Insights into cystic fibrosis polymicrobial consortia: the role of species interactions in biofilm development, phenotype, and response to in-use antibiotics

The Supplementary Material for this article can be found online at: http://journal.frontiersin.org/article/10.3389/fmicb. 2016.02146/full#supplementary-materialCystic Fibrosis (CF) airways disease involves complex polymicrobial infections where different bacterial species can interact and influence each other and/or even interfere with the whole community. To gain insights into the role that interactions between Pseudomonas aeruginosa in co-culture with Staphylococcus aureus, Inquilinus limosus,and Stenotrophomonas maltophilia may play in infection, the reciprocal effect during biofilm formation and the response of dual biofilms toward ciprofloxacin under in vitro atmospheres with different oxygen availabilities were evaluated. Biofilm formation kinetics showed that the growth of S. aureus, I. limosus, and S. maltophilia was disturbed in the presence of P. aeruginosa, under both aerobic and anaerobic environments. On the other hand, under aerobic conditions, I. limosus led to a decrease in biofilm mass production by P. aeruginosa, although biofilm-cells viability remains unaltered. The interaction between S. maltophilia and P. aeruginosa positively influenced dual biofilm development by increasing its biomass. Compared with monocultures, biomass of P. aeruginosaC S. aureus biofilms was significantly reduced by reciprocal interference. When grown in dual biofilms with P. aeruginosa, ciprofloxacin was less effective against S. aureus, I. limosus, and S. maltophilia, with increasing antibiotic doses leading to drastic inhibitions of P. aeruginosa cultivability. Therefore, P. aeruginosa might be responsible for the protection of the whole dual consortia against ciprofloxacin activity. Based on the overall data, it can be speculated that reciprocal interferences occur between the different bacterial species in CF lung, regardless the level of oxygen. The findings also suggest that alterations of bacterial behavior due to species interplay may be important for disease progression in CF infection.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2013 and COMPETE 2020 (POCI01-0145-FEDER-006684). This study was also supported by FCT and the European Community fund FEDER, through Program COMPETE, under the scope of the Projects RECI/BBBEBI/0179/2012 (FCOMP-01-0124-FEDER-027462), “BioHealth– Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE-07-0124-FEDER-000027 and NORTE-070124-FEDER-000025 – RL2_ Environment & Health, co-funded by the Programa Operacional Regional do Norte (ON.2 – O NovoNorte), QREN, FEDER. The authors also acknowledge the grants of Susana P. Lopes (SFRH/BPD/95616/2013) and Andreia P.Magalhães (UMINHO/BD/25/2016)

Calcifediol-loaded liposomes for local treatment of pulmonary bacterial infections.

The influence of vitamin D3 and its metabolites calcifediol (25(OH)D) and calcitriol on immune regulation and inflammation is well described, and raises the question of potential benefit against bacterial infections. In the current study, 25(OH)D was encapsulated in liposomes to enable aerosolisation, and tested for the ability to prevent pulmonary infection by Pseudomonas aeruginosa. Prepared 25(OH)D-loaded liposomes were nanosized and monodisperse, with a negative surface charge and a 25(OH)D entrapment efficiency of approximately 23%. Jet nebulisation of liposomes was seen to yield an aerosol suitable for tracheo-bronchial deposition. Interestingly, 25(OH)D in either liposomes or ethanolic solution had no effect on the release of the proinflammatory cytokine KC from Pseudomonas-infected murine epithelial cells (LA-4); treatment of infected, human bronchial 16-HBE cells with 25(OH)D liposomes however resulted in a significant reduction in bacterial survival. Together with the importance of selecting an application-appropriate in vitro model, the current study illustrates the feasibility and practicality of employing liposomes as a means to achieve 25(OH)D lung deposition. 25(OH)D-loaded liposomes further demonstrated promising effects regarding prevention of Pseudomonas infection in human bronchial epithelial cells

Challenging scenarios in nontuberculous mycobacterial infection in cystic fibrosis

This review summarizes the discussion of a session held during the 2018 North American Cystic Fibrosis (CF) Conference titled “Challenging Cases in Nontuberculous Mycobacterial (NTM) Management.” In this session, a multidisciplinary panel of NTM experts discussed clinical challenges related to the management of NTM infection in people with CF in which decision-making falls outside of the Cystic Fibrosis Foundation/European Cystic Fibrosis Society NTM guidelines. Topics discussed included managing newly acquired NTM infection, selecting and monitoring treatment regimens, determining treatment endpoints, and caring for patients after NTM treatment

Highlights from the 2015 North American Cystic Fibrosis Conference

The 29th Annual North American Cystic Fibrosis Conference was held in Phoenix, Arizona on October 8-10, 2015. Abstracts were published in a supplement to Pediatric Pulmonology.1 In this review, we summarize presentations in several of the topic areas addressed at the conference. Our goal is to provide an overview of presentations with relevance to emerging or changing concepts in several areas rather than a comprehensive review. Citations from the conference are by first author and abstract number or symposium number, as designated in the supplement

Microbiological efficacy of early MRSA treatment in cystic fibrosis in a randomised controlled trial

OBJECTIVE: To evaluate microbiological effectiveness, that is, culture negativity of a non-blinded eradication protocol (Rx) compared with observation (Obs) in clinically stable cystic fibrosis participants with newly positive methicillin resistant Staphylococcusaureus (MRSA) cultures. DESIGN: This non-blinded trial randomised participants ages 4-45 years with first or early (≤2 positive cultures within 3 years) MRSA-positive culture without MRSA-active antibiotics within 4 weeks 1:1 to Rx or Obs. The Rx protocol was: oral trimethoprim-sulfamethoxazole or if sulfa-allergic, minocycline plus oral rifampin; chlorhexidine mouthwash for 2 weeks; nasal mupirocin and chlorhexidine body wipes for 5 days and environmental decontamination for 21 days. The primary end point was MRSA culture status at day 28. RESULTS: Between 1 April 2011 to September 2014, 45 participants (44% female, mean age 11.5 years) were randomised (24 Rx, 21 Obs). At day 28, 82% (n=18/22) of participants in the Rx arm compared with 26% (n=5/19) in the Obs arm were MRSA-negative. Adjusted for interim monitoring, this difference was 52% (95% CI 23% to 80%, p<0.001). Limiting analyses to participants who were MRSA-positive at the screening visit, 67% (8/12) in the Rx arm and 13% (2/15) in the Obs arm were MRSA-negative at day 28, adjusted difference: 49% (95% CI 22% to 71%, p<0.001). Fifty-four per cent in the Rx arm compared with 10% participants in the Obs arm remained MRSA-negative through day 84. Mild gastrointestinal side effects were higher in the Rx arm. CONCLUSIONS: This MRSA eradication protocol for newly acquired MRSA demonstrated microbiological efficacy with a large treatment effect. TRIAL REGISTRATION NUMBER: NCT01349192

Highlights from the 2016 North American Cystic Fibrosis Conference

The 30th annual North American Cystic Fibrosis Conference (NACFC) was held in Orlando, FL, on October 27-29, 2016. Abstracts were published in a supplement to Pediatric Pulmonology. This review summarizes several major topic areas addressed at the conference: the pathophysiology of cystic fibrosis (CF) lung disease, clinical trials, clinical management issues, and quality improvement. We sought to provide an overview of emerging concepts in several areas of CF research and care, rather than a comprehensive review of the conference. Citations from the conference are by first author and abstract number or symposium number, as designated in the supplement

Development of a National Academic Boot Camp to Improve Fellowship Readiness.

Background: Pulmonary and critical care medicine (PCCM) fellowship requires a high degree of medical knowledge and procedural competency. Gaps in fellowship readiness can result in significant trainee anxiety related to starting fellowship training. Objective: To improve fellowship readiness and alleviate anxiety for PCCM-bound trainees by improving confidence in procedural skills and cognitive domains. Methods: Medical educators within the American Thoracic Society developed a national resident boot camp (RBC) to provide an immersive, experiential training program for physicians entering PCCM fellowships. The RBC curriculum is a 2-day course designed to build procedural skills, medical knowledge, and clinical confidence through high-fidelity simulation and active learning methodology. Separate programs for adult and pediatric providers run concurrently to provide unique training objectives targeted to their learners needs. Trainee assessments include multiple-choice pre- and post-RBC knowledge tests and confidence assessments, which are scored on a four-point Likert scale, for specific PCCM-related procedural and cognitive skills. Learners also evaluate course material and educator effectiveness, which guide modifications of future RBC programs and provide feedback for individual educators, respectively. Results: The American Thoracic Society RBC was implemented in 2014 and has grown annually to include 132 trainees and more than 100 faculty members. Mean knowledge test scores for participants in the 2019 RBC adult program increased from 55% (±14% SD) on the pretest to 72% (±11% SD; P &lt; 0.001) after RBC completion. Similarly, mean pretest scores for pediatric course attendees increased from 54% (±13% SD) to 62% (±19% SD; P = 0.17). Specific content domains that improved by 10% or more between pre- and posttests included airway management, bronchoscopy, pulmonary function testing, and code management for adult course participants, and airway management, pulmonary function testing, and extracorporeal membrane oxygenation for pediatric course participants. Trainee confidence also significantly improved across all procedural and cognitive domains for adult trainees and in 10 of 11 domains for pediatric course attendees. Course content for the 2019 RBC was overwhelmingly rated as on target for the level of learner, with &lt;4% of respondents indicating any specific session was much too basic or much too advanced. Conclusion: RBC participation improved PCCM-bound trainee knowledge, procedural familiarity, and confidence. Refinement of the RBC curriculum over the past 7 years has been guided by educator and course evaluations, with the ongoing goal of meeting the evolving educational needs of rising PCCM trainees