RESUMO
Pseudomonas aeruginosa produces quorum sensing signal molecules that are potential biomarkers for infection.A prospective study of 60 cystic fibrosis patients with chronic P. aeruginosa, who required intravenous antibiotics for pulmonary exacerbations, was undertaken. Clinical measurements and biological samples were obtained at the start and end of the treatment period. Additional data were available for 29 of these patients when they were clinically stable.Cross-sectionally, quorum sensing signal molecules were detectable in the sputum, plasma and urine of 86%, 75% and 83% patients, respectively. They were positively correlated between the three biofluids. Positive correlations were observed for most quorum sensing signal molecules in sputum, plasma and urine, with quantitative measures of pulmonary P. aeruginosa load at the start of a pulmonary exacerbation. Plasma concentrations of 2-nonyl-4-hydroxy-quinoline (NHQ) were significantly higher at the start of a pulmonary exacerbation compared to clinical stability (p<0.01). Following the administration of systemic antibiotics, plasma 2-heptyl-4-hydroxyquinoline (p=0.02) and NHQ concentrations (p<0.01) decreased significantly.In conclusion, quorum sensing signal molecules are detectable in cystic fibrosis patients with pulmonary P. aeruginosa infection and are positively correlated with quantitative measures of P. aeruginosa. NHQ correlates with clinical status and has potential as a novel biomarker for P. aeruginosa infection.
Assuntos
Fibrose Cística/microbiologia , Infecções por Pseudomonas/sangue , Infecções por Pseudomonas/urina , Percepção de Quorum , Adolescente , Adulto , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Biomarcadores/sangue , Biomarcadores/urina , Estudos Transversais , Fibrose Cística/sangue , Fibrose Cística/urina , Feminino , Humanos , Hidroxiquinolinas/sangue , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pseudomonas aeruginosa/metabolismo , Quinolinas/sangue , Escarro/metabolismo , Escarro/microbiologia , Adulto JovemRESUMO
Pseudomonas aeruginosa produces specific signalling molecules, 2-alkyl-4-quinolones (AQs) that are detectable in the sputum of adults with cystic fibrosis (CF) and who have pulmonary infection with this opportunistic pathogen. This study aimed to determine whether AQs could be detected in saliva of patients with CF and known infection with Pseudomonas aeruginosa. Saliva and sputum samples were obtained from 89 adults with CF and analyzed using liquid chromatography-tandem mass spectrometry. AQs were detected in 39/89 (43.8%) saliva samples and 70/77(90.9%) sputum samples. Salivary AQs had a sensitivity of 50% (95%CI; 37.8; 62.2), specificity of 100% (95%CI; 47.8; 100), when compared to a molecular microbiological measure of P. aeruginosa in sputum as measured using polymerase chain reaction. Specific AQs produced by P. aeruginosa can be detected in the saliva and warrant investigation as potential non-invasive biomarkers of pulmonary P. aeruginosa.
Assuntos
Fibrose Cística , Infecções por Pseudomonas , Adulto , Biomarcadores/análise , Fibrose Cística/diagnóstico , Fibrose Cística/microbiologia , Humanos , Pulmão/microbiologia , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa , Percepção de Quorum , Saliva/química , Escarro/microbiologiaRESUMO
Although anaerobic bacteria exist in abundance in cystic fibrosis (CF) airways, their role in disease progression is poorly understood. We hypothesized that the presence and relative abundance of the most prevalent, live, anaerobic bacteria in sputum of adults with CF were associated with adverse clinical outcomes. This is the first study to prospectively investigate viable anaerobic bacteria present in the sputum microbiota and their relationship with long-term outcomes in adults with CF. We performed 16S rRNA analysis using a viability quantitative PCR technique on sputum samples obtained from a prospective cohort of 70 adults with CF and collected clinical data over an 8 year follow-up period. We examined the associations of the ten most abundant obligate anaerobic bacteria present in the sputum with annual rate of FEV1 change. The presence of Porphyromonas pasteri and Prevotella nanceiensis were associated with a greater annual rate of FEV1 change; -52.3 ml yr-1 (95â% CI-87.7;-16.9), -67.9 ml yr-1 (95â% CI-115.6;-20.1), respectively. Similarly, the relative abundance of these live organisms were associated with a greater annual rate of FEV1 decline of -3.7 ml yr-1 (95â% CI: -6.1 to -1.3, P=0.003) and -5.3 ml yr-1 (95â% CI: -8.7 to -1.9, P=0.002) for each log2 increment of abundance, respectively. The presence and relative abundance of certain anaerobes in the sputum of adults with CF are associated with a greater rate of long-term lung function decline. The pathogenicity of anaerobic bacteria in the CF airways should be confirmed with further longitudinal prospective studies with a larger cohort of participants.
Assuntos
Fibrose Cística , Microbiota , Porphyromonas , Prevotella , Adulto , Fibrose Cística/complicações , Fibrose Cística/microbiologia , Humanos , Pulmão/fisiopatologia , Porphyromonas/isolamento & purificação , Porphyromonas/patogenicidade , Prevotella/isolamento & purificação , Prevotella/patogenicidade , Estudos Prospectivos , RNA Ribossômico 16S/genética , Escarro/microbiologiaRESUMO
BACKGROUND: Studies in separate cohorts suggest possible discrepancies between inhaled medicines supplied (median 50-60%) and medicines used (median 30-40%). We performed the first study that directly compares CF medicine supply against use to identify the cost of excess medicines supply. METHODS: This cross-sectional study included participants from 12 UK adult centres with ≥1 year of continuous adherence data from data-logging nebulisers. Medicine supply was measured as medication possession ratio (MPR) for a 1-year period from the first suitable supply date. Medicine use was measured as electronic data capture (EDC) adherence over the same period. The cost of excess medicines was calculated as whole excess box(es) supplied after accounting for the discrepancy between EDC adherence and MPR with 20% contingency. RESULTS: Among 275 participants, 133 (48.4%) were females and mean age was 30 years (95% CI 29-31 years). Median EDC adherence was 57% (IQR 23-86%), median MPR was 74% (IQR 46-96%) and the discrepancy between measures was median 14% (IQR 2-29%). Even with 20% contingency, mean potential cost of excess medicines was £1,124 (95% CI £855-1,394), ranging from £183 (95% CI £29-338) for EDC adherence ≥80% to £2,017 (95% CI £1,507-2,526) for EDC adherence <50%. CONCLUSIONS: This study provides a conservative estimate of excess inhaled medicines supply cost among adults with CF in the UK. The excess supply cost was highest among those with lowest EDC adherence, highlighting the importance of adherence support and supplying medicine according to actual use. MPR provides information about medicine supply but over-estimates actual medicine use.
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Fibrose Cística , Sistema de Aprendizagem em Saúde , Adulto , Estudos Transversais , Fibrose Cística/tratamento farmacológico , Fibrose Cística/epidemiologia , Feminino , Humanos , Adesão à Medicação , Nebulizadores e Vaporizadores , Estudos RetrospectivosRESUMO
BACKGROUND: Cystic fibrosis (CF) is a multi-system genetic disorder affecting >72,000 people worldwide. Most CF patients experience gastrointestinal symptoms and can develop complications. However, the mechanisms of CF gut disease are not well understood. We evaluated gut function and transit in CF using magnetic resonance imaging (MRI). We hypothesised oro-caecal transit time (OCTT) is longer in CF; with lower small bowel water content (SBWC). METHODS: Twelve CF patients aged 12-40 years and 12 age and sex-matched controls underwent serial MRIs over 1 day with standardised meals. The primary endpoint was OCTT, assessed by the appearance of a food bolus in the caecum. Other measures included corrected SBWC and corrected colonic volume (both area under the curve, AUC), gastric half-emptying time and gastrointestinal symptoms. RESULTS: OCTT was longer in CF (CF 330 mins [270, >360] vs. controls 210 mins [173, 315], p = 0.04), with no difference in gastric half-emptying times. Corrected SBWC was higher in CF (CF 62 L.min/m2 [36, 80] vs. controls 34 L.min/m2 [28, 41], p = 0.021); minimal postprandial decrease between T240 and T300 (CF 13 mL/m2 [-13, 57] vs. controls 102 mL/m2 [67, 108], p = 0.002) suggests impaired ileal emptying. Corrected colonic volumes were higher in CF (CF 186 L.min/m2 [167, 206] vs. controls 123 L.min/m2 [89, 146], p = 0.012). There were no differences in gastrointestinal symptoms. CONCLUSIONS: MRI provides novel insights into CF pathophysiology. Sub-clinical ileal obstruction may be more prevalent than previously thought. Gastrointestinal MRI shows promise as an investigational tool in CF.
Assuntos
Fibrose Cística/fisiopatologia , Trato Gastrointestinal/diagnóstico por imagem , Trato Gastrointestinal/fisiopatologia , Trânsito Gastrointestinal , Imageamento por Ressonância Magnética , Período Pós-Prandial , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto JovemRESUMO
Introduction. Pseudomonas aeruginosa produces quorum sensing signalling molecules including 2-alkyl-4-quinolones (AQs), which regulate virulence factor production in the cystic fibrosis (CF) airways.Hypothesis/Gap statement. Culture can lead to condition-dependent artefacts which may limit the potential insights and applications of AQs as minimally-invasive biomarkers of bacterial load.Aim. We aimed to use culture-independent methods to explore the correlations between AQ levels and live P. aeruginosa load in adults with CF.Methodology. Seventy-five sputum samples at clinical stability and 48 paired sputum samples obtained at the beginning and end of IV antibiotics for a pulmonary exacerbation in adults with CF were processed using a viable cell separation technique followed by quantitative P. aeruginosa polymerase chain reaction (qPCR). Live P. aeruginosa qPCR load was compared with the concentrations of three AQs (HHQ, NHQ and HQNO) detected in sputum, plasma and urine.Results. At clinical stability and the beginning of IV antibiotics for pulmonary exacerbation, HHQ, NHQ and HQNO measured in sputum, plasma and urine were consistently positively correlated with live P. aeruginosa qPCR load in sputum, compared to culture. Following systemic antibiotics live P. aeruginosa qPCR load decreased significantly (P<0.001) and was correlated with a reduction in plasma NHQ (plasma: r=0.463, P=0.003).Conclusion. In adults with CF, AQ concentrations correlated more strongly with live P. aeruginosa bacterial load measured by qPCR compared to traditional culture. Prospective studies are required to assess the potential of systemic AQs as biomarkers of P. aeruginosa bacterial burden.
Assuntos
4-Quinolonas/isolamento & purificação , Fibrose Cística/complicações , Infecções por Pseudomonas/complicações , Pseudomonas aeruginosa/isolamento & purificação , Percepção de Quorum , 4-Quinolonas/sangue , 4-Quinolonas/urina , Adolescente , Adulto , Carga Bacteriana , Biomarcadores , Fibrose Cística/microbiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Pseudomonas/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Escarro/química , Adulto JovemRESUMO
Introduction. Pseudomonas aeruginosa is an important respiratory pathogen in cystic fibrosis (CF), which is associated with an accelerated decline in lung function, frequent pulmonary exacerbations and increased mortality. P. aeruginosa produces intercellular signalling molecules including 2-alkyl-4-quinolones (AQs), which regulate virulence-factor production and biofilm formation in the CF airways. Studies have shown that AQs are detectable in the sputum and plasma of adults with CF and chronic pulmonary P. aeruginosa.Aim. We tested the hypothesis that the presence of six AQs in plasma or sputum obtained from adults with CF was associated with long-term adverse clinical outcomes.Methodology. We analysed clinical data over an 8 year follow period for 90 people with CF who had previously provided samples for AQ analysis at clinical stability. The primary outcome was all cause mortality or lung transplantation. Secondary outcomes were the rate of lung-function decline and the number of intravenous (IV) antibiotic days for pulmonary exacerbations.Results. There was no statistical association between the presence of any of the six measured AQs and the primary outcomes or the secondary outcome of decline in lung function. One of the six AQs was associated with IV antibiotic usage. The presence of 2-nonyl-3-hydroxy-4(1 h)-quinolone (C9-PQS) in sputum was associated with an increase in the number of IV antibiotic days in the follow-up period (Mann-Whitney; P=0.011).Conclusion. Further investigation to confirm the hypothesis that C9-PQS may be associated with increased antibiotic usage for pulmonary exacerbations is warranted as AQ-dependent signalling is a potential future target for anti-virulence therapies.
Assuntos
Fibrose Cística/microbiologia , Pseudomonas aeruginosa/fisiologia , Quinolonas , Percepção de Quorum/fisiologia , Adolescente , Adulto , Antibacterianos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Weight gain during treatment for a cystic fibrosis exacerbation http://ow.ly/f1zl30dU9AO.
RESUMO
BACKGROUND: Pulmonary P. aeruginosa infection is associated with poor outcomes in cystic fibrosis (CF) and early diagnosis is challenging, particularly in those who are unable to expectorate sputum. Specific P. aeruginosa 2-alkyl-4-quinolones are detectable in the sputum, plasma and urine of adults with CF, suggesting that they have potential as biomarkers for P. aeruginosa infection. AIM: To investigate systemic 2-alkyl-4-quinolones as potential biomarkers for pulmonary P. aeruginosa infection. METHODS: A multicentre observational study of 176 adults and 68 children with CF. Cross-sectionally, comparisons were made between current P. aeruginosa infection using six 2-alkyl-4-quinolones detected in sputum, plasma and urine against hospital microbiological culture results. All participants without P. aeruginosa infection at baseline were followed up for one year to determine if 2-alkyl-4-quinolones were early biomarkers of pulmonary P. aeruginosa infection. RESULTS: Cross-sectional analysis: the most promising biomarker with the greatest diagnostic accuracy was 2-heptyl-4-hydroxyquinoline (HHQ). In adults, areas under the ROC curves (95% confidence intervals) for HHQ analyses were 0.82 (0.75-0.89) in sputum, 0.76 (0.69-0.82) in plasma and 0.82 (0.77-0.88) in urine. In children, the corresponding values for HHQ analyses were 0.88 (0.77-0.99) in plasma and 0.83 (0.68-0.97) in urine. Longitudinal analysis: Ten adults and six children had a new positive respiratory culture for P. aeruginosa in follow-up. A positive plasma HHQ test at baseline was significantly associated with a new positive culture for P. aeruginosa in both adults and children in follow-up (odds ratio (OR)=6.67;-95% CI:-1.48-30.1;-p=0.01 and OR=70; 95% CI: 5-956;-p<0.001 respectively). CONCLUSIONS: AQs measured in sputum, plasma and urine may be used to diagnose current infection with P. aeruginosa in adults and children with CF. These preliminary data show that plasma HHQ may have potential as an early biomarker of pulmonary P. aeruginosa. Further studies are necessary to evaluate if HHQ could be used in clinical practice to aid early diagnosis of P. aeruginosa infection in the future.
Assuntos
Fibrose Cística , Infecções por Pseudomonas , Pseudomonas aeruginosa , Quinolonas , Infecções Respiratórias , Adulto , Biomarcadores/análise , Biomarcadores/metabolismo , Criança , Estudos Transversais , Fibrose Cística/diagnóstico por imagem , Fibrose Cística/microbiologia , Diagnóstico Precoce , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Prognóstico , Infecções por Pseudomonas/diagnóstico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/fisiologia , Quinolonas/análise , Quinolonas/metabolismo , Reprodutibilidade dos Testes , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/microbiologia , Reino UnidoRESUMO
RATIONALE: Pulmonary infection and malnutrition in cystic fibrosis are associated with decreased survival. Glutamine has a possible anti-microbial effect, with a specific impact against Pseudomonas aeruginosa. We aimed to test the hypothesis that oral glutamine supplementation (21 g/day) for 8 weeks in adults with cystic fibrosis would decrease pulmonary inflammation and improve clinical status. METHODS: The study design was a randomized double-blind placebo-controlled study design with an iso-nitrogenous placebo. The primary analysis was intention to treat, and the primary outcome was change in induced sputum neutrophils. RESULTS: Thirty-nine individuals were recruited and thirty-six completed the study. Glutamine supplementation had no impact on any of the outcome measures in the intention-to-treat analysis. In the per protocol analysis, glutamine supplementation was associated with an increase in induced sputum neutrophils (P = 0.046), total cells (P = 0.03), and in Pseudomonas isolation agar colony forming units (P = 0.04) compared to placebo. CONCLUSIONS: There was no effect of glutamine supplementation on markers of pulmonary inflammation in the intention-to-treat analysis.
Assuntos
Fibrose Cística/complicações , Suplementos Nutricionais , Glutamina/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Infecções Respiratórias/tratamento farmacológico , Adulto , Antibacterianos/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Masculino , Pseudomonas aeruginosa/isolamento & purificação , Infecções Respiratórias/complicações , Resultado do Tratamento , Adulto JovemRESUMO
The Cystic Fibrosis (CF) lung harbors a complex, polymicrobial ecosystem, in which Pseudomonas aeruginosa is capable of sustaining chronic infections, which are highly resistant to multiple antibiotics. Here, we investigate the phenotypic and genotypic diversity of 44 morphologically identical P. aeruginosa isolates taken from a single CF patient sputum sample. Comprehensive phenotypic analysis of isolates revealed large variances and trade-offs in growth, virulence factors and quorum sensing (QS) signals. Whole genome analysis of 22 isolates revealed high levels of intra-isolate diversity ranging from 5 to 64 SNPs and that recombination and not spontaneous mutation was the dominant driver of diversity in this population. Furthermore, phenotypic differences between isolates were not linked to mutations in known genes but were statistically associated with distinct recombination events. We also assessed antibiotic susceptibility of all isolates. Resistance to antibiotics significantly increased when multiple isolates were mixed together. Our results highlight the significant role of recombination in generating phenotypic and genetic diversification during in vivo chronic CF infection. We also discuss (i) how these findings could influence how patient-to-patient transmission studies are performed using whole genome sequencing, and (ii) the need to refine antibiotic susceptibility testing in sputum samples taken from patients with CF.
Assuntos
Fibrose Cística/microbiologia , Variação Genética , Genoma Bacteriano , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/fisiologia , Recombinação Genética , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Evolução Molecular , Feminino , Genótipo , Técnicas de Genotipagem , Humanos , Testes de Sensibilidade Microbiana , Mutação/genética , Fenótipo , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/isolamento & purificação , Percepção de Quorum/efeitos dos fármacos , Recombinação Genética/efeitos dos fármacos , Alinhamento de Sequência , Escarro/microbiologia , Adulto JovemRESUMO
OBJECTIVE: To determine the trend in the association between socioeconomic status and sex and median age at death from cystic fibrosis in England and Wales, over the past 50 years. DESIGN: Series of annual cross sectional studies of all registered deaths with a diagnosis of cystic fibrosis in England and Wales, from 1959 to 2008. METHODS: We obtained national mortality data for cystic fibrosis from the Office for National Statistics. From 1959 to 2000, the Registrar General's Social Class coded socioeconomic status as manual or non-manual. From 2001 onwards, the National Statistics Socioeconomic Classification was implemented and socioeconomic status was split into three groups: professional and managerial, intermediate, and routine and manual. We calculated median age at death for every study year. We calculated the effects of sex and socioeconomic status on the odds of death above the median age at death for every study decade using logistic regression. RESULTS: From 1959 to 2008, 6750 deaths were attributed to cystic fibrosis in England and Wales. Males were more likely to die above the annual median age at death than females (from 1959 to 1999, adjusted odds ratio for socioeconomic status 1.28, 95% confidence intervals 1.13 to 1.45; from 2000 to 2008, 1.57, 1.18 to 2.08). Individuals in the highest socioeconomic class were also more likely to die above the median age of death than those in the lowest socioeconomic class (from 1959 to 2000, adjusted odds ratio for sex 2.50, 2.16 to 2.90; from 2001 to 2008, 1.89, 1.20 to 2.97). CONCLUSIONS: Socioeconomic status and sex remain strong determinants of survival from cystic fibrosis in England and Wales, and the magnitude of these effects does not appear to have substantially reduced over time.