Glycan cross-feeding supports mutualism between Fusobacterium and the vaginal microbiota.

Women with bacterial vaginosis (BV), an imbalance of the vaginal microbiome, are more likely to be colonized by potential pathogens such as Fusobacterium nucleatum, a bacterium linked with intrauterine infection and preterm birth. However, the conditions and mechanisms supporting pathogen colonization during vaginal dysbiosis remain obscure. We demonstrate that sialidase activity, a diagnostic feature of BV, promoted F. nucleatum foraging and growth on mammalian sialoglycans, a nutrient resource that was otherwise inaccessible because of the lack of endogenous F. nucleatum sialidase. In mice with sialidase-producing vaginal microbiotas, mutant F. nucleatum unable to consume sialic acids was impaired in vaginal colonization. These experiments in mice also led to the discovery that F. nucleatum may also "give back" to the community by reinforcing sialidase activity, a biochemical feature of human dysbiosis. Using human vaginal bacterial communities, we show that F. nucleatum supported robust outgrowth of Gardnerella vaginalis, a major sialidase producer and one of the most abundant organisms in BV. These results illustrate that mutually beneficial relationships between vaginal bacteria support pathogen colonization and may help maintain features of dysbiosis. These findings challenge the simplistic dogma that the mere absence of "healthy" lactobacilli is the sole mechanism that creates a permissive environment for pathogens during vaginal dysbiosis. Given the ubiquity of F. nucleatum in the human mouth, these studies also suggest a possible mechanism underlying links between vaginal dysbiosis and oral sex.

Vaginal sialoglycan foraging by Gardnerella vaginalis: mucus barriers as a meal for unwelcome guests?

Bacterial vaginosis (BV) is a condition of the vaginal microbiome in which there are few lactobacilli and abundant anaerobic bacteria. Members of the genus Gardnerella are often one of the most abundant bacteria in BV. BV is associated with a wide variety of poor health outcomes for women. It has been recognized since the 1980s that women with BV have detectable and sometimes markedly elevated levels of sialidase activity in vaginal fluids and that bacteria associated with this condition produce this activity in culture. Mounting evidence collected using diverse methodologies points to the conclusion that BV is associated with a reduction in intact sialoglycans in cervicovaginal secretions. Here we review evidence for the contributions of vaginal bacteria, especially Gardnerella, in the processes of mucosal sialoglycan degradation, uptake, metabolism and depletion. Our understanding of the impacts of vaginal sialoglycan degradation is still limited. However, the potential implications of sialic acid depletion are discussed in light of our current understanding of the roles played by sialoglycans in vaginal physiology.

EMI and microwave absorbing efficiency of polyaniline-functionalized reduced graphene oxide/γ-Fe2O3/epoxy nanocomposite.

Polyaniline-decorated reduced graphene oxide/ferrite nanofiller (RGPF) prepared by the solution mixing method in three different ratios (1 : 3, 1 : 1 and 3 : 1) of polyaniline-decorated reduced graphene oxide and ferrite have been studied for microwave absorption properties in defence application. The polyaniline-decorated reduced graphene oxide/ferrite and neat ferrite nano-fillers have been used for the preparation of an epoxy nanocomposite (RGPFE) of 60 wt%. The distribution of the RGPF nanofiller in the epoxy matrix was analyzed by field emission scanning electron microscopy. Further, thermal gravimetric analyses revealed the excellent thermal stability of the nanocomposites. A vibrating sample magnetometer was employed to find out the magnetic behavior of the prepared nanocomposites. The complex permittivity and permeability were investigated to evaluate the principal properties in the frequency range from 2 to 18 GHz. These results show that an epoxy nanocomposite with 60 wt% RGPF filler in the ratio of 3 : 1 has maximum dielectric loss. Finally, these electromagnetic data were used to calculate the reflection loss of the epoxy nanocomposites, and showed good agreement between the calculated and measured data of these nanocomposites. The minimum reflection loss was observed as -10.26 dB in the X band with a thickness of 3.0 mm, and the bandwidth was 8.47 GHz for RL ≤-10 dB. On the basis of the above observations, these nanocomposites could be a good candidate for electromagnetic interference shielding (EMI) and microwave absorption applications.

Differential inhibition of mucin-type O-glycosylation (MTOG) induced by peracetyl N-thioglycolyl-d-galactosamine (Ac5GalNTGc) in myeloid cells.

Investigations on the structure and functional roles of glycosylation - an intricate, complex, and dynamic post translational modification on proteins - in biological processes has been a challenging task. Glycan modifications vary depending on the specific cell type, its developmental stage, and resting or activated state. In the present study, we aim to understand the differences between the mucin-type O-glycosylation (MTOG) of two functionally divergent human cell lines, K562 (chronic myeloid leukemia) and U937 (histiocytic lymphoma), having myeloid origins. MTOG is initiated by the addition of N-acetyl-α-d-galactosamine (GalNAc) to Ser/Thr of glycoproteins. We exploited the metabolic glycan engineering (MGE) strategy using the peracetyl N-thioglycolyl-d-galactosamine (Ac5GalNTGc), a synthetic GalNAc analogue, to engineer the glycoconjugates. Ac5GalNTGc was metabolized and incorporated as N-thioglycolyl-d-galactosamine (GalNTGc) in cell surface glycoproteins in both the cell lines with varying degrees of efficiency. Notably, metabolic incorporation of GalNTGc resulted in differential inhibition of MTOG. It was observed that endogenous glycosylation machinery of K562 is relatively more stringent for selecting GalNTGc whereas U937 is flexible towards this selection. Additionally, we studied how the glycan modifications vary on a given CD antigen in these cell lines. Particularly, MTOG on CD43 was differentially inhibited in K562 and U937 as revealed by glycan-dependent and glycan-independent antibodies. It was observed that the effect of MGE on CD43 was similar to global effects on both cell lines. Consequences of MGE using GalNAc analogues depend on the expression and activity of various glycosyl transferases which determine global glycosylation on cell surface as well as on specific glycoproteins.

'Nano on micro' hierarchical porous all carbon structures: an insight into interfacial interactions with bacteria.

Micron long carbon nanofibers (CNFs) were grown on porous carbon beads to give an active surface for rapid immobilization of guest molecules. The fabrication of nanostructures using a catalytic route involving chemical vapour deposition on a porous substrate was accomplished by the controlled synthesis of iron nanoclusters on the surface of porous carbon beads. The challenge of catalyst nanoparticle diffusion into the porous substrate was addressed by using iron coordinated ligand complexes and optimizing the loading percentage of metal salts onto beads. The effect of using tethered bottom up surface processed CNFs on the porous beads' morphologies was established using structural characterization. The protruding architecture of CNFs on the porous carbon surface was subjected to bacterial colonisation in order to determine the efficiency of cell conjugation onto hairy structures, particularly at a low concentration. The interfaces of immobilized bacteria on the textured surface were studied by varying the pH and external physical stimuli to check the biofilm formation. The strategy of fabricating all carbon porous beads, which had topologically controlled 'nano on micro' geometries, to give fast immobilization of guest molecules could be useful in the future for developing an active disinfectant surface.

Discovery and characterization of de novo sialic acid biosynthesis in the phylum Fusobacterium.

Sialic acids are nine-carbon backbone carbohydrates found in prominent outermost positions of glycosylated molecules in mammals. Mimicry of sialic acid (N-acetylneuraminic acid, Neu5Ac) enables some pathogenic bacteria to evade host defenses. Fusobacterium nucleatum is a ubiquitous oral bacterium also linked with invasive infections throughout the body. We employed multidisciplinary approaches to test predictions that F. nucleatum engages in de novo synthesis of sialic acids. Here we show that F. nucleatum sbsp. polymorphum ATCC10953 NeuB (putative Neu5Ac synthase) restores Neu5Ac synthesis to an Escherichia coli neuB mutant. Moreover, purified F. nucleatum NeuB participated in synthesis of Neu5Ac from N-acetylmannosamine and phosphoenolpyruvate in vitro Further studies support the interpretation that F. nucleatum ATCC10953 NeuA encodes a functional CMP-sialic acid synthetase and suggest that it may also contain a C-terminal sialic acid O-acetylesterase. We also performed BLAST queries of F. nucleatum genomes, revealing that only 4/31 strains encode a complete pathway for de novo Neu5Ac synthesis. Biochemical studies including mass spectrometry were consistent with the bioinformatic predictions, showing that F. nucleatum ATCC10953 synthesizes high levels of Neu5Ac, whereas ATCC23726 and ATCC25586 do not express detectable levels above background. While there are a number of examples of sialic acid mimicry in other phyla, these experiments provide the first biochemical and genetic evidence that a member of the phylum Fusobacterium can engage in de novo Neu5Ac synthesis.

Inhibition of mucin-type O-glycosylation through metabolic processing and incorporation of N-thioglycolyl-D-galactosamine peracetate (Ac5GalNTGc).

Mucin-type O-glycans form one of the most abundant and complex post-translational modifications (PTM) on cell surface proteins that govern adhesion, migration, and trafficking of hematopoietic cells. Development of targeted approaches to probe functions of O-glycans is at an early stage. Among several approaches, small molecules with unique chemical functional groups that could modulate glycan biosynthesis form a critical tool. Herein, we show that metabolism of peracetyl N-acyl-D-galactosamine derivatives carrying an N-thioglycolyl (Ac5GalNTGc, 1) moiety-but not N-glycolyl (Ac5GalNGc, 2) and N-acetyl (Ac4GalNAc, 3)-through the N-acetyl-D-galactosamine (GalNAc) salvage pathway induced abrogation of MAL-II and PNA epitopes in Jurkat cells. Mass spectrometry of permethylated O-glycans from Jurkat cells confirmed the presence of significant amounts of elaborated O-glycans (sialyl-T and disialyl-T) which were inhibited upon treatment with 1. O-Glycosylation of CD43, a cell surface antigen rich in O-glycans, was drastically reduced by 1 in a thiol-dependent manner. By contrast, only mild effects were observed for CD45 glycoforms. Direct metabolic incorporation of 1 was confirmed by thiol-selective Michael addition reaction of immunoprecipitated CD43-myc/FLAG. Mechanistically, CD43 glycoforms were unperturbed by peracetylated N-(3-acetylthiopropanoyl) (4), N-(4-acetylthiobutanoyl) (5), and N-methylthioacetyl (6) galactosamine derivatives, N-thioglycolyl-D-glucosamine (7, C-4 epimer of 1), and α-O-benzyl 2-acetamido-2-deoxy-D-galactopyranoside (8), confirming the critical requirement of both free sulfhydryl and galactosamine moieties for inhibition of mucin-type O-glycans. Similar, yet differential, effects of 1 were observed for CD43 glycoforms in multiple hematopoietic cells. Development of small molecules that could alter glycan patterns in an antigen-selective and cell-type selective manner might provide avenues for understanding biological functions of glycans.

Evaluation of acceptability, safety, and continuation rates of centchroman as postabortion nonsteroidal contraceptive pill.

OBJECTIVES: To evaluate acceptability, safety, and continuation rates of centchroman following abortion. STUDY DESIGN: Prospective, observational study. Following spontaneous/induced abortion, women were offered centchroman, 30-mg tablet twice weekly for first 3 months, then once weekly with 1 year of follow-up. RESULTS: Of 120 women who opted for centchroman, continuation rate was 91% at 12 months. There was one case of user failure and one method failure and 26% had infrequent cycles. CONCLUSIONS: Centchroman is safe, effective, has good acceptance, and continuation rate post abortion with infrequent menstrual cycles as the main limiting factor for its continuation. IMPLICATIONS: Centchroman, available in Government scheme for contraception, has good acceptance and continuation rate post abortion. Its inclusion in contraceptive choices offered for postabortion contraception can go a long way in spacing of pregnancies, decreasing repeated unintended pregnancies, unsafe abortions, maternal morbidity, and mortality.

Procalcitonin levels in maternal serum and cord blood as marker for diagnosis of early onset neonatal sepsis.

Objectives: To assess the diagnostic accuracy of Procalcitonin in maternal serum and umbilical cord blood samples to predict Early onset neonatal sepsis (EONS). Study Design: It was a Prospective analytical cohort study. Pregnant women ≥ 34 weeks gestation in active labour, with risk factors for EONS were included in the study. Maternal blood samples at recruitment and umbilical cord blood samples after delivery were taken for Total leucocyte count (TLC), high sensitivity C-Reactive Protein (hs-CRP) and Procalcitonin. Newborns were classified into non-infected, suspected and proven infection. Sensitivity, specificity and diagnostic accuracy of maternal and cord blood procalcitonin, TLC and hs-CRP were calculated. Results: A total of 200 women were recruited. Maternal procalcitonin had a superior diagnostic accuracy of 99% compared to maternal TLC and maternal hs-CRP. Also, cord blood procalcitonin had a diagnostic accuracy of 95%. Conclusion: Procalcitonin in both maternal as well as cord blood is a promising biomarker to detect EONS with high diagnostic accuracy.

Resident microbes shape the vaginal epithelial glycan landscape.

Epithelial cells are covered in carbohydrates (glycans). This glycan coat or "glycocalyx" interfaces directly with microbes, providing a protective barrier against potential pathogens. Bacterial vaginosis (BV) is a condition associated with adverse health outcomes in which bacteria reside in direct proximity to the vaginal epithelium. Some of these bacteria, including Gardnerella, produce glycosyl hydrolase enzymes. However, glycans of the human vaginal epithelial surface have not been studied in detail. Here, we elucidate key characteristics of the "normal" vaginal epithelial glycan landscape and analyze the impact of resident microbes on the surface glycocalyx. In human BV, glycocalyx staining was visibly diminished in electron micrographs compared to controls. Biochemical and mass spectrometric analysis showed that, compared to normal vaginal epithelial cells, BV cells were depleted of sialylated N- and O-glycans, with underlying galactose residues exposed on the surface. Treatment of primary epithelial cells from BV-negative women with recombinant Gardnerella sialidases generated BV-like glycan phenotypes. Exposure of cultured VK2 vaginal epithelial cells to recombinant Gardnerella sialidase led to desialylation of glycans and induction of pathways regulating cell death, differentiation, and inflammatory responses. These data provide evidence that vaginal epithelial cells exhibit an altered glycan landscape in BV and suggest that BV-associated glycosidic enzymes may lead to changes in epithelial gene transcription that promote cell turnover and regulate responses toward the resident microbiome.

Role of hemoglobin and serum iron in oral submucous fibrosis: a clinical study.

BACKGROUND: Oral submucous fibrosis is a chronic, insidious oral mucosal condition affecting the most parts of the oral cavity with high malignant transformation rate triggered by areca nut chewing, nutritional deficiencies, immunologic processes, and genetic predisposition. OSF causes significant hematological abnormalities resulting in anemia and a decrease in serum iron levels. AIM: The aim of this study was to estimate the hemoglobin and serum iron levels among patients with oral submucous fibrosis and to compare the values with healthy subjects. MATERIALS AND METHODS: In this hospital-based study 30 diagnosed patients of OSMF and 15 healthy individuals were included, and the values of hemoglobin and serum iron levels were estimated using Sahli's and Ferrene methods. RESULTS: OSMF patients showed significantly lower levels of hemoglobin and serum iron when compared with the healthy subjects. CONCLUSION: The findings of the study emphasizes on the assessment of hemoglobin and serum iron for patients with oral submucous fibrosis. Also iron therapy should be instituted concomitantly with the initial diagnosis which helps to cease the further progression of the condition. Further extensive studies are indicated to understand the correlation between OSMF and iron deficiency.

Models of Murine Vaginal Colonization by Anaerobically Grown Bacteria.

The mammalian vagina can be colonized by many bacterial taxa. The human vaginal microbiome is often dominated by Lactobacillus species, but one-in-four women experience bacterial vaginosis, in which a low level of lactobacilli is accompanied by an overgrowth of diverse anaerobic bacteria. This condition has been associated with many health complications, including risks to reproductive and sexual health. While there is growing evidence showing the complex nature of microbial interactions in human vaginal health, the individual roles of these different anaerobic bacteria are not fully understood. This is complicated by the lack of adequate models to study anaerobically grown vaginal bacteria. Mouse models allow us to investigate the biology and virulence of these organisms in vivo. Other mouse models of vaginal bacterial inoculation have previously been described. Here, we describe methods for the inoculation of anaerobically grown bacteria and their viable recovery in conventionally raised C57Bl/6 mice. A new, less stressful procedural method for vaginal inoculation and washing is also described. Inoculation and viable recovery of Gardnerella are outlined in detail, and strategies for additional anaerobes such as Prevotella bivia and Fusobacterium nucleatum are discussed.

Assisted reproduction in patients with cardiac disease: A retrospective review.

OBJECTIVE: To assess risks of assisted reproduction in patients with cardiac disease. STUDY DESIGN: Retrospective case note review of patients with cardiac disease undergoing ART over a 10 year period in the obstetric cardiac services of three UK tertiary centres. Assessment of maternal, obstetric and fetal complications during ART and resultant pregnancies. RESULTS: 34 patients with cardiac disease underwent 51 cycles of assisted reproduction. 24 patients (71%) received pre-pregnancy counselling. Mean age at the start of an assisted reproduction cycle was 32 years. Modified WHO (mWHO) risk category for the 34 patients was mWHO I, n = 3; mWHO II, n = 13; mWHO II- III, n = 10; mWHO III, n = 7; mWHO IV, n = 1. The 51 assisted reproduction cycles resulted in 31 pregnancies in 29 patients, and 31 live births, including two sets of twins. Live birth rate per cycle was 60.8%. Twin pregnancy rate per cycle was 5.8%. Four patients experienced complications during assisted reproduction treatment (7.8% per cycle); one major intra-abdominal haemorrhage following egg collection in a patient with a mechanical aortic valve, one endocarditis, one mild ovarian hyperstimulation syndrome and one vagal syncope during egg collection. Four other patients experienced cardiac complications during resultant pregnancies (12.9%). 43% of mWHO class III patients experienced cardiac, obstetric or neonatal complications. Five babies were delivered pre-term (<37/40). CONCLUSIONS: This small study demonstrates that assisted reproduction carries increased risks of complications in patients with cardiac disease, but can be undertaken without major complication in the majority, as long as appropriate adjustments to treatment pathways are made, and they are managed through a multi-disciplinary team.

COVID pandemic analysis using Auto- Regression-Based moving average method.

COVID (Corona Virus) 2019 proved to be a pandemic worldwide, with more than 30 lakhs of life's in danger and more than 2 lakh people dead as of 01 May 2020. The disease is spreading across the world in various phases, with assumptions of having an impact based on the weather conditions, where the true reason is not yet confirmed. However, several precautionary measures such as maintaining social distancing, covering mouth and hands using masks and gloves, avoiding huge public gatherings to attend conferences, meetings, worship places, etc proved to put a pause on the spread of this air-borne contagious disease. Though there is an impact on the overall economy world-wide, lockdown is strictly implemented in countries like India and also at various other places to control the spread and save several lives. There is a necessity to track the spread to find out the rate at which the virus is spreading and accordingly taking measures to control the same. This work presents an analysis of the growth rate and death rate of the COVID pandemic in developing countries like India using the Auto regression-based Moving Average method. The results presented in this work show the future predictions analyzed via the proposed model and drives a path to take preventive measures accordingly and curb the COVID spread.

Screening of core filter layer for the development of respiratory mask to combat COVID-19.

The severe outbreak of respiratory coronavirus disease 2019 has increased the significant demand of respiratory mask and its use become ubiquitous worldwide to control this unprecedented respiratory pandemic. The performance of a respiratory mask depends on the efficiency of the filter layer which is mostly made of polypropylene melt blown non-woven (PP-MB-NW). So far, very limited characterization data are available for the PPE-MB-NW in terms to achieve desired particulate filtration efficiency (PFE) against 0.3 µm size, which are imperative in order to facilitate the right selection of PP-MB-NW fabric for the development of mask. In present study, eight different kinds of PP-MB-NW fabrics (Sample A-H) of varied structural morphology are chosen. The different PP-MB-NW were characterized for its pore size and distribution by mercury porosimeter and BET surface area analyzer was explored first time to understand the importance of blind pore in PFE. The PP-MB-NW samples were characterized using scanning electron microscopy so as to know the surface morphology. The filtration efficiency, pressure drop and breathing resistance of various PP-MB-NW fabric samples are investigated in single and double layers combination against the particle size of 0.3, 0.5 and 1 µm. The samples which are having low pore dia, high solid fraction volume, and low air permeability has high filtration efficiency (> 90%) against 0.3 µm particle with high pressure drop (16.3-21.3 mm WC) and breathing resistance (1.42-1.92 mbar) when compared to rest of the samples. This study will pave the way for the judicial selection of right kind of filter layer i.e., PP-MB-NW fabric for the development of mask and it will be greatly helpful in manufacturing of mask in this present pandemic with desired PFE indicating considerable promise for defense against respiratory pandemic.

Efficient inhibition of O-glycan biosynthesis using the hexosamine analog Ac5GalNTGc.

There is a critical need to develop small-molecule inhibitors of mucin-type O-linked glycosylation. The best-known reagent currently is benzyl-GalNAc, but it is effective only at millimolar concentrations. This article demonstrates that Ac5GalNTGc, a peracetylated C-2 sulfhydryl-substituted GalNAc, fulfills this unmet need. When added to cultured leukocytes, breast cells, and prostate cells, Ac5GalNTGc increased cell-surface VVA binding by ∼10-fold, indicating truncation of O-glycan biosynthesis. Cytometry, mass spectrometry, and western blot analysis of HL-60 promyelocytes demonstrated that 50-80 µM Ac5GalNTGc prevented elaboration of 30%-60% of the O-glycans beyond the Tn-antigen (GalNAcα1-Ser/Thr) stage. The effect of the compound on N-glycans and glycosphingolipids was small. Glycan inhibition induced by Ac5GalNTGc resulted in 50%-80% reduction in leukocyte sialyl-Lewis X expression and L-/P-selectin-mediated rolling under flow conditions. Ac5GalNTGc was pharmacologically active in mouse. It reduced neutrophil infiltration to sites of inflammation by ∼60%. Overall, Ac5GalNTGc may find diverse applications as a potent inhibitor of O-glycosylation.

Association of Hypovitaminosis D with Metabolic Syndrome in Postmenopausal Women.

The prevalence of vitamin D deficiency and metabolic syndrome is spreading like a pandemic globally; postmenopausal women are particularly vulnerable population. Hypovitaminosis D is reported to predispose to various components of metabolic syndrome like dyslipidemia, hypertension, diabetes and obesity. The purpose of this review is to highlight the recently published evidence, evaluating the association of vitamin D deficiency with metabolic syndrome in postmenopausal women. Besides, it emphasizes the long-term risks involved with low vitamin D levels and importance of vitamin D supplementation. Data were obtained from PubMed, Google Scholar and individual searches.

Low-dose inoculation of Escherichia coli achieves robust vaginal colonization and results in ascending infection accompanied by severe uterine inflammation in mice.

Escherichia coli infection of the female reproductive tract is a significant cause of disease in humans and animals, but simple animal models are lacking. Here we report that vaginal inoculation of uropathogenic E. coli strains UTI89 and CFT073 in non-pregnant, estrogen-treated mice resulted in robust colonization of the vagina and uterine horns, whereas titers of the lab strain MG1655 were significantly lower. Non-estrogenized mice also became colonized, but there was more variation in titers. A dose of 104 colony-forming units (CFU) UTI89 was sufficient to result in colonization in all estrogenized mice, and we also observed bacterial transfer between inoculated and uninoculated estrogenized cage mates. UTI89 infection led to inflammation and leukocyte infiltration into the uterine horns as evidenced by tissue histology. Flow cytometry experiments revealed that neutrophil, monocyte and eosinophil populations were significantly increased in infected uterine horns. This model is a simple way to study host-pathogen interactions in E. coli vaginal colonization and uterine infection. There are immediate implications for investigators studying urinary tract infection using mouse models, as few E. coli are required to achieve reproductive colonization, resulting in an additional, underappreciated mucosal reservoir.