55 research outputs found
Specific fungi associated with response to capsulized fecal microbiota transplantation in patients with active ulcerative colitis
ObjectiveFecal microbiota transplantation (FMT) is a novel microbial treatment for patients with ulcerative colitis (UC). In this study, we performed a clinical trial of capsulized FMT in UC patients to determine the association between the gut fungal community and capsulized FMT outcomes.DesignThis study recruited patients with active UC (N = 22) and healthy individuals (donor, N = 9) according to the criteria. The patients received capsulized FMT three times a week. Patient stool samples were collected before (week 0) and after FMT follow-up visits at weeks 1, 4, and 12. Fungal communities were analysed using shotgun metagenomic sequencing.ResultsAccording to metagenomic analysis, fungal community evenness index was greater in samples collected from patients, and the overall fungal community was clustered among the samples collected from donors. The dominant fungi in fecal samples collected from donors and patients were Ascomycota and Basidiomycota. However, capsulized FMT ameliorated microbial fungal diversity and altered fungal composition, based on metagenomic analysis of fecal samples collected before and during follow-up visits after capsulized FMT. Fungal diversity decreased in samples collected from patients who achieved remission after capsulized FMT, similar to samples collected from donors. Patients achieving remission after capsulized FMT had specific enrichment of Kazachstania naganishii, Pyricularia grisea, Lachancea thermotolerans, and Schizosaccharomyces pombe compared with patients who did not achieve remission. In addition, the relative abundance of P. grisea was higher in remission fecal samples during the follow-up visit. Meanwhile, decreased levels of pathobionts, such as Candida and Debaryomyces hansenii, were associated with remission in patients receiving capsulized FMT.ConclusionIn the metagenomic analysis of fecal samples from donors and patients with UC receiving capsulized FMT, shifts in gut fungal diversity and composition were associated with capsulized FMT and validated in patients with active UC. We also identified the specific fungi associated with the induction of remission. ClinicalTrails.gov (NCT03426683)
Leveraging Fecal Bacterial Survey Data to Predict Colorectal Tumors
Colorectal cancer (CRC) ranks second in cancer-associated mortality and third in the incidence worldwide. Most of CRC follow adenoma-carcinoma sequence, and have more than 90% chance of survival if diagnosed at early stage. But the recommended screening by colonoscopy is invasive, expensive, and poorly adhered to. Recently, several studies reported that the fecal bacteria might provide non-invasive biomarkers for CRC and precancerous tumors. Therefore, we collected and uniformly re-analyzed these published fecal 16S rDNA sequencing datasets to verify the association and identify biomarkers to classify and predict colorectal tumors by random forest method. A total of 1674 samples (330 CRC, 357 advanced adenoma, 141 adenoma, and 846 control) from 7 studies were analyzed in this study. By random effects model and fixed effects model, we observed significant differences in alpha-diversity and beta-diversity between individuals with CRC and the normal colon, but not between adenoma and the normal. We identified various bacterial genera with significant odds ratios for colorectal tumors at different stages. Through building random forest model with 10-fold cross-validation as well as new test datasets, we classified individuals with CRC, advanced adenoma, adenoma and normal colon. All approaches obtained comparable performance at entire OTU level, entire genus level, and the common genus level as measured using AUC. When combined all samples, the AUC of random forest model based on 12 common genera reached 0.846 for CRC, although the predication performed poorly for advance adenoma and adenoma
Lytic and Chemotactic Features of the Plaque-Forming Bacterium KD531 on Phaeodactylum tricornutum
Phaeodactylum tricornutum is a dominant bloom forming species and potential biofuel feedstock. To control P. tricornutum bloom or to release lipids from P. tricornutum, we previously screened and identified the lytic bacterium Labrenzia sp. KD531 toward P. tricornutum. In the present study, we evaluated the lytic activity of Labrenzia sp. KD531 on microalgae and investigated its lytic mechanism. The results indicated that the lytic activity of KD531 was temperature- and pH-dependent, but light-independent. In addition to P. tricornutum, KD531 also showed lytic activity against other algal species, especially green algae. A quantitative analysis of algal cellular protein, carbohydrate and lipid content together with measurements of dry weight after exposure to bacteria-infected algal lysate indicated that the bacterium KD531 influenced the algal biomass by disrupting the algal cells. Both chemotactic analysis and microscopic observations of subsamples from different regions of formed plaques showed that KD531 could move toward and then directly contact algal cells. Direct contact between P. tricornutum and KD531 cells was essential for the lytic process
Comprehensive insights into the response of Alexandrium tamarense to algicidal component secreted by a marine bacterium
Lytic and Chemotactic Features of the Plaque-Forming Bacterium KD531 on Phaeodactylum tricornutum
Alterations of bacteriome, mycobiome and metabolome characteristics in PCOS patients with normal/overweight individuals
Abstract To characterize the gut bacteriome, mycobiome and serum metabolome profiles in polycystic ovary syndrome (PCOS) patients with normal/overweight individuals and evaluate a potential microbiota-related diagnostic method development for PCOS, 16S rRNA and ITS2 gene sequencing using 88 fecal samples and 87 metabolome analysis from serum samples are conducted and PCOS classifiers based on multiomics markers are constructed. There are significant bacterial, fungal community and metabolite differences among PCOS patients and healthy volunteers with normal/overweight individuals. Healthy individuals with overweight/obesity display less abnormal metabolism than PCOS patients and uniquely higher abundance of the fungal genus Mortierella. Nine bacterial genera, 4 predicted pathways, 11 fungal genera and top 30 metabolites are screened out which distinguish PCOS from healthy controls, with AUCs of 0.84, 0.64, 0.85 and 1, respectively. The metabolite-derived model is more accurate than the microbe-based model in discriminating normal BMI PCOS (PCOS-LB) from normal BMI healthy (Healthy-LB), PCOS-HB from Healthy-HB. Featured bacteria, fungi, predicted pathways and serum metabolites display higher associations with free androgen index (FAI) in the cooccurrence network. In conclusion, our data reveal that hyperandrogenemia plays a central role in the dysbiosis of intestinal microecology and the change in metabolic status in patients with PCOS and that its effect exceeds the role of BMI. Healthy women with high BMI showed unique microbiota and metabolic features.The priority of predictive models in discriminating PCOS from healthy status in this study were serum metabolites, fungal taxa and bacterial taxa.
Tenacibaculum xiamenense sp nov, an algicidal bacterium isolated from coastal seawater
National Nature Science Foundation of China [40930847]; Special Fund for PhD Program in University [20120121130001]; Public Science and Technology Research Funds Projects of Ocean [201305016, 201305041, 201305022]A Gram-stain-negative, elongated rod-shaped, yellow-pigmented, aerobic bacterial strain, designated WJ-1(T), was isolated from coastal seawater in Xiamen, Fujian province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain WJ-1(T) fell within the genus Tenacibaculum and was most closely associated with Tenacibaculum aestuarii SMK-4(T) (96.7% 16S rRNA gene sequence similarity); lower similarities were shown to other members of the genus Tenacibaculum (<96.2%). The strain formed a distinct lineage with Tenacibaculum litopenaei B-I-T (96.0 %), Tenacibaculum geojense YCS-6(T) (94.5 %) and Tenacibaculum jejuense CNURIC 013(T) (95.4%). Growth was observed at temperatures from 16 to 38 degrees C, at salinities from 2 to 4% and at pH 6-9. The major fatty acids were summed feature 3 (C-16:1 omega 6c and/or C-16:1 omega 7c), iso-C-17:0 3-OH, iso-C-15:0 and iso-C-15:0 3-OH. The DNA G+C content of strain WJ-1(T) was 33.2 mol% and the major respiratory quinone was menaquinone-6 (MK-6). Differential phenotypic properties and phylogenetic distinctiveness in this study distinguished strain WJ-1(T) from all other members of the genus Tenacibaculum. According to the morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain WJ-1(T) represents a novel species of the genus Tenacibaculum, for which the name Tenacibaculum xiamenense sp. nov. is proposed. The type strain is WJ-1(T) (=CGMCC 1.12378(T)=LMG 27422(T))
Mangrovimonas yunxiaonensis gen nov, sp nov, isolated from mangrove sediment
National Nature Science Foundation [40930847, 31070442]; Nature Science Foundation of Fujian Province [2012J01150]; Public Science and Technology Research Funds Projects of Ocean [201305016, 201305041, 201305022]; program for Changjiang Scholars and Innovative Research Team in University [41121091]A Gram-negative, short-rod-shaped, orange-pigmented bacterium, strain LYYY01(T), was isolated from a mangrove sediment sample collected from Yunxiao mangrove National Nature Reserve, Fujian Province, China. 16S rRNA gene sequence comparisons showed that strain LYYY01(T) is a member of the family Flavobacteriaceae, forming a distinct lineage with species of the genera Meridianimaribacter, Sediminibacter, Gelidibacter and Subsaximicrobium. The 16S rRNA gene sequence similarity between strain LYYY01(T) and the type strains of related species ranged from 93.9 to 90.9%. Growth was observed at temperatures from 10 to 38 degrees C, at salinities from 1 to 7% and at pH from 6 to 10. The DNA G+C content of the strain was 38.6 mol% and the major respiratory quinone was menaquinone-6 (MK-6). The major fatty acids were iso-C-15:1 (27.6%), iso-C-15:0 (24.0%), iso-C-17:0 3-OH (12.0%) and iso-C-16:0 3-OH (6.2%). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain LYYY01(T) is considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the name Mangrovimonas yunxiaonensis gen. nov., sp. nov. is proposed. The type strain of Mangrovimonas yunxiaonensis is LYYY01(T) (=CGMCC 1.12280(T)=LMG 27142(T))
A Novel Algicide: Evidence of the Effect of a Fatty Acid Compound from the Marine Bacterium, Vibrio sp BS02 on the Harmful Dinoflagellate, Alexandrium tamarense
National Nature Science Foundation of China [40930847]; Special Fund for Ph.D. Program in University [20120121130001]; Public Science and Technology Research Funds Projects of Ocean [201305016, 201305041, 201305022]Alexandrium tamarense is a notorious bloom-forming dinoflagellate, which adversely impacts water quality and human health. In this study we present a new algicide against A. tamarense, which was isolated from the marine bacterium Vibrio sp. BS02. MALDI-TOF-MS, NMR and algicidal activity analysis reveal that this compound corresponds to palmitoleic acid, which shows algicidal activity against A. tamarense with an EC50 of 40 mu g/mL. The effects of palmitoleic acid on the growth of other algal species were also studied. The results indicate that palmitoleic acid has potential for selective control of the Harmful algal blooms (HABs). Over extended periods of contact, transmission electron microscopy shows severe ultrastructural damage to the algae at 40 mu g/mL concentrations of palmitoleic acid. All of these results indicate potential for controlling HABs by using the special algicidal bacterium and its active agent
Toxicity of algicidal extracts from Mangrovimonas yunxiaonensis strain LY01 on a HAB causing Alexandrium tamarense
Toxicity of algicidal extracts from Mangrovimonas yunxiaonensis strain LY01 on Alexandrium tamarense were measured through studying the algicidal procedure, nuclear damage and transcription of related genes. Medium components were optimized to improve algicidal activity, and characteristics of algicidal extracts were determined. Transmission electron microscope analysis revealed that the cell structure was broken. Cell membrane integrity destruction and nuclear structure degradation were monitored using confocal laser scanning microscope, and the rbcS, hsp and proliferating cell nuclear antigen (PCNA) gene expressions were studied. Results showed that 1.0% tryptone, 0.4% glucose and 0.8% MgCl2 were the optimal nutrient sources. The algicidal extracts were heat and pH stable, non-protein and less than 1kD. Cell membrane and nuclear structure integrity were lost, and the transcription of the rbcS and PCNA genes were significantly inhibited and there was up-regulation of hsp gene expression during the exposure procedure. The algicidal extracts destroyed the cell membrane and nuclear structure integrity, inhibited related gene expression and, eventually, lead to the inhibition of algal growth. All the results may elaborate firstly the cell death process and nuclear damage in A. tamarense which was induced by algicidal extracts, and the algicidal extracts could be potentially used as bacterial control of HABs in future. ? 2014 Elsevier B.V
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