Development of Novel Membrane Disrupting Lipoguanidine Compounds Sensitizing Gram-Negative Bacteria to Antibiotics.

A new class of amphiphilic molecules, the lipoguanidines, designed as hybrids of guanidine and fatty acid compounds, has been synthesized and developed. The new molecules present both a guanidine polar head and a lipophilic tail that allow them to disrupt bacterial membranes and to sensitize Gram-negative bacteria to the action of the narrow-spectrum antibiotics rifampicin and novobiocin. The lipoguanidine 5g sensitizes Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli to rifampicin, thereby reducing the antibiotic minimum inhibitory concentrations (MIC) up to 256-fold. Similarly, 5g is able to potentiate novobiocin up to 64-fold, thereby showing a broad spectrum of antibiotic potentiating activity. Toxicity and mechanism studies revealed the potential of 5g to work synergistically with rifampicin through the disruption of bacterial membranes without affecting eukaryotic cells.

Design and manufacture of a lyophilised faecal microbiota capsule formulation to GMP standards.

Faecal microbiota transplant (FMT) is an established and effective treatment for recurrent Clostridioides difficile infection (CDI) and has many other potential clinical applications. However, preparation and quality of FMT is poorly standardised and clinical studies are hampered by a lack of well-defined FMT formulations that meet regulatory standards for medicines. As an alternative to FMT suspensions for administration by nasojejunal tube or colonoscopy, which is invasive and disliked by many patients, this study aimed to develop a well-controlled, standardised method for manufacture of lyophilised FMT capsules and to provide stability data allowing storage for extended time periods. Faecal donations were collected from healthy, pre-screened individuals, homogenised, filtered and centrifuged to remove dietary matter. The suspension was centrifuged to pellet bacteria, which were resuspended with trehalose and lyophilised to produce a powder which was filled into 5 enteric-coated capsules (size 0). Live-dead bacterial cell quantitative PCR assay showed <10 fold viable bacterial load reduction through the manufacturing process. No significant loss of viable bacterial load was observed after storage at -80 °C for 36 weeks (p = 0.24, n = 5). Initial clinical experience demonstrated that the capsules produced clinical cure in patients with CDI with no adverse events reported (n = 7). We provide the first report of a detailed manufacturing protocol and specification for an encapsulated lyophilised formulation of FMT. As clinical trials into intestinal microbiota interventions proceed, it is important to use a well-controlled investigational medicinal product in the studies so that any beneficial results can be replicated in clinical practice.

Porphyromonas pasteri and Prevotella nanceiensis in the sputum microbiota are associated with increased decline in lung function in individuals with cystic fibrosis.

Although anaerobic bacteria exist in abundance in cystic fibrosis (CF) airways, their role in disease progression is poorly understood. We hypothesized that the presence and relative abundance of the most prevalent, live, anaerobic bacteria in sputum of adults with CF were associated with adverse clinical outcomes. This is the first study to prospectively investigate viable anaerobic bacteria present in the sputum microbiota and their relationship with long-term outcomes in adults with CF. We performed 16S rRNA analysis using a viability quantitative PCR technique on sputum samples obtained from a prospective cohort of 70 adults with CF and collected clinical data over an 8 year follow-up period. We examined the associations of the ten most abundant obligate anaerobic bacteria present in the sputum with annual rate of FEV1 change. The presence of Porphyromonas pasteri and Prevotella nanceiensis were associated with a greater annual rate of FEV1 change; -52.3 ml yr-1 (95 % CI-87.7;-16.9), -67.9 ml yr-1 (95 % CI-115.6;-20.1), respectively. Similarly, the relative abundance of these live organisms were associated with a greater annual rate of FEV1 decline of -3.7 ml yr-1 (95 % CI: -6.1 to -1.3, P=0.003) and -5.3 ml yr-1 (95 % CI: -8.7 to -1.9, P=0.002) for each log2 increment of abundance, respectively. The presence and relative abundance of certain anaerobes in the sputum of adults with CF are associated with a greater rate of long-term lung function decline. The pathogenicity of anaerobic bacteria in the CF airways should be confirmed with further longitudinal prospective studies with a larger cohort of participants.

Rifaximin-α reduces gut-derived inflammation and mucin degradation in cirrhosis and encephalopathy: RIFSYS randomised controlled trial.

BACKGROUND & AIMS: Rifaximin-α is efficacious for the prevention of recurrent hepatic encephalopathy (HE), but its mechanism of action remains unclear. We postulated that rifaximin-α reduces gut microbiota-derived endotoxemia and systemic inflammation, a known driver of HE. METHODS: In a placebo-controlled, double-blind, mechanistic study, 38 patients with cirrhosis and HE were randomised 1:1 to receive either rifaximin-α (550 mg BID) or placebo for 90 days. PRIMARY OUTCOME: 50% reduction in neutrophil oxidative burst (OB) at 30 days. SECONDARY OUTCOMES: changes in psychometric hepatic encephalopathy score (PHES) and neurocognitive functioning, shotgun metagenomic sequencing of saliva and faeces, plasma and faecal metabolic profiling, whole blood bacterial DNA quantification, neutrophil toll-like receptor (TLR)-2/4/9 expression and plasma/faecal cytokine analysis. RESULTS: Patients were well-matched: median MELD (11 rifaximin-α vs. 10 placebo). Rifaximin-α did not lead to a 50% reduction in spontaneous neutrophil OB at 30 days compared to baseline (p = 0.48). However, HE grade normalised (p = 0.014) and PHES improved (p = 0.009) after 30 days on rifaximin-α. Rifaximin-α reduced circulating neutrophil TLR-4 expression on day 30 (p = 0.021) and plasma tumour necrosis factor-α (TNF-α) (p <0.001). Rifaximin-α suppressed oralisation of the gut, reducing levels of mucin-degrading sialidase-rich species, Streptococcus spp, Veillonella atypica and parvula, Akkermansia and Hungatella. Rifaximin-α promoted a TNF-α- and interleukin-17E-enriched intestinal microenvironment, augmenting antibacterial responses to invading pathobionts and promoting gut barrier repair. Those on rifaximin-α were less likely to develop infection (odds ratio 0.21; 95% CI 0.05-0.96). CONCLUSION: Rifaximin-α led to resolution of overt and covert HE, reduced the likelihood of infection, reduced oralisation of the gut and attenuated systemic inflammation. Rifaximin-α plays a role in gut barrier repair, which could be the mechanism by which it ameliorates bacterial translocation and systemic endotoxemia in cirrhosis. CLINICAL TRIAL NUMBER: ClinicalTrials.gov NCT02019784. LAY SUMMARY: In this clinical trial, we examined the underlying mechanism of action of an antibiotic called rifaximin-α which has been shown to be an effective treatment for a complication of chronic liver disease which effects the brain (termed encephalopathy). We show that rifaximin-α suppresses gut bacteria that translocate from the mouth to the intestine and cause the intestinal wall to become leaky by breaking down the protective mucus barrier. This suppression resolves encephalopathy and reduces inflammation in the blood, preventing the development of infection.

Novel detection of specific bacterial quorum sensing molecules in saliva: Potential non-invasive biomarkers for pulmonary Pseudomonas aeruginosa in cystic fibrosis.

Pseudomonas aeruginosa produces specific signalling molecules, 2-alkyl-4-quinolones (AQs) that are detectable in the sputum of adults with cystic fibrosis (CF) and who have pulmonary infection with this opportunistic pathogen. This study aimed to determine whether AQs could be detected in saliva of patients with CF and known infection with Pseudomonas aeruginosa. Saliva and sputum samples were obtained from 89 adults with CF and analyzed using liquid chromatography-tandem mass spectrometry. AQs were detected in 39/89 (43.8%) saliva samples and 70/77(90.9%) sputum samples. Salivary AQs had a sensitivity of 50% (95%CI; 37.8; 62.2), specificity of 100% (95%CI; 47.8; 100), when compared to a molecular microbiological measure of P. aeruginosa in sputum as measured using polymerase chain reaction. Specific AQs produced by P. aeruginosa can be detected in the saliva and warrant investigation as potential non-invasive biomarkers of pulmonary P. aeruginosa.

2-Alkyl-4-quinolone quorum sensing molecules are biomarkers for culture-independent Pseudomonas aeruginosa burden in adults with cystic fibrosis.

Introduction. Pseudomonas aeruginosa produces quorum sensing signalling molecules including 2-alkyl-4-quinolones (AQs), which regulate virulence factor production in the cystic fibrosis (CF) airways.Hypothesis/Gap statement. Culture can lead to condition-dependent artefacts which may limit the potential insights and applications of AQs as minimally-invasive biomarkers of bacterial load.Aim. We aimed to use culture-independent methods to explore the correlations between AQ levels and live P. aeruginosa load in adults with CF.Methodology. Seventy-five sputum samples at clinical stability and 48 paired sputum samples obtained at the beginning and end of IV antibiotics for a pulmonary exacerbation in adults with CF were processed using a viable cell separation technique followed by quantitative P. aeruginosa polymerase chain reaction (qPCR). Live P. aeruginosa qPCR load was compared with the concentrations of three AQs (HHQ, NHQ and HQNO) detected in sputum, plasma and urine.Results. At clinical stability and the beginning of IV antibiotics for pulmonary exacerbation, HHQ, NHQ and HQNO measured in sputum, plasma and urine were consistently positively correlated with live P. aeruginosa qPCR load in sputum, compared to culture. Following systemic antibiotics live P. aeruginosa qPCR load decreased significantly (P<0.001) and was correlated with a reduction in plasma NHQ (plasma: r=0.463, P=0.003).Conclusion. In adults with CF, AQ concentrations correlated more strongly with live P. aeruginosa bacterial load measured by qPCR compared to traditional culture. Prospective studies are required to assess the potential of systemic AQs as biomarkers of P. aeruginosa bacterial burden.

Gut microbiota development during infancy: Impact of introducing allergenic foods.

BACKGROUND: The gut microbiota potentially plays an important role in the immunologic education of the host during early infancy. OBJECTIVE: We sought to determine how the infant gut microbiota evolve during infancy, particularly in relation to hygiene-related environmental factors, atopic disorders, and a randomized introduction of allergenic solids. METHODS: A total of 1303 exclusively breast-fed infants were enrolled in a dietary randomized controlled trial (Enquiring About Tolerance study) from 3 months of age. In this nested longitudinal study, fecal samples were collected at baseline, with additional sampling of selected cases and controls at 6 and 12 months to study the evolution of their gut microbiota, using 16S ribosomal RNA gene-targeted amplicon sequencing. RESULTS: In the 288 baseline samples from exclusively breast-fed infant at 3 months, the gut microbiota was highly heterogeneous, forming 3 distinct clusters: Bifidobacterium-rich, Bacteroides-rich, and Escherichia/Shigella-rich. Mode of delivery was the major discriminating factor. Increased Clostridium sensu stricto relative abundance at 3 months was associated with presence of atopic dermatitis on examination at age 3 and 12 months. From the selected cases and controls with longitudinal samples (n = 70), transition to Bacteroides-rich communities and influx of adult-specific microbes were observed during the first year of life. The introduction of allergenic solids promoted a significant increase in Shannon diversity and representation of specific microbes, such as genera belonging to Prevotellaceae and Proteobacteria (eg, Escherichia/Shigella), as compared with infants recommended to exclusively breast-feed. CONCLUSIONS: Specific gut microbiota characteristics of samples from 3-month-old breast-fed infants were associated with cesarean birth, and greater Clostridium sensu stricto abundance was associated with atopic dermatitis. The randomized introduction of allergenic solids from age 3 months alongside breast-feeding was associated with differential dynamics of maturation of the gut microbial communities.

Peripheral airways type 2 inflammation, neutrophilia and microbial dysbiosis in severe asthma.

BACKGROUND: IL-13 is considered an archetypal T2 cytokine central to the clinical disease expression of asthma. The IL-13 response genes, which are upregulated in central airway bronchial epithelial of asthma patients, can be normalized by high-dose inhaled steroid therapy in severe asthma. However, this is not the case within the peripheral airways. We have sought to further understand IL-13 in the peripheral airways in severe asthma through bronchoalveolar analysis. METHODS: Bronchoalveolar lavage samples were collected from 203 asthmatic and healthy volunteers, including 78 with severe asthma. Inflammatory mediators were measured using a multiple cytokine immunoassay platform. This analysis was replicated in a further 59 volunteers, in whom 16S rRNA analysis of BAL samples was undertaken by terminal restriction fragment length polymorphism. RESULTS: Severe asthma patients with high BAL IL-13, despite treatment with high-dose inhaled corticosteroids, had more severe lung function and significantly higher BAL neutrophil percentages, but not BAL eosinophils than those with normal BAL-13 concentrations. This finding was replicated in the second cohort, which further associated BAL IL-13 and neutrophilia with a greater abundance of potentially pathogenic bacteria in the peripheral airways. CONCLUSION: Our findings demonstrate a steroid unresponsive source of IL-13 that is associated with BAL neutrophilia and bacterial dysbiosis in severe asthma. Our findings highlight the biological complexity of severe asthma and the importance of a greater understanding of the innate and adaptive immune responses in the peripheral airways in this disease.

The airways microbiome of individuals with asthma treated with high and low doses of inhaled corticosteroids.

BACKGROUND: Inhaled corticosteroids (ICS) are the mainstay of asthma treatment, but evidence suggests a link between ICS usage and increased rates of respiratory infections. We assessed the composition of the asthmatic airways microbiome in asthma patients taking low and high dose ICS and the stability of the microbiome over a 2 week period. METHODS: We prospectively recruited 55 individuals with asthma. Of these, 22 were on low-dose ICS and 33 on high-dose ICS (16 on budesonide, 17 on fluticasone propionate). Sputum from each subject underwent DNA extraction, amplification and 16S rRNA gene sequencing of the bacterial component of the microbiome. 19 subjects returned for further sputum induction after 24 h and 2 weeks. RESULTS: A total of 5,615,037 sequencing reads revealed 167 bacterial taxa in the asthmatic airway samples, with the most abundant being Streptococcus spp. No significant differences in sputum bacterial load or overall community composition were seen between the low- and high-dose ICS groups. However, Streptococcus spp. showed significantly higher relative abundance in subjects taking low-dose ICS (p = 0.002). Haemophilus parainfluenzae was significantly more abundant in subjects on high-dose fluticasone propionate than those on high-dose budesonide (p = 0.047). There were no statistically significant changes in microbiota composition over a 2-week period. DISCUSSION: Whilst no significant differences were observed between the low- and high-dose ICS groups, increased abundance of the potential pathogen H. parainfluenzae was observed in patients taking high-dose fluticasone propionate compared to those taking high-dose budesonide. The microbiota were stable over fourteen days, providing novel evidence of the established community of bacteria in the asthmatic airways. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT02671773.

Amoebae in Chronic, Polymicrobial Endodontic Infections Are Associated with Altered Microbial Communities of Increased Virulence.

BACKGROUND: Infections of the root canal space involve polymicrobial biofilms and lead to chronic, low grade inflammatory responses arising from the seeding of microbes and by-products. Acute exacerbation and/or disseminating infections occur when established microbial communities undergo sudden changes in phenotypic behaviour. METHODS: Within clinical endodontic infections, we assessedcategorical determinants comprising, and changing microbial composition of, chronic polymicrobial infections and their association with amoebae. After standardised assessment, primary or secondary infections underwent sampling and DNA processing, targeting bacteria, fungi and amoebae, including 16S high-throughput sequencing. After taxonomic assignment, community composition was correlated with clinical signs and symptoms. Diversity and abundance analyses were carried out in relation to the presence of non-bacterial amplicons. RESULTS: Clinical specimens revealed two distinct community clusters, where specific changes correlated with clinical signs. An association between the compositions of microbiomes was found between these groups and the presence of Entamoeba gingivalis in 44% of cases. When amoebae were present in endodontic infections, we demonstrate changes in microbial community structure that mirror those observed in treatment-resistant or recurrent infections. CONCLUSIONS: Amoeba are present in endodontic infections at a high prevalence, and may promote increased virulence by enrichment for phagocytosis-resistant bacteria.

Antibiotic-in-Cyclodextrin-in-Liposomes: Formulation Development and Interactions with Model Bacterial Membranes.

Gram-negative bacteria possess numerous defenses against antibiotics, due to the intrinsic permeability barrier of their outer membrane (OM), explaining the recalcitrance of some common and life-threatening infections. We report the formulation of a new drug, PPA148, which shows promising activity against all Gram-negative bacteria included in the ESKAPEE pathogens. PPA148 was solubilized by inclusion complexation with cyclodextrin followed by encapsulation in liposomes. The complex and liposomal formulation presented increased activity against E. coli compared to the pure drug when assessed with the Kirby Bauer assay. The novel formulation containing 1 µg PPA148 reached similar efficacy levels equivalent to those of 30 µg of pure rifampicin. A range of biophysical techniques was used to explore the mechanism of drug uptake. Langmuir trough (LT) and neutron reflectivity (NR) techniques were employed to monitor the interactions between the drug and the formulation with model membranes. We found evidence for liposome fusion with the model Gram-negative outer membrane and for cyclodextrins acting as inner membrane (IM) permeation enhancers without presenting intrinsic antimicrobial activity. An antibiotic-in-cyclodextrin-in-liposomes (ACL) formulation was developed, which targets both the bacterial OM and IM, and offers promise as a means to breach the Gram-negative cell envelope.

Lung function and microbiota diversity in cystic fibrosis.

BACKGROUND: Chronic infection and concomitant airway inflammation is the leading cause of morbidity and mortality for people living with cystic fibrosis (CF). Although chronic infection in CF is undeniably polymicrobial, involving a lung microbiota, infection surveillance and control approaches remain underpinned by classical aerobic culture-based microbiology. How to use microbiomics to direct clinical management of CF airway infections remains a crucial challenge. A pivotal step towards leveraging microbiome approaches in CF clinical care is to understand the ecology of the CF lung microbiome and identify ecological patterns of CF microbiota across a wide spectrum of lung disease. Assessing sputum samples from 299 patients attending 13 CF centres in Europe and the USA, we determined whether the emerging relationship of decreasing microbiota diversity with worsening lung function could be considered a generalised pattern of CF lung microbiota and explored its potential as an informative indicator of lung disease state in CF. RESULTS: We tested and found decreasing microbiota diversity with a reduction in lung function to be a significant ecological pattern. Moreover, the loss of diversity was accompanied by an increase in microbiota dominance. Subsequently, we stratified patients into lung disease categories of increasing disease severity to further investigate relationships between microbiota characteristics and lung function, and the factors contributing to microbiota variance. Core taxa group composition became highly conserved within the severe disease category, while the rarer satellite taxa underpinned the high variability observed in the microbiota diversity. Further, the lung microbiota of individual patient were increasingly dominated by recognised CF pathogens as lung function decreased. Conversely, other bacteria, especially obligate anaerobes, increasingly dominated in those with better lung function. Ordination analyses revealed lung function and antibiotics to be main explanators of compositional variance in the microbiota and the core and satellite taxa. Biogeography was found to influence acquisition of the rarer satellite taxa. CONCLUSIONS: Our findings demonstrate that microbiota diversity and dominance, as well as the identity of the dominant bacterial species, in combination with measures of lung function, can be used as informative indicators of disease state in CF. Video Abstract.

Selection and assembly of indigenous bacteria and methanogens from spent metalworking fluids and their potential as a starting culture in a fluidized bed reactor.

Waste metalworking fluids (MWFs) are highly biocidal resulting in real difficulties in the, otherwise favoured, bioremediation of these high chemical oxygen deman (COD) wastes anaerobically in bioreactors. We have shown, as a proof of concept, that it is possible to establish an anaerobic starter culture using strains isolated from spent MWFs which are capable of reducing COD or, most significantly, methanogenesis in this biocidal waste stream. Bacterial strains (n = 99) and archaeal methanogens (n = 28) were isolated from spent MWFs. The most common bacterial strains were Clostridium species (n = 45). All methanogens were identified as Methanosarcina mazei. Using a random partitions design (RPD) mesocosm experiment, we found that bacterial diversity and species-species interactions had significant effects on COD reduction but that bacterial composition did not. The RPD study showed similar effects on methanogenesis, except that composition was also significant. We identified bacterial species with positive and negative effects on methane production. A consortium of 16 bacterial species and three methanogens was used to initiate a fluidized bed bioreactor (FBR), in batch mode. COD reduction and methane production were variable, and the reactor was oscillated between continuous and batch feeds. In both microcosm and FBR experiments, periodic inconsistencies in bacterial reduction in fermentative products to formic and acetic acids were identified as a key issue.

Correction: Santos, J., et al. Proteomic Analysis of Cyclic Ketamine Compounds Ability to Induce Neural Differentiation in Human Adult Mesenchymal Stem Cells. International Journal of Molecular Sciences 2019, 20, 523.

The authors wish to make the following corrections to this paper [...].

Proteomic Analysis of Cyclic Ketamine Compounds Ability to Induce Neural Differentiation in Human Adult Mesenchymal Stem Cells.

Neural regeneration is of great interest due to its potential to treat traumatic brain injuries and diseases that impact quality of life. Growth factor mediated differentiation can take up to several weeks to months to produce the cell of interest whereas chemical stimulation may be as minimal as a few hours. The smaller time scale is of great clinical relevance. Adipose derived stem cells (ADSCs) were treated for up to 24 h with a novel differentiation media containing the cyclic ketamine compounds to direct neurogenic induction. The extent of differentiation was investigated by proteome changes occurring during the process. The treatments indicated the ADSCs responded favorably to the neurogenic induction media by presenting a number of morphological cues of neuronal phenotype previously seen and a higher cell population post induction compared to previous studies. Furthermore, approximately 3500 proteins were analyzed and identified by mass spectrometric iTRAQ analyses. The bioinformatics analyses revealed hundreds of proteins whose expression level changes were statistically significant and biologically relevant to neurogenesis and annotated as being involved in neurogenic development. Complementing this, the Bioplex cytokine assay profiles present evidence of decreased panel of stress response cytokines and a relative increase in those involved in neurogenesis.

Circadian leaf movements facilitate overtopping of neighbors.

Many plants exhibit circadian clock-driven leaf movements whereby the leaves are raised during the day to achieve a relatively high angle during the evening, before lowering late in the night. Such leaf movements were first recorded over 2000 years ago but there is still much debate as to their purpose. We investigated whether such leaf movements within Arabidopsis, a ruderal rosette plant, can aid in overtopping leaves of neighboring plants. Wild type and circadian clock mutant plants were grown in an alternating grid system so that their leaves would meet as the plants grew. Experiments were performed using day lengths that matched the endogenous rhythm of either wild type or mutant. Plants grown in a day length shorter than their endogenous rhythm were consistently overtopped by plants which were in synchrony with the day night cycle, demonstrating a clear overtopping advantage resulting from circadian leaf movement rhythms. Furthermore, we found that this leaf overtopping as a result of correctly synchronized circadian leaf movements is additive to leaf overtopping due to shade avoidance. Curiously, this did not apply to plants grown in a day length longer than their endogenous period. Plants grown in a day length longer than their endogenous period were able to adapt their leaf rhythms and suffered no overtopping disadvantage. Crucially, our results show that, in a context-dependent manner, circadian clock-driven leaf movements in resonance with the external light/dark cycle can facilitate overtopping of the leaves of neighboring plants.

Fungal and Bacterial Diversity of Airway Microbiota in Adults with Cystic Fibrosis: Concordance Between Conventional Methods and Ultra-Deep Sequencing, and Their Practical use in the Clinical Laboratory.

Given the complexity of the airway microbiota in the respiratory tract of cystic fibrosis (CF) patients, it seems crucial to compile the most exhaustive and exact list of the microbial communities inhabiting CF airways. The aim of the present study was to compare the bacterial and fungal diversity of sputa from adult CF patients during non-exacerbation period by culture-based and molecular methods, and ultra-deep-sequencing (UDS). Sputum samples from four CF patients were cultured and analysed by DNA extractions followed by terminal restriction fragment length polymorphism analysis through resolution of bacterial ribosomal gene (rDNA) fragments, and cloning plus sequencing of part of fungal rRNA genes. These approaches were compared with UDS method targeting 16S rDNA gene and the internal transcribed spacer (ITS) 2 region of rDNA. A total of 27 bacterial and 18 fungal genera were detected from the four patients. Five (18%) and 3 (16%) genera were detected by culture for bacteria and fungi, respectively, 9 (33%) and 3 (16%) by first generation sequencing (FGS) methods, and 26 (96%) and 18 (100%) by UDS. The mean number of genera detected by UDS per patient was statistically higher than by culture or FGS methods. Patients with severe airway disease as assessed by standard spirometry exhibited a reduced fungal and bacterial diversity. UDS approach evaluates more extensively the diversity of fungal and bacterial flora compared with cultures. However, it currently remains difficult to routinely use UDS mainly because of the lack of standardization, and the current cost of this method.

Clinical and symptom scores are significantly correlated with fecal microbiota features in patients with symptomatic uncomplicated diverticular disease: a pilot study.

BACKGROUND: There is growing consensus that symptomatic uncomplicated diverticular disease is a chronic inflammatory condition, and that alterations in the fecal microbiota may contribute to its pathogenesis. OBJECTIVE: The aim of this study was to relate the fecal microbiota composition in symptomatic uncomplicated diverticular disease to measures of inflammation, symptoms, and history of previous acute diverticulitis. PARTICIPANTS AND METHODS: Fecal microbiota composition in 28 individuals with symptomatic uncomplicated diverticular disease was characterized by 16S RNA gene amplicon sequencing. Microbiota composition was related to clinical history, symptom and inflammation measures, and demographic variables. RESULTS: Previous acute diverticulitis was associated with higher relative abundance of Pseudobutyrivibrio, Bifidobacterium, Christensenellaceae family, and Mollicutes RF9 order (P=0.004, 0.006, 0.010, and 0.019, respectively), but not microbiota alpha or beta diversity. A higher bloating severity score was significantly correlated with a higher relative abundance of Ruminococcus (P=0.032), and significantly inversely correlated with the relative abundance of the Roseburia (P=0.002). Fecal calprotectin levels were positively correlated with alpha diversity (Shannon index, P=0.005) and the relative abundance of Lactobacillus (P=0.004). Pain score was positively correlated with the relative abundance of Cyanobacterium (adjusted P=0.032). CONCLUSION: Patient symptoms in symptomatic diverticular disease are significantly correlated with features of the fecal microbiota. Our findings suggest the potential utility of therapies that target intestinal microbiology, such as dietary prebiotic supplements.

Bacterial Contamination of Endodontic Materials before and after Clinical Storage.

INTRODUCTION: The aim of this study was to evaluate the bacterial contamination in endodontic consumables (gutta-percha points, rubber dams, paper mixing pads, caulking agents, and endodontic instrument sponges [EISs]) before and after clinical use and storage. METHODS: Materials were randomly sampled in triplicates at 3 time points (t0, at package opening; t1, at 7 days; and t2, at 14 days) during their clinical usage. The gutta-percha points and caulking agent (25 mg) were added to 1 mL phosphate-buffered saline (PBS). The rubber dam, paper mixing pad, and EIS were added to 25 mL PBS. After vortexing, centrifuging, and removing the supernatant, the pellet was resuspended in 1 mL PBS, plated on fastidious anaerobic agar, and incubated aerobically and anaerobically. The grown colonies were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The total bacterial load was calculated in the remaining volume (800 µL) from each sample by quantitative polymerase chain reaction after DNA extraction. RESULTS: All tested materials showed a varied number of contaminated samples at the 3 time points (except EIS at t0) using MALDI-TOF MS. The most isolated genera were Propionibacterium (42%) and Staphylococcus (32%). By using non-culture-based approaches, all tested materials at the 3 time points (except gutta-percha at t0 and the caulking agent at t0, t1, and t2) carried bacterial DNA. CONCLUSIONS: The majority of the tested materials harbored bacteria in their samples before and after clinical storage. Nosocomial infection derived from commonly used consumables could have an impact on the outcome of endodontic treatment.

How can the cystic fibrosis respiratory microbiome influence our clinical decision-making?

PURPOSE OF REVIEW: Almost 15 years have now passed since bacterial community profiling techniques were first used to analyse respiratory samples from people with cystic fibrosis. Since then, many different analytical approaches have been used to try to better understand the contribution of the cystic fibrosis lung microbiota to disease, with varying degrees of success. We examine the extent to which cystic fibrosis respiratory microbiome research has been successful in informing clinical decision-making, and highlight areas that we believe have the potential to yield important insight. RECENT FINDINGS: Recent research on the cystic fibrosis lung microbiome can be broadly divided into efforts to better characterize microbiota composition, particularly relative to key clinical events, and attempts to understand the cystic fibrosis lung microbiology as an interactive microbial system. The latter, in particular, has led to the development of a number of models in which microbiome-mediated processes precipitate clinical events. SUMMARY: Growing technological sophistication is enabling increasingly detailed microbiological data to be generated from cystic fibrosis respiratory samples. However, translating these data into clinically useful measures that accurately predict outcomes and guide treatments remains a formidable challenge. The development of systems biology approaches that enable the integration of complex microbiome and host-derived data provide an exciting opportunity to address this goal.