scholarly journals Impact of air pollution on buff-tailed bumblebees (Bombus terrestris) and their gut microbiome

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Hannah Sampson ◽  
Julian Ketley ◽  
Eamonn Mallon ◽  
Julie Morrissey
Keyword(s):  
Air Pollution ◽  
Gut Microbiome ◽  
Bombus Terrestris ◽  
Bacterial Species ◽  
Published Data ◽  
Bacterial Cells ◽  
Microbiome Composition ◽  
Bee Health

Bumblebees play a major role in global pollination. Consequently, their health is of high importance for food security worldwide. Yet, recent population estimates show that their numbers are declining. This decline has been attributed to habitat loss, infection and use of pesticides. An important factor for bee health that contributes to population survival is the gut microbiome composition. The bee gut microbiome provides protection from pathogens, is specific to the host and helps break down food. Without a balanced gut microbiome, the health of the bee is threatened through increased infection and mortality. The bee gut microbiome is relatively simple, being dominated by 8 core bacterial species providing a convenient study system. Previous published data shows that air pollution has an impact on bacterial behaviour. Therefore, our hypothesis is exposure to air pollution causes an imbalance in the bee gut microbiome. To test this, we exposed bees to black carbon (BC), a major component of air pollution particulate matter. We assessed the effects on bee behaviour, microbiome composition and gut bacteria treated in vitro. Bees treated with BC showed a significant increase in viable bacterial cells in their faecal community. Independent culture of gut commensals showed that BC significantly alters the structure of their biofilms, which are important for colonisation in vivo. This supports the hypothesis that air pollution can cause an imbalance in the bee gut microbiome, and may adversely influence bee health and pollinator populations.

scholarly journals Use of Quantum Dot Luminescent Probes To Achieve Single-Cell Resolution of Human Oral Bacteria in Biofilms

2006 ◽  
Vol 73 (2) ◽  
pp. 630-636 ◽  
Author(s):  
Natalia I. Chalmers ◽  
Robert J. Palmer ◽  
Laurence Du-Thumm ◽  
Richard Sullivan ◽  
Wenyuan Shi ◽  
...  
Keyword(s):  
Single Cell ◽  
Bacterial Species ◽  
Semiconductor Nanocrystals ◽  
Spatial Relationship ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Interspecies Interactions ◽  
Promising Tool

ABSTRACT Oral biofilms are multispecies communities, and in their nascent stages of development, numerous bacterial species engage in interspecies interactions. Better insight into the spatial relationship between different species and how species diversity increases over time can guide our understanding of the role of interspecies interactions in the development of the biofilms. Quantum dots (QD) are semiconductor nanocrystals and have emerged as a promising tool for labeling and detection of bacteria. We sought to apply QD-based primary immunofluorescence for labeling of bacterial cells with in vitro and in vivo biofilms and to compare this approach with the fluorophore-based primary immunofluorescence approach we have used previously. To investigate QD-based primary immunofluorescence as the means to detect distinct targets with single-cell resolution, we conjugated polyclonal and monoclonal antibodies to the QD surface. We also conducted simultaneous QD conjugate-based and fluorophore conjugate-based immunofluorescence and showed that these conjugates were complementary tools in immunofluorescence applications. Planktonic and biofilm cells were labeled effectively by considering two factors: the final nanomolar concentration of QD conjugate and the amount of antibody conjugated to the QD, which we define as the degree of labeling. These advances in the application of QD-based immunofluorescence for the study of biofilms in vitro and in vivo will help to define bacterial community architecture and to facilitate investigations of interactions between bacterial species in these communities.

Production of Novel Bioactive Compounds by the Bacteria Associated with Some Marine Sponges of Gulf of Mannar and Palk Bay, Southeast Coast of India

2018 ◽  
Vol 6 (8) ◽  
pp. 183
Author(s):  
V. Ramadas ◽  
G. Chandralega
Keyword(s):  
Bioactive Compounds ◽  
Bacterial Species ◽  
Marine Sponges ◽  
Marine Organisms ◽  
Gulf Of Mannar ◽  
Bacterial Symbionts ◽  
Palk Bay ◽  
Excellent Source

Sponges, exclusively are aquatic and mostly marine, are found from the deepest oceans to the edge of the sea. There are approximately 15,000 species of sponges in the world, of which, 150 occur in freshwater, but only about 17 are of commercial value. A total of 486 species of sponges have been identified in India. In the Gulf of Mannar and Palk Bay a maximum of 319 species of sponges have been recorded. It has been proved that marine organisms are excellent source of bioactive secondary metabolites and number of compounds of originated from marine organisms had been reported to possess in-vitro and in-vivo immuno stimulatory activity. Extracts from 20 sponge species were tested for bacterial symbionts and bioactive compounds were isolated from such associated bacterial species in the present study.

scholarly journals Review of T-2307, an Investigational Agent That Causes Collapse of Fungal Mitochondrial Membrane Potential

2021 ◽  
Vol 7 (2) ◽  
pp. 130
Author(s):  
Nathan P. Wiederhold
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Candida Species ◽  
Mammalian Cells ◽  
Mitochondrial Membrane ◽  
Fungal Infections ◽  
Published Data ◽  
Candida Auris

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.

scholarly journals Xylitol enhances synthesis of propionate in the colon via cross-feeding of gut microbiota

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Shasha Xiang ◽  
Kun Ye ◽  
Mian Li ◽  
Jian Ying ◽  
Huanhuan Wang ◽  
...  
Keyword(s):  
Gut Microbiome ◽  
Lactobacillus Reuteri ◽  
Carbon Sources ◽  
Short Chain Fatty Acids ◽  
Microbial Composition ◽  
Key Enzymes ◽  
Rrna Sequencing ◽  
Phosphate Acetyltransferase

Abstract Background Xylitol, a white or transparent polyol or sugar alcohol, is digestible by colonic microorganisms and promotes the proliferation of beneficial bacteria and the production of short-chain fatty acids (SCFAs), but the mechanism underlying these effects remains unknown. We studied mice fed with 0%, 2% (2.17 g/kg/day), or 5% (5.42 g/kg/day) (weight/weight) xylitol in their chow for 3 months. In addition to the in vivo digestion experiments in mice, 3% (weight/volume) (0.27 g/kg/day for a human being) xylitol was added to a colon simulation system (CDMN) for 7 days. We performed 16S rRNA sequencing, beneficial metabolism biomarker quantification, metabolome, and metatranscriptome analyses to investigate the prebiotic mechanism of xylitol. The representative bacteria related to xylitol digestion were selected for single cultivation and co-culture of two and three bacteria to explore the microbial digestion and utilization of xylitol in media with glucose, xylitol, mixed carbon sources, or no-carbon sources. Besides, the mechanisms underlying the shift in the microbial composition and SCFAs were explored in molecular contexts. Results In both in vivo and in vitro experiments, we found that xylitol did not significantly influence the structure of the gut microbiome. However, it increased all SCFAs, especially propionate in the lumen and butyrate in the mucosa, with a shift in its corresponding bacteria in vitro. Cross-feeding, a relationship in which one organism consumes metabolites excreted by the other, was observed among Lactobacillus reuteri, Bacteroides fragilis, and Escherichia coli in the utilization of xylitol. At the molecular level, we revealed that xylitol dehydrogenase (EC 1.1.1.14), xylulokinase (EC 2.7.1.17), and xylulose phosphate isomerase (EC 5.1.3.1) were key enzymes in xylitol metabolism and were present in Bacteroides and Lachnospiraceae. Therefore, they are considered keystone bacteria in xylitol digestion. Also, xylitol affected the metabolic pathway of propionate, significantly promoting the transcription of phosphate acetyltransferase (EC 2.3.1.8) in Bifidobacterium and increasing the production of propionate. Conclusions Our results revealed that those key enzymes for xylitol digestion from different bacteria can together support the growth of micro-ecology, but they also enhanced the concentration of propionate, which lowered pH to restrict relative amounts of Escherichia and Staphylococcus. Based on the cross-feeding and competition among those bacteria, xylitol can dynamically balance proportions of the gut microbiome to promote enzymes related to xylitol metabolism and SCFAs.

scholarly journals Novel Insights on the Role of Nitric Oxide in the Ovary: A Review of the Literature

2021 ◽  
Vol 18 (3) ◽  
pp. 980
Author(s):  
Maria Cristina Budani ◽  
Gian Mario Tiboni
Keyword(s):  
Nitric Oxide ◽  
In Vivo Studies ◽  
Published Data ◽  
Vitro Fertilization ◽  
Peripheral Neurons ◽  
Relevant Role ◽  
Oocyte Meiotic Maturation

Nitric oxide (NO) is formed during the oxidation of L-arginine to L-citrulline by the action of multiple isoenzymes of NO synthase (NOS): neuronal NOS (nNOS), endotelial NOS (eNOS), and inducible NOS (iNOS). NO plays a relevant role in the vascular endothelium, in central and peripheral neurons, and in immunity and inflammatory systems. In addition, several authors showed a consistent contribution of NO to different aspects of the reproductive physiology. The aim of the present review is to analyse the published data on the role of NO within the ovary. It has been demonstrated that the multiple isoenzymes of NOS are expressed and localized in the ovary of different species. More to the point, a consistent role was ascribed to NO in the processes of steroidogenesis, folliculogenesis, and oocyte meiotic maturation in in vitro and in vivo studies using animal models. Unfortunately, there are few nitric oxide data for humans; there are preliminary data on the implication of nitric oxide for oocyte/embryo quality and in-vitro fertilization/embryo transfer (IVF/ET) parameters. NO plays a remarkable role in the ovary, but more investigation is needed, in particular in the context of human ovarian physiology.

scholarly journals Isolation and structural elucidation of dimeric epigallocatechin-3-gallate autoxidation products and their antioxidant capacity

2021 ◽  
Author(s):  
Julian Alfke ◽  
Uta Kampermann ◽  
Svetlana Kalinina ◽  
Melanie Esselen
Keyword(s):  
Antioxidant Capacity ◽  
Antioxidant Properties ◽  
Cd Spectroscopy ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Published Data ◽  
Dietary Polyphenols ◽  
Cellular Effects ◽  
The Impact

AbstractDietary polyphenols like epigallocatechin-3-gallate (EGCG)—which represents the most abundant flavan-3-ol in green tea—are subject of several studies regarding their bioactivity and health-related properties. On many occasions, cell culture or in vitro experiments form the basis of published data. Although the stability of these compounds is observed to be low, many reported effects are directly related to the parent compounds whereas the impact of EGCG degradation and autoxidation products is not yet understood and merely studied. EGCG autoxidation products like its dimers theasinensin A and D, “P2” and oolongtheanin are yet to be characterized in the same extent as their parental polyphenol. However, to investigate the bioactivity of autoxidation products—which would minimize the discrepancy between in vitro and in vivo data—isolation and structure elucidation techniques are urgently needed. In this study, a new protocol to acquire the dimers theasinensin A and D as well as oolongtheanin is depicted, including a variety of spectroscopic and quadrupole time-of-flight high-resolution mass spectrometric (qTOF-HRMS) data to characterize and assign these isolates. Through nuclear magnetic resonance (NMR) spectroscopy, polarimetry, and especially circular dichroism (CD) spectroscopy after enzymatic hydrolysis the complementary atropisomeric stereochemistry of the isolated theasinensins is illuminated and elucidated. Lastly, a direct comparison between the isolated EGCG autoxidation products and the monomer itself is carried out regarding their antioxidant properties featuring Trolox equivalent antioxidant capacity (TEAC) values. These findings help to characterize these products regarding their cellular effects and—which is of special interest in the flavonoid group—their redox properties.

scholarly journals The sugar composition of the fibre in selected plant foods modulates weaning infants’ gut microbiome composition and fermentation metabolites in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shanthi G. Parkar ◽  
Jovyn K. T. Frost ◽  
Doug Rosendale ◽  
Halina M. Stoklosinski ◽  
Carel M. H. Jobsis ◽  
...  
Keyword(s):  
Gut Microbiome ◽  
Gas Production ◽  
Sugar Composition ◽  
Microbiome Composition ◽  
Fibre Concentration ◽  
Microbiome Profile ◽  
Infant Gut Microbiome ◽  
Immune Health ◽  
Faecal Bacteria

AbstractEight plant-based foods: oat flour and pureed apple, blackcurrant, carrot, gold- and green-fleshed kiwifruit, pumpkin, sweetcorn, were pre-digested and fermented with pooled inocula of weaning infants’ faecal bacteria in an in vitro hindgut model. Inulin and water were included as controls. The pre-digested foods were analysed for digestion-resistant fibre-derived sugar composition and standardised to the same total fibre concentration prior to fermentation. The food-microbiome interactions were then characterised by measuring microbial acid and gas metabolites, microbial glycosidase activity and determining microbiome structure. At the physiologically relevant time of 10 h of fermentation, the xyloglucan-rich apple and blackcurrant favoured a propiogenic metabolic and microbiome profile with no measurable gas production. Glucose-rich, xyloglucan-poor pumpkin caused the greatest increases in lactate and acetate (indicative of high fermentability) commensurate with increased bifidobacteria. Glucose-rich, xyloglucan-poor oats and sweetcorn, and arabinogalactan-rich carrot also increased lactate and acetate, and were more stimulatory of clostridial families, which are indicative of increased microbial diversity and gut and immune health. Inulin favoured a probiotic-driven consortium, while water supported a proteolytic microbiome. This study shows that the fibre-derived sugar composition of complementary foods may shape infant gut microbiome structure and metabolic activity, at least in vitro.

scholarly journals Function-adaptive clustered nanoparticles reverse Streptococcus mutans dental biofilm and maintain microbiota balance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fatemeh Ostadhossein ◽  
Parikshit Moitra ◽  
Esra Altun ◽  
Debapriya Dutta ◽  
Dinabandhu Sar ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Ex Vivo ◽  
Bacterial Species ◽  
Reactive Oxygen Species Generation ◽  
Biofilm Inhibition ◽  
16S Rrna Analysis ◽  
Dental Biofilm ◽  
Dental Plaques

AbstractDental plaques are biofilms that cause dental caries by demineralization with acidogenic bacteria. These bacteria reside inside a protective sheath which makes any curative treatment challenging. We propose an antibiotic-free strategy to disrupt the biofilm by engineered clustered carbon dot nanoparticles that function in the acidic environment of the biofilms. In vitro and ex vivo studies on the mature biofilms of Streptococcus mutans revealed >90% biofilm inhibition associated with the contact-mediated interaction of nanoparticles with the bacterial membrane, excessive reactive oxygen species generation, and DNA fragmentation. An in vivo examination showed that these nanoparticles could effectively suppress the growth of S. mutans. Importantly, 16S rRNA analysis of the dental microbiota showed that the diversity and richness of bacterial species did not substantially change with nanoparticle treatment. Overall, this study presents a safe and effective approach to decrease the dental biofilm formation without disrupting the ecological balance of the oral cavity.

A novel design of wound bandage using heparin-polyvinylpyrrolidone/TiO2 nanocomposite to improved antibacterial treatment and burn wound healing effect: In vitro and in vivo evaluation

2021 ◽  
Vol 11 (11) ◽  
pp. 1808-1818
Author(s):  
Xiuli Li ◽  
Jigang Wang ◽  
Xin Li ◽  
Xiaoqian Hou ◽  
Hao Wang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Dermal Fibroblast ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Human Dermal Fibroblast ◽  
Burn Wound ◽  
In Vivo Evaluation ◽  
Closure Rate

In our current study, porous heparin-polyvinylpyrrolidone/TiO2 nanocomposite (HpPVP/TiO2) bandage were prepared via the incorporation of TiO2 into HpPVP hydrogels for biomedical applications such as burn infection. The effect of the HpPVP hydrogels and the nanoparticles of TiO2 composition on the functional group and the surface properties of the as-fabricated bandages were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). The presence of TiO2 nanoparticles created the internal structure of the HpPVP hydrogel that aids in a homogeneous porous structure, as indicated by the scanning electron microscope (SEM). The size distribution of the TiO2 nanoparticles was measured using a transmission electron microscope (TEM). The studies on the mechanical properties of the HpPVP hydrogel indicate that the addition of TiO2 nanoparticles increases its strength. The prepared HpPVP/TiO2 nanocomposite dressing has excellent antimicrobial activity were tested against bacterial species (Staphylococcus aureus and Escherichia coli) and has good biocompatibility against human dermal fibroblast cells (HFFF2) for biological applications. In addition, in vivo evaluations in Kunming mice exposed that the as-fabricated HpPVP/TiO2 nanocomposite bandages increased the wound curing and facilitated accelerate skin cell construction along with collagen development. The synergistic effects of the HpPVP/TiO2 nanocomposite hydrogel dressing material, such as its excellent hydrophilic nature, good bactericidal activity, biocompatibility and wound closure rate through in vivo test makes it a suitable candidate for burn infections.

scholarly journals Nature, Position, and Frequency of Mutations Made in a Single Cycle of HIV-1 Replication

2010 ◽  
Vol 84 (19) ◽  
pp. 9864-9878 ◽  
Author(s):  
Michael E. Abram ◽  
Andrea L. Ferris ◽  
Wei Shao ◽  
W. Gregory Alvord ◽  
Stephen H. Hughes
Keyword(s):  
Viral Replication ◽  
Mutation Rate ◽  
Hot Spots ◽  
High Rate ◽  
Published Data ◽  
Single Cycle ◽  
Efficient System ◽  
Hiv 1

ABSTRACT There is considerable HIV-1 variation in patients. The extent of the variation is due to the high rate of viral replication, the high viral load, and the errors made during viral replication. Mutations can arise from errors made either by host DNA-dependent RNA polymerase II or by HIV-1 reverse transcriptase (RT), but the relative contributions of these two enzymes to the mutation rate are unknown. In addition, mutations in RT can affect its fidelity, but the effect of mutations in RT on the nature of the mutations that arise in vivo is poorly understood. We have developed an efficient system, based on existing technology, to analyze the mutations that arise in an HIV-1 vector in a single cycle of replication. A lacZα reporter gene is used to identify viral DNAs that contain mutations which are analyzed by DNA sequencing. The forward mutation rate in this system is 1.4 × 10−5 mutations/bp/cycle, equivalent to the retroviral average. This rate is about 3-fold lower than previously reported for HIV-1 in vivo and is much lower than what has been reported for purified HIV-1 RT in vitro. Although the mutation rate was not affected by the orientation of lacZα, the sites favored for mutations (hot spots) in lacZα depended on which strand of lacZα was present in the viral RNA. The pattern of hot spots seen in lacZα in vivo did not match any of the published data obtained when purified RT was used to copy lacZα in vitro.

Sign in / Sign up

Export Citation Format

Share Document