Targeted next-generation sequencing reveals pathogen spectrum distribution and hematological correlations in children with acute lower respiratory infections.

Background and ObjectivesTo investigate the impact of pathogenic bacterial distribution in the nasal cavity on postoperative nasal function recovery in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) after endoscopic sinus surgery (ESS), and to analyze the risk factors for postoperative recurrence.MethodsA total of 178 CRSwNP patients who underwent ESS in our hospital from May 2021 to May 2023 were selected. Based on preoperative nasal secretion pathogen culture results, patients were categorized into the pathogen-negative group (42 cases), bacterial-positive group (90 cases), and fungal-positive group (46 cases). The nasal symptom visual analogue scale (VAS) score, Lund-Kennedy endoscopic score, and Lund-Mackay computed tomography (CT) score were assessed preoperatively and at 12 weeks postoperatively. Patients were followed up for 24 months and categorized into the recurrence group (36 cases) and the recurrence-free group (142 cases) based on postoperative recurrence. Relevant risk factors for recurrence were analyzed.ResultsAmong the 178 patients, the bacterial positivity rate was 50.56% (mainly Corynebacterium, Staphylococcus, and Haemophilus influenzae), while the fungal positivity rate was 25.84% (mainly Candida albicans and Aspergillus). Postoperatively, the nasal symptom VAS scores for individual items, Lund-Kennedy endoscopic scores, and Lund-Mackay CT scores showed significant improvement compared to preoperative values (P < 0.05). Comparisons among the 3 groups revealed a trend of pathogen-negative group < bacterial-positive group < fungal-positive group in nasal symptom VAS scores, Lund-Kennedy endoscopic scores, and Lund-Mackay CT scores, with significant differences observed between each pair of groups (P < 0.05). Univariate analysis showed that the proportions of asthma, history of revision surgery, eosinophilic (EOS)-type nasal polyps, and preoperative Lund-Mackay CT scores were all higher in the recurrence group than in the recurrence-free group (P < 0.05). Multivariate analysis identified history of revision surgery (OR = 6.963, 95% CI: 2.275-21.313), EOS-type nasal polyps (OR = 4.566, 95% CI: 1.449-14.392), and high preoperative Lund-Mackay CT scores (OR = 1.928, 95% CI: 1.475-2.522) as independent risk factors for postoperative recurrence (P < 0.05). Corynebacterium infection might reduce the risk of recurrence (P = 0.065).ConclusionNasal bacterial and fungal colonization in patients with CRSwNP are associated with poor postoperative nasal function recovery, with fungal colonization leading to the worst prognosis. Postoperative recurrence is closely related to EOS-type nasal polyps, a history of previous surgery, and a high preoperative Lund-Mackay CT score. Corynebacterium may serve as a protective microbial population.

Comorbid diabetes disease severity and microbial changes in patients with bronchiectasis: a combined analysis of data from the EMBARC, EMBARC-India, Australian, and BE-China registries.

DNA sequencing has revealed extensive airborne microbial diversity beyond culturable taxa. However, DNA from viable cells and extracellular sources is often conflated, obscuring their distinct health and ecological implications. Here, we partitioned airborne bacterial DNA into three fractions: extracellular DNA (eDNA) recovered from Cetyltrimethylammonium bromide (CTAB)-treated supernatants, cellular DNA (celDNA) from pellets containing intact and compromised cells, and DNA from intact cells (iDNA) obtained after propidium monoazide (PMA) pretreatment. Each fraction was characterized using 16S rRNA gene sequencing. Ambient eDNA harbored significantly higher species richness than iDNA and celDNA, whereas this pattern was absent in an unoccupied indoor environment. The three fractions displayed distinct community structures that varied by season and environment type (ambient vs indoor). dbRDA (distance-based redundancy analysis) identified season and temperature as major drivers. The iDNA fraction was enriched in host-associated bacteria from human, animal, and plant sources. Potentially pathogenic respiratory species, including Haemophilus influenzae, Pseudomonas aeruginosa, and Streptococcus pneumoniae, were significantly enriched in the ambient iDNA fraction during winter, and negatively correlated with ambient temperature. These findings highlight the importance of DNA partitioning in deciphering inhalation risks and ecological impacts of bioaerosols.

Direct Whole-Genome Sequencing of Clinical Specimens Highlights the Emergence of Neisseria meningitidis ST-10217 in Chad.

Fatty acid-binding protein 5 deficiency impairs alveolar macrophage function and metabolism.

Children with rheumatologic diseases often require immunosuppressive therapies, which can compromise their immune response and increase susceptibility to infections. Despite the heightened risk, vaccination coverage in this population is frequently suboptimal, largely due to concerns over vaccine safety, especially live attenuated vaccines, and the absence of clear, universally adopted guidelines. This retrospective study aims to evaluate the vaccination status and serological immunity of pediatric patients with rheumatologic diseases at the time of diagnosis, prior to initiation of immunosuppressive therapy. We conducted a retrospective review of medical records from children under 16 years of age diagnosed with a rheumatologic disease at Geneva University Hospitals (HUG) between 2005 and 2023. Demographic data, clinical diagnosis, vaccination history, and available vaccine-specific serologies were collected and analysed. Seventy-four patients were included, with a median age at diagnosis of 6 years. At the time of diagnosis, vaccination coverage was highest for Haemophilus influenzae type b (Hib; 93%), followed by diphtheria and tetanus (91%), measles-mumps-rubella (MMR; 80%), pertussis and poliomyelitis (77-78%), pneumococcus (77%), varicella-zoster virus (VZV; 72%), and hepatitis B virus (HBV; 64%). Baseline serological testing was available in only half of the patients (38/74, 51%). Among those tested, seroprotection was highest for Hib (100%), followed by tetanus (91%), measles (89%), diphtheria (88%), hepatitis B (58%), varicella (47%), and pneumococcus (42%). Longitudinal follow-up revealed limited and inconsistent serological monitoring, with only a minority of patients undergoing repeat testing, and very few receiving booster vaccinations, despite the generally stable protection levels observed over time. Vaccination coverage in children with rheumatologic diseases remains suboptimal, particularly for varicella, hepatitis B, and pneumococcus. These findings underscore the critical importance of optimizing vaccination coverage at diagnosis and establishing systematic serologic surveillance protocols in this high-risk population, rather than relying solely on vaccine history.

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract disease in infants and immunocompromised adults, and secondary bacterial infections are recognized as important contributors to disease severity. Recent microbiome studies have shown that Haemophilus influenzae is frequently co-detected in severe RSV cases and ranks among the bacteria most closely correlated with disease severity; however, its causal role and underlying mechanisms remain unclear. Here, we used a murine model to examine the manner in which H. influenzae influences RSV-associated airway inflammation. We established a murine respiratory infection model by infecting mice with RSV and subsequently intratracheally inoculating them with live, ultraviolet (UV)-killed, or heat-killed nontypeable H. influenzae (NTHi). Body weight, viral and bacterial loads, bronchoalveolar lavage fluid (BALF) cytokine levels, and immune cell populations were analyzed. Live NTHi inoculation following RSV infection induced severe lower airway inflammation, characterized by pronounced body weight loss and lung injury along with increased CD8+ T-cell accumulation and enhanced interleukin (IL)-6 inflammatory mediator production in BALF. Additionally, CD8+ T-cell depletion modestly attenuated body weight loss, altered the recruited innate immune cell composition, and reduced BALF IL-6 levels. However, RSV-infected mice inoculated with UV- or heat-killed NTHi exhibited CD8+ T-cell accumulation without developing body weight loss, which suggested that CD8+ T-cell accumulation alone may be insufficient to drive full disease manifestation. In contrast to that observed for non-viable NTHi, live NTHi induced robust neutrophil recruitment along with strong production of inflammatory mediators. Additionally, BALF IL-6 levels showed a strong negative correlation with body weight; hence, IL-6 was identified as a potential marker associated with disease severity. This mouse model shows that pulmonary inoculation of live NTHi after RSV infection induces severe lower airway inflammation partially involving CD8+ T cells and that IL-6 is a potential biomarker associated with disease severity. Overall, this study suggests a novel pathological role for NTHi in the exacerbation mechanism of secondary bacterial infection in RSV infection.

Background/Objectives: Re-emergence of Haemophilus influenzae serotype b (Hib) was reported in several European countries. We aimed to characterize the age distribution of H. influnezae carriage before and after Hib vaccination. Methods: We conducted a systematic review and meta-analysis to reassess H. influenzae carriage dynamics in the pre- and post-Hib vaccination eras, focusing on age-specific patterns in childhood. Searches were performed with no date restriction and included PubMed/MEDLINE, Scopus, Web of Science, WHO Global Index Medicus, and the Cochrane Library. Eligible studies reported nasopharyngeal and/or oropharyngeal carriage prevalence and serotype distribution. Pooled estimates with 95% confidence intervals (CIs) were calculated using random-effects models, with age-stratified analyses. Results: Twenty-two studies were included (12 pre- and 10 post-Hib vaccination). Pre-vaccination, pooled H. influenzae carriage prevalence was 24.3% (95% CI, 18.9-30.7%), including 6% (95% CI, 3.4-12.8%) for Hib and 17.5% (95% CI, 12.6-23.9%) for non-type b strains. Post-vaccination, overall carriage remained similar (21.8%; 95% CI, 14.6-31.2%), but Hib carriage declined markedly to 0.67% (95% CI, 0.26-1.71%), while non-type b strains predominated (16.7%; 95% CI, 10.4-25.6%). Meta-analysis showed that carriage peaked around 4-5 years of age and persisted into later childhood. Conclusions: Hib vaccination has reduced Hib carriage, but overall H. influenzae carriage persists due to non-type b strains. Age-related persistence of carriage may have implications for herd protection, particularly in the context of evolving vaccination schedules with early childhood boosters. Continued surveillance integrating carriage and immunological data is needed to inform optimization of vaccination strategies.

To investigate the clinical features and treatment of children with primary ciliary dyskinesia (PCD), aiming to improve early recognition of the disease among pediatricians and reduce misdiagnosis and missed diagnosis. A retrospective analysis was conducted on the clinical data of 24 children with PCD admitted to the Children's Medical Center of People's Hospital of Hunan Province from January 2014 to December 2025. Among the 24 children, there were 12 boys and 12 girls, aged from 2 months to 15 years. The median age of onset was 6 months, and the median age at diagnosis was 98 months. All patients presented with recurrent respiratory tract infections and chronic productive cough; 21 had chronic sinusitis, 9 had neonatal pneumonia, and 3 had visceral inversion. The most frequently detected bacteria were Haemophilus influenzae and Streptococcus pneumoniae. Bronchiectasis was identified in 16 cases, atelectasis in 10 cases, and 19 cases showed fishbone-shaped changes in the bronchial lumen. Nasal nitric oxide testing was performed in 21 children, with all values markedly decreased (2.4-27 nL/min). Fourteen children underwent genetic testing, with 12 testing positive for autosomal recessive mutations involving 9 genes including HYDIN, DNAH11, and TUBB4B. Airway management and long-term low-dose macrolide therapy were key in treatment. Primary ciliary dyskinesia is a rare genetic disorder with early onset, often before 6 months of age. Children presenting with chronic productive cough combined with chronic sinusitis, bronchiectasis, abundant airway secretions, and visceral inversion warrant high suspicion for this disease.

ABSTRACTAcetate is a major metabolic end‐product of Haemophilus influenzae and is produced via the phosphotransacetylase–acetate kinase (Pta–AckA) pathway, which also generates adenosine triphosphate (ATP). Despite its importance, the contribution of this pathway to H. influenzae physiology and virulence remains poorly understood. Here, we have investigated the individual roles of AckA and Pta for these processes by generating nonpolar single‐gene knockouts in a chronic obstructive pulmonary disease (COPD)‐isolate strain (Hi2019) and characterized their metabolic and infection phenotypes. Both mutants exhibited significant growth impairments under microaerobic and anaerobic conditions, with reductions in growth rate of up to 50% compared with the wild type. Loss of AckA or Pta decreased ATP levels to ~ 50% of wild‐type values and caused marked overoxidation of the NAD+/NADH pool. Metabolomic analyses revealed distinct perturbations at the pyruvate node: the pta mutant produced minimal acetate but accumulated pyruvate and d‐lactate, while the ackA mutant continued to produce acetate, likely via nonenzymatic breakdown of acetyl‐phosphate. Both mutations also increased sensitivity to oxidative stress and enhanced biofilm formation. In infection models, including bronchial epithelial cells, primary human nasal epithelia, and murine macrophages, intracellular survival of both mutants was significantly reduced during early infection stages, although attenuation diminished over time. These findings demonstrate that the Pta–AckA pathway is critical for metabolic homeostasis, stress resistance, and early intracellular colonization, highlighting its potential as a target for management of early‐stage H. influenzae infections.

Severe pneumonia remains a leading cause of pediatric mortality, with increasing β-lactamase-producing pathogens challenging traditional penicillin efficacy. This study compared the clinical efficacy and safety of piperacillin–tazobactam (PT) versus ampicillin (AMP) in children with severe community-acquired pneumonia (CAP). This retrospective cohort study with propensity score matching (PSM) enrolled children aged 6 months to 5 years with severe CAP from January 2022 to June 2024. After 1:1 PSM, 95 children per group received either PT or AMP. Primary endpoints included early clinical failure rate, end-of-therapy clinical cure rate, and sustained clinical success at test of cure (TOC). Secondary endpoints encompassed symptom resolution time, pathogen eradication rate, and safety profile. The PT group demonstrated significantly lower early clinical failure rate (2.11% vs 9.47%, P = .030; RR = 0.22, 95% CI: 0.05–0.98) and higher end-of-therapy clinical cure rate (88.17% vs 76.74%, P = .044) compared with AMP. PT achieved superior overall pathogen eradication (88.73% vs 73.13%, P = .019), particularly for Haemophilus influenzae (95.83% vs 68.00%, P = .012) and Pseudomonas aeruginosa (100.00% vs 40.00%, P = .038). Hospital stay was shorter in the PT group (8.65 ± 2.30 vs 9.81 ± 2.73 days, P = .002). Adverse event rates were comparable (10.53% vs 9.47%, P = .809). Piperacillin–tazobactam demonstrated superior efficacy over ampicillin for severe pediatric CAP, with comparable safety. These findings suggest PT offers a favorable benefit-risk profile for severe pediatric CAP, particularly in areas with documented β-lactamase-producing bacterial prevalence.

Infants in resource-limited areas frequently receive early-life antibiotic treatment for respiratory and diarrheal illness, but the influence of antibiotics on parenteral vaccine immunogenicity in these settings remains underexplored. Therefore, we conducted a retrospective cohort study within a randomized, controlled, oral rotavirus and poliovirus vaccine trial performed in Dhaka, Bangladesh. Among 582 evaluable infants at 53 weeks of age, plasma antibody concentrations against measles, pertussis, diphtheria, tetanus, and Haemophilus influenzae type b (Hib) were evaluated for associations with prior antibiotic exposure. Most antibiotic prescriptions were broad-spectrum, with a mean of 85.5 days of antibiotics in the first year. Most children demonstrated protective antibody levels against measles (96%), tetanus (88%), and Hib (91%) at 53 weeks of age; fewer maintained protective levels against pertussis antigens (25-42%) and diphtheria (28%). Antibiotic exposure through 14 weeks of age, before completion of the primary vaccination series, did not significantly affect antibody concentrations at 53 weeks of age against diphtheria, tetanus, pertussis, and Hib antigens. Antibiotic exposure through 14 weeks of age was positively associated with measles antibodies at 53 weeks of age (change in concentration per antibiotic course was 9.09%; 95% CI: 5.13 to 12.75; q-value = 0.0003), but despite this association, nearly all children had protective antibody levels, limiting clinical significance. Although antibody levels varied by antigen, infant antibiotic exposure did not appear to clinically impact parenteral vaccine-induced antibody concentrations in this population. These findings support the robustness of parenteral vaccine responses in resource-limited settings despite high antibiotic use.

Muco-obstructive airway diseases result in an increase in mucus accumulation and a decrease in mucus clearance. MUC5B is the most abundant secreted mucin in the human airways, and MUC5B mucin strands dimerize to create the mucus mesh network in the healthy respiratory tract. In muco-obstructive airway diseases like cystic fibrosis (CF), immune cells and bacteria release enzymes that degrade MUC5B into smaller fragments that become entangled and compacted, contributing to pathogenesis. We utilized synthetic cystic fibrosis sputum media (SCFM) to examine how mucin polymers can impact Staphylococcus aureus, a common CF pathogen that persists despite highly effective modulator therapies to correct CF disease. We found that low-molecular-weight (LMW) mucin negatively impacts S. aureus survival and biofilm biomass compared to high-molecular-weight (HMW) mucin. Adding extracellular DNA to SCFM with LMW mucin was not sufficient to restore growth. LMW mucin had a broad negative impact on S. aureus laboratory strains and CF clinical isolates. We next tested other CF pathogens, including Pseudomonas aeruginosa and nontypeable Haemophilus influenzae, and saw no significant differences in growth in HMW or LMW mucin. LMW mucin did not significantly impact Staphylococcus epidermidis growth, indicating that there may be specific interactions with S. aureus. Overall, this work highlights how interactions with pathogenic mucins may limit S. aureus growth in the diseased airways while supporting low-level persistence, and its ability to thrive in the presence of longer mucin strands may help explain why S. aureus is well adapted to survive in the healthy respiratory tract.

Linear IgA bullous dermatosis of childhood is a rare autoimmune blistering disorder that typically presents with cutaneous manifestations but may involve ocular structures. This case highlights diagnostic challenges and treatment strategies of a 3-year-old girl with corneal involvement, initially misdiagnosed with a viral etiology. The patient presented with left-eye redness, photophobia, and eyelid swelling, preceded by a blistering rash. Evaluation included ocular examinations under anesthesia (EUA), autoimmune screening, and skin biopsy with direct immunofluorescence. Pediatric and dermatology teams provided joint care. Initial EUA identified a shield ulcer in the left cornea, managed with topical antibiotics, corticosteroids, and lubricants. Despite this, the ulcer progressed, necessitating partial tarsorrhaphy. Antiviral therapy was initiated when viral keratitis was suspected. As the cutaneous eruption advanced, dermatology review was obtained, and autoimmune testing revealed elevated MPO-ANCA. A repeat EUA demonstrated worsening corneal ulceration with conjunctival inflammation and early contralateral involvement. An amniotic membrane graft was applied. Skin biopsy confirmed linear IgA bullous dermatosis with subepidermal blisters and linear IgA deposits. Systemic corticosteroids led to marked improvement in ocular and cutaneous disease. Follow-up EUA showed early epithelial healing, although Haemophilus influenzae was cultured and treated with topical levofloxacin. A second graft was required, after which EUA confirmed complete resolution of the epithelial defect. The patient was transitioned to dapsone for long-term management. Autoimmune blistering disease should be considered in children with ocular ulcers, especially when accompanied by cutaneous manifestations. Early biopsy, timely diagnosis, and multidisciplinary management can lead to significant clinical improvement.

Severity and recurrence of Haemophilus influenzae pneumonia in adults are frequent and associated with distinct pathogenic patterns.

Optimized De novo assembly of Haemophilus influenzae using oxford nanopore sequencing without short-read data on a graphical user interface-based galaxy platform: Accurate detection of MLST, PBP3 mutations, and phylogenetic clustering.

Strengthening regional surveillance: MenMap Network's year 1 findings on bacterial meningitis in Jordan, Egypt, and Iraq (2023-2024).

A Systematic Review and Meta-Analysis of Bacterial Pathogen Prevalence in Acute and Chronic Rhinosinusitis: Implications for Empiric Antibiotic Therapy and Antimicrobial Stewardship.

Children with repaired esophageal atresia with or without tracheoesophageal fistula (EA/TEF) frequently have chronic respiratory morbidity, but airway inflammation is poorly defined. We described bronchoalveolar lavage (BAL) cell patterns in symptomatic EA/TEF and compared them with primary ciliary dyskinesia (PCD), protracted bacterial bronchitis (PBB), and healthy controls (HC). BAL profiles from symptomatic EA/TEF patients (n = 44) were analyzed against PCD (n = 10), PBB (n = 21), and HC (n = 16). Endoscopic bronchitis severity was assessed using the BScore. Associations between BScore and BAL profiles were assessed using multivariable modeling. All EA/TEF patients had pulmonary exacerbations. BAL neutrophils were higher in EA TEF than HC (median 8.0%, IQR 3-25 vs 1.0%, IQR 0-2, p < 0.001) and similarly elevated in PBB and PCD. BScore correlated with neutrophils (Spearman rho 0.69, p < 0.001) and independently predicted neutrophilic inflammation (beta 4.53, 95% CI 1.78-7.28, p = 0.002). Pathogenic bacteria were cultured in 61%, most commonly Haemophilus influenzae (29.5%) and Staphylococcus aureus (25.0%). This is the first study to systematically demonstrate neutrophil-driven airway inflammation in symptomatic children with repaired EA/TEF. These findings underscore the need for structured pulmonary follow up and the evaluation of anti inflammatory strategies in EA/TEF patients. Children with repaired EA/TEF and respiratory symptoms show frequent pulmonary exacerbations and neutrophil driven BAL inflammation. Neutrophil levels resemble protracted bacterial bronchitis and primary ciliary dyskinesia and track bronchoscopic bronchitis severity. Bronchoscopic bronchitis severity tracks neutrophilic inflammation and independently predicts it. Bacterial pathogens are common in BAL of EA/TEF children, supporting infection related airway injury risk. Results inform phenotype driven care pathways to reduce exacerbations and long term airway damage in EA/TEF children.