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International Journal of Molecular... Mar 2024Cystic fibrosis (CF) is an inherited genetic disorder which manifests primarily in airway disease. Recent advances in molecular technologies have unearthed the diverse...
Cystic fibrosis (CF) is an inherited genetic disorder which manifests primarily in airway disease. Recent advances in molecular technologies have unearthed the diverse polymicrobial nature of the CF airway. Numerous studies have characterised the genus-level composition of this airway community using targeted 16S rDNA sequencing. Here, we employed whole-genome shotgun metagenomics to provide a more comprehensive understanding of the early CF airway microbiome. We collected 48 sputum samples from 11 adolescents and children with CF over a 12-month period and performed shotgun metagenomics on the Illumina NextSeq platform. We carried out functional and taxonomic analysis of the lung microbiome at the species and strain levels. Correlations between microbial diversity measures and independent demographic and clinical variables were performed. Shotgun metagenomics detected a greater diversity of bacteria than culture-based methods. A large proportion of the top 25 most-dominant species were anaerobes. Samples dominated by and had significantly higher microbiome diversity, while no CF pathogen was associated with reduced microbial diversity. There was a diverse resistome present in all samples in this study, with 57.8% agreement between shotgun metagenomics and culture-based methods for detection of resistance. Pathogenic sequence types (STs) of , , and were observed to persist in young CF patients, while STs of were both persistent and shared between patients. This study provides new insight into the temporal changes in strain level composition of the microbiome and the landscape of the resistome in young people with CF. Shotgun metagenomics could provide a very useful one-stop assay for detecting pathogens, emergence of resistance and conversion to persistent colonisation in early CF disease.
Topics: Child; Humans; Adolescent; Cystic Fibrosis; Staphylococcus aureus; Biological Assay; DNA, Ribosomal; Microbiota
PubMed: 38612702
DOI: 10.3390/ijms25073893 -
Cureus Mar 2024Congenital nasal pyriform aperture stenosis (CNPAS) is a very rare cause of neonatal respiratory distress and is often missed because of its rarity. It arises from the...
Congenital nasal pyriform aperture stenosis (CNPAS) is a very rare cause of neonatal respiratory distress and is often missed because of its rarity. It arises from the overgrowth of the nasal process of the maxilla. Maxillofacial CT scan findings of pyriform aperture width <11 mm in a full-term baby, median central incisor, triangular-shaped palate, and median palatal ridge confirm the diagnosis. We describe here a case of CNPAS admitted with respiratory distress that increased further on feeding. An infant feeding tube of size 6 was not negotiable through the nostrils. Resistance was appreciated at the inlet of the nostril. Maxillofacial CT showed pyriform aperture stenosis of 3.4 mm, suggesting CNPAS. The child could not be weaned off a high-flow nasal cannula despite conservative management with decongestants, steroids spray, dilatation, and stenting for 20 days. Subsequently, surgical widening of the nasal aperture by a sublabial approach was done. The child was discharged on the 10th postoperative day on full oral feeds. It is important to suspect CNPAS in neonates with respiratory distress where other common causes have been ruled out, as it can be treated by surgery in cases refractory to conservative management.
PubMed: 38606260
DOI: 10.7759/cureus.56017 -
Respiratory Physiology & Neurobiology Jul 2024Eight pig tracheal strips were stimulated to contract with log increments of methacholine from 10 to 10 M. For each strip, the concentration-response was repeated four...
Eight pig tracheal strips were stimulated to contract with log increments of methacholine from 10 to 10 M. For each strip, the concentration-response was repeated four times in a randomized order to measure isometric force, isotonic shortening against a load corresponding to either 5 or 10 % of a reference force, and average force, stiffness, elastance and resistance over one cycle while the strip length was oscillating sinusoidally by 5 % at 0.2 Hz. For each readout, the logEC50 was calculated and compared. Isotonic shortening with a 5 % load had the lowest logEC50 (-7.13), yielding a greater sensitivity than any other contractile readout (p<0.05). It was followed by isotonic shortening with a 10 % load (-6.66), elastance (-6.46), stiffness (-6.46), resistance (-6.38), isometric force (-6.32), and average force (-6.30). Some of these differences were significant. For example, the EC50 with the average force was 44 % greater than with the elastance (p=0.001). The methacholine sensitivity is thus affected by the contractile readout being measured.
Topics: Animals; Muscle, Smooth; Methacholine Chloride; Swine; Trachea; Bronchoconstrictor Agents; Muscle Contraction; Dose-Response Relationship, Drug; Elasticity; Isometric Contraction
PubMed: 38599345
DOI: 10.1016/j.resp.2024.104264 -
Respiratory Research Apr 2024Airway remodelling plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Epithelial-mesenchymal transition (EMT) is a significant...
BACKGROUND
Airway remodelling plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Epithelial-mesenchymal transition (EMT) is a significant process during the occurrence of airway remodelling. Increasing evidence suggests that glucose transporter 3 (GLUT3) is involved in the epithelial mesenchymal transition (EMT) process of various diseases. However, the role of GLUT3 in EMT in the airway epithelial cells of COPD patients remains unclear.
METHODS
We detected the levels of GLUT3 in the peripheral lung tissue of COPD patients and cigarette smoke (CS)-exposed mice. Two Gene Expression Omnibus GEO datasets were utilised to analyse GLUT3 gene expression profiles in COPD. Western blot and immunofluorescence were used to detect GLUT3 expression. In addition, we used the AAV9-GLUT3 inhibitor to reduce GLUT3 expression in the mice model. Masson's staining and lung function measurement were used detect the collagen deposition and penh in the mice. A cell study was performed to confirm the regulatory effect of GLUT3. Inhibition of GLUT3 expression with siRNA, Western blot, and immunofluorescence were used to detect the expression of E-cadherin, N-cadherin, vimentin, p65, and ZEB1.
RESULTS
Based on the GEO data set analysis, GLUT3 expression in COPD patients was higher than in non-smokers. Moreover, GLUT3 was highly expressed in COPD patients, CS exposed mice, and BEAS-2B cells treated with CS extract (CSE). Further research revealed that down-regulation of GLUT3 significantly alleviated airway remodelling in vivo and in vitro. Lung function measurement showed that GLUT3 reduction reduced airway resistance in experimental COPD mice. Mechanistically, our study showed that reduction of GLUT3 inhibited CSE-induced EMT by down-regulating the NF-κB/ZEB1 pathway.
CONCLUSION
We demonstrate that CS enhances the expression of GLUT3 in COPD and further confirm that GLUT3 may regulate airway remodelling in COPD through the NF-κB/ZEB1 pathway; these findings have potential value in the diagnosis and treatment of COPD. The down-regulation of GLUT3 significantly alleviated airway remodelling and reduced airway resistance in vivo. Our observations uncover a key role of GLUT3 in modulating airway remodelling and shed light on the development of GLUT3-targeted therapeutics for COPD.
Topics: Humans; Mice; Animals; NF-kappa B; Airway Remodeling; Cigarette Smoking; Glucose Transporter Type 3; Pulmonary Disease, Chronic Obstructive; Epithelial-Mesenchymal Transition; Epithelial Cells; Zinc Finger E-box-Binding Homeobox 1
PubMed: 38594707
DOI: 10.1186/s12931-024-02785-3 -
Communications Biology Apr 2024Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other...
Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other inflammatory factors. We identified a previously uncharacterized peptide in the Klebsiella pneumoniae secretome, which enters Streptococcus pneumoniae via its AmiA-AliA/AliB permease. Subsequent downregulation of genes for amino acid biosynthesis and peptide uptake was associated with reduction of pneumococcal growth in defined medium and human cerebrospinal fluid, irregular cell shape, decreased chain length and decreased genetic transformation. The bacteriostatic effect was specific to S. pneumoniae and Streptococcus pseudopneumoniae with no effect on Streptococcus mitis, Haemophilus influenzae, Staphylococcus aureus or K. pneumoniae. Peptide sequence and length were crucial to growth suppression. The peptide reduced pneumococcal adherence to primary human airway epithelial cell cultures and colonization of rat nasopharynx, without toxicity. We identified a peptide with potential as a therapeutic for pneumococcal diseases suppressing growth of multiple clinical isolates, including antibiotic resistant strains, while avoiding bacterial lysis and dysbiosis.
Topics: Rats; Animals; Humans; Streptococcus pneumoniae; Klebsiella pneumoniae; Membrane Transport Proteins; Nasopharynx; Pneumococcal Infections; Peptides
PubMed: 38589539
DOI: 10.1038/s42003-024-06113-9 -
BioRxiv : the Preprint Server For... Mar 2024Versatility in carbon source utilization assists in its adaptation to various niches. Recently, we characterized the role of malonate, an understudied carbon source, in...
UNLABELLED
Versatility in carbon source utilization assists in its adaptation to various niches. Recently, we characterized the role of malonate, an understudied carbon source, in quorum sensing regulation, antibiotic resistance, and virulence factor production in . These results indicate that global responses to malonate metabolism remain to be uncovered. We leveraged a publicly available metabolomic dataset on human airway and found malonate to be as abundant as glycerol, a common airway metabolite and carbon source for . Here, we explored and compared adaptations of UCBPP-PA14 (PA14) in response to malonate or glycerol as a sole carbon source using transcriptomics and phenotypic assays. Malonate utilization activated glyoxylate and methylcitrate cycles and induced several stress responses, including oxidative, anaerobic, and metal stress responses associated with increases in intracellular aluminum and strontium. Some induced genes were required for optimal growth of in malonate. To assess the conservation of malonate-associated responses among strains, we compared our findings in strain PA14 with other lab strains and cystic fibrosis isolates of . Most strains grew on malonate as a sole carbon source as efficiently as or better than glycerol. While not all responses to malonate were conserved among strains, formation of biomineralized biofilm-like aggregates, increased tolerance to kanamycin, and increased susceptibility to norfloxacin were the most frequently observed phenotypes. Our findings reveal global remodeling of gene expression during its growth on malonate as a sole carbon source that is accompanied by several important phenotypic changes. These findings add to accumulating literature highlighting the role of different carbon sources in the physiology of and its niche adaptation.
IMPORTANCE
is a notorious pathogen that causes local and systemic infections in immunocompromised individuals. Different carbon sources can uniquely modulate metabolic and virulence pathways in , highlighting the importance of the environment that the pathogen occupies. In this work, we used a combination of transcriptomic analysis and phenotypic assays to determine how malonate utilization impacts as recent evidence indicates this carbon source may be relevant to certain niches associated within the human host. We found that malonate utilization can induce global stress responses, alter metabolic circuits, and influence various phenotypes of that could influence host colonization. Investigating the metabolism of malonate provides insight into adaptations to specific niches where this substrate is abundant, and how it can be leveraged in the development of much-needed antimicrobial agents or identification of new therapeutic targets of this difficult-to-eradicate pathogen.
PubMed: 38585990
DOI: 10.1101/2024.03.26.586813 -
FEMS Microbes 2024Asthma is a common allergic airway disease that has been associated with the development of the human microbiome early in life. Both the composition and function of the...
Asthma is a common allergic airway disease that has been associated with the development of the human microbiome early in life. Both the composition and function of the infant gut microbiota have been linked to asthma risk, but functional alterations in the gut microbiota of older patients with established asthma remain an important knowledge gap. Here, we performed whole metagenomic shotgun sequencing of 95 stool samples from a cross-sectional cohort of 59 healthy and 36 subjects with moderate-to-severe asthma to characterize the metagenomes of gut microbiota in adults and children 6 years and older. Mapping of functional orthologs revealed that asthma contributes to 2.9% of the variation in metagenomic content even when accounting for other important clinical demographics. Differential abundance analysis showed an enrichment of long-chain fatty acid (LCFA) metabolism pathways, which have been previously implicated in airway smooth muscle and immune responses in asthma. We also observed increased richness of antibiotic resistance genes (ARGs) in people with asthma. Several differentially abundant ARGs in the asthma cohort encode resistance to macrolide antibiotics, which are often prescribed to patients with asthma. Lastly, we found that ARG and virulence factor (VF) richness in the microbiome were correlated in both cohorts. ARG and VF pairs co-occurred in both cohorts suggesting that virulence and antibiotic resistance traits are coselected and maintained in the fecal microbiota of people with asthma. Overall, our results show functional alterations via LCFA biosynthetic genes and increases in antibiotic resistance genes in the gut microbiota of subjects with moderate-to-severe asthma and could have implications for asthma management and treatment.
PubMed: 38560624
DOI: 10.1093/femsmc/xtae010 -
Respiratory Research Mar 2024The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the...
BACKGROUND
The clinical significance of the impulse oscillometry-defined small airway bronchodilator response (IOS-BDR) is not well-known. Accordingly, this study investigated the clinical characteristics of IOS-BDR and explored the association between lung function decline, acute respiratory exacerbations, and IOS-BDR.
METHODS
Participants were recruited from an Early Chronic Obstructive Pulmonary Disease (ECOPD) cohort subset and were followed up for two years with visits at baseline, 12 months, and 24 months. Chronic obstructive pulmonary disease (COPD) was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV)/forced vital capacity (FVC) ratio < 0.70. IOS-BDR was defined as meeting any one of the following criteria: an absolute change in respiratory system resistance at 5 Hz ≤ - 0.137 kPa/L/s, an absolute change in respiratory system reactance at 5 Hz ≥ 0.055 kPa/L/s, or an absolute change in reactance area ≤ - 0.390 kPa/L. The association between IOS-BDR and a decline in lung function was explored with linear mixed-effects model. The association between IOS-BDR and the risk of acute respiratory exacerbations at the two-year follow-up was analyzed with the logistic regression model.
RESULTS
This study involved 466 participants (92 participants with IOS-BDR and 374 participants without IOS-BDR). Participants with IOS-BDR had higher COPD assessment test and modified Medical Research Council dyspnea scale scores, more severe emphysema, air trapping, and rapid decline in FVC than those without IOS-BDR over 2-year follow-up. IOS-BDR was not associated with the risk of acute respiratory exacerbations at the 2-year follow-up.
CONCLUSIONS
The participants with IOS-BDR had more respiratory symptoms, radiographic structural changes, and had an increase in decline in lung function than those without IOS-BDR.
TRIAL REGISTRATION
Chinese Clinical Trial Registry, ChiCTR1900024643. Registered on 19 July, 2019.
Topics: Humans; Asthma; Bronchodilator Agents; Forced Expiratory Volume; Oscillometry; Pulmonary Disease, Chronic Obstructive; Respiratory Function Tests; Spirometry
PubMed: 38555433
DOI: 10.1186/s12931-024-02765-7 -
Journal of Clinical Medicine Mar 2024The phenomenon of antimicrobial resistance (AMR) is a critical global health challenge, with prospects indicating its potential to become the leading cause of death... (Review)
Review
The phenomenon of antimicrobial resistance (AMR) is a critical global health challenge, with prospects indicating its potential to become the leading cause of death worldwide in the coming years. Individuals with pre-existing conditions, such as neoplastic disease undergoing chemotherapy, those on immunosuppressive therapy, and individuals with rare diseases like cystic fibrosis (CF), face heightened challenges due to AMR. CF is a rare disease caused by a deficiency in the synthesis of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) channel protein, resulting in multi-organ clinical symptoms, particularly in the respiratory system. PwCF experience recurrent pulmonary exacerbations triggered by bacterial or viral infections, making them particularly vulnerable to the impact of AMR. This review delves into the complex relationship between AMR and climate dynamics, focusing on the unique challenges faced by individuals with CF. It discusses the methods employed to measure AMR, its global impact on antibiotic resistance, and the specific microbial communities present in the CF airway. The review also explores the intricacies of antimicrobial resistance within the context of cystic fibrosis, emphasizing the urgent need for research in this field.
PubMed: 38541936
DOI: 10.3390/jcm13061711