children with Mycoplasma pneumoniae pneumonia, and diagnostic accuracy was significantly improved with combined microR-29c and microR-146a detection. Therefore, both microR-29c and microR-146a levels can be used as biomarkers for the diagnosis of Mycoplasma pneumoniae pneumonia.

Pre-Pandemic Distribution of Bacterial Species in Nasopharyngeal Swab Specimens from Pediatric and Adult Patients Detected via RT-PCR Using the Allplex Respiratory Panel

Background: Recently, panel-based molecular diagnostics for the simultaneous detection of respiratory viruses and bacteria in nasopharyngeal swab (NPS) specimens have been highlighted. We identified the distribution of bacterial species in NPS specimens collected from pediatric and adult patients by employing RT-PCR (Allplex respiratory panel 4, RP4, Seegene) to estimate its applicability in a panel-based assay for detecting respiratory viruses. Methods: We used 271 and 173 NPS specimens from pediatric and adult patients, respectively. The results of the Allplex RP4 panel using NPS (NPS-RP4) from adult patients were compared with those of the Seeplex PneumoBacter ACE Detection assay (Seegene), which used sputum for testing (sputum-Seeplex). Results: A total of 147 specimens (54.2%) were positive for the NPS-RP4 panel in pediatric patients. There were 94, 77, 10, 3, 3, and 2 specimens that were positive for Haemophilus influenzae (HI), Streptococcus pneumoniae (SP), Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), Bordetella pertussis (BP), and B. parapertussis (BPP), respectively. Among 173 adult patients, 39 specimens (22.5%) were positive in the NPS-RP4. Thirty specimens were positive for HI, and 13 were positive for SP. One specimen tested positive for both MP and Legionella pneumophila (LP). CP, BP, and BPP results were all negative. However, 126 specimens (72.8%) had positive results with sputum-Seeplex (99 SP, 59 HI, three LP, and two MP), and the overall percentage of agreement between the two assays was 39.3% in the adult patients. Conclusions: Bacterial species in NPS from more than half of pediatric patients were detected. Performing the Allplex RP4 assay with NPS revealed additional respiratory bacteria that are not detected in current clinical practices, which do not include bacterial testing, demanding the use of sputum specimens. However, the use of NPS showed low agreement with standard assays using sputum in adult patients. Thus, more research is needed to develop a reliable RT-PCR method using NPS specimens in adult patients.

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

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

Interaction between alveolar macrophages and epithelial cells during Mycoplasma pneumoniae infection

Mycoplasma pneumoniae, as one of the most common pathogens, usually causes upper respiratory tract infections and pneumonia in humans and animals. It accounts for 10% to 40% of community-acquired pneumonia in children. The alveolar epithelial cells (AECs) are the first barrier against pathogen infections, triggering innate immune responses by recruiting and activating immune cells when pathogens invade into the lung. Alveolar macrophages (AMs) are the most plentiful innate immune cells in the lung, and are the first to initiate immune responses with pathogens invasion. The cross-talk between the alveolar epithelium and macrophages is necessary to maintain physiological homeostasis and to eradicate invaded pathogen by regulating immune responses during Mycoplasma pneumoniae infections. This review summarizes the communications between alveolar macrophages and epithelial cells during Mycoplasma pneumoniae infections, including cytokines-medicated communications, signal transduction by extracellular vesicles, surfactant associated proteins-medicated signal transmission and establishment of intercellular gap junction channels.

Application value of antibody titres and RNA detection in the early prediction of Mycoplasma pneumoniae pneumonia in children: a retrospective study

BACKGROUND

Children with Mycoplasma pneumoniae pneumonia (MPP) are prone to a missed diagnosis at the early stages of the disease, which greatly affects the prognosis of children. In this study, the application value of Mycoplasma pneumoniae (MP) antibody titres and RNA detection for diagnosing MP infection in children with community-acquired pneumonia (CAP) was evaluated. The present study aimed to seek appropriate detection methods and strategies for early rapid diagnosis in children with MPP.

METHODS

A retrospective study was conducted on 563 paediatric patients aged 1 month to 15 years with CAP who were admitted to Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology between July 2021 and February 2022. In all patients, throat swabs were collected for MP-RNA detection (simultaneous amplification and testing, SAT), and paired serum samples were collected for MP total antibody detection (particle agglutination, PA).

RESULTS

The classification as MPP or non-MPP was based on clinical diagnosis, serum MP antibody titre, and clinical or laboratory evidence of infection by other pathogen(s). Among the 563 patients with pneumonia, 187 patients were in the MPP group, and 376 patients were in the non-MPP group. The Kappa values between the particle agglutination test at different titres (1:80, 1:160) and MP-RNA detection were 0.612 and 0.660 (P<0.01), and the consistency of the three methods was acceptable. When the single screening method was used, MP-RNA had the highest sensitivity (93.05%), while PA (1:160) had the highest specificity (100%). PA (1:80), with an area under the curve (AUC) of 0.822, was better than PA (1:160), with an AUC of 0.783, and there was a significant difference. When the combined screening methods were used, the AUC of MP-RNA parallel PA (1:160) was significantly higher than that of titres (1:80) (z=-4.906, P < 0.01). Except for MP-80, the efficacy of the other three test methods in females was slightly better than that in males. Among the differences in age distribution, PA (1:80) was slightly less effective in the 13-72 months age group than at other ages, and MP-RNA parallel PA (1:160) was slightly better than the younger age group (≤ 36 m). In the older age group (> 36 m), PA (1:160) was just the opposite, while MP-RNA was slightly better than other age groups in the 13-72 months age group.

CONCLUSIONS

For the diagnosis of MPP in children at the early of the disease, the antibody titre (1:160) parallel MP-RNA should be given preference, and then the disease should be further classified according to the antibody titre level and the age of the child. The combined application of the two detection methods could complement each other and strengthen the advantages, providing reliable laboratory evidence for the clinical diagnosis and timely treatment of MPP. When using the PA method alone to provide a reference standard to clarify MP infection, the differential diagnosis ability of 1:80 for MPP is better than 1:160, especially for children younger than 36 months.

Public knowledge of antibiotics, self-medication, and household disposal practices in Jordan

BACKGROUND

This study aimed to assess public understanding of antibiotics, self-medication, and drug disposal practices.

METHODS

A cross-sectional self-administered online survey was undertaken in Jordan.

RESULTS

The study was completed by 1,105 participants. When asked about their knowledge of antibiotics, rational antibiotic use, and disposal practices, 16% percent believed they should discontinue antibiotics once they felt better, and 12% agreed to take the same antibiotics prescribed to others for the same illness. Self-medication with antibiotics was practiced by 44% of the participants. Prior experience, healthcare costs, and pharmacy location were all major determinants of self-medication. Only 6.4% of unneeded antibiotics were returned to the pharmacy, 60% were kept at home, and 26.6% were disposed of at home. Almost half of those who kept the antibiotics said they would use them again, and one-third said they would give them to friends and family. Respondents who had used antibiotics within the previous 6 months (p = 0.052) and relied on medication leaflets (p = 0.031) and physician recommendations (p = 0.001) were less likely to self-medicate with antibiotics.

CONCLUSIONS

The study highlighted areas of inappropriate use of antibiotics, self-medication and the improper antibiotic disposal that can inform antimicrobial stewardship.

Necrotizing Pneumonia in Children: Early Recognition and Management

Necrotizing pneumonia (NP) is an uncommon complicated pneumonia with an increasing incidence. Early recognition and timely management can bring excellent outcomes. The diagnosis of NP depends on chest computed tomography, which has radiation damage and may miss the optimal treatment time. The present review aimed to elaborate on the reported predictors for NP. The possible pathogenesis of Streptococcus pneumoniae, Staphylococcus aureus, Mycoplasma pneumoniae and coinfection, clinical manifestations and management were also discussed. Although there is still a long way for these predictors to be used in clinical, it is necessary to investigate early predictors for NP in children.

The immunogenic involvement of miRNA-492 in mycoplasma pneumoniae infection in pediatric patients

OBJECTIVE

This study aimed to evaluate the role of miRNA-492 in the progression of mycoplasma pneumoniae (MP) infection in pediatric patients.

METHODS

Forty-six children admitted to the present study's hospital and diagnosed with mycoplasma pneumonia were recruited as the study group from March 2018 to August 2019, and 40 healthy children were selected as the control group.

RESULTS

The expression levels of miRNA-492, TNF-α, IL-6 and IL-18 in the study group were significantly higher than those in the control group (p < 0.05). There was no significant correlation between miRNA-492 and most of the immune-correlated indicators in the study group, except for IL-6, IL-18 and HMGB1. Meanwhile, overexpression of miRNA-492 increased IL-6 secretion in PMA-activated monocytes (p < 0.01).

CONCLUSION

The present study's results suggested that miRNA-492 might play a role in the pathogenesis of mycoplasma pneumoniae pneumonia in children by regulating the secretion of immune-inflammatory factors such as IL-6 and IL-18 in the mononuclear macrophages.

Modern approaches at the management of children with community-acquired pneumonia

Experts of The Union of Pediatricians of Russia have developed current clinical guidelines for management of children with community-acquired pneumonia, which were approved by the Scientific and Practice Council of Ministry of Public Health of the Russian Federation in January 2022. Particular attention is paid to the etiological structure, modern classification, diagnostic tests and flagship approaches to antibacterial therapy of community-acquired pneumonia in children based on the principles of evidentiary medicine. 

The molecular characteristics, diagnosis, and treatment of macrolide-resistant Mycoplasma pneumoniae in children

The purpose of this study is to review the molecular characteristics, the diagnosis, and treatment of the widespread infection of macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae; MRMP) in children, thus providing a better knowledge of this infection and presenting the associated problems. Single point mutations in the V region of the 23S rRNA gene of M. pneumoniae genome are associated with macrolide resistance. P1-1, MLVA4-5-7-2, and ST3 are usually the predominated genetic types in the M. pneumoniae epidemics. The short-term two times serological IgM (or together with IgG) test in the acute stage can be used for confirmation. Combined serological testing and PCR might be a more prudent method to reduce macrolide consumption and antibiotic selective pressure in a clinical setting. Molecular methods for the detection of single-nucleotide mutations in the V region of the 23S rRNA gene can be used for the diagnosis of MRMP. The routine use of macrolide for the treatment of macrolide-sensitive Mycoplasma pneumoniae (MSMP) infections can get good effect, but the effects are limited for severe MRMP infections. Additional corticosteroids may be required for the treatment of severe MRMP infections in children in China during the era of MRMP.

Diagnostic value of serum LDH in children with refractory Mycoplasma pneumoniae pneumoniae: A systematic review and meta-analysis

Background

To investigate the relationship between serum Lactate dehydrogenase (LDH) and refractory Mycoplasma pneumoniae pneumonia (RMPP) in juvenile individuals.

Methods

Search Chinese databases and English databases. The retrieval time limit is from the establishment of the database to 2022-04-27. And screening and inclusion of relevant diagnostic test literature. The QUADAS-2 method was used to evaluate the quality of the included literature. The random effects model was used to combine sensitivity, specificity, likelihood ratio, diagnostic odds ratio, summary receiver operating characteristic curve, and area under summary receiver operating characteristic curve to evaluate the prediction value of LDH for RMPP. Subgroup analyses were used to explore sources of heterogeneity.

Results

① A total of 29 literatures that met the criteria were included in the study, and the quality of the literature was medium and high, with a total of 702,2 patients. ② The combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve of the studies were: 0.75 (95% CI = 0.73-0.76), 0.73 (95% CI = 0.72-0.74), 3.61 (95% CI = 2.86-4.56), 0.30 (95% CI = 0.23-0.39), 13.04 (95% CI = 8.24-20.63), and 0.85(95% CI = 0.82-0.88). ③ The results of subgroup analysis showed that Compared with the subgroup with LDH threshold ≤400 IU/L, the AUC increased from 0.84 (95% CI = 0.80-0.87) to 0.89 (95% CI = 0.86-0.91).

Conclusions

The serum LDH has good accuracy for the diagnosis of RMPP and can serve as a diagnostic marker for RMPP.

Opportunistic etiological agents causing lung infections: emerging need to transform lung-targeted delivery

Lung diseases continue to draw considerable attention from biomedical and public health care agencies. The lung with the largest epithelial surface area is continuously exposed to the external environment during exchanging gas. Therefore, the chances of respiratory disorders and lung infections are overgrowing. This review has covered promising and opportunistic etiologic agents responsible for lung infections. These pathogens infect the lungs either directly or indirectly. However, it is difficult to intervene in lung diseases using available oral or parenteral antimicrobial formulations. Many pieces of research have been done in the last two decades to improve inhalable antimicrobial formulations. However, very few have been approved for human use. This review article discusses the approved inhalable antimicrobial agents (AMAs) and identifies why pulmonary delivery is explored. Additionally, the basic anatomy of the respiratory system linked with barriers to AMA delivery has been discussed here. This review opens several new scopes for researchers to work on pulmonary medicines for specific diseases and bring more respiratory medication to market.

Duplex-specific nuclease and Exo-III enzyme-assisted signal amplification cooperating DNA-templated silver nanoclusters for label-free and sensitive miRNA detection

Development of novel miRNA detection strategies plays a crucial role in fundamental research and clinical diagnosis of various diseases, such as infantile pneumonia. We herein develop a rapid and sensitive DNA-templated AgNCs-based miRNA detection approach, pinning the hope on an improved detection sensitivity in an easy-to-operate way. In the method, a hairpin probe is designed to specifically bind with target miRNA, and to initiate the DSN enzyme and Exo-III-assisted dual signal recycles. The resultant guanine-rich DNA sequences after signal amplification turn on the fluorescence of the dark AgNCs by hybridizing with the DNA template of the dark AgNCs. The generated signals are correlated with the amounts of target miRNA in the sensing system. Through a series of experiments, the established approach exhibits a great dynamic range of more than seven orders of magnitude with a low limit of detection of 245 aM, holding great promises for miRNA-related researches and disease diagnosis.

Graphical abstract

Epidemiology and surveillance implications of community-acquired pneumonia in children

Community-acquired pneumonia (CAP) is the single largest infectious cause of hospitalization and death in children worldwide. With improved immunizations, the incidence of bacterial pneumonia and the number of colonized bacteria have decreased. However, respiratory viruses are still an important cause of CAP, especially as new infectious agents such severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. The SARS-CoV-2 virus emerged in 2019 and caused the current coronavirus disease 2019 pandemic. Therefore, it is necessary to elucidate the epidemiology and causative pathogens of CAP. Recently, the Pneumonia and Respiratory Disease Study Group, affiliated with the Korean Academy of Pediatric Allergy and Respiratory Disease, investigated the causative pathogens of respiratory infections in children hospitalized with CAP, the serotype of Streptococcus pneumoniae, and the prevalence of Mycoplasma pneumoniae with gene mutations. Antibiotic resistance and serotype test results can determine the use of empirical antibiotics. Moreover, it is possible to help develop future vaccines by comparing bacterial culture results with vaccine serotype and identifying the changes and prevalence of each serotype. Therefore, we will perform continuous national surveillance and monitor the epidemiology of respiratory pathogens in Korea and worldwide. The surveillance of these respiratory infections can play a role in monitoring the emergence of new infectious diseases such as SARS-CoV-2.

Mycoplasma pneumoniae triggers pneumonia epidemic in autumn and winter in Beijing: a multicentre, population-based epidemiological study between 2015 and 2020

The objective of this paper is to explore the characteristics of Mycoplasma pneumoniae (MP) epidemics in Beijing, China. Patients with acute respiratory tract infection (ARTI) were enrolled from 35 sentinel hospitals in Beijing, 2015–2020. Their medical records were reviewed and respiratory specimens were collected for assay for nucleic acids of 24 respiratory pathogens, including MP. The genotypes of MP were analysed using a real-time PCR method. The domain V of 23s rRNA gene was sequenced to identify macrolide-resistant mutations. A total of 41,677 specimens of ARTI patients were included, with an MP positive rate of 6.16%. MP prevalence mainly occurred between August and January, and peaked in October. The increase in the MP detection rate was coincident with the elevation of the reported number of patients with pneumonia in the 35 sentinel hospitals. One or more respiratory pathogens were co-detected in 27.1% of the MP-positive patients. Type 1 MP remained predominant, and the macrolide-resistant rate of MP had exceeded over 90%. A2063G mutation accounted for 99.0% of macrolide-resistant MP infections. MP epidemic in Beijing mainly occurred between August and January with a remarkable high macrolide-resistant rate. MP is one of the important contributors to the pneumonia epidemic in autumn and winter in Beijing.

Assessment of variables associated with prolonged admission duration in children with Mycoplasma pneumoniae pneumonia

Introduction

Macrolide‐resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide‐sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children.

Methods

A prospective multicenter study was conducted in 1063 children <18 years old in July 2018–June 2020. The 454 had a positive M. pneumoniae polymerase chain reaction assay.

Results

Most subjects had MRMP (78.4%), and all mutated strains had the A2063G transition. We defined MRMP* (n = 285) as MRMP pneumonia requiring admission and MSMP* (n = 72) as MSMP pneumonia requiring admission. Patients with MRMP pneumonia were older, more likely to have segmental/lobar pneumonia, and had more febrile days than those with MSMP pneumonia. C‐reactive protein (CRP), lactate dehydrogenase (LDH), and percentage neutrophils were more strongly associated with MRMP* than MSMP* groups. Percentage neutrophils, CRP, and alanine aminotransferase significantly changed between admission and follow‐up measurements in patients with MRMP* (P < 0.05). The duration of admission positively correlated with the number of febrile days after initiation of antibiotic medication and laboratory variables (white blood cell count, CRP, and aspartate aminotransferase [AST]) (P < 0.05). Random forest analysis indicated that the number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission was over five.

Conclusions

This study indicated that children with M. pneumoniae pneumonia with a higher number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission were more likely to have prolonged admission duration.

Clinical Usefulness of Serum Lactate Dehydrogenase Levels in Mycoplasma pneumoniae Pneumonia in Children

OBJECTIVE

To elucidate the clinical usefulness of lactate dehydrogenase (LDH) levels in children with Mycoplasma pneumoniae (MP) pneumonia and identify cut-off levels in various clinical conditions.

METHODS

The study was retrospectively performed in 145 children who were hospitalized with MP pneumonia. Laboratory findings, including LDH levels at admission and clinical features were retrospectively reviewed from patients' electronic medical records.

RESULTS

The mean age of the study population was 5.9 y, and the mean value of LDH was 809.7 U/L. Poor response to treatment for MP pneumonia, respiratory virus coinfection, severe MP pneumonia, development of postinfectious bronchiolitis obliterans (PIBO) after MP pneumonia, pleural effusion, and oxygen need during illness were significantly associated with serum LDH levels. The cutoff levels of LDH for predicting poor response to treatment for MP pneumonia and respiratory virus coinfection were 1058 U/L [area under the curve (AUC), 0.729] and 803 U/L (AUC, 0.682), respectively. Those for pneumonic lesions involving at least one-third of the total lung volume, prediction of PIBO development, and extrapulmonary manifestations were 1098 U/L (AUC, 0.715), 676 U/L (AUC, 0.714), and 859 U/L (AUC, 0.710), respectively. The cutoff levels for pleural effusion during illness and for the prediction of oxygen need were 894 U/L (AUC, 0.699) and 1114 U/L (AUC, 0.771), respectively.

CONCLUSION

LDH levels are elevated in diverse clinical conditions in children with MP pneumonia and may be useful in the identification of severe clinical courses of MP pneumonia in children.

Clinical characteristics of patients with Mycoplasma pneumoniae infection

OBJECTIVE

To describe the characteristics of patients diagnosed with Mycoplasma pneumoniae infection.

METHODS

A retrospective study of clinical and epidemiological characteristics of acute infections by M. pneumoniae confirmed by PCR was carried out in the Navarra Health Service (Spain) in 2014-2018.

RESULTS

M. pneumoniae infection was confirmed in 9.5% of analyzed patients. Among 123 confirmed cases, 65% were 5-14 years old, 21.1% &lt;5 years old, and 13.8% were ≥14 years old. Pneumonia was radiologically confirmed in 83.7% of cases, and 22.0% presented extra-respiratory manifestations. A total of 44.7% of cases required hospitalization. Bilateral pneumonia, asthmatic crisis and extra-respiratory manifestations were associated to higher risk of hospitalization (81.3, 72.2 and 66.7%, respectively). Microbiological targeted treatment was monotherapy with macrolides in 60.2% of cases and combined with other antibiotics in 13.0%.

CONCLUSION

M. pneumoniae was the cause of acute respiratory infection affecting mainly to children younger than 14 years old and frequently required hospitalization.

Clinical analysis of the epidemiology and changes in inflammatory indexes of Mycoplasma pneumonia in acute and recovery stage pediatric patients

BACKGROUND

As Mycoplasma pneumoniae pneumonia (MPP) is on the rise in children and adolescents, this work explored the clinical analysis of epidemiological and inflammatory changes in children with MPP during the acute and convalescent phases, and analyzed their relationship with clinical manifestations.

METHODS

One hundred and twenty MP patients (experimental group) and 100 healthy children (control group) were selected as the research objects. Enzyme-linked immunosorbent assay (ELISA) was used to detect the changes in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10) and procalcitonin (PCT).

RESULTS

The proportion of children aged 3-7 years was significantly higher than that of other age groups (0-1, 1-3, and 7-14 years old) (P<0.05). The serum levels of TNF-α, IL-6, IL-8, IL-10, and PCT in children with MP were significantly higher than those in the control group (P<0.05). Changes in pulmonary fibrosis and serum and pleural fluid TNF-α, IL-6, IL-8, IL-10, and PCT concentrations on chest X-ray and computed tomography (CT) in children with MP with pleural effusion significantly higher than that in children without pulmonary fibrosis (P<0.05).

CONCLUSIONS

MPP was more common in children aged 3-7 years. In addition, the changes of inflammatory markers TNF-α, IL-6, IL-8, IL-10, and PCT in serum and pleural effusion of children with MP were of great value for the diagnosis, treatment, and prognosis of the disease.

The efficacy and safety of minocycline as adjuvant therapy in refractory mycoplasma pneumonia in Chinese children: a meta-analysis

Background

To explore the efficacy and safety of minocycline as adjuvant therapy for refractory mycoplasma pneumonia in Chinese children.

Methods

PubMed, EMBASE, Cochrane Library, CNKI, Wanfang database and VIP database were systematically searched. Studies where minocycline was used as adjuvant therapy for refractory mycoplasma pneumonia in Chinese children were included. The effect of numeration data and the measurement data were represented by odds ratios (OR) and weighted mean differences (MD), respectively. Review Manager version 5.3 was used to compare the treatment efficacy, time for the cough to subside, defervescence time, hospitalisation time, adverse events and other indicators.

Results

Ten studies involving 857 patients were included in the final analysis. Compared with the conventional treatment of refractory mycoplasma pneumonia in children, the addition of minocycline as adjuvant therapy was found to improve the treatment efficacy (OR: 5.45; 95% CI: 3.46, 8.57, p < 0.001); shorten the duration of cough (MD: -3.61; 95%CI: -4.25, -2.97, p < 0.001), fever time (MD: -4.77; 95% CI: -6.30, -3.23, p < 0.001) and hospitalisation time (MD: -5.53 (95% CI: -7.19, -3.88, p < 0.001); and decrease the concentration of C-reactive protein (MD: -13.95; 95%CI: -18.61, -9.29; p < 0.001) and the erythrocyte sedimentation rate (MD: -10.88; 95% CI: -14.05, -7.72, p < 0.001). The use of minocycline did not lead to significant adverse events (OR = 0.63; 95% CI: 0.39, 1.01, p = 0.05).

Conclusion

The use of minocycline as adjuvant treatment of refractory mycoplasma pneumonia in Chinese children has good efficacy and safety and may be promoted in clinical practice.

Macrolide versus Non-Macrolide in Combination with Steroids for the Treatment of Lobar or Segmental Mycoplasma pneumoniae Pneumonia Unresponsive to Initial Macrolide Monotherapy

In the last few decades, macrolide-resistant Mycoplasma pneumoniae (MRMP) has been increasing in proportion. This study aimed to evaluate the treatment outcomes of children with lobar or segmental MP pneumonia unresponsive to the initial 3−5-day macrolide therapy, who then switched to either a non-macrolide, macrolide + steroid, or a non-macrolide + steroid regimen, according to the 2019 KSPID and KAPARD guideline during the 2019−2020 Mycoplasma epidemic in South Korea. A total of 190 patients <18 years old were admitted during the study period for MP lobar or segmental pneumonia, and 16.8% (n = 32/190) were responsive to the initial macrolide monotherapy, whereas 83.2% (158/190) were refractory. The median age of the patients was 7 (interquartile range [IQR], 5−9) years old and 46.2% (n = 73/158) were male. The overall treatment success rates of non-macrolide, macrolide + steroid, and non-macrolide + steroid groups were 46.2%, 80.8%, and 100.0%, respectively. Patients in the non-macrolide + steroid group had the shortest fever duration after a regimen change of 1 (IQR, 0−3) day compared with patients in the non-macrolide group and macrolide + steroid group; 2 (IQR, 1−4) days and 2 (IQR, 1−3.3) days (p = 0.004), respectively. Follow-up CRP (ß, 0.169; CI, 0.050−0.287; p = 0.006), macrolide + steroid therapy (ß, −1.694; CI, −2.463−−0.925; p < 0.001), and non-macrolide+ steroid therapy (ß, −2.224; CI, −3.321−−1.127; p < 0.001) were shown to be significantly associated with the duration of fever after admission. To conclude, in patients with severe MP pneumonia that failed to respond to the initial macrolide therapy, a non-macrolide + steroid had the highest treatment success rate and a shorter duration of fever.

Efficacy and safety of Chinese herbal medicine for pneumonia convalescence in children: A systematic review and meta-analysis

Background: Chinese herbal medicine (CHM) has advantages in treating sequela symptoms of pediatric pneumonia convalescence. Hence, this study aims to evaluate the efficacy and safety of CHM using a meta-analysis approach.

Methods: The randomized controlled trials (RCTs) that met the search strategy were selected from seven databases from the inception date to December 17, 2021. Based on the Cochrane handbook, the quality of the selected studies was assessed using the risk of bias. Data were expressed as relative risk (RR) or mean difference (MD) and with 95% confidence interval (CI). Subgroup analyses and sensitivity analyses were performed. The Grading Recommendation Assessment, Development, and Evaluation (GRADE) method was used to assess the evidence certainty.

Result: Twenty RCTs with 2,241 participants were identified using the search criteria. CHMs included Danshen injection, Liujunzi decoction, Qingfei Tongluo decoction, Yiqi Huoxue decoction, Yupingfeng granule, XiaoErFeiKe granule, Sha-Sheng-Mai-Dong decoction, and so on. Results indicated that CHM combined with Western medicine (WM) or CHM alone improved the total clinical effective rate (RR = 1.22; 95% CI: 1.15–1.29), reduced cough relief time (MD = −2.16; 95% CI: −2.46 to −1.85), lung rales disappearance time (MD = −1.82; 95% CI: −2.17 to −1.47), and length of hospital stay (MD = −2.01, 95% CI: −3.81 to −0.22) in the treatment of pneumonia convalescence in children. However, there was no significant statistical difference regarding the incidence of adverse reactions (RR = 0.57; 95% CI: 0.23–1.43).

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/; Identifier CRD42022298936

Antimicrobial Susceptibility Profiles and Genetic Characteristics of Mycoplasma pneumoniae in Shanghai, China, from 2017 to 2019

Objective

The current study investigated the recent genetic characteristics and antimicrobial susceptibility profiles of Mycoplasma pneumoniae (M. pneumoniae) in Shanghai, becoming a clinical reference for treating M. pneumoniae infection in Shanghai.

Methods

Clinical strains were isolated from nasopharyngeal aspirates of the pediatric patients in Shanghai from 2017 to 2019. Nine antimicrobial agents of three antimicrobial classes macrolides, fluoroquinolones and tetracyclines, against M. pneumoniae isolates were investigated using the broth microdilution method. The mechanism of macrolide resistance was analyzed by evaluating the sequences of the 23S rRNA gene and the ribosomal protein genes L4 and L22. Molecular genotyping was undergone to classify the P1 subtypes and the multi-locus variable-number tandem-repeat analysis (MLVA) types.

Results

A total of 72 isolates were resistant to macrolides (MICs > 64 mg/L for erythromycin) based on the A2063G mutation in the 23S rRNA gene. These strains were susceptible to tetracyclines and fluoroquinolones. P1 type 1 (166/182, 91.2%) and MLVA type 4-5-7-2 (165/182, 90.7%) were the dominant subtypes. MLVA type was associated with the P1 subtypes. The distribution of the P1 subtypes and MLVA types did not change over time. The macrolide-resistant rate in P1 type 2 and MLVA type 3-5-6-2 strains were increased during the three-year study. The 5-loci MLVA typing scheme revealed the clonal expansion of MLVA type 3-4-5-7-2 strains which are macrolide-resistant in 2019.

Conclusion

Macrolide resistance in M. pneumoniae in Shanghai is very high and is evolving among certain subtypes. Cautions should be taken for the possible clonal spreading of macrolide-resistant genotypes within this populated region.

Toll-Like Receptor 4 Exacerbates Mycoplasma pneumoniaevia Promoting Transcription Factor EB-Mediated Autophagy

Mycoplasma pneumoniae (M. pneumoniae) is the most common cause of community-acquired pneumonia. Toll-like receptors (TLRs) play an essential role in pneumonia. The purpose of this study was to investigate the roles of TLR4 in M. pneumoniae. Mice were administrated with 100 μl (1 × 107 ccu/ml) of M. pneumoniae. HE staining was applied for histological analysis. The protein expression was determined by western blot. The cytokine level was detected by ELISA. The results showed that TLR4-deficient mice were protected from M. pneumoniae. However, downregulation of TLR4 inhibited inflammatory response and autophagy. Moreover, transcription factor EB (TFEB) participated in M. pneumoniae-induced inflammatory response and autophagy, while knockdown of TLR4 downregulated TFEB and its nuclear translocation.

Association of Intrauterine Microbes with Endometrial Factors in Intrauterine Adhesion Formation and after Medicine Treatment

Intrauterine adhesions (IUAs) have caused serious harm to women’s reproductive health. Although emerging evidence has linked intrauterine microbiome to gynecological diseases, the association of intrauterine microbiome with IUA, remains unknown. We performed metagenome-wide association, metabolomics, and transcriptomics studies on IUA and non-IUA uteri of adult rats to identify IUA-associated microbial species, which affected uterine metabolites and endometrial transcriptions. A rat model was used with one side of the duplex uterus undergoing IUA and the other remaining as a non-IUA control. Both 16S rRNA sequencing and metagenome-wide association analysis revealed that instead of Mycoplasmopsis specie in genital tract, murine lung pathogen Mycoplasmopsispulmonis markedly increased in IUA samples and displayed a distinct positive interaction with the host immune system. Moreover, most of the IUA-enriched 58 metabolites positively correlate with M.pulmonis, which inversely correlates with a mitotic progression inhibitor named 3-hydroxycapric acid. A comparison of metabolic profiles of intrauterine flushing fluids from human patients with IUA, endometritis, and fallopian tube obstruction suggested that rat IUA shared much similarity to human IUA. The endometrial gene Tenascin-N, which is responsible for extracellular matrix of wounds, was highly up-regulated, while the key genes encoding parvalbumin, trophectoderm Dkkl1 and telomerase involved in leydig cells, trophectoderm cells, activated T cells and monocytes were dramatically down-regulated in rat IUA endometria. Treatment for rat IUA with estrogen (E2), oxytetracycline (OTC), and a traditional Chinese patent medicine GongXueNing (GXN) did not reduce the incidence of IUA, though inflammatory factor IL-6 was dramatically down-regulated (96–86%) with all three. Instead, in both the E2 and OTC treated groups, IUA became worse with a highly up-regulated B cell receptor signaling pathway, which may be associated with the significantly increased proportions of Ulvibacter or Staphylococcus. Our results suggest an association between intrauterine microbiota alterations, certain uterine metabolites, characteristic changes in endometrial transcription, and IUA and the possibility to intervene in IUA formation by targeting the causal factors, microbial infection, and Tenascin-like proteins.

Systematic review of clinical practice guidelines on the management of community acquired pneumonia in children

Childhood community acquired pneumonia (CAP) is the leading cause of mortality in children under 5 years worldwide. Clinical practice guidelines (CPGs) may be limited by method of development, scope of recommendations and the quality of supporting evidence. This study systematically identified, appraised and compared the recommendations of CPGs for the management of paediatric CAP using the AGREE II tool. The systematic review yielded 1409 non-duplicate results, of which 14 CPGs were appraised. Four of the fourteen CPGs were deemed high quality. Most CPGs were considered low-medium quality with 'rigour of development' and 'applicability' the weakest domains. These areas should be considered in deriving CPGs in the future. Recommendations were generally similar across all guidelines; however, there was notable heterogeneity in three areas. This suggests the need for further evidence to guide management decisions on oxygen saturation thresholds for admission, the utility of investigations such as acute phase reactants, and the duration of antibiotic therapy.

Pediatric Critical Illness Score, Clinical Characteristics and Comprehensive Treatment of Children with Severe Mycoplasma Pneumoniae Pneumonia

Objective

To investigate the clinical characteristics of children with severe Mycoplasma pneumoniae pneumonia (SMPP) and the correlation with pediatric critical illness score (PICS), and to explore the effect of combined treatment with antibiotics and glucocorticoids.

Methods

The medical records of 120 children with SMPP admitted to our hospital from January 2020 to June 2021 were retrospectively analyzed. Children with a PICS score greater than 80 within 24 h of admission were included in the non-critical group, those with a score of 71–80 were included in the critical group, and those with a score of ≤70 were included in the extremely critical group. The relevant clinical data and examination indicators of the three groups of children were intercepted and compared. Univariate and multifactorial logistic regression analyses were performed to analyze the correlation between clinical characteristics of children with SMPP and PICS. According to the different treatment methods, the children were subdivided into the control group (n = 54) who received antibiotics alone and the comprehensive group (n = 66) who received antibiotics combined with glucocorticoid therapy. The erythrocyte sedimentation rate (ESR), inflammation and immune indexes, symptom relief or disappearance time, hospitalization days, and clinical efficacy were compared between the two groups before and after treatment.

Result

Within 24 h of admission, among the 120 children with SMPP, 79 had PICS >80, 32 had PICS 71–80, and 9 had PICS ≤70. Before discharge, among the 120 children with SMPP, 99 had PICS >80, 17 had PICS 71–80, and 4 had PICS ≤70. Univariate analysis showed that there were no significant differences in gender ratio, ratio of fever duration >10 days, age and WBC among the three groups (p > 0.05), the differences in the ratio of abnormal ECG, the ratio of ≥2 pathogenic infections, the ratio of ≥2 systemic damages, CRP levels, and D-dimer levels were statistically significant when compared among the three groups (p < 0.05). Multivariate Logistic regression analysis showed that the number of Co-systemic damages and the level of D-dimer were negatively correlated with PICS classification (p < 0.05). After medication, ESR, CRP, IL-6, and CD8+ levels decreased and CD4+ and CD4+/CD8+ levels increased in both the control and comprehensive groups, and all changes were significant in the comprehensive group compared with the control group (p < 0.05). The antipyretic time, cough relief time, disappearance time of lung rales and hospitalization days in the comprehensive group were shorter than those in the control group (p < 0.05). The total effective rate of the comprehensive group (95.45%) was better than that of the control group (83.33%) (p < 0.05).

Conclusion

PICS can effectively reflect the clinical characteristics of children with SMPP. The comprehensive treatment effect of azithromycin combined with glucocorticoid is significantly better than that of azithromycin alone. It can effectively reduce the level of inflammation in children with SMPP, improve the immune function of children, and accelerate clinical recovery. It has promotion value.

Study on the Therapeutic Effect of Azithromycin Combined with Glucocorticoid on Pulmonary Function and Inflammatory Response in Children with Pneumonia

Objective

The objective is to explore the efficacy of azithromycin combined with glucocorticoids in the treatment of children with pneumonia and its effect on the inflammatory response.

Methods

A total of 86 children with pneumonia were divided into the experimental group (EG) and the control group (CG). Both groups received conventional treatment, the CG was treated with azithromycin and the EG was additionally treated with glucocorticoid methylprednisolone. The therapeutic effect, disappearance time of clinical symptoms, pulmonary function, inflammatory factors, immune function, quality of life, and adverse reactions were measured in the two groups.

Results

After treatment, compared with CG, the total effective rate was significantly elevated, the disappearance time of various clinical symptoms was earlier, and various pulmonary function indexes were increased in the EG. The interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C reactive protein (CRP), and CD8+ levels were reduced, and CD3+ and CD4+ levels were increased in the EG. The quality-of-life scores were upregulated in the EG. Moreover, there was no significant difference in the incidence of adverse reactions between the two groups.

Conclusion

The combined use of azithromycin and glucocorticoids in the treatment of children with Mycoplasma pneumoniae infection has a good curative effect, can significantly improve lung function, restore pulmonary inflammatory indexes to normal, and enhance patients' immune function and improve their quality of life, with fewer adverse reactions and safety.

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.

Mycoplasma pneumoniae among Chinese Outpatient Children with Mild Respiratory Tract Infections during the Coronavirus Disease 2019 Pandemic

Mycoplasma pneumoniae is a common pathogen causing respiratory disease in children. We sought to investigate the epidemiology of M. pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the coronavirus disease 2019 (COVID-19) pandemic. Eligible patients were prospectively enrolled from January 2020 to June 2021. Throat swabs were tested for M. pneumoniae RNA. M. pneumoniae IgM was tested by a colloidal gold assay. Macrolide resistance and the effect of the COVID-19 countermeasures on M. pneumoniae prevalence were assessed. Symptom scores, treatments, and outcomes were evaluated. Eight hundred sixty-two eligible children at 15 centers in China were enrolled. M. pneumoniae was detected in 78 (9.0%) patients. Seasonally, M. pneumoniae peaked in the first spring and dropped dramatically to extremely low levels over time until the next summer. Decreases in COVID-19 prevalence were significantly associated with decreases in M. pneumoniae prevalence (r = 0.76, P = 0.001). The macrolide resistance rate was 7.7%. The overall sensitivity and specificity of the colloidal gold assay used in determining M. pneumoniae infection were 32.1% and 77.9%, respectively. No more benefits for improving the severity of symptoms and outcomes were observed in M. pneumoniae-infected patients treated with a macrolide than in those not treated with a macrolide during follow-up. The prevalences of M. pneumoniae and macrolide resistance in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs. IMPORTANCE This is the first and largest prospective, multicenter, active, population-based surveillance study of the epidemiology of Mycoplasma pneumoniae among outpatient children with mild respiratory tract infections (RTIs) during the COVID-19 pandemic. Nationwide measures like strict face mask wearing and restrictions on population movement implemented to prevent the spread of COVID-19 might also effectively prevent the spread of M. pneumoniae. The prevalence of M. pneumoniae and the proportion of drug-resistant M. pneumoniae isolates in outpatient children with mild RTIs were at low levels in the early stage of the COVID-19 pandemic but may have rebounded recently. The colloidal gold assay for M. pneumoniae IgM may be not appropriate for screening and diagnosis of M. pneumoniae infection. Macrolides should be used with caution among outpatients with mild RTIs.

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.

Effects of bronchoalveolar lavage on Mycoplasma Pneumoniae pneumonia: A propensity score matched-cohort study

BACKGROUND

The purpose of this study was to evaluate the efficacy and safety of BAL in treating MPP.

METHODS

From January 2013 to January 2019, 1,689 pediatric patients with MPP were analyzed retrospectively. Patients were subdivided into BAL group and non-BAL group according to whether they received BAL treatment within seven days after admission. The propensity score matching method matched patients' baseline characteristics (1:1). The primary outcomes were hospital stays and the cure rate. Secondary outcomes included mortality, co-infection, repeat hospitalization within 30 days, and total cost of treatment.

RESULTS

After matching, 524 patients (BAL: 262; control: 262) were recorded. The BAL group had significantly shorter hospital stays (OR: 0.5, 95% CI: 0.4-0.7). Meanwhile, BAL did not significantly modify the cost, co-infection rate, and mortality. In subgroup analyses, the group with BAL intervention within three days had a significantly shorter hospital stay (OR: 0.4, 95% CI: 0.3-0.5) compared with the group with BAL intervention three days after admission.

CONCLUSIONS

Early BAL intervention is a better treatment than conventional drug therapy alone, and no significant complications were seen in this study. BAL intervention has an excellent clinical benefit. The earlier the intervention, the better the effect.

Drug-Induced Esophageal Ulcer in Adolescent Population: Experience at a Single Medical Center in Central Taiwan

Background and Objectives: Drug-induced esophageal ulcer is caused by focal drug stimulation. It may occur in adults and children. Limited research is available in pediatric patients with drug-induced esophageal ulcer; therefore, we designed this study to determine the characteristics of this disease in this population. Materials and Methods: Thirty-two pediatric patients diagnosed with drug-induced esophageal ulcers from a hospital database of upper gastrointestinal tract endoscopies were included. After treatment, patients were followed for 2 months after upper gastrointestinal endoscopy. Results: Female patients were predominant (56.2%/43.8%). The mean age of patients was 15.6 years (median, 16 years; interquartile range, 2 years). Doxycycline was administered in most cases (56.3%); other drugs were dicloxacillin, amoxicillin, clindamycin, L-arginine, and nonsteroidal anti-inflammatory drugs. Doxycycline was associated with kissing ulcers. Esophageal ulcers induced by nonsteroidal anti-inflammatory drugs were more often associated with gastric or duodenal ulcers. The most common location was the middle-third of the esophagus (78.1%). Patients were treated with proton pump inhibitors, sucralfate, or H2-blockers. The mean duration for which symptoms lasted was 9.2 days. No esophageal stricture was found in 24 patients who were followed for 2 months after upper gastrointestinal endoscopy. Conclusions: The authors suggest informing patients to take medicine with enough water (approximately 100 mL) and enough time (15–30 min) before recumbency, especially high-risk drugs, such as doxycycline or nonsteroidal anti-inflammatory drugs.

A new Bi(III)-based coordination complex: Treatment and nursing application values on pediatric pneumonia

In the current work, through applying the mixed-ligand generation method, [Bi4Cl8(PDC)2 (2,2′-bpy)4]·2MeCN (1), a fresh bismuth (III)-organic compound synthesized with the solvothermal reactions between 2,2′-bipyridine (2,2′-bpy); 2,6-pyridinedicarboxylic acid (H2PDC); and bismuth chloride. The structural characterization results show that complex 1 features a binuclear discrete structure which is further extended into a 1D chain–like supramolecular network via π–π interactions. Furthermore, the compound’s treatment and nursing application values on pediatric pneumonia was explored and the novel compound’s corresponding mechanism was also investigated. First of all, in our research, the enzyme-linked immunosorbent assay (ELISA) detection kit was employed for the determination of the inflammatory cytokines content released into alveolar lavage fluid. Subsequently, the adenosine 5‘-monophosphate (AMP)–activated protein kinase (AMPK) signaling pathway activation in alveolar epithelial cells was explored exploiting the real-time reverse transcription–polymerase chain reaction (RT-PCR). Molecular docking demonstrated that although multiple pyridine rings are presented in the Bi complex, however, only the carboxylate groups have been observed to interact with the active residues.

Clinical Efficacy and Safety of Shashen Maidong Decoction in the Treatment of Pediatric Mycoplasma Pneumonia: A Systematic Review and Meta-Analysis

Objective: This study was intended to provide data to support the effect of Shashen Maidong Decoction in improving mycoplasma pneumonia in pediatric patients through systematic evaluation.

Methods: PubMed, the Web of Science, EMbase, CNKI, CQVIP, Wan-Fang, and CBM databases were comprehensively searched from established in June 2021. Randomized controlled trials of TRQI were selected by screening the literature and extracting information. The Cochrane RCT Evaluation Manual was used to evaluate the methodological quality of all included studies, and Meta-analysis was performed using Stata 14.0 and Review Manager 5.4 software.

Results: A total of 1,127 patients from 12 clinical studies met the inclusion criteria. Meta-analysis results showed that the treatment group of Shashen Maidong Decoction was able to significantly increase the overall efficiency level and significantly reduce the incidence of adverse reactions, time for disappearance of cough, time for relief of cough, time for defervescence, time for disappearance of lung rales, time for return to normal of chest X-ray, T lymphocyte subpopulation (CD3⁺) and tumor necrosis factor-α (TNF-α) and other index levels (p < 0.05).

Conclusion: Shashen Maidong Decoction has a significant improvement in the levels of relevant indexes in pediatric mycoplasma pneumonia, which provides a basis for the safety and efficacy of pediatric mycoplasma pneumonia. However, due to the small sample size included in the study, the study quality was not high, and more randomized controlled trials of high quality are required for further validation.