A Continuous-Flow Model for in vitro Cultivation of Mixed Microbial Populations Associated With Cystic Fibrosis Airway Infections

The airways of people with cystic fibrosis (CF) provide a nutrient-rich environment which favours colonisation by a variety of bacteria and fungi. Although the dominant pathogen associated with CF airway infections is Pseudomonas aeruginosa, it is becoming increasingly clear that inter-species interactions between P. aeruginosa and other colonists in the airways may have a large impact on microbial physiology and virulence. However, there are currently no suitable experimental models that permit long-term co-culture of P. aeruginosa with other CF-associated pathogens. Here, we redress this problem by describing a “3R’s-compliant” continuous-flow in vitro culture model which enables long-term co-culture of three representative CF-associated microbes: P. aeruginosa, Staphylococcus aureus and Candida albicans. Although these species rapidly out-compete one another when grown together or in pairs in batch culture, we show that in a continuously-fed setup, they can be maintained in a very stable, steady-state community. We use our system to show that even numerically (0.1%) minor species can have a major impact on intercellular signalling by P. aeruginosa. Importantly, we also show that co-culturing does not appear to influence species mutation rates, further reinforcing the notion that the system favours stability rather than divergence. The model is experimentally tractable and offers an inexpensive yet robust means of investigating inter-species interactions b...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

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Aim: To investigate the role of different types of bronchial infection and respiratory symptoms upon lung function decline.Methods: 89 children and adults with CF (mean (SD) age: 11.71 (6) years) performed 1340 serial Multiple Breath Washout (MBW) tests and 980 spirometries over a 5-year period. Respiratory symptoms (cough, sputum, nasal congestion) and Pulmonary Exacerbations (PEx) were recorded. Pseudomonas Aeruginosa, Staphylococcus aureus infection, as well as aspergillus, candida, Achromobacter, Acinetobacter, Serratia and Stenotrophomonas Maltophilia isolated from cough swabs/ sputum cultures were recorded.Results: M...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Cystic fibrosis Source Type: research
Santosh K. Ghosh1*, Thomas S. McCormick1,2 and Aaron Weinberg1* 1Biological Sciences, School of Dental Medicine, Case Western Reserve University, Cleveland, OH, United States 2Dermatology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States Human beta-defensins (hBDs, −1, 2, 3) are a family of epithelial cell derived antimicrobial peptides (AMPs) that protect mucosal membranes from microbial challenges. In addition to their antimicrobial activities, they possess other functions; e.g., cell activation, proliferation, regulation of cytokine/chemokine production, migration, diffe...
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research
We examined whether the high charge on ZmD32 would allow this defensin to retain activity in media with elevated salt concentrations. ZmD32 inhibited C. albicans, C. auris, C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis growth with IC50 values ranging from 0.7 to 3.0 in ½ PDB medium containing 100 mM NaCl. In contrast, NaD1 was only active against C. parapsilosis and C. tropicalis with IC50 values of 3.4 and 1.3 μM, respectively, in medium with added NaCl. ZmD32 also retained activity against E. coli when NaC1 concentrations were raised to 100 mM while NaD1 did not (Table 1). For C. albicans and C. kr...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In this study they also showed PTX3 localized in NETs formed after neutrophil activation (5). Proteomics analysis revealed that PTX3 forms complexes with two anti-microbial proteins [azurocidin (AZU1) and myeloperoxidase (MPO)] associated to NETs (30). More recently, PTX3 localization in NETs has been confirmed, and the colocalization with AZU1 and MPO has been defined more accurately (31). Further investigation will be needed to understand the involvement of PTX3 interaction with AZU1 and MPO in their antibacterial role during NET formation. Regulation of Complement Activation PTX3 interaction with microorganisms is not...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Raquel Ferrer-Espada1,2, Xiaojing Liu1,2, Xueping Sharon Goh1,2 and Tianhong Dai1,2* 1Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States 2Vaccine &Immunotherapy Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States Polymicrobial biofilms, in which mixed microbial species are present, play a significant role in persistent infections. Furthermore, polymicrobial biofilms promote antibiotic resistance by allowing interspecies transfer of antibiotic resistance genes. In the present study, we investigated the effec...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Interactions in the airway ecology of cystic fibrosis may alter organism persistence and clinical outcomes. Better understanding of such interactions could guide clinical decisions. We used generalized estimating equations to fit logistic regression models to longitudinal 2-year patient cohorts in the Cystic Fibrosis Foundation Patient Registry, 2003 to 2011, in order to study associations between the airway organisms present in each calendar year and their presence in the subsequent year. Models were adjusted for clinical characteristics and multiple observations per patient. Adjusted models were tested for sensitivity to...
Source: Journal of Clinical Microbiology - Category: Microbiology Authors: Tags: Epidemiology Source Type: research
Abstract Lung infections with multiresistant pathogens are a major problem of patients suffering from cystic fibrosis (CF). N-chlorotaurine (NCT), a microbicidal active chlorine compound with no resistance development, is well tolerated upon inhalation. The aim of this study was to investigate NCT on its bactericidal and fungicidal activity in vitro in artificial sputum medium (ASM) mimicking the composition of cystic fibrosis mucus.The medium was inoculated with bacteria (Staphylococcus aureus including some MRSA strains, Pseudomonas aeruginosa, Escherichia coli) or spores of fungi (Aspergillus fumigatus, Aspergi...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research
A 26 year old female with a history of cystic fibrosis (homozygous delta F508) and bilateral lung transplant presented with a bi-frontal headache one month post bilateral sinus surgery for chronic sinusitis. The provisional diagnosis was bacterial sinusitis. Although nasal swabs had grown Candida and Staphylococcus aureus, blood cultures were negative. One week after presentation, despite empiric antibacterial and antifungal therapy she developed septic shock and respiratory failure requiring veno-venous extra-corporeal membrane oxygenation (ECMO). There was further broadening of her antimicrobial cover and pulse methyl-pr...
Source: European Heart Journal - Category: Cardiology Source Type: research
DISCUSSION SESSION 1: Food allergy (PD01 –PD05)PD01 Allergen-specific humoral and cellular responses in children who fail egg oral immunotherapy due to allergic reactionsMarta Vazquez-Ortiz, Mariona Pascal, Ana Maria Plaza, Manel JuanPD02 FoxP3 epigenetic features in children with cow milk allergyLorella Paparo, Rita Nocerino, Rosita Aitoro, Ilaria Langella, Antonio Amoroso, Alessia Amoroso, Carmen Di Scala, Roberto Berni CananiPD04 Combined milk and egg allergy in early childhood: let them eat cake?Santanu Maity, Giuseppina Rotiroti, Minal GandhiPD05 Introduction of complementary foods in relation to allergy and gut...
Source: Clinical and Translational Allergy - Category: Allergy & Immunology Source Type: research
Conclusion: High and frequent occurrence of C. dubliniensis as the persistent species isolated from the lower respiratory secretions of CF patients.
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: 7.3 Cystic Fibrosis Source Type: research
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