Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
39
result(s) for
"Plant, Barry J."
Sort by:
The Effects of Freezing on Faecal Microbiota as Determined Using MiSeq Sequencing and Culture-Based Investigations
2015
High-throughput sequencing has enabled detailed insights into complex microbial environments, including the human gut microbiota. The accuracy of the sequencing data however, is reliant upon appropriate storage of the samples prior to DNA extraction. The aim of this study was to conduct the first MiSeq sequencing investigation into the effects of faecal storage on the microbiota, compared to fresh samples. Culture-based analysis was also completed.
Seven faecal samples were collected from healthy adults. Samples were separated into fresh (DNA extracted immediately), snap frozen on dry ice and frozen for 7 days at -80°C prior to DNA extraction or samples frozen at -80°C for 7 days before DNA extraction. Sequencing was completed on the Illumina MiSeq platform. Culturing of total aerobes, anaerobes and bifidobacteria was also completed.
No significant differences at phylum or family levels between the treatment groups occurred. At genus level only Faecalibacterium and Leuconostoc were significantly different in the fresh samples compared to the snap frozen group (p = 0.0298; p = 0.0330 respectively). Diversity analysis indicated that samples clustered based on the individual donor, rather than by storage group. No significant differences occurred in the culture-based analysis between the fresh, snap or -80°C frozen samples.
Using the MiSeq platform coupled with culture-based analysis, this study highlighted that limited significant changes in microbiota occur following rapid freezing of faecal samples prior to DNA extraction. Thus, rapid freezing of samples prior to DNA extraction and culturing, preserves the integrity of the microbiota.
Journal Article
Individualized approach to elexacaftor/tezacaftor/ivacaftor dosing in cystic fibrosis, in response to self-reported anxiety and neurocognitive adverse events: A case series
2023
The prevalence of mental health disorders is high among people with Cystic Fibrosis. The psychological symptoms in CF are associated with poor adherence, worse treatment outcomes, and greater health utilization/cost. Mental health and neurocognitive Adverse Events (AEs) have been reported with all available Cystic Fibrosis Transmembrane conductance Regulator (CFTR) modulators in small groups of patients. We report our experience with a dose reduction strategy in 10 of our patients on elexacaftor/tezacaftor/ivacaftor (7.9% of total number of patients) who self-reported developing intense anxiety, irritability, sleep disturbance and/or mental slowness after initiation of full dose treatment. Standard dose elexacaftor/tezacaftor/ivacaftor resulted in 14.3 points improvement in mean Percent Predicted Forced Expiratory Volume in 1 s (ppFEV 1 ), and a mean difference in sweat chloride of −39.3 mmol/L. We initially discontinued and/or reduced therapy according to the AEs severity, with a subsequent planned dose escalation every 4–6 weeks guided by sustainability of clinical effectiveness, absence of AEs recurrence, and patients’ preferences. Clinical parameters including lung function and sweat chloride were monitored for up to 12 weeks to assess ongoing clinical response to the reduced dose regimen. Dose reduction resulted in resolution of self-reported mental/psychological AEs, without loss of clinical effectiveness (ppFEV 1 was 80.7% on standard dose, and 83.4% at 12 weeks on reduced dose; sweat chloride was 33.4 and 34 mmol/L on standard and reduced dose, respectively). Furthermore, in a subgroup of patients who completed 24 weeks of the reduced dose regimen, repeat low dose Computed Tomography imaging showed a significant response when compared to pre-initiation of elexacaftor/tezacaftor/ivacaftor.
Journal Article
Ultralow dose computed tomography as an alternative to conventional chest radiography for the evaluation of disease severity in paediatric cystic fibrosis
2025
Chest computed tomography (CT) surpasses chest radiography (CR) in accurately assessing disease severity and detecting early structural pulmonary changes in patients with cystic fibrosis (CF). Chest CT provides detailed visualisation and quantification of CF-specific lung pathologies and can reveal these changes before they manifest clinically or become detectable on CR. The past decade has witnessed the advent and refinement of radiation-reducing techniques in CT which have enabled substantial dose reductions. Our study prospectively evaluates the efficacy of ultra-low dose CT (ULDCT) chest in identifying pulmonary changes within a paediatric patient cohort. Paediatric patients with CF, who presented for routine clinical outpatient follow-up between 01/07/2022, and 01/07/2023 underwent ULDCT and CR (if not recently performed) and image analysis was performed. Radiation dose, subjective and objective image quality and disease severity were recorded. 45 patients (mean age 10.5 years) underwent clinically indicated ULDCT chest ± CR. The mean effective dose was of ULDCT was 0.07 ± 0.01 mSv, a dose that approximates that of a frontal and lateral chest radiograph. The average ULDCT Brody II severity score across the entire cohort was 5.62, with excellent inter-rater reliability and intra-class correlation coefficient (ICC) of 0.98 (95% CI = 0.96, 0.99). The average Chrispin-Norman score on chest radiograph was 0.93 with moderate inter-rater reliability and ICC of 0.64 (95% CI = 0.19, 0.83). In light of its superior diagnostic capabilities, minimal radiation dose penalty, we advocate for ULDCT to be the preferred modality for surveillance imaging in paediatric patients with CF.
Journal Article
Microbiota and Metabolite Profiling Reveal Specific Alterations in Bacterial Community Structure and Environment in the Cystic Fibrosis Airway during Exacerbation
2013
Chronic polymicrobial infections of the lung are the foremost cause of morbidity and mortality in cystic fibrosis (CF) patients. The composition of the microbial flora of the airway alters considerably during infection, particularly during patient exacerbation. An understanding of which organisms are growing, their environment and their behaviour in the airway is of importance for designing antibiotic treatment regimes and for patient prognosis. To this end, we have analysed sputum samples taken from separate cohorts of CF and non-CF subjects for metabolites and in parallel, and we have examined both isolated DNA and RNA for the presence of 16S rRNA genes and transcripts by high-throughput sequencing of amplicon or cDNA libraries. This analysis revealed that although the population size of all dominant orders of bacteria as measured by DNA- and RNA- based methods are similar, greater discrepancies are seen with less prevalent organisms, some of which we associated with CF for the first time. Additionally, we identified a strong relationship between the abundance of specific anaerobes and fluctuations in several metabolites including lactate and putrescine during patient exacerbation. This study has hence identified organisms whose occurrence within the CF microbiome has been hitherto unreported and has revealed potential metabolic biomarkers for exacerbation.
Journal Article
Bacterial cis-2-unsaturated fatty acids found in the cystic fibrosis airway modulate virulence and persistence of Pseudomonas aeruginosa
by
Plant, Barry J
,
Ryan, Robert P
,
O'Connell, Oisin J
in
Animals
,
Antibiotic resistance
,
Antibiotics
2012
There is an increasing appreciation of the polymicrobial nature of many bacterial infections such as those associated with cystic fibrosis (CF) and of the potentially important role for interspecies interactions in influencing both bacterial virulence and response to therapy. Patients with CF are often co-infected with
Pseudomonas aeruginosa
and other pathogens including
Burkholderia cenocepacia
and
Stenotrophomonas maltophilia
. These latter bacteria produce signal molecules of the diffusible signal factor (DSF) family, which are
cis
-2-unsaturated fatty acids. We have previously shown by
in vitro
studies that DSF from
S. maltophilia
leads to altered biofilm formation and increased resistance to antibiotics by
P. aeruginosa
; these responses of
P. aeruginosa
require the sensor kinase PA1396. Here we show that DSF signals are present in sputum taken from patients with CF. Presence of these DSF signals was correlated with patient colonization by
S. maltophilia
and/or
B. cenocepacia
. Analysis of 50 clinical isolates of
P. aeruginosa
showed that each responded to the presence of synthetic DSF by increased antibiotic resistance and these strains demonstrated little sequence variation in the PA1396 gene. In animal experiments using CF transmembrane conductance regulator knockout mice, the presence of DSF promoted
P. aeruginosa
persistence. Furthermore, antibiotic resistance of
P. aeruginosa
biofilms grown on human airway epithelial cells was enhanced in the presence of DSF. Taken together, these data provide substantial evidence that interspecies DSF-mediated bacterial interactions occur in the CF lung and may influence the efficacy of antibiotic treatment, particularly for chronic infections involving persistence of bacteria.
Journal Article
Considerations for the use of inhaled antibiotics for Pseudomonas aeruginosa in people with cystic fibrosis receiving CFTR modulator therapy
by
Plant, Barry J
,
Smyth, Alan
,
Burgel, Pierre-Régis
in
Administration, Inhalation
,
Adults
,
Anti-Bacterial Agents - administration & dosage
2024
The major cause of mortality in people with cystic fibrosis (pwCF) is progressive lung disease characterised by acute and chronic infections, the accumulation of mucus, airway inflammation, structural damage and pulmonary exacerbations. The prevalence of Pseudomonas aeruginosa rises rapidly in the teenage years, and this organism is the most common cause of chronic lung infection in adults with cystic fibrosis (CF). It is associated with an accelerated decline in lung function and premature death. New P. aeruginosa infections are treated with antibiotics to eradicate the organism, while chronic infections require long-term inhaled antibiotic therapy. The prevalence of P. aeruginosa infections has decreased in CF registries since the introduction of CF transmembrane conductance regulator modulators (CFTRm), but clinical observations suggest that chronic P. aeruginosa infections usually persist in patients receiving CFTRm. This indicates that pwCF may still need inhaled antibiotics in the CFTRm era to maintain long-term control of P. aeruginosa infections. Here, we provide an overview of the changing perceptions of P. aeruginosa infection management, including considerations on detection and treatment, the therapy burden associated with inhaled antibiotics and the potential effects of CFTRm on the lung microbiome. We conclude that updated guidance is required on the diagnosis and management of P. aeruginosa infection. In particular, we highlight a need for prospective studies to evaluate the consequences of stopping inhaled antibiotic therapy in pwCF who have chronic P. aeruginosa infection and are receiving CFTRm. This will help inform new guidelines on the use of antibiotics alongside CFTRm.
Journal Article
Biologically Relevant Murine Models of Chronic Pseudomonas aeruginosa Respiratory Infection
2023
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen and the leading cause of infection in patients with cystic fibrosis (CF). The ability of P. aeruginosa to evade host responses and develop into chronic infection causes significant morbidity and mortality. Several mouse models have been developed to study chronic respiratory infections induced by P. aeruginosa, with the bead agar model being the most widely used. However, this model has several limitations, including the requirement for surgical procedures and high mortality rates. Herein, we describe novel and adapted biologically relevant models of chronic lung infection caused by P. aeruginosa. Three methods are described: a clinical isolate infection model, utilising isolates obtained from patients with CF; an incomplete antibiotic clearance model, leading to bacterial bounce-back; and the establishment of chronic infection; and an adapted water bottle chronic infection model. These models circumvent the requirement for a surgical procedure and, importantly, can be induced with clinical isolates of P. aeruginosa and in wild-type mice. We also demonstrate successful induction of chronic infection in the transgenic βENaC murine model of CF. We envisage that the models described will facilitate the investigations of host and microbial factors, and the efficacy of novel antimicrobials, during chronic P. aeruginosa respiratory infections.
Journal Article
VX-659–Tezacaftor–Ivacaftor in Patients with Cystic Fibrosis and One or Two Phe508del Alleles
2018
This companion article to the VX-445 report shows that VX-659, a new CFTR potentiator, when administered with tezacaftor and ivacaftor improved lung function, sweat chloride concentration, and symptoms in patients with cystic fibrosis who harbored one or two Phe508del alleles.
Journal Article
Virtual monitoring in CF – the importance of continuous monitoring in a multi-organ chronic condition
by
Ranganathan, Sarath C.
,
Vagg, Tamara
,
Plant, Barry J.
in
Antibiotics
,
chronic condition
,
Chronic illnesses
2023
Cystic Fibrosis (CF) is a chronic life-limiting condition that affects multiple organs within the body. Patients must adhere to strict medication regimens, physiotherapy, diet, and attend regular clinic appointments to manage their condition effectively. This necessary but burdensome requirement has prompted investigations into how different digital health technologies can enhance current care by providing the opportunity to virtually monitor patients. This review explores how virtual monitoring has been harnessed for assessment or performance of physiotherapy/exercise, diet/nutrition, symptom monitoring, medication adherence, and wellbeing/mental-health in people with CF. This review will also briefly discuss the potential future of CF virtual monitoring and some common barriers to its current adoption and implementation within CF. Due to the multifaceted nature of CF, it is anticipated that this review will be relevant to not only the CF community, but also those investigating and developing digital health solutions for the management of other chronic diseases.
Journal Article