Association between Lactobacillus species and bacterial vaginosis-related bacteria, and bacterial vaginosis scores in pregnant Japanese women

<p>Abstract</p> <p>Background</p> <p>Bacterial vaginosis (BV), the etiology of which is still uncertain, increases the risk of preterm birth. Recent PCR-based studies suggested that BV is associated with complex vaginal bacterial communities, including many newly recognized bacterial species in non-pregnant women.</p> <p>Methods</p> <p>To examine whether these bacteria are also involved in BV in pregnant Japanese women, vaginal fluid samples were taken from 132 women, classified as normal (n = 98), intermediate (n = 21), or BV (n = 13) using the Nugent gram stain criteria, and studied. DNA extracted from these samples was analyzed for bacterial sequences of any <it>Lactobacillus</it>, four <it>Lactobacillus </it>species, and four BV-related bacteria by PCR with primers for 16S ribosomal DNA including a universal <it>Lactobacillus </it>primer, <it>Lactobacillus </it>species-specific primers for <it>L. crispatus</it>, <it>L. jensenii</it>, <it>L. gasseri</it>, and <it>L. iners</it>, and BV-related bacterium-specific primers for BVAB2, <it>Megasphaera</it>, <it>Leptotrichia</it>, and <it>Eggerthella</it>-like bacterium.</p> <p>Results</p> <p>The prevalences of <it>L. crispatus</it>, <it>L. jensenii</it>, and <it>L. gasseri </it>were significantly higher, while those of BVAB2, <it>Megasphaera</it>, <it>Leptotrichia</it>, and <it>Eggerthella</it>-like bacterium were significantly lower in the normal group than in the BV group. Unlike other <it>Lactobacillus </it>species, the prevalence of <it>L. iners </it>did not differ between the three groups and women with <it>L. iners </it>were significantly more likely to have BVAB2, <it>Megasphaera, Leptotrichia</it>, and <it>Eggerthella</it>-like bacterium. Linear regression analysis revealed associations of BVAB2 and <it>Megasphaera </it>with Nugent score, and multivariate regression analyses suggested a close relationship between <it>Eggerthella</it>-like bacterium and BV.</p> <p>Conclusion</p> <p>The BV-related bacteria, including BVAB2, <it>Megasphaera</it>, <it>Leptotrichia</it>, and <it>Eggerthella</it>-like bacterium, are common in the vagina of pregnant Japanese women with BV. The presence of <it>L. iners </it>may be correlated with vaginal colonization by these BV-related bacteria.</p

Identifying metabolite markers for preterm birth in cervicovaginal fluid by magnetic resonance spectroscopy

Introduction Preterm birth (PTB) may be preceded by changes in the vaginal microflora and metabolite profiles. Objectives We sought to characterise the metabolite profile of cervicovaginal fluid (CVF) of pregnant women by 1H NMR spectroscopy, and assess their predictive value for PTB. Methods A pair of high-vaginal swabs was obtained from pregnant women with no evidence of clinical infection and grouped as follows: asymptomatic low risk (ALR) women with no previous history of PTB, assessed at 20–22 gestational weeks, g.w., n = 83; asymptomatic high risk (AHR) women with a previous history of PTB, assessed at both 20–22 g.w., n = 71, and 26–28 g.w., n = 58; and women presenting with symptoms of preterm labor (PTL) (SYM), assessed at 24–36 g.w., n = 65. Vaginal secretions were dissolved in phosphate buffered saline and scanned with a 9.4 T NMR spectrometer. Results Six metabolites (lactate, alanine, acetate, glutamine/glutamate, succinate and glucose) were analysed. In all study cohorts vaginal pH correlated with lactate integral (r = -0.62, p\0.0001). Lactate integrals were higher in the term ALR compared to the AHR (20–22 g.w.) women (p = 0.003). Acetate integrals were higher in the preterm versus term women for the AHR (20–22 g.w.) (p = 0.048) and SYM (p = 0.003) groups; and was predictive of PTB\37 g.w. (AUC 0.78; 95 % CI 0.61–0.95), and delivery within 2 weeks of the index assessment (AUC 0.84; 95 % CI 0.64–1) in the SYM women, whilst other metabolites were not. Conclusion High CVF acetate integral of women with symptoms of PTL appears predictive of preterm delivery, as well as delivery within 2 weeks of presentation

Advancing the understanding of treponemal disease in the past and present

Syphilis was perceived to be a new disease in Europe in the late 15th century, igniting a debate about its origin that continues today in anthropological, historical, and medical circles. We move beyond this age-old debate using an interdisciplinary approach that tackles broader questions to advance the understanding of treponemal infection (syphilis, yaws, bejel, and pinta). How did the causative organism(s) and humans co-evolve? How did the related diseases caused by Treponema pallidum emerge in different parts of the world and affect people across both time and space? How are T. pallidum subspecies related to the treponeme causing pinta? The current state of scholarship in specific areas is reviewed with recommendations made to stimulate future work. Understanding treponemal biology, genetic relationships, epidemiology, and clinical manifestations is crucial for vaccine development today and for investigating the distribution of infection in both modern and past populations. Paleopathologists must improve diagnostic criteria and use a standard approach for recording skeletal lesions on archaeological human remains. Adequate contextualization of cultural and environmental conditions is necessary, including site dating and justification for any corrections made for marine or freshwater reservoir effects. Biogeochemical analyses may assess aquatic contributions to diet, physiological changes arising from treponemal disease and its treatments (e.g., mercury), or residential mobility of those affected. Shifting the focus from point of origin to investigating who is affected (e.g., by age/sex or socioeconomic status) and disease distribution (e.g., coastal/ inland, rural/urban) will advance our understanding of the treponemal disease and its impact on people through time

Comparison of Storage Conditions for Human Vaginal Microbiome Studies

BACKGROUND: The effect of storage conditions on the microbiome and metabolite composition of human biological samples has not been thoroughly investigated as a potential source of bias. We evaluated the effect of two common storage conditions used in clinical trials on the bacterial and metabolite composition of the vaginal microbiota using pyrosequencing of barcoded 16S rRNA gene sequencing and (1)H-NMR analyses. METHODOLOGY/PRINCIPAL FINDINGS: Eight women were enrolled and four mid-vaginal swabs were collected by a physician from each woman. The samples were either processed immediately, stored at -80°C for 4 weeks or at -20°C for 1 week followed by transfer to -80°C for another 4 weeks prior to analysis. Statistical methods, including Kolmogorovo-Smirnov and Wilcoxon tests, were performed to evaluate the differences in vaginal bacterial community composition and metabolites between samples stored under different conditions. The results showed that there were no significant differences between samples processed immediately after collection or stored for varying durations. (1)H-NMR analysis of the small molecule metabolites in vaginal secretions indicated that high levels of lactic acid were associated with Lactobacillus-dominated communities. Relative abundance of lactic acid did not appear to correlate with relative abundance of individual Lactobacillus sp. in this limited sample, although lower levels of lactic acid were observed when L. gasseri was dominant, indicating differences in metabolic output of seemingly similar communities. CONCLUSIONS/SIGNIFICANCE: These findings benefit large-scale, field-based microbiome and metabolomic studies of the vaginal microbiota

On the fixed point theory of soft metric spaces

[EN] The aim of this paper is to show that a soft metric induces a compatible metric on the collection of all soft points of the absolute soft set, when the set of parameters is a finite set. We then show that soft metric extensions of several important fixed point theorems for metric spaces can be directly deduced from comparable existing results. We also present some examples to validate and illustrate our approach.Salvador Romaguera thanks the support of Ministry of Economy and Competitiveness of Spain, Grant MTM2012-37894-C02-01.Abbas, M.; Murtaza, G.; Romaguera Bonilla, S. (2016). On the fixed point theory of soft metric spaces. Fixed Point Theory and Applications. 2016(17):1-11. https://doi.org/10.1186/s13663-016-0502-yS111201617Zadeh, LA: Fuzzy sets. Inf. Control 8, 103-112 (1965)Molodtsov, D: Soft set theory - first results. Comput. Math. Appl. 37, 19-31 (1999)Aktaş, H, Çağman, N: Soft sets and soft groups. Inf. 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Revealing pyrolysis chemistry for biofuels production: Conversion of cellulose to furans and small oxygenates

Biomass pyrolysis utilizes high temperatures to produce an economically renewable intermediate (pyrolysis oil) that can be integrated with the existing petroleum infrastructure to produce biofuels. The initial chemical reactions in pyrolysis convert solid biopolymers, such as cellulose (up to 60% of biomass), to a short-lived (less than 0.1 s) liquid phase, which subsequently reacts to produce volatile products. In this work, we develop a novel thin-film pyrolysis technique to overcome typical experimental limitations in biopolymer pyrolysis and identify α-cyclodextrin as an appropriate small-molecule surrogate of cellulose. Ab initio molecular dynamics simulations are performed with this surrogate to reveal the long-debated pathways of cellulose pyrolysis and indicate homolytic cleavage of glycosidic linkages and furan formation directly from cellulose without any small-molecule (e.g., glucose) intermediates. Our strategy combines novel experiments and first-principles simulations to allow detailed chemical mechanisms to be constructed for biomass pyrolysis and enable the optimization of next-generation biorefineries

Fructose–Water–Dimethylsulfoxide Interactions by Vibrational Spectroscopy and Molecular Dynamics Simulations

The solvation of fructose in dimethyl sulfoxide (DMSO) and DMSO–H₂O (or DMSO–D₂O) mixtures was investigated using vibrational spectroscopy (Raman, ATR/FTIR) and molecular dynamics (MD) simulations. The analysis of the fructose hydroxyl hydrogen–DMSO oxygen radial distribution function showed that the coordination number of DMSO around the furanose form of fructose is ∼3.5. This number is smaller than the number of hydroxyl groups of fructose because one DMSO molecule is shared between two hydroxyl groups and because intramolecular hydrogen bonds are formed. In the case of fructose–DMSO mixtures, a red shift of the Raman SO asymmetric stretch is observed, which indicates that fructose breaks the DMSO clusters through strong hydrogen bonding between the hydrogen atoms of its hydroxyl groups and the oxygen atom of DMSO. The Raman scattering cross sections of the DMSO SO stretch when a DMSO molecule interacts with another DMSO molecule, a fructose molecule, or a water molecule were estimated from the spectra of the binary mixtures using the coordination numbers from MD simulations. It was also possible to use these values together with the MD-estimated coordination numbers to satisfactorily predict the effect of the water fraction on the Raman scattering intensity of the SO stretching band in ternary mixtures. MD simulations also showed that, with increasing water content, the DMSO orientation around fructose changed, with the sulfur atom moving away from the carbohydrate. The deconvolution of the fructose IR OH stretching region revealed that the hydroxyls of fructose can be separated into two groups that participate in hydrogen bonds of different strengths. MD simulations showed that the three hydroxyls of the fructose ring form stronger hydrogen bonds with the solvent than the remaining hydroxyls, providing an explanation for the experimental observations. Finally, analysis of ATR/FTIR spectra revealed that, with increasing water content, the average hydrogen-bond enthalpy of the fructose hydroxyls decreases by ∼2.5 kJ/mol

Effect of Temperature and Transport on the Yield and Composition of Pyrolysis-Derived Bio-Oil from Glucose

The fast pyrolysis of biomass forms bio-oil, char, and light noncondensable gases. Bio-oil is the desired product in context of converting biomass to biofuel. The effect of temperature on bio-oil yield and composition is anticipated to be different under reaction-limited and transport-limited operating conditions. Attaining fundamental understanding of the effect of temperature and transport on bio-oil yield and composition is challenging, because of limited knowledge of pyrolysis chemistry and the inter-relationship between chemistry and transport. In this work, we performed thin-film and powder pyrolysis experiments to investigate the thermal decomposition of glucose (biomass model compound) under both reaction-controlled and transport-limited operating conditions. In thin-film (size ≤10 μm) experiments, the effect of temperature on pyrolysis product distribution, especially on bio-oil yield and composition, was studied. In addition, using the thin-film data, mechanistic insights into glucose decomposition were provided and a map of reaction pathways was proposed. Decomposition of glucose in the reaction-controlled regime is initiated by dehydration reactions. With increase in temperature, anhydrosugars (viz, levoglucosan and levoglucosenone) apparently converted to furans (hydroxymethylfurfural) and light oxygenates (formic acid/methyl glyoxal), respectively, as ring opening and fragmentation reactions became more facile. Pyrans remained relatively stable. The effect of transport was investigated by performing pyrolysis experiments with different particle sizes. The variation in the yield and composition of bio-oil, with respect to temperature and particle size, was also analyzed. In the case of glucose powder, levoglucosan yield increased significantly with particle size but decreased marginally with temperature, while hydroxymethylfurfural, furfural, formic acid, and methyl glyoxal yields monotonically increased as the temperature and particle size each increased. A thin film of glucose gave a lower yield of bio-oil and a higher yield of char than that of glucose powder

Insights into the Interplay of Lewis and Brønsted Acid Catalysts in Glucose and Fructose Conversion to 5‑(Hydroxymethyl)furfural and Levulinic Acid in Aqueous Media

5-(Hydroxymethyl)­furfural (HMF) and levulinic acid production from glucose in a cascade of reactions using a Lewis acid (CrCl₃) catalyst together with a Brønsted acid (HCl) catalyst in aqueous media is investigated. It is shown that CrCl₃ is an active Lewis acid catalyst in glucose isomerization to fructose, and the combined Lewis and Brønsted acid catalysts perform the isomerization and dehydration/rehydration reactions. A CrCl₃ speciation model in conjunction with kinetics results indicates that the hydrolyzed Cr­(III) complex [Cr­(H₂O)₅OH]²⁺ is the most active Cr species in glucose isomerization and probably acts as a Lewis acid–Brønsted base bifunctional site. Extended X-ray absorption fine structure spectroscopy and Car–Parrinello molecular dynamics simulations indicate a strong interaction between the Cr cation and the glucose molecule whereby some water molecules are displaced from the first coordination sphere of Cr by the glucose to enable ring-opening and isomerization of glucose. Additionally, complex interactions between the two catalysts are revealed: Brønsted acidity retards aldose-to-ketose isomerization by decreasing the equilibrium concentration of [Cr­(H₂O)₅OH]²⁺. In contrast, Lewis acidity increases the overall rate of consumption of fructose and HMF compared to Brønsted acid catalysis by promoting side reactions. Even in the absence of HCl, hydrolysis of Cr­(III) decreases the solution pH, and this intrinsic Brønsted acidity drives the dehydration and rehydration reactions. Yields of 46% levulinic acid in a single phase and 59% HMF in a biphasic system have been achieved at moderate temperatures by combining CrCl₃ and HCl