Does Ivacaftor Taken Twice a Day Keep the Pseudomonas Away?

Ann Am Thorac Soc. 2019 11;16(11):1366-1367

Authors: Gifford AH, Heltshe SL

PMID: 31674815 [PubMed - indexed for MEDLINE]

Importance of Nebulizer Drying for Patients With Cystic Fibrosis.

Respir Care. 2020 Mar 24;:

Authors: Moore JE, Moore RE, Bell J, Millar BC

Abstract
BACKGROUND: Nebulizer therapy is an important treatment component for patients with cystic fibrosis (CF). Nebulizer manufacturers' guidelines advocate thorough nebulizer drying after washing. The aim of this study, therefore, was to examine the microbiology associated with nebulizer drying, particularly related to Pseudomonas control, and to examine microbiologically non-adherence to the recommended drying procedures.
METHODS: Four aspects of nebulizer drying were examined in 3 common nebulizers, including examination of the drying profile, improvement to the drying profile of assembled nebulizers, survival of Pseudomonas aeruginosa in tap water and in tap water plus 0.5% (v/v) dishwashing detergent, and the effect of drying of P. aeruginosa in tap water and tap water plus residual sputum (1%v/v, 10%v/v). Microbiologic examination was performed by using P. aeruginosa (5 clinical CF strains plus 1 National Collection of Type Cultures Reference strain).
RESULTS: There were differences in the time to complete dryness between disassembled and fully assembled nebulizers. Vigorous repeated shaking was unable to drive off all residual water on assembled nebulizers. P. aeruginosa counts did not decrease significantly in either tap water or in tap water plus detergent after 24 h storage at ambient temperature. In contrast, all Pseudomonas organisms were killed when nebulizers were dried for 24 h, even when contaminated with 1% and 10% sputum. Dishwashing detergent did not demonstrate any antibacterial activity.
CONCLUSIONS: This study demonstrated that nebulizer drying, if applied properly, had the ability to reduce counts of P. aeruginosa to non-detectable levels. Equally, this study showed that, if the device was not dried thoroughly and moisture remained, then the device was able to support the survival of P. aeruginosa at high numbers, which constituted an infection risk to the patient with CF. This information may help educate and inform the patient with CF about the importance of proper nebulizer drying for Pseudomonas control to improve patient awareness and safety.

PMID: 32209705 [PubMed - as supplied by publisher]

How adherent are obese children with sleep-disordered breathing on positive airway pressure therapy?

J Clin Sleep Med. 2020 Mar 25;:

Authors: Kothare SV, Kelly-Pieper K

PMID: 32209224 [PubMed - as supplied by publisher]

Surfing motility is a complex adaptation dependent on the stringent stress response in Pseudomonas aeruginosa LESB58.

PLoS Pathog. 2020 Mar 24;16(3):e1008444

Authors: Pletzer D, Sun E, Ritchie C, Wilkinson L, Liu LT, Trimble MJ, Wolfmeier H, Blimkie TM, Hancock REW

Abstract
Cystic fibrosis (CF) is a genetic disease that affects mucin-producing body organs such as the lungs. Characteristic of CF is the production of thick, viscous mucus, containing the glycoprotein mucin, that can lead to progressive airway obstruction. Recently, we demonstrated that the presence of mucin induced a rapid surface adaptation in motile bacteria termed surfing motility, which data presented here indicates is very different from swarming motility. Pseudomonas aeruginosa, the main colonizing pathogen in CF, employs several stress coping mechanisms to survive the highly viscous environment of the CF lung. We used motility-based assays and RNA-Seq to study the stringent stress response in the hypervirulent CF isolate LESB58 (Liverpool Epidemic Strain). Motility experiments revealed that an LESB58 stringent response mutant (ΔrelAΔspoT) was unable to surf. Transcriptional profiling of ΔrelAΔspoT mutant cells from surfing agar plates, when compared to wild-type cells from the surfing edge, revealed 2,584 dysregulated genes. Gene Ontology and KEGG enrichment analysis revealed effects of the stringent response on amino acid, nucleic acid and fatty acid metabolism, TCA cycle and glycolysis, type VI secretion, as well as chemotaxis, cell communication, iron transport, nitrogen metabolic processes and cyclic-di-GMP signalling. Screening of the ordered PA14 transposon library revealed 224 mutants unable to surf and very limited overlap with genes required for swarming. Mutants affecting surfing included two downstream effector genes of the stringent stress response, the copper regulator cueR and the quinolone synthase pqsH. Both the cueR and pqsH cloned genes complemented the surfing deficiency of ΔrelAΔspoT. Our study revealed insights into stringent stress dependency in LESB58 and showed that surfing motility is stringently-controlled via the expression of cueR and pqsH. Downstream factors of the stringent stress response are important to investigate in order to fully understand its ability to colonize and persist in the CF lung.

PMID: 32208458 [PubMed - as supplied by publisher]

Single Cell Flow Cytometry Profiling of Bronchoalveolar Lavage in Children.

Am J Respir Cell Mol Biol. 2020 Mar 24;:

Authors: Shanthikumar S, Burton M, Saffery R, Ranganathan SC, Neeland MR

Abstract
Childhood pulmonary diseases not only cause childhood morbidity and mortality, but can also cause long term pulmonary impairment. The clinical management of many childhood pulmonary diseases is hampered by a limited understanding of the underlying pathophysiological mechanisms. Flow cytometry, which can be used to phenotype individual cell populations or isolate cells for downstream analysis, represents a crucial technology which can help to elucidate the pathophysiology of these conditions. Here, we describe a flow cytometry-based method for purification and characterisation of cell populations in bronchoalveolar lavage (BAL) from children. This includes assessment of the effect of cryopreservation on cell phenotype and frequency, a knowledge gap recently identified by an American Thoracic Society report on flow cytometry in lung samples. To our knowledge, this is the first study to simultaneously quantify alveolar macrophages, T cells (CD4 and CD8), B cells, NK cells, dendritic cells, granulocytes and monocytes (CD16+/CD16-) in the BAL of children. The protocols described can be used to advance investigation of the pathophysiology of childhood pulmonary diseases.

PMID: 32207982 [PubMed - as supplied by publisher]

Herbal dry extract BNO 1011 improves clinical and mucociliary parameters in a rabbit model of chronic rhinosinusitis.

Int Forum Allergy Rhinol. 2019 06;9(6):629-637

Authors: Cho DY, Skinner D, Mackey C, Lampkin HB, Elder JB, Lim DJ, Zhang S, McCormick J, Tearney GJ, Rowe SM, Woodworth BA

Abstract
BACKGROUND: Enhancing chloride (Cl- ) secretion in sinus epithelia represents a novel therapeutic approach to chronic rhinosinusitis (CRS). Herbal dry extract BNO 1011 enhances mucociliary clearance (MCC) via upregulation of Cl- secretion in sinonasal cultures in vitro and murine epithelium in vivo. The objective of this study is to evaluate whether the BNO 1011 improves MCC and clinical parameters in a rabbit model of CRS.
METHODS: After the development of CRS in 30 New Zealand white rabbits, animals were randomly assigned to receive oral placebo (n = 10), BNO 1011 (low dose [LD], 25 mg/kg/daily) (n = 10), or BNO1011 (high dose [HD], 125 mg/kg/daily) (n = 10) for 4 weeks. Outcomes included sinus opacification (Kerschner's rabbit sinus CT grade), maxillary epithelial Cl- secretion (sinus potential difference [PD] assay), airway surface liquid (ASL) depth using micro-optical coherence tomography (μOCT), and submucosal gland density (SMD) on histopathology. Outcome parameters were analyzed by 2 blinded investigators.
RESULTS: BNO 1011 significantly cleared sinus opacification (HD = 1.21 ± 0.63, LD = 1.26 ± 0.37,) compared to placebo (4.02 ± 0.92) (p = 0.009). BNO 1011 resulted in markedly greater mean sinus PD polarization (HD = -12.23 ± 1.4 mV, LD = -12.0 ± 3.0 mV) when compared to rabbits treated with placebo (-4.1 ± 1.1 mV) (p = 0.03). ASL depth was significantly improved when treated with HD (4.08 ± 0.06 μm) and LD (4.05 ± 0.06 μm) compared to placebo (3.5 ± 0.05 μm) (post hoc analysis, p < 0.0001). Histologically, epithelial thickness (HD = 10.0 ± 0.7 μm; LD = 13.7 ± 0.9 μm; placebo = 21.1 ± 2.3 μm; p < 0.005), subepithelial thickness (HD = 63.1 ± 6.6 μm; LD = 103.2 ± 6.7 μm; placebo = 113.3 ± 6.0 μm; p < 0.001), and SMD (HD = 22.2 ± 2.9%; LD = 31.8 ± 1.1%; placebo = 43.8 ± 1.7%; p < 0.0001) were noticeably better with the HD.
CONCLUSION: Herbal dry extract BNO 1011 improves radiographic, histologic, and MCC parameters in a rabbit model of CRS.

PMID: 30657641 [PubMed - indexed for MEDLINE]

Ethnogeographic and inter-individual variability of human ABC transporters.

Hum Genet. 2020 Mar 23;:

Authors: Xiao Q, Zhou Y, Lauschke VM

Abstract
ATP-binding cassette (ABC) transporters constitute a superfamily of 48 structurally similar membrane transporters that mediate the ATP-dependent cellular export of a plethora of endogenous and xenobiotic substances. Importantly, genetic variants in ABC genes that affect gene function have clinically important effects on drug disposition and can be predictors of the risk of adverse drug reactions and efficacy of chemotherapeutics, calcium channel blockers, and protease inhibitors. Furthermore, loss-of-function of ABC transporters is associated with a variety of congenital disorders. Despite their clinical importance, information about the frequencies and global distribution of functionally relevant ABC variants is limited and little is known about the overall genetic complexity of this important gene family. Here, we systematically mapped the genetic landscape of the entire human ABC superfamily using Next-Generation Sequencing data from 138,632 individuals across seven major populations. Overall, we identified 62,793 exonic variants, 98.5% of which were rare. By integrating five computational prediction algorithms with structural mapping approaches using experimentally determined crystal structures, we found that the functional ABC variability is extensive and highly population-specific. Every individual harbored between 9.3 and 13.9 deleterious ABC variants, 76% of which were found only in a single population. Carrier rates of pathogenic variants in ABC transporter genes associated with autosomal recessive congenital diseases, such as cystic fibrosis or pseudoxanthoma elasticum, closely mirrored the corresponding population-specific disease prevalence, thus providing a novel resource for rare disease epidemiology. Combined, we provide the most comprehensive, systematic, and consolidated overview of ethnogeographic ABC transporter variability with important implications for personalized medicine, clinical genetics, and precision public health.

PMID: 32206879 [PubMed - as supplied by publisher]

Genetic testing in male infertility - reassessing screening thresholds.

Curr Opin Urol. 2020 Mar 19;:

Authors: Liu JL, Peña V, Fletcher SA, Kohn TP

Abstract
PURPOSE OF REVIEW: Genetic testing in male infertility is an essential part of the process of diagnosis. Genetic abnormalities, such as Y-chromosome microdeletion, chromosomal abnormalities and mutations for cystic fibrosis, can all negatively impact a male's fertility and can be tested for during a fertility evaluation. Both Y-chromosome microdeletion and chromosomal abnormalities increase in prevalence as sperm concentrations decrease, and azoospermic men have the greatest frequency of genetic abnormalities.
RECENT FINDINGS: These genetic abnormalities can also be found in oligospermic men; however, on the basis of several recent studies, the prevalence of genetic abnormalities is lower in oligospermic men than previously thought.
SUMMARY: The current screening thresholds are devised from the previously determined prevalences and have not been revised based on the emerging data; thus, in this review of the literature, we will discuss this new evidence and whether screening thresholds should be changed.

PMID: 32205813 [PubMed - as supplied by publisher]

Fis Contributes to Resistance of Pseudomonas aeruginosa to Ciprofloxacin by Regulating Pyocin synthesis.

J Bacteriol. 2020 Mar 23;:

Authors: Long Y, Fu W, Wang S, Deng X, Jin Y, Bai F, Cheng Z, Wu W

Abstract
Fis is a versatile DNA binding protein that plays an important role in coordinating bacterial global gene expression in response to growth phases and environmental stresses. Previously, we demonstrated that Fis regulates the type III secretion system in Pseudomonas aeruginosa In this study, we explored the role of Fis in the antibiotic resistance of P. aeruginosa and found that mutation of the fis gene increases the bacterial susceptibility to ciprofloxacin. We further demonstrated that genes related to pyocin biosynthesis are upregulated in the fis mutant. The pyocins are produced in response to genotoxic agents including ciprofloxacin and the release of pyocins results in lysis of the producer cell. Thus, pyocin biosynthesis genes sensitize P. aeruginosa to ciprofloxacin. We found that PrtN, the positive regulator of the pyocin biosynthesis genes is upregulated in the fis mutant. Genetic experiments and electrophoretic mobility shift assays revealed that Fis directly binds to the promoter region of prtN and represses its expression. Therefore, our results revealed a novel Fis mediated regulation on the pyocin production and the bacterial resistance to ciprofloxacin in P. aeruginosa Importance Pseudomonas aeruginosa is an important opportunistic pathogenic bacterium that causes various acute and chronic infections in human, especially patients with compromised immunity, cystic fibrosis and severe burn wound. About 60% of cystic fibrosis patients have a chronic respiratory infection caused by P. aeruginosa The bacterium is intrinsically highly resistant to antibiotics, which greatly increases the difficulties in the clinical treatment. Therefore, it is critical to understand the mechanisms and the regulatory pathways that are involved in the antibiotic resistance. In this study, we elucidated a novel regulatory pathway that controls the bacterial resistance to fluoroquinolone antibiotics, which enhances our understanding of how P. aeruginosa responses to ciprofloxacin.

PMID: 32205461 [PubMed - as supplied by publisher]

Antibiofilm and mucolytic action of nitric oxide delivered via gas or macromolecular donor using in vitro and ex vivo models.

J Cyst Fibros. 2020 Mar 20;:

Authors: Rouillard KR, Hill DB, Schoenfisch MH

Abstract
BACKGROUND: The combination of antibacterial and mucolytic actions makes nitric oxide (NO) an attractive dual-action cystic fibrosis (CF) therapeutic. The delivery of any therapeutic agent through pathological mucus is difficult, and the use of inhaled NO gas is inherently limited by toxicity concerns. Herein, we directly compare the ability of NO to eradicate infection and decrease mucus viscoelastic moduli as a function of delivery method (i.e., as a gas or water-soluble chitosan donor).
METHODS: To compare bactericidal action in tissue, an ex vivo porcine lung model was infected and treated with either gaseous NO or NO-releasing chitosan for 5 h. In vitro Pseudomonas aeruginosa biofilm viability was quantified after NO treatment. Human bronchial epithelial mucus and CF sputum were exposed to NO and their viscoelastic moduli measured with parallel plate macrorheology.
RESULTS: Larger NO concentrations were achieved in solution when delivered by chitosan relative to gas exposure. The bactericidal action in tissue of the NO-releasing chitosan was greater compared to NO gas in the infected tissue model. Chitosan delivery also resulted in improved antibiofilm action and reduced biofilm viability (2-log) while gaseous delivery had no impact at an equivalent dose (~0.8 µmol/mL). At equivalent NO doses, mucus and sputum rheology were significantly reduced after treatment with NO-releasing chitosan with NO gas having no significant effect.
CONCLUSIONS: Delivery of NO by chitosan allows for larger in-solution concentrations than achievable via direct gas with superior bactericidal and mucolytic action.

PMID: 32205069 [PubMed - as supplied by publisher]

Practical aspects of inner ear gene delivery for research and clinical applications.

Hear Res. 2020 Mar 06;:107934

Authors: Lee S, Dondzillo A, Gubbels SP, Raphael Y

Abstract
The application of gene therapy is widely expanding in research and continuously improving in preparation for clinical applications. The inner ear is an attractive target for gene therapy for treating environmental and genetic diseases in both the auditory and vestibular systems. With the lack of spontaneous cochlear hair cell replacement, hair cell regeneration in adult mammals is among the most important goals of gene therapy. In addition, correcting gene defects can open up a new era for treating inner ear diseases. The relative isolation and small size of the inner ear dictate local administration routes and carefully calculated small volumes of reagents. In the current review, we will cover effective timing, injection routes and types of vectors for successful gene delivery to specific target cells within the inner ear. Differences between research purposes and clinical applications are also discussed.

PMID: 32204962 [PubMed - as supplied by publisher]

Comparison of a handheld turbine spirometer to conventional spirometry in children with cystic fibrosis.

Pediatr Pulmonol. 2020 Mar 23;:

Authors: Avdimiretz N, Wilson D, Grasemann H

Abstract
BACKGROUND: In pediatric cystic fibrosis (CF) ambulatory care, handheld spirometry in individual clinic rooms would improve patient flow and potentially reduce patient-to-patient contact. A validation study was conducted to examine the accuracy of an entirely handheld turbine spirometer vs a standard laboratory device in pediatric CF patients.
METHODS: Spirometric data were obtained from 76 CF patients aged less than 18 years in the ambulatory setting using the Micro Loop Spirometer (CareFusion) and compared to same-day data from conventional laboratory spirometry.
RESULTS: Linear relationships were obtained between devices, demonstrating good correlation: r = .99, .99, .97, and .82 for forced expiratory volume in 1 second (FEV1) , forced vital capacity (FVC), FEF25%-75% , and peak expiratory flow, respectively (P < .001 for all). Biases (mean differences between devices) were -65 mL for FEV1 (P < .001) and -115 mL for FVC (P < .001) on the handheld. Bland-Altman plots demonstrated scatter in bias across all volumes. Limits of agreement (defined as mean ± 2 standard deviations [SD]) were large: +189 to -319 mL for FEV1 , equating to large limits of agreement for FEV1 percent predicted of +9.0% to -13.9%. For repeated measurements on the same device on different days, a larger percent SD was obtained with the handheld compared to the conventional spirometer (6.7% vs 5.1%, respectively). Importantly, a relatively large number (15%) demonstrated a decrease in FEV1 percent predicted of ≥10% on the handheld compared to conventional.
CONCLUSIONS: This suggests that while both devices have passed the recommendations for spirometry testing per American Thoracic Society/European Respiratory Society, handheld turbine vs conventional spirometers may not be used interchangeably in the pediatric CF population.

PMID: 32203645 [PubMed - as supplied by publisher]

Newborn Screening for Cystic Fibrosis in Mersin Province: Yearly Assessment of the National Program.

Turk Thorac J. 2020 Mar 01;21(2):100-104

Authors: Özdemir A, Doğruel D

Abstract
OBJECTIVES: A national newborn screening program for cystic fibrosis (CF) was started using immunoreactive trypsinogen (IRT) test on January 1, 2015, in Turkey. We aimed to analyze the characteristics of newborn screen-positive (NBSP) infants in Mersin province.
MATERIALS AND METHODS: The data on NBSP infants were retrospectively analyzed between 2015 and 2017 from records of Mersin Women & Children's Hospital and Mersin City Training and Research Hospital.
RESULTS: A total of 82,273 newborns were screened for CF by IRT test between January 2015 and December 2017 in Mersin. Among those, 512 infants were defined as NBSP after two repeated IRT tests (IRT/IRT) (138 infants in 2015, 217 in 2016, and 157 in 2017). Sweat test was normal in the majority of infants (115 infants [83.3%] in 2015, 189 [87.1%] in 2016, and 129 [82.2%] in 2017). Overall, between 2015 and 2017, after two repeated sweat tests, 4 infants had sweat test results in the intermediate range and 9 infants had positive sweat tests. The incidence of CF for a 3-year period was approximately 1/9300 in our region. The positive predictive value of IRT test for defining CF was 1.8%, with a sensitivity of 90.0% and specificity of 99.4%.
CONCLUSION: IRT/IRT test as a newborn screening strategy provides the opportunity for earlier diagnosis and treatment of CF patients. More data are needed to understand the frequency of CF on a national level.

PMID: 32202999 [PubMed - as supplied by publisher]

Vitamin D Deficiency and Radiological Findings in Adult Non-Cystic Fibrosis Bronchiectasis.

Turk Thorac J. 2020 Mar 01;21(2):87-92

Authors: Niksarlıoğlu EY, Kılıç L, Bilici D, Yiğitbaş B, Uysal MA, Çamsarı G

Abstract
OBJECTIVES: Vitamin D may play an important role in immunity and its deficiency has been related to increased respiratory infections. The aim of this study was to detect the prevalence of vitamin D deficiency and to investigate the relationship between radiological and clinical effects on adult bronchiectasis (BR) patients.
MATERIALS AND METHODS: A total of 130 patients with BR and 73 healthy individuals (control group) were enrolled in this study. Radiological severity was assessed using Modified Reiff Score.
RESULTS: The mean age of patients was 41.9±9.1 years (range, 18-85). The mean 25-hydroxyvitamin D (25(OH)D) level was 14.7±9.6 ng/mL in BR patients and 19.8±6.9 ng/mL in the control group (p=0.001). Moreover, 95 (73.1%) adult BR patients were categorized as vitamin D deficient. Patients in the vitamin D deficiency group had significantly higher Modified Medical Research Council scores than those in the group without vitamin D deficiency (p=0.036) The mean modified Reiff score was higher in the vitamin D deficient group than the without vitamin D deficiency group (6.9±3.8 vs 4.9± 2.7, p=0.001). Additionally, the vitamin D deficient group had lower forced vital capacity% predicted value (p=0.02). This model showed that Reiff score (OR, 1.285[1.039-1.590]; p=0.021) was independently related to vitamin D deficiency.
CONCLUSION: We found that vitamin D deficiency is commonly seen in adult BR patients in a stable period. Moreover, it might be related to severe radiological findings on chest computed tomography and worse lung functions.

PMID: 32202997 [PubMed - as supplied by publisher]

Finding sense in the context.

Elife. 2020 Mar 23;9:

Authors: Keeling KM, Bedwell DM

Abstract
Ribosomal profiling has shed new light on how ribosomes can ignore stop codons in messenger RNA.

PMID: 32202493 [PubMed - as supplied by publisher]

Nitrogen offset in N2 multiple washout method.

ERJ Open Res. 2020 Jan;6(1):

Authors: Bayfield KJ, Alton E, Irving S, Bush A, Davies JC

Abstract
Addressing concerns with use of the Exhalyzer D multiple breath washout device http://bit.ly/2ug0fAi.

PMID: 32201685 [PubMed]

Microbicidal activity of N-chlorotaurine can be enhanced in the presence of lung epithelial cells.

J Cyst Fibros. 2020 Mar 19;:

Authors: Leiter H, Toepfer S, Messner P, Rabensteiner M, Gostner JM, Lackner M, Hermann M, Nagl M

Abstract
BACKGROUND: N-chlorotaurine (NCT) is an endogenous active chlorine compound that can be used as an antiseptic and anti-infective in different body regions. Recently, tolerability of inhaled NCT has been demonstrated in humans so that it is of interest for future treatment of cystic fibrosis. In the present study, we tested the bactericidal and fungicidal activity of NCT in different lung cell culture models.
METHODS: Bacteria (Staphylococcus aureus, Pseudomonas aeruginosa) and fungi (Candida albicans, Exophiala dermatitidis) were co-incubated with lung epithelial cell cultures, and after 4 h NCT was added. After different incubation times, aliquots were removed and quantitative cultures were performed.
RESULTS: NCT at the therapeutically applied concentration of 1% (55 mM) completely killed the test pathogens within 15 - 30 min at 20 °C and at 37 °C. Killing by 0.3% NCT lasted up to 4 h dependent on the pathogen at 20 °C and up to 1 h at 37 °C. 0.1% NCT was the threshold concentration for killing since this amount of oxidation capacity was consumed by reactions with the organic compounds of the medium within 3 h (20 °C) and 0.5 h (37 °C).
CONCLUSIONS: NCT in therapeutic concentration demonstrated its microbicidal activity in the presence of lung epithelial cells. Remarkably, particularly the fungicidal activity was higher under these conditions than in phosphate buffer. This can be explained by formation of the stronger microbicidal monochloramine in equilibrium by transchlorination. The results suggest the suitability of NCT as inhalation medication in the lung.

PMID: 32201161 [PubMed - as supplied by publisher]

Effect of one-year lumacaftor-ivacaftor treatment on glucose tolerance abnormalities in cystic fibrosis patients.

J Cyst Fibros. 2020 Mar 19;:

Authors: Misgault B, Chatron E, Reynaud Q, Touzet S, Abely M, Melly L, Dominique S, Troussier F, Ronsin-Pradel O, Gerardin M, Mankikian J, Cosson L, Chiron R, Bounyar L, Porzio M, Durieu I, Weiss L, Kessler R, Kessler L

Abstract
OBJECTIVES: To investigate the effects of 1-year lumacaftor-ivacaftor treatment on abnormalities in glucose tolerance (AGT) in Phe508del homozygous cystic fibrosis (CF) patients.
METHODS: Untreated CF patients with glucose intolerance or newly diagnosed diabetes were included in a prospective, observational study. After 1-year lumacaftor-ivacaftor treatment, AGT were evaluated by using oral glucose tolerance test.
RESULTS: Forty patients participated. 78% of patients had glucose intolerance and 22% diabetes at baseline. After one-year treatment, 50% of patients had normal glucose tolerance, 40% glucose intolerance, and 10% diabetes (p <0.001). The two-hour OGTT glycemia decreased from 171 (153-197) to 139 (117-162) mg/dL (p <0.001). 57.5% (n = 23) of patients improved their glucose tolerance with a significant decrease in both 1-hour (p<0.01) and 2-hour (p<0.001) OGTT glycemia.
CONCLUSION: Improvements in AGT were observed following 1-year lumacaftor-ivacaftor treatment. Larger studies are needed to comprehensively assess CF transmembrane conductance regulator (CFTR) modulators.

PMID: 32201160 [PubMed - as supplied by publisher]

Total bacterial load, inflammation, and structural lung disease in paediatric cystic fibrosis.

J Cyst Fibros. 2020 Mar 18;:

Authors: Taylor SL, Leong LEX, Ivey KL, Wesselingh S, Grimwood K, Wainwright CE, Rogers GB, Australasian Cystic Fibrosis Bronchoalveolar Lavage (ACFBAL) study group

Abstract
BACKGROUND: Cystic fibrosis (CF) is characterised by reduced airway clearance, microbial accumulation, inflammation, and lung function decline. Certain bacterial species may contribute disproportionately to worsening lung disease. However, the relative importance of these microorganisms compared to the absolute abundance of all bacteria is uncertain. We aimed to identify the characteristics of lower airway microbiology that best reflect CF airway inflammation and disease in children.
METHODS: Analysis was performed on bronchoalveolar lavage (BAL) fluid from 78 participants of the Australasian CF Bronchoalveolar Lavage (ACFBAL) clinical trial, aged 4.5-5.5 years. Universal bacterial quantitative PCR (qPCR), species-specific qPCR, and 16S rRNA gene sequencing were performed on DNA extracts to determine total bacterial load, species-specific load and taxa relative abundance. Quantification of pre-specified pathogens was performed by culture-based methods. Bacteriological data were related to neutrophil counts, interleukin-8, lung function, and two computed-tomography based measures, CF-CT (as the primary measure) and PRAGMA.
RESULTS: Of all bacteriological measures assessed, total bacterial load determined by qPCR correlated most strongly with structural disease (CF-CT total score, rs=0.30, P=0.0095). Specifically, total bacterial load correlated with bronchiectasis, airway wall thickening, mucus plugging and parenchymal disease sub-scores. In contrast, culture-based quantification, microbiota-derived measures, and pathogen-specific qPCR-based quantification were weakly associated with total CF-CT. Regression analyses supported correlation findings, with total bacterial load explaining the greatest variance in total CF-CT (R2=0.097, P=0.0061). Correlations with PRAGMA score were comparable to CF-CT total score.
CONCLUSIONS: Within the ACFBAL trial, culture-independent quantification of total bacteria provided the most clinically-informative bacteriological measure in 5-year-old CF patients.

PMID: 32199729 [PubMed - as supplied by publisher]

Analysis of volatile metabolites from in vitro biofilms of Pseudomonas aeruginosa with thin-film microextraction by thermal desorption gas chromatography-mass spectrometry.

Anal Bioanal Chem. 2020 Mar 20;:

Authors: Koehler T, Ackermann I, Brecht D, Uteschil F, Wingender J, Telgheder U, Schmitz OJ

Abstract
Cystic fibrosis (CF) is an autosomal recessive inherited disease which leads to a production of thickened mucus in the airways. These conditions are conducive to poly-microbial infections, like chronic lung infection, in which Pseudomonas aeruginosa (P. aeruginosa) is the major pathogenic bacterium colonizing CF lungs at the end of the lifetime of CF patients. This in vitro study uses a P. aeruginosa biofilm model under partly cystic fibrosis conditions, with a sampling of volatile extracellular metabolites. The gas sampling was done with thin-film microextraction (TFME) and commercial polydimethylsiloxane (PDMS) films, whereas the analysis of loaded films was done by gas chromatography coupled to quadrupole mass spectrometry and thermodesorption (TD-GC-qMS). For this purpose, two commercially available films were characterized by means of thermogravimetry coupled to a qMS with atmospheric pressure photo ionization (TG-APPI-qMS), regarding homogeneity and temperature stability. The selected film was cleaned using a method developed in this study. The TD-GC-qMS method was successfully used for standards of volatile metabolites which were known to be produced by P. aeruginosa. Limits of detection and quantification of the method for middle and less polar compounds in low nanomolar range (0.5 nM and 1.5 nM) were achieved. The developed method was finally applied to investigate the extracellular volatile metabolites produced by biofilms of the strain P. aeruginosa DSM 50071 under aerobic and anaerobic conditions. In sum, eleven metabolites could be found under both conditions. Furthermore, it was shown in this study that different oxygen conditions (aerobic and anaerobic) resulted in emitting different extracellular volatile metabolites. Specific metabolites, like 1-undecene (aerobic) and 2-undecanone (anaerobic), could be identified. The results are promising, in that the biofilm model may be applicable for the identification of P. aeruginosa under clinical conditions. Furthermore, the model could be the basis for studying extracellular volatile metabolites from different mono- or co-cultures of various bacteria, as well as the implementation of pulmonary conditions, like these in CF lungs. This possibility allows the development of a non-invasive "at-bedside" breath analysis method for CF patients in focus of various bacterial infections. Graphical abstract.

PMID: 32198528 [PubMed - as supplied by publisher]