Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 156
Filtrar
Mais filtros










Intervalo de ano de publicação
3.
Allergy ; 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506971

RESUMO

BACKGROUND: Whether the clinical or pathophysiologic significance of the "treatable trait" high blood eosinophil count in COPD is the same as for asthma remains controversial. We sought to determine the relationship between the blood eosinophil count, clinical characteristics and gene expression from bronchial brushings in COPD and asthma. METHODS: Subjects were recruited into a COPD (emphysema versus airway disease [EvA]) or asthma cohort (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes, U-BIOPRED). We determined gene expression using RNAseq in EvA (n = 283) and Affymetrix microarrays in U-BIOPRED (n = 85). We ran linear regression analysis of the bronchial brushings transcriptional signal versus blood eosinophil counts as well as differential expression using a blood eosinophil > 200 cells/µL as a cut-off. The false discovery rate was controlled at 1% (with continuous values) and 5% (with dichotomized values). RESULTS: There were no differences in age, gender, lung function, exercise capacity and quantitative computed tomography between eosinophilic versus noneosinophilic COPD cases. Total serum IgE was increased in eosinophilic asthma and COPD. In EvA, there were 12 genes with a statistically significant positive association with the linear blood eosinophil count, whereas in U-BIOPRED, 1197 genes showed significant associations (266 positive and 931 negative). The transcriptome showed little overlap between genes and pathways associated with blood eosinophil counts in asthma versus COPD. Only CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts. CONCLUSION: Despite shared "treatable traits" between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different.

4.
Allergy ; 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31556120

RESUMO

BACKGROUND: Airway ecology is altered in asthma and chronic obstructive pulmonary disease (COPD). Anti-microbial interventions might have benefit in subgroups of airway disease. Differences in sputum microbial profiles at acute exacerbation of airways disease are reflected by the γProteobacteria:Firmicutes (γP:F) ratio. We hypothesized that sputum microbiomic clusters exist in stable airways disease, which can be differentiated by the sputum γP:F ratio. METHODS: Sputum samples were collected from 63 subjects with severe asthma and 78 subjects with moderate-to-severe COPD in a prospective single centre trial. Microbial profiles were obtained through 16S rRNA gene sequencing. Topological data analysis was used to visualize the data set and cluster analysis performed at genus level. Clinical characteristics and sputum inflammatory mediators were compared across the clusters. RESULTS: Two ecological clusters were identified across the combined airways disease population. The smaller cluster was predominantly COPD and was characterized by dominance of Haemophilus at genus level (n = 20), high γP:F ratio, increased H influenzae, low diversity measures and increased pro-inflammatory mediators when compared to the larger Haemophilus-low cluster (n = 121), in which Streptococcus demonstrated the highest relative abundance at the genus level. Similar clusters were identified within disease groups individually and the γP:F ratio consistently differentiated between clusters. CONCLUSION: Cluster analysis by airway ecology of asthma and COPD in stable state identified two subgroups differentiated according to dominance of Haemophilus. The γP:F ratio was able to distinguish the Haemophilus-high versus Haemophilus-low subgroups, whether the Haemophilus-high group might benefit from treatment strategies to modulate the airway ecology warrants further investigation.

5.
Respir Res ; 20(1): 170, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362723

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is predominantly associated with neutrophilic inflammation. Active neutrophil elastase (NE) is a serine proteinase, secreted by neutrophils, in response to inflammation and pathogen invasion. We sought to investigate if NE could be used as a biomarker for bacterial infection in patients with COPD. METHODS: NE was quantified using ProteaseTag® Active NE Immunoassay (ProAxsis, Belfast) from the sputum of COPD subjects at stable state, exacerbation and 2 weeks post treatment visit. RESULTS: NE was measured in 90 samples from 30 COPD subjects (18 males) with a mean (range) age of 65 (45-81) years and mean (SD) FEV1 of 47% (18). The geometric mean (95%CI) of NE at stable state was 2454 ng/mL (1460 to 4125 ng/mL). There was a significant increase in NE levels at an exacerbation (p = 0.003), and NE levels were higher in a bacterial-associated exacerbation (NE log difference 3.873, 95% CI of log difference 1.396 to 10.740, p = 0.011). NE was an accurate predictor of a bacteria-associated exacerbation (area (95%CI) under the receiver operator characteristic curve 0.812 (0.657 to 0.968). CONCLUSION: NE is elevated during exacerbations of COPD. NE may be a viable biomarker for distinguishing a bacterial exacerbation in patients with COPD. TRIAL REGISTRATION: Leicestershire, Northamptonshire and Rutland ethics committee (reference number: 07/H0406/157).

7.
J Allergy Clin Immunol Pract ; 7(6): 1740-1747, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31279462

RESUMO

Eosinophilic airway inflammation is observed in 30% to 50% of chronic cough sufferers. It is a common feature of asthma and upper airway cough syndrome, and it is required in the diagnosis of nonasthmatic eosinophilic bronchitis. Our understanding of the mechanisms underlying allergic and nonallergic eosinophilic inflammation have evolved tremendously in the last 2 decades, but the cause of this inflammation in any individual is often uncertain. Inhaled corticosteroids are the mainstay therapy for cough due to asthma or nonasthmatic eosinophilic bronchitis, and response is related to the presence of biomarkers of eosinophilic airway inflammation. In upper airway cough syndrome, nasal topical corticosteroids are beneficial in allergic rhinitis and chronic rhinosinusitis with polyposis. This review will describe the diagnosis, current and possible future treatments, and prognosis of chronic cough in adults with eosinophilic inflammation.

8.
Allergy ; 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31355946

RESUMO

Current research suggests that the prostaglandin D2 (PGD2 ) receptor 2 (DP2 ) is a principal regulator in the pathophysiology of asthma, because it stimulates and amplifies the inflammatory response in this condition. The DP2 receptor can be activated by both allergic and nonallergic stimuli, leading to several pro-inflammatory events, including eosinophil activation and migration, release of the type 2 cytokines interleukin (IL)-4, IL-5 and IL-13 from T helper 2 (Th2) cells and innate lymphoid cells type 2 (ILCs), and increased airway smooth muscle mass via recruitment of mesenchymal progenitors to the airway smooth muscle bundle. Activation of the DP2 receptor pathway has potential downstream effects on asthma pathophysiology, including on airway epithelial cells, mucus hypersecretion, and airway remodelling, and consequently might impact asthma symptoms and exacerbations. Given the broad distribution of DP2 receptors on immune and structural cells involved in asthma, this receptor is being explored as a novel therapeutic target.

9.
Int J Chron Obstruct Pulmon Dis ; 14: 1177-1185, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239655

RESUMO

We hypothesized whether the reduction in eosinophilic airway inflammation in patients with chronic obstructive pulmonary disease (COPD) following treatment with benralizumab, a humanized, afucosylated, monoclonal antibody that binds to interleukin-5 receptor α, increases the airway bacterial load. Analysis of sputum samples of COPD patients participating in a Phase II trial of benralizumab indicated that sputum 16S rDNA load and Streptococcus pneumoniae were reduced following treatment with benralizumab. However, in vitro, eosinophils did not affect the killing of the common airway pathogens S. pneumoniae or Haemophilus influenzae. Thus, benralizumab may have an indirect effect upon airway bacterial load.

10.
J Allergy Clin Immunol Pract ; 7(5): 1405-1416, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31076058

RESUMO

Chronic obstructive pulmonary disease (COPD) is a significant cause of morbidity and mortality worldwide. In contrast to other chronic diseases, COPD is increasing in prevalence and is projected to be the third leading cause of death and disability worldwide by 2030. Recent advances in understanding the underlying pathophysiology of COPD has led to the development of novel targeted therapies (biologics and small molecules) that address the underlying pathophysiology of the disease. In severe asthma, biologics targeting type 2 (T2)- mediated immunity have been successful and have changed the treatment paradigm. In contrast, no biologics are currently licensed for the treatment of COPD. Those targeting non-T2 pathways have not demonstrated efficacy and in some cases raised concerns related to safety. With the increasing recognition of the eosinophil and perhaps T2-immunity possibly playing a role in a subgroup of patients with COPD, T2 biologics, specifically anti-IL-5(R), have been tested and demonstrated modest reductions in exacerbation frequency. Potential benefit was related to the baseline blood eosinophil count. These benefits were small compared with asthma. Thus, whether a subgroup of COPD sufferers might respond to anti-IL-5 or other T2-directed biologics remains to be fully addressed and requires further investigation.

12.
N Engl J Med ; 381(11): 1023-1034, 2019 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-31112385

RESUMO

BACKGROUND: The efficacy and safety of benralizumab, an interleukin-5 receptor alpha-directed cytolytic monoclonal antibody, for the prevention of exacerbations in patients with moderate to very severe chronic obstructive pulmonary disease (COPD) are not known. METHODS: In the GALATHEA and TERRANOVA trials, we enrolled patients with COPD (at a ratio of approximately 2:1 on the basis of eosinophil count [≥220 per cubic millimeter vs. <220 per cubic millimeter]) who had frequent exacerbations despite receiving guideline-based inhaled treatment. Patients were randomly assigned to receive benralizumab (30 or 100 mg in GALATHEA; 10, 30, or 100 mg in TERRANOVA) every 8 weeks (every 4 weeks for the first three doses) or placebo. The primary end point was the treatment effect of benralizumab, measured as the annualized COPD exacerbation rate ratio (benralizumab vs. placebo) at week 56 in patients with baseline blood eosinophil counts of 220 per cubic millimeter or greater. Safety was also assessed. RESULTS: In GALATHEA, the estimates of the annualized exacerbation rate were 1.19 per year (95% confidence interval [CI], 1.04 to 1.36) in the 30-mg benralizumab group, 1.03 per year (95% CI, 0.90 to 1.19) in the 100-mg benralizumab group, and 1.24 per year (95% CI, 1.08 to 1.42) in the placebo group; the rate ratio as compared with placebo was 0.96 for 30 mg of benralizumab (P = 0.65) and 0.83 for 100 mg of benralizumab (P = 0.05). In TERRANOVA, the estimates of the annualized exacerbation rate for 10 mg, 30 mg, and 100 mg of benralizumab and for placebo were 0.99 per year (95% CI, 0.87 to 1.13), 1.21 per year (95% CI, 1.08 to 1.37), 1.09 per year (95% CI, 0.96 to 1.23), and 1.17 per year (95% CI, 1.04 to 1.32), respectively; the corresponding rate ratios were 0.85 (P = 0.06), 1.04 (P = 0.66), and 0.93 (P = 0.40). At 56 weeks, none of the annualized COPD exacerbation rate ratios for any dose of benralizumab as compared with placebo reached significance in either trial. Types and frequencies of adverse events were similar with benralizumab and placebo. CONCLUSIONS: Add-on benralizumab was not associated with a lower annualized rate of COPD exacerbations than placebo among patients with moderate to very severe COPD, a history of frequent moderate or severe exacerbations, and blood eosinophil counts of 220 per cubic millimeter or greater (Funded by AstraZeneca [GALATHEA and TERRANOVA] and Kyowa Hakko Kirin [GALATHEA]; GALATHEA and TERRANOVA ClinicalTrials.gov numbers, NCT02138916 and NCT02155660.).


Assuntos
Antiasmáticos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Eosinófilos/metabolismo , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Receptores de Interleucina-5/antagonistas & inibidores , Idoso , Antiasmáticos/administração & dosagem , Antiasmáticos/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Injeções Subcutâneas , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Doença Pulmonar Obstrutiva Crônica/imunologia
13.
BMJ Open ; 9(3): e025486, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30852546

RESUMO

INTRODUCTION: Patients presenting with acute undifferentiated breathlessness are commonly encountered in admissions units across the UK. Existing blood biomarkers have clinical utility in distinguishing patients with single organ pathologies but have poor discriminatory power in multifactorial presentations. Evaluation of volatile organic compounds (VOCs) in exhaled breath offers the potential to develop biomarkers of disease states that underpin acute cardiorespiratory breathlessness, owing to their proximity to the cardiorespiratory system. To date, there has been no systematic evaluation of VOC in acute cardiorespiratory breathlessness. The proposed study will seek to use both offline and online VOC technologies to evaluate the predictive value of VOC in identifying common conditions that present with acute cardiorespiratory breathlessness. METHODS AND ANALYSIS: A prospective real-world observational study carried out across three acute admissions units within Leicestershire. Participants with self-reported acute breathlessness, with a confirmed primary diagnosis of either acute heart failure, community-acquired pneumonia and acute exacerbation of asthma or chronic obstructive pulmonary disease will be recruited within 24 hours of admission. Additionally, school-age children admitted with severe asthma will be evaluated. All participants will undergo breath sampling on admission and on recovery following discharge. A range of online technologies including: proton transfer reaction mass spectrometry, gas chromatography ion mobility spectrometry, atmospheric pressure chemical ionisation-mass spectrometry and offline technologies including gas chromatography mass spectroscopy and comprehensive two-dimensional gas chromatography-mass spectrometry will be used for VOC discovery and replication. For offline technologies, a standardised CE-marked breath sampling device (ReCIVA) will be used. All recruited participants will be characterised using existing blood biomarkers including C reactive protein, brain-derived natriuretic peptide, troponin-I and blood eosinophil levels and further evaluated using a range of standardised questionnaires, lung function testing, sputum cell counts and other diagnostic tests pertinent to acute disease. ETHICS AND DISSEMINATION: The National Research Ethics Service Committee East Midlands has approved the study protocol (REC number: 16/LO/1747). Integrated Research Approval System (IRAS) 198921. Findings will be presented at academic conferences and published in peer-reviewed scientific journals. Dissemination will be facilitated via a partnership with the East Midlands Academic Health Sciences Network and via interaction with all UK-funded Medical Research Council and Engineering and Physical Sciences Research Council molecular pathology nodes. TRIAL REGISTRATION NUMBER: NCT03672994.

14.
Sci Transl Med ; 11(479)2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760581

RESUMO

Increased airway smooth muscle mass, a feature of airway remodeling in asthma, is the strongest predictor of airflow limitation and contributes to asthma-associated morbidity and mortality. No current drug therapy for asthma is known to affect airway smooth muscle mass. Although there is increasing evidence that prostaglandin D2 type 2 receptor (DP2) is expressed in airway structural and inflammatory cells, few studies have addressed the expression and function of DP2 in airway smooth muscle cells. We report that the DP2 antagonist fevipiprant reduced airway smooth muscle mass in bronchial biopsies from patients with asthma who had participated in a previous randomized placebo-controlled trial. We developed a computational model to capture airway remodeling. Our model predicted that a reduction in airway eosinophilia alone was insufficient to explain the clinically observed decrease in airway smooth muscle mass without a concomitant reduction in the recruitment of airway smooth muscle cells or their precursors to airway smooth muscle bundles that comprise the airway smooth muscle layer. We experimentally confirmed that airway smooth muscle migration could be inhibited in vitro using DP2-specific antagonists in an airway smooth muscle cell culture model. Our analyses suggest that fevipiprant, through antagonism of DP2, reduced airway smooth muscle mass in patients with asthma by decreasing airway eosinophilia in concert with reduced recruitment of myofibroblasts and fibrocytes to the airway smooth muscle bundle. Fevipiprant may thus represent a potential therapy to ameliorate airway remodeling in asthma.

16.
Phys Med Biol ; 64(5): 055013, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30673634

RESUMO

Image registration of lung CT images acquired at different inflation levels has been proposed as a surrogate method to map lung 'ventilation'. Prior to clinical use, it is important to understand how this technique compares with direct ventilation imaging modalities such as hyperpolarised gas MRI. However, variations in lung inflation level have been shown to affect regional ventilation distributions. Therefore, the aim of this study was to evaluate the impact of lung inflation levels when comparing CT ventilation imaging to ventilation from 3He-MRI. Seven asthma patients underwent breath-hold CT at total lung capacity (TLC) and functional residual capacity (FRC). 3He-MRI and a same-breath 1H-MRI were acquired at FRC+1L and TLC. Percentage ventilated volumes (%VVs) were calculated for FRC+1L and TLC 3He-MRI. TLC-CT and registered FRC-CT were used to compute a surrogate ventilation map from voxel-wise intensity differences in Hounsfield unit values, which was thresholded at the 10th and 20th percentiles. For direct comparison of CT and 3He-MRI ventilation, FRC+1L and TLC 3He-MRI were registered to TLC-CT indirectly via the corresponding same-breath 1H-MRI data. For 3He-MRI and CT ventilation comparison, Dice similarity coefficients (DSCs) between the binary segmentations were computed. The median (range) of %VVs for FRC+1L and TLC 3He-MRI were 90.5 (54.9-93.6) and 91.8 (67.8-96.2), respectively (p  = 0.018). For MRI versus CT ventilation comparison, statistically significant improvements in DSCs were observed for TLC 3He MRI when compared with FRC+1L, with median (range) values of 0.93 (0.86-0.93) and 0.86 (0.68-0.92), respectively (p  = 0.017), for the 10-100th percentile and 0.87 (0.83-0.88) and 0.81 (0.66-0.87), respectively (p  = 0.027), for the 20-100th percentile. Correlation of CT ventilation imaging and hyperpolarised gas MRI is sensitive to lung inflation level. For ventilation maps derived from CT acquired at FRC and TLC, a higher correlation with gas ventilation MRI can be achieved if the MRI is acquired at TLC.

17.
Lancet Respir Med ; 7(1): 20-34, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30552067

RESUMO

BACKGROUND: Few genetic studies that focus on moderate-to-severe asthma exist. We aimed to identity novel genetic variants associated with moderate-to-severe asthma, see whether previously identified genetic variants for all types of asthma contribute to moderate-to-severe asthma, and provide novel mechanistic insights using expression analyses in patients with asthma. METHODS: In this genome-wide association study, we used a two-stage case-control design. In stage 1, we genotyped patient-level data from two UK cohorts (the Genetics of Asthma Severity and Phenotypes [GASP] initiative and the Unbiased BIOmarkers in PREDiction of respiratory disease outcomes [U-BIOPRED] project) and used data from the UK Biobank to collect patient-level genomic data for cases and controls of European ancestry in a 1:5 ratio. Cases were defined as having moderate-to-severe asthma if they were taking appropriate medication or had been diagnosed by a doctor. Controls were defined as not having asthma, rhinitis, eczema, allergy, emphysema, or chronic bronchitis as diagnosed by a doctor. For stage 2, an independent cohort of cases and controls (1:5) was selected from the UK Biobank only, with no overlap with stage 1 samples. In stage 1 we undertook a genome-wide association study of moderate-to-severe asthma, and in stage 2 we followed up independent variants that reached the significance threshold of p less than 1 × 10-6 in stage 1. We set genome-wide significance at p less than 5 × 10-8. For novel signals, we investigated their effect on all types of asthma (mild, moderate, and severe). For all signals meeting genome-wide significance, we investigated their effect on gene expression in patients with asthma and controls. FINDINGS: We included 5135 cases and 25 675 controls for stage 1, and 5414 cases and 21 471 controls for stage 2. We identified 24 genome-wide significant signals of association with moderate-to-severe asthma, including several signals in innate or adaptive immune-response genes. Three novel signals were identified: rs10905284 in GATA3 (coded allele A, odds ratio [OR] 0·90, 95% CI 0·88-0·93; p=1·76 × 10-10), rs11603634 in the MUC5AC region (coded allele G, OR 1·09, 1·06-1·12; p=2·32 × 10-8), and rs560026225 near KIAA1109 (coded allele GATT, OR 1·12, 1·08-1·16; p=3·06 × 10-9). The MUC5AC signal was not associated with asthma when analyses included mild asthma. The rs11603634 G allele was associated with increased expression of MUC5AC mRNA in bronchial epithelial brush samples via proxy SNP rs11602802; (p=2·50 × 10-5) and MUC5AC mRNA was increased in bronchial epithelial samples from patients with severe asthma (in two independent analyses, p=0·039 and p=0·022). INTERPRETATION: We found substantial shared genetic architecture between mild and moderate-to-severe asthma. We also report for the first time genetic variants associated with the risk of developing moderate-to-severe asthma that regulate mucin production. Finally, we identify candidate causal genes in these loci and provide increased insight into this difficult to treat population. FUNDING: Asthma UK, AirPROM, U-BIOPRED, UK Medical Research Council, and Rosetrees Trust.


Assuntos
Asma/genética , Fator de Transcrição GATA3/genética , Predisposição Genética para Doença , Mucina-5AC , Proteínas , Adulto , Idoso , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença
18.
Int J Chron Obstruct Pulmon Dis ; 13: 3663-3667, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30510409

RESUMO

Purpose: Moraxella catarrhalis is implicated in the pathogenesis of some COPD exacerbations. We sought to investigate whether the M. catarrhalis strain is variable between COPD subjects; that an exacerbation is associated with acquisition of a new strain and that certain strains are more commonly associated with exacerbations. Patients and methods: Sputum samples were collected at stable and exacerbation visits from COPD subjects from a single center as part of the COPDMAP consortium. Samples identified as M. catarrhalis positive by qPCR were recultured in liquid cultures grown to extract genomic DNA; underwent Illumina MiSeq and bacterial genome sequences were de novo assembled and Multi Locus Sequence Type (MLST) was determined. Results: Thirty-five samples were obtained from 18 subjects. These included 13 stable and 22 exacerbation samples. The diversity between samples was very large with 25 different M. catarrhalis MLSTs being identified out of the 35 samples of which 12 MSLTs have not been described previously. Change and persistence of M. catarrhalis strain were observed between stable visits, from stable to exacerbation and vice-a-versa, and between exacerbation visits. Conclusion: Sputum M. catarrhalis strains exhibit marked diversity within and between COPD subjects. Acquisition of a new strain is common between stable and exacerbation events such that no strain is specifically associated with an exacerbation.

19.
BMJ Open Respir Res ; 5(1): e000321, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30271606

RESUMO

Introduction: The degree to which bacteria in the human respiratory tract are aerosolised by individuals is not established. Building on our experience sampling bacteria exhaled by individuals with pulmonary tuberculosis using face masks, we hypothesised that patients with conditions frequently treated with antimicrobials, such as chronic obstructive pulmonary disease (COPD), might exhale significant numbers of bacteria carrying antimicrobial resistance (AMR) genes and that this may constitute a previously undefined risk for the transmission of AMR. Methods: Fifteen-minute mask samples were taken from 13 patients with COPD (five paired with contemporaneous sputum samples) and 10 healthy controls. DNA was extracted from cell pellets derived from gelatine filters mounted within the mask. Quantitative PCR analyses directed to the AMR encoding genes: blaTEM (ß-lactamase), ErmB (target methylation), mefA (macrolide efflux pump) and tetM (tetracycline ribosomal protection protein) and six additional targets were investigated. Positive signals above control samples were obtained for all the listed genes; however, background signals from the gelatine precluded analysis of the additional targets. Results: 9 patients with COPD (69%), aerosolised cells containing, in order of prevalence, mefA, tetM, ErmB and blaTEM, while three healthy controls (30%) gave weak positive signals including all targets except blaTEM. Maximum estimated copy numbers of AMR genes aerosolised per minute were mefA: 3010, tetM: 486, ErmB: 92 and blaTEM: 24. The profile of positive signals found in sputum was not concordant with that in aerosol in multiple instances. Discussion: We identified aerosolised AMR genes in patients repeatedly exposed to antimicrobials and in healthy volunteers at lower frequencies and levels. The discrepancies between paired samples add weight to the view that sputum content does not define aerosol content. Mask sampling is a simple approach yielding samples from all subjects and information distinct from sputum analysis. Our results raise the possibility that patient-generated aerosols may be a significant means of AMR dissemination that should be assessed further and that consideration be given to related control measures.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA