Cystic Fibrosis

Ivacaftor and symptoms of extra-oesophageal reflux in patients with cystic fibrosis and G551D mutation.

Mon, 2016-08-01 08:42

Ivacaftor and symptoms of extra-oesophageal reflux in patients with cystic fibrosis and G551D mutation.

J Cyst Fibros. 2016 Jul 27;

Authors: Zeybel GL, Pearson JP, Krishnan A, Bourke SJ, Doe S, Anderson A, Faruqi S, Morice AH, Jones R, McDonnell M, Zeybel M, Dettmar PW, Brodlie M, Ward C

Abstract
BACKGROUND: Extra-oesophageal reflux (EOR) may lead to microaspiration in patients with cystic fibrosis (CF), a probable cause of deteriorating lung function. Successful clinical trials of ivacaftor highlight opportunities to understand EOR in a real world study.
METHODS: Data from 12 patients with CF and the G551D mutation prescribed ivacaftor (150mg bd) was collected at baseline, 6, 26 and 52weeks. The changes in symptoms of EOR were assessed by questionnaire (reflux symptom index (RSI) and Hull airway reflux questionnaire (HARQ)).
RESULTS: Six patients presented EOR at baseline (RSI >13; median 13; range 2-29) and 5 presented airway reflux (HARQ >13; median 12; range 3 to 33). Treatment with ivacaftor was associated with a significant reduction of EOR symptoms (P<0∙04 versus baseline) denoted by the reflux symptom index and Hull airway reflux questionnaire.
CONCLUSION: Ivacaftor treatment was beneficial for patients with symptoms of EOR, thought to be a precursor to microaspiration.

PMID: 27475719 [PubMed - as supplied by publisher]

Categories: Literature Watch

Impact of rare diseases in oral health.

Mon, 2016-08-01 08:42

Impact of rare diseases in oral health.

Med Oral Patol Oral Cir Bucal. 2016 Jul 31;:0

Authors: Molina-García A, Castellanos-Cosano L, Machuca-Portillo G, Posada-de la Paz M

Abstract
BACKGROUND: Rare diseases (RD) are those that present a lower prevalence than 5 cases per 10.000 population. The main objective of this review was to study the effect on oral health in rare diseases, while the secondary objective of the study is theme upgrade.
MATERIAL AND METHODS: Comparative observational case-control studies were analysed and a systematic review was conducted in PubMed. Each rare disease listed on the statistical data record of the Health Portal of the Ministry of Equality, Health and Social Policies Board of Andalusia was associated with "oral health". The variables studied included dental, oral mucosa and occlusion alterations, oral pathologies (caries, periodontal disease) and other alterations (mouth breathing, parafunctional habits, etc). A bias analysis of the variable caries was conducted.
RESULTS: Six RD were selected through our inclusion and exclusion criteria (hypogammaglobulinemia, Rett syndrome, Marfan syndrome, Prader-Willi syndrome, cystic fibrosis and Cri du chat syndrome) in a total of 8 publications, of which four trials were classified as high risk of bias and one of them as medium risk. There were not trials with low risk of bias.
CONCLUSIONS: The main statistically significant differences found by Syndrome compared to a control group were in Hypogammaglobulinemia with a greater tendency to enamel hypoplasia and dry mouth. The Rett syndrome had, as well, a greater tendency to an anterior open bite, ogival palate, bruxism, mouth breathing and tongue thrusting. Prader-Willi syndrome had a tendency of dental erosion, and Cri du chat syndrome showed a higher association to Tannerella forsythia.

PMID: 27475682 [PubMed - as supplied by publisher]

Categories: Literature Watch

Cystic Fibrosis Papers of the Year 2015.

Mon, 2016-08-01 08:42

Cystic Fibrosis Papers of the Year 2015.

Paediatr Respir Rev. 2016 Jun 15;

Authors: Doull I

Abstract
Studies published in the last year have expanded our knowledge of potential disease modifying agents in the treatment of class II, III and IV CFTR mutations, and included the first report of an efficacious gene therapy for CF. There is also an important message on increasing use of conventional chronic therapies even in milder disease, and the pernicious effect of chronic infection on pulmonary function.

PMID: 27475293 [PubMed - as supplied by publisher]

Categories: Literature Watch

Trafficking and Function of the Cystic Fibrosis Transmembrane Conductance Regulator: A Complex Network of Post-Translational Modifications.

Sun, 2016-07-31 08:27

Trafficking and Function of the Cystic Fibrosis Transmembrane Conductance Regulator: A Complex Network of Post-Translational Modifications.

Am J Physiol Lung Cell Mol Physiol. 2016 Jul 29;:ajplung.00431.2015

Authors: McClure ML, Barnes S, Brodsky JL, Sorscher EJ

Abstract
Post-translational modifications add diversity to protein function. Throughout its life cycle, the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) undergoes numerous covalent post-translational modifications (PTMs), including glycosylation, ubiquitination, sumoylation, phosphorylation, and palmitoylation. These modifications regulate key steps during protein biogenesis, such as protein folding, trafficking, stability, function, and association with protein partners, and therefore may serve as targets for therapeutic manipulation. More generally, an improved understanding of molecular mechanisms that underlie CFTR PTMs may suggest novel treatment strategies for CF and perhaps other protein conformational diseases. This review provides a comprehensive summary of co- and post-translational CFTR modifications and their significance with regard to protein biogenesis.

PMID: 27474090 [PubMed - as supplied by publisher]

Categories: Literature Watch

The effects of ivacaftor on CF fatty acid metabolism: An analysis from the GOAL study.

Sun, 2016-07-31 08:27

The effects of ivacaftor on CF fatty acid metabolism: An analysis from the GOAL study.

J Cyst Fibros. 2016 Jul 26;

Authors: O'Connor MG, Seegmiller A

Abstract
BACKGROUND: Ivacaftor has produced significant improvement in certain individuals with cystic fibrosis (CF), though the full metabolic effects of treatment remain unknown. Abnormalities in fatty acid metabolism have previously been shown to be a characteristic of CFTR dysfunction. We hypothesized that as a reflection of this clinical improvement, ivacaftor would improve plasma fatty acid levels and decrease urine prostaglandin E metabolite levels.
METHODS: This study analyzed plasma fatty acid levels and urine prostaglandin E metabolites (PGE-M) in 40 subjects with CF participating in the G551D observational (GOAL) study who demonstrated response to the medication by a significant decrease in sweat Cl levels. Paired samples were analyzed before and after 6months of ivacaftor treatment.
RESULTS: Linoleic acid and docosahexaenoic acid levels, which are typically low in individuals with CF, did not significantly increase with ivacaftor treatment. However, arachidonic acid levels did decrease with ivacaftor treatment and there was a significant decrease in the arachidonic acid metabolite PGE-M as measured in the urine [median: before treatment 17.03ng/mg Cr; after treatment 9.06ng/mg Cr; p<0.001]. Furthermore, there were fatty acid age differences observed, including pediatric participants having significantly greater linoleic acid levels at baseline.
CONCLUSION: Ivacaftor reduces inflammatory PGE without fully correcting the plasma fatty acid abnormalities of CF. Age-related differences in fatty acid levels were observed, that may be a result of other clinical factors, such as diet, clinical care, or drug response.

PMID: 27473897 [PubMed - as supplied by publisher]

Categories: Literature Watch

Synthesis and electrochemical detection of a thiazolyl-indole natural product isolated from the nosocomial pathogen Pseudomonas aeruginosa.

Sun, 2016-07-31 08:27

Synthesis and electrochemical detection of a thiazolyl-indole natural product isolated from the nosocomial pathogen Pseudomonas aeruginosa.

Anal Bioanal Chem. 2016 Jul 29;

Authors: Buzid A, Muimhneacháin EÓ, Reen FJ, Hayes PE, Pardo LM, Shang F, O'Gara F, Sperry J, Luong JH, Glennon JD, McGlacken GP

Abstract
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen, capable of surviving in a broad range of natural environments and quickly acquiring resistance. It is associated with hospital-acquired infections, particularly in patients with compromised immunity, and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. P. aeruginosa is also of nosocomial importance on dairy farms and veterinary hospitals, where it is a key morbidity factor in bovine mastitis. P. aeruginosa uses a cell-cell communication system consisting of signalling molecules to coordinate bacterial secondary metabolites, biofilm formation, and virulence. Simple and sensitive methods for the detection of biomolecules as indicators of P. aeruginosa infection would be of great clinical importance. Here, we report the synthesis of the P. aeruginosa natural product, barakacin, which was recently isolated from the bovine ruminal strain ZIO. A simple and sensitive electrochemical method was used for barakacin detection using a boron-doped diamond (BDD) and glassy carbon (GC) electrodes, based on cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The influence of electrolyte pH on the peak potential and peak currents was also investigated. At pH 2.0, the peak current was linearly dependent on barakacin concentration (in the range used, 1-10 μM), with correlation coefficients greater than 0.98 on both electrodes. The detection limit (S/N = 3) on the BDD electrode was 100-fold lower than that obtained on the GC electrode. The optimized method using the BDD electrode was extended to bovine (cow feces) and human (sputum of a CF patient) samples. Spiked barakacin was easily detected in these matrices at a limit of 0.5 and 0.05 μM, respectively. Graphical abstract Electrochemical detection of barakacin.

PMID: 27473426 [PubMed - as supplied by publisher]

Categories: Literature Watch

Pathogen-induced secretory diarrhea and its prevention.

Sun, 2016-07-31 08:27

Pathogen-induced secretory diarrhea and its prevention.

Eur J Clin Microbiol Infect Dis. 2016 Jul 29;

Authors: Anand S, Mandal S, Patil P, Tomar SK

Abstract
Secretory diarrhea is a historically known serious health implication around the world which primarily originates through pathogenic microorganisms rather than immunological or genetical disorders. This review highlights infective mechanisms of non-inflammatory secretory diarrhea causing pathogens, known therapeutics and their efficacy against them. These non-inflammatory diarrheal pathogens breach cell barriers, induce inflammation, disrupt fluid secretion across the epithelium by alteration in ion transport by faulting cystic fibrosis transmembrane conductance regulator (CFTR), calcium activated chloride channels and ion exchanger functions. Currently, a variety of prevention strategies have been used to treat these symptoms like use of antibacterial drugs, vaccines, fluid and nutritional therapy, probiotics and prebiotics as adjuncts. In progression of the need for a therapy having quick physiological effects, withdrawing the symptoms with a wide and safe therapeutic index, newer antisecretory agents like potent inhibitors, agonists and herbal remedies are some of the interventions which have come into light through greater understanding of the mechanisms and molecular targets involved in intestinal fluid secretion. Although these therapies have their own pros and cons inside the host, the quest for new antisecretory agents has been a successful elucidation to reduce burden of diarrheal disease.

PMID: 27473379 [PubMed - as supplied by publisher]

Categories: Literature Watch

Pf4 bacteriophage produced by Pseudomonas aeruginosa inhibits Aspergillus fumigatus metabolism via iron sequestration.

Sun, 2016-07-31 08:27

Pf4 bacteriophage produced by Pseudomonas aeruginosa inhibits Aspergillus fumigatus metabolism via iron sequestration.

Microbiology. 2016 Jul 29;

Authors: Penner JC, Ferreira JA, Secor PR, Sweere JM, Birukova M, Joubert LM, Haagensen JA, Garcia O, Malkovskiy AV, Kaber G, Nazik H, Manasherob R, Spormann AM, Clemons KV, Stevens DA, Bollyky PL

Abstract
Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) are major human pathogens known to interact in a variety of disease settings, including airway infections in cystic fibrosis (CF). We recently reported that clinical isolates of Pa inhibit the formation and growth of Af biofilms. Here we report that the bacteriophage Pf4, produced by Pa, can inhibit the metabolic activity of Af biofilms. This phage-mediated inhibition was dose-dependent, ablated by phage denaturation, and was more pronounced against preformed Af biofilm rather than biofilm formation. In contrast, planktonic conidial growth was unaffected. Two other phages, Pf1 and fd, did not inhibit Af, nor did supernatant from a Pa strain incapable of producing Pf4. Pf4, but not Pf1, attaches to Af hyphae in an avid and prolonged manner, suggesting that Pf4-mediated inhibition of Af may occur at the biofilm surface. We show Pf4 binds iron, thus denying Af a crucial resource. Consistent with this, the inhibition of Af metabolism by Pf4 could be overcome with supplemental ferric iron, with preformed biofilm more resistant to reversal. To our knowledge, this is the first report of a bacterium producing a phage that inhibits the growth of a fungus and the first description of a phage behaving as an iron chelator in a biological system.

PMID: 27473221 [PubMed - as supplied by publisher]

Categories: Literature Watch

"Cystic Fibrosis"; +20 new citations

Sat, 2016-07-30 08:13

20 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/30

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

U.S. Medical Eligibility Criteria for Contraceptive Use, 2016.

Fri, 2016-07-29 07:57

U.S. Medical Eligibility Criteria for Contraceptive Use, 2016.

MMWR Recomm Rep. 2016;65(3):1-103

Authors: Curtis KM, Tepper NK, Jatlaoui TC, Berry-Bibee E, Horton LG, Zapata LB, Simmons KB, Pagano HP, Jamieson DJ, Whiteman MK

Abstract
The 2016 U.S. Medical Eligibility Criteria for Contraceptive Use (U.S. MEC) comprises recommendations for the use of specific contraceptive methods by women and men who have certain characteristics or medical conditions. These recommendations for health care providers were updated by CDC after review of the scientific evidence and consultation with national experts who met in Atlanta, Georgia, during August 26-28, 2015. The information in this report updates the 2010 U.S. MEC (CDC. U.S. medical eligibility criteria for contraceptive use, 2010. MMWR 2010:59 [No. RR-4]). Notable updates include the addition of recommendations for women with cystic fibrosis, women with multiple sclerosis, and women receiving certain psychotropic drugs or St. John's wort; revisions to the recommendations for emergency contraception, including the addition of ulipristal acetate; and revisions to the recommendations for postpartum women; women who are breastfeeding; women with known dyslipidemias, migraine headaches, superficial venous disease, gestational trophoblastic disease, sexually transmitted diseases, and human immunodeficiency virus; and women who are receiving antiretroviral therapy. The recommendations in this report are intended to assist health care providers when they counsel women, men, and couples about contraceptive method choice. Although these recommendations are meant to serve as a source of clinical guidance, health care providers should always consider the individual clinical circumstances of each person seeking family planning services. This report is not intended to be a substitute for professional medical advice for individual patients. Persons should seek advice from their health care providers when considering family planning options.

PMID: 27467196 [PubMed - as supplied by publisher]

Categories: Literature Watch

Acquired Cystic Fibrosis Transmembrane Conductance Regulator Deficiency.

Fri, 2016-07-29 07:57

Acquired Cystic Fibrosis Transmembrane Conductance Regulator Deficiency.

Adv Otorhinolaryngol. 2016;79:78-85

Authors: Cho DY, Woodworth BA

Abstract
In the genetic airway disease cystic fibrosis (CF), deficiency or dysfunction of the cystic fibrosis membrane conductance regulator (CFTR) alters anion transport in respiratory epithelium and consequently disrupts mucociliary clearance. An enriched understanding of the role of CFTR in the maintenance of normal epithelial function has revealed that mild and variable CFTR mutations play a causative role in a number of diseases not classically associated with CF. Furthermore, recent evidence indicates that acquired defects in wild-type CFTR protein processing, endocytic recycling and function can contribute to the pathogenesis of airway diseases, such as chronic obstructive pulmonary disease. In this chapter, we discuss emerging findings implicating acquired CFTR dysfunction in the pathogenesis of chronic rhinosinusitis and propose a new and leading edge approach to future CRS therapy using CFTR potentiators.

PMID: 27466849 [PubMed - as supplied by publisher]

Categories: Literature Watch

Cystic Fibrosis Sinusitis.

Fri, 2016-07-29 07:57

Cystic Fibrosis Sinusitis.

Adv Otorhinolaryngol. 2016;79:29-37

Authors: Le C, McCrary HC, Chang E

Abstract
Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the CF transmembrane conductance regulator gene(CFTR) resulting in impaired ion transport. Nearly all people with CF will develop chronic rhino-sinusitis (CRS) and present with the characteristic viscous mucus, impaired mucociliary clearance and chronic inflammation/infection of the sinonasal cavity. While some individuals with CF can appear relatively asymptomatic in terms of their sinus disease, commonly reported symptoms include anosmia, headache, facial pain, nasal obstruction, chronic congestion and nasal discharge. Nasal endoscopy typically reveals mucosal edema, purulent discharge and nasal polyposis. Computed tomography (CT) imaging classically demonstrates the distinguishing findings of sinus hypoplasia or aplasia with generalized opacification, medial bulging of the lateral sinonasal sidewall and a demineralized uncinate process. Current treatment for CF sinusitis includes the use of hypertonic saline, topical and systemic steroids, antibiotics and endoscopic surgery. Research investigating novel therapies designed at targeting the primary defect of CF is showing promise for reversal of CF sinus disease, in addition to potential for disease prevention.

PMID: 27466844 [PubMed - as supplied by publisher]

Categories: Literature Watch

Differential Diagnosis of Chronic Rhinosinusitis with Nasal Polyps.

Fri, 2016-07-29 07:57

Differential Diagnosis of Chronic Rhinosinusitis with Nasal Polyps.

Adv Otorhinolaryngol. 2016;79:1-12

Authors: London NR, Reh DD

Abstract
Nasal polyps are semi-translucent mucosal outgrowths of the paranasal sinuses which typically arise in the setting of chronic rhinosinusitis (CRS). Nasal polyps are also associated with asthma, aspirin sensitivity, cystic fibrosis and allergic fungal rhinosinusitis (AFS). The majority of nasal polyps are bilateral and characterized by tissue edema and eosinophil infiltration. Patients with nasal polyps often present with complaints including nasal obstruction, congestion, rhinorrhea or altered sense of smell. The differential diagnosis ranges from benign masses such as schneiderian papilloma, antrochoanal polyp, angiofibroma and encephalocele to malignant neoplasms such as squamous cell carcinoma (SCC), esthesioneuroblastoma, nasal lymphoma and rhabdomyosarcoma. These lesions may have a similar appearance as nasal polyps and particular attention to an alternative diagnosis for nasal polyps should be entertained if the mass is unilateral or congenital in nature. Workup for patients with a unilateral mass should include radiographic imaging, possible biopsy and careful follow-up when appropriate. Here, we review the disease etiology of nasal polyps and describe the approach to the patient with nasal polyps with emphasis on differential diagnosis and workup.

PMID: 27466841 [PubMed - as supplied by publisher]

Categories: Literature Watch

Lichen secondary metabolite evernic acid as potential quorum sensing inhibitor against Pseudomonas aeruginosa.

Fri, 2016-07-29 07:57

Lichen secondary metabolite evernic acid as potential quorum sensing inhibitor against Pseudomonas aeruginosa.

World J Microbiol Biotechnol. 2016 Sep;32(9):150

Authors: Gökalsın B, Sesal NC

Abstract
Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential. Lichens have ethnobotanical value for their medicinal properties and it is possible that their secondary metabolites have quorum sensing inhibitor properties. This study aims to investigate an alternative treatment approach by utilizing lichen secondary metabolite evernic acid to reduce the expressions of Pseudomonas aeruginosa virulence factors by inhibiting quorum sensing. For this purpose, fluorescent monitor strains were utilized for quorum sensing inhibitor screens and quantitative reverse-transcriptase PCR analyses were conducted for comparison. Results indicate that evernic acid is capable of inhibiting Pseudomonas aeruginosa quorum sensing systems.

PMID: 27465850 [PubMed - in process]

Categories: Literature Watch

"Cystic Fibrosis"; +29 new citations

Thu, 2016-07-28 07:39

29 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/28

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

"Cystic Fibrosis"; +8 new citations

Mon, 2016-07-25 00:43

8 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/25

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

"Cystic Fibrosis"; +8 new citations

Fri, 2016-07-22 08:58

8 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/22

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

"Cystic Fibrosis"; +7 new citations

Thu, 2016-07-21 14:43

7 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results:

"Cystic Fibrosis"

These pubmed results were generated on 2016/07/21

PubMed comprises more than 24 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Categories: Literature Watch

Long Non-coding RNA BGas Regulates the Cystic Fibrosis Transmembrane Conductance Regulator.

Wed, 2016-07-20 17:32
Related Articles

Long Non-coding RNA BGas Regulates the Cystic Fibrosis Transmembrane Conductance Regulator.

Mol Ther. 2016 Jul 19;

Authors: Saayman SM, Ackley A, Burdach J, Clemson M, Gruenert DC, Tachikawa K, Chivukula P, Weinberg MS, Morris KV

Abstract
Cystic fibrosis (CF) is a life-shortening genetic disease. The root cause of CF is heritable recessive mutations that affect the cystic fibrosis transmembrance conductance regulator (CFTR) gene and the subsequent expression and activity of encoded ion channels at the cell surface. We show that CFTR is regulated transcriptionally by the actions of a novel long noncoding RNA (lncRNA), designated as BGas, that emanates from intron 11 of the CFTR gene and is expressed in the antisense orientation relative to the protein coding sense strand. We find that BGas functions in concert with several proteins including HMGA1, HMGB1, and WIBG to modulate the local chromatin and DNA architecture of intron 11 of the CFTR gene and thereby affects transcription. Suppression of BGas or its associated proteins results in a gain of both CFTR expression and chloride ion function. The observations described here highlight a previously underappreciated mechanism of transcriptional control and suggest that BGas may serve as a therapeutic target for specifically activating expression of CFTR.Molecular Therapy (2016); doi:10.1038/mt.2016.112.

PMID: 27434588 [PubMed - as supplied by publisher]

Categories: Literature Watch

Bile signalling promotes chronic respiratory infections and antibiotic tolerance.

Wed, 2016-07-20 17:32
Related Articles

Bile signalling promotes chronic respiratory infections and antibiotic tolerance.

Sci Rep. 2016;6:29768

Authors: Reen FJ, Flynn S, Woods DF, Dunphy N, Chróinín MN, Mullane D, Stick S, Adams C, O'Gara F

Abstract
Despite aggressive antimicrobial therapy, many respiratory pathogens persist in the lung, underpinning the chronic inflammation and eventual lung decline that are characteristic of respiratory disease. Recently, bile acid aspiration has emerged as a major comorbidity associated with a range of lung diseases, shaping the lung microbiome and promoting colonisation by Pseudomonas aeruginosa in Cystic Fibrosis (CF) patients. In order to uncover the molecular mechanism through which bile modulates the respiratory microbiome, a combination of global transcriptomic and phenotypic analyses of the P. aeruginosa response to bile was undertaken. Bile responsive pathways responsible for virulence, adaptive metabolism, and redox control were identified, with macrolide and polymyxin antibiotic tolerance increased significantly in the presence of bile. Bile acids, and chenodeoxycholic acid (CDCA) in particular, elicited chronic biofilm behaviour in P. aeruginosa, while induction of the pro-inflammatory cytokine Interleukin-6 (IL-6) in lung epithelial cells by CDCA was Farnesoid X Receptor (FXR) dependent. Microbiome analysis of paediatric CF sputum samples demonstrated increased colonisation by P. aeruginosa and other Proteobacterial pathogens in bile aspirating compared to non-aspirating patients. Together, these data suggest that bile acid signalling is a leading trigger for the development of chronic phenotypes underlying the pathophysiology of chronic respiratory disease.

PMID: 27432520 [PubMed - in process]

Categories: Literature Watch

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