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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The composition of bacteria within the vaginal microbiome has garnered a lot of recent attention and has been associated with reproductive health and disease. Despite the common occurrence of yeast ...(primarily Candida) within the vaginal microbiome, there is still an incomplete picture of relationships between yeast and bacteria (especially lactobacilli), as well as how such associations are governed. Such relationships could be important to a more holistic understanding of the vaginal microbiome and its connection to reproductive health.
The objective of the study was to perform molecular characterization of clinical specimens to define associations between vaginal bacteria (especially Lactobacillus species) and Candida colonization. In vitro studies were conducted to test the 2 most common dominant Lactobacillus species (Lactobacillus crispatus and Lactobacillus iners) in their ability to inhibit Candida growth and to examine the basis for such inhibition.
A nested cross-sectional study of reproductive-age women from the Contraceptive CHOICE Project was conducted. Vaginal swabs from 299 women were selected to balance race and bacterial vaginosis status, resulting in a similar representation of black and white women in each of the 3 Nugent score categories (normal 0–3, intermediate 4–6, and bacterial vaginosis 7–10). Sequencing of the 16S ribosomal gene (V4 region) was used to determine the dominant Lactobacillus species present (primarily Lactobacillus iners and Lactobacillus crispatus), defined as >50% of the community. Subjects without dominance by a single Lactobacillus species were classified as Diverse. A Candida-specific quantitative polymerase chain reaction targeting the internally transcribed spacer 1 was validated using vaginal samples collected from a second cohort of women and used to assess Candida colonization. Two hundred fifty-five nonpregnant women with sufficient bacterial biomass for analysis were included in the final analysis. Generalized linear models were used to evaluate associations between Lactobacillus dominance, sociodemographic and risk characteristics, and vaginal Candida colonization. In separate in vitro studies, the potential of cell-free supernatants from Lactobacillus crispatus and Lactobacillus iners cultures to inhibit Candida growth was evaluated.
Forty-two women (16%) were vaginally colonized with Candida. Microbiomes characterized as Diverse (38%), Lactobacillus iners-dominant (39%), and Lactobacillus crispatus-dominant (20%) were the most common. The microbiome, race, and Candida colonization co-varied with a higher prevalence of Candida among black women and Lactobacillus iners-dominant communities compared with white women and Lactobacillus crispatus-dominant communities. Lactobacillus iners-dominant communities were more likely to harbor Candida than Lactobacillus crispatus-dominant communities (odds ratio, 2.85, 95% confidence interval, 1.03–7.21; Fisher exact test, P = .048). In vitro, Lactobacillus crispatus produced greater concentrations of lactic acid and exhibited significantly more pH-dependent growth inhibition of Candida albicans, suggesting a potential mechanism for the clinical observations.
In nonpregnant women, Lactobacillus iners-dominant communities were significantly more likely to harbor Candida than Lactobacillus crispatus-dominant communities, suggesting that Lactobacillus species have different relationships with Candida. In vitro experiments indicate that Lactobacillus crispatus may impede Candida colonization more effectively than Lactobacillus iners through a greater production of lactic acid.
Feasibility studies with non-French speaking migrants in France are needed to inform appropriate adaptation of psychosocial intervention procedures.
To test the WHO Problem Management Plus (PM+) ...intervention protocol for Arabic-speaking migrants in the Paris metropolitan region.
Between 2019 and 2021 we recruited participants from three accommodation centres receiving asylum seekers or migrants experiencing social and economic difficulties. Participants experiencing psychological distress underwent five PM + sessions with trained helpers. Feasibility was evaluated through 15 interviews with 8 participants, 4 helpers, and 3 study supervisors. Interview topics covered PM + implementation in general and for each component. We also sought to understand problems with delivery and gathered suggestions for improvement. Data were analysed thematically using a deductive approach.
We found implementation of PM + to be feasible, with predominantly positive reactions from participants, helpers and study staff. All intervention components were considered beneficial, with breathing exercises considered easy to implement and often sustained. Selection of problems and strategies to address them were described as challenging to execute. Psychosocial support from and rapport with helpers and the use of the native language were considered key strengths of the programme. However, we observed the need for complementary or higher intensity psychological support in some cases. Findings also highlighted the importance of addressing distress among non-specialist helpers delivering PM + . Finally, local guidance to social resources were suggested to be added in the protocol.
PM + was well-liked and feasible, with cultural adjustments and increased access to community resources for migrants needed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Purpose
Increased risk of schizophrenia and other psychotic disorders among black Caribbean migrants and their descendants have been described since the 1960s. It remains unclear whether this risk ...varies over time, between rural and urban areas, or according to methodological artefact.
Methods
We conducted a systematic review of the incidence of adult-onset psychotic disorders in black Caribbean groups relative to the baseline population in England, published 1950–2013. Subject to sufficient data (
N
≥ 5) we used random effects meta-analyses to estimate pooled incidence rates (IR) and rate ratios (IRR) of seven psychotic disorder outcomes, and meta-regression to inspect whether any variation was attributable to study-level methodological features, including case ascertainment, denominator reliability, choice of baseline population and study quality.
Results
Eighteen studies met inclusion for review. Sixteen demonstrated statistically significant elevated incidence rates in the black Caribbean group, present across all major psychotic disorders, including schizophrenia and bipolar disorder. Methodological quality increased over time (
p
= 0.01), but was not associated with estimated IR or IRR. For schizophrenia (
N
= 11 studies) the pooled IRR in the black Caribbean group was 4.7 (95 % CI 3.9–5.7) relative to the baseline; no evidence of publication bias was observed. We found weak evidence to suggest schizophrenia IRRs were smaller from studies in more urban settings (odds ratio 0.98; 95 % CI 0.96–1.00;
p
= 0.06).
Conclusions
Higher incidence rates of psychotic disorders have been present for more than 60 years amongst black Caribbean ethnic groups in England, despite improved study methodologies over time. Aetiological explanations appear to more parsimoniously account for this excess than methodological biases.
Suicidal ideation is common among individuals with first episode psychosis (FEP), with prevalence estimates up to 56.5 %. Despite its high prevalence, relatively little is known about how ...sociodemographic, clinical and/or developmental characteristics contribute to the experience of suicidal ideation in individuals with FEP.
In this cross-sectional study (FEP n = 551 and controls n = 857), univariate logistic regression analyses were performed to study the associations of sociodemographic, clinical, and developmental factors with suicidal ideation in individuals with FEP as well as controls. Suicidal ideation was assessed using the Community Assessment of Psychic Experiences (CAPE). In addition, multivariate logistic regression analyses were conducted based on a stepwise approach.
In FEP, only depressive symptoms remained significantly associated with suicidal ideation when all correlates were integrated into one model. In the multivariate model in controls, depressive symptoms, positive symptoms, and traumatic childhood experiences were significantly associated with suicidal ideation.
This study showed that depressive symptoms are an important factor relating to suicidal ideation in individuals with FEP, over and above other clinical, sociodemographic, and developmental factors. This underscores the relevance of screening for suicidal ideation in individuals with FEP, and highlights the need for a better understanding of the diagnostic uncertainty and course of mood symptoms in early psychosis.
Cross-sectional study design, self-reported questionnaires.
Purpose
Epidemiological studies in the Netherlands have reported an excessive gender gap in the risk for non-affective psychotic disorder (NAPD) among immigrants from Morocco with a higher risk ...elevation in males compared to females. We examined the consistency of these findings and their generalizability to immigrants from the Maghreb (Mauritania, Morocco, Algeria, Tunisia and Libya) in other European countries.
Methods
Systematic review and meta-analysis. Medline, PsychINFO and EMBASE databases were searched for publications in the period from January 1970 to April 2014. We included incidence and prevalence studies of non-affective psychotic disorder (NAPD) among migrants from the Maghreb in Europe and studies of subclinical psychotic symptoms (SPS) in representative samples. A meta-analysis was performed on the subgroup of incidence studies.
Results
Five incidence and three prevalence studies of NAPD, and two prevalence studies of SPS, conducted in the Netherlands (
n
=7), Belgium (
n
=1), France (
n
=1) and Italy (
n
=1) met our inclusion criteria. Across all research designs, the risks of NAPD and SPS were consistently increased among male, not female immigrants from the Maghreb. The meta-analysis of incidence studies of NAPD yielded male-to-female risk ratios of 5.1 95 % confidence interval (CI) 3.1–8.4 for migrants from the Maghreb, 2.0 (95 % CI 1.6–2.5) for other migrant groups, and 1.8 (95 % CI 1.3–2.5) for non-migrant Europeans.
Conclusions
The marked gender gap in psychosis risk among migrants from the Maghreb appears a consistent finding, foremost among the Moroccan-Dutch. The small number of studies limits the strength of conclusions that can be drawn about countries other than the Netherlands. Achievement–expectation mismatch, social marginalization and an increased prevalence of illicit drug use are possible explanations.
Abstract
Aims
Gene x environment (G×E) interactions, i.e. genetic modulation of the sensitivity to environmental factors and/or environmental control of the gene expression, have not been reliably ...established regarding aetiology of psychotic disorders. Moreover, recent studies have shown associations between the polygenic risk scores for schizophrenia (PRS-SZ) and some risk factors of psychotic disorders, challenging the traditional gene
v.
environment dichotomy. In the present article, we studied the role of GxE interaction between psychosocial stressors (childhood trauma, stressful life-events, self-reported discrimination experiences and low social capital) and the PRS-SZ on subclinical psychosis in a population-based sample.
Methods
Data were drawn from the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study, in which subjects without psychotic disorders were included in six countries. The sample was restricted to European descendant subjects (
n
= 706). Subclinical dimensions of psychosis (positive, negative, and depressive) were measured by the Community Assessment of Psychic Experiences (CAPE) scale. Associations between the PRS-SZ and the psychosocial stressors were tested. For each dimension, the interactions between genes and environment were assessed using linear models and comparing explained variances of ‘Genetic’ models (solely fitted with PRS-SZ), ‘Environmental’ models (solely fitted with each environmental stressor), ‘Independent’ models (with PRS-SZ and each environmental factor), and ‘Interaction’ models (Independent models plus an interaction term between the PRS-SZ and each environmental factor). Likelihood ration tests (LRT) compared the fit of the different models.
Results
There were no genes-environment associations. PRS-SZ was associated with positive dimensions (
β
= 0.092,
R
2
= 7.50%), and most psychosocial stressors were associated with all three subclinical psychotic dimensions (except social capital and positive dimension). Concerning the positive dimension, Independent models fitted better than Environmental and Genetic models. No significant GxE interaction was observed for any dimension.
Conclusions
This study in subjects without psychotic disorders suggests that (i) the aetiological continuum hypothesis could concern particularly the positive dimension of subclinical psychosis, (ii) genetic and environmental factors have independent effects on the level of this positive dimension, (iii) and that interactions between genetic and individual environmental factors could not be identified in this sample.
Background Previous studies suggested that migrants are at higher risk for psychosis 1 but that this risk is inversely correlated with the size of their ethnic group 2. However, less is known about ...the influence of proportion of migrants in a population - a simple and readily available parameter - on the incidence of psychosis in the whole population - a measure of interest for mental health policies. Methods We prospectively collected data over 3 years in an urban area with a population of N=133000 at risk subjects. The area was divided in 80 geographical units classified in four categories (quartiles) according to the proportion of migrants in the latest census. For each of the geographic units we calculated the standardized incidence rates of affective, non-affective and total psychoses. We tested the hypothesis of unequal rates of psychosis according to migrants’ density quartiles using a Poisson model. Results The proportion of migrants significantly influenced the incidence of total psychoses and affective psychoses. However, in this sample, an increase in migrant density was not linked to an increase in cases of psychosis over the entire spectrum of migrants’ density. A raise in the third quartile was followed by lower incidence rates in populations with the largest proportion of migrants (see figure) Discussion More research is needed to confirm or contradict this result and test for different explanatory hypotheses.
The vaginal microbiome plays an important role in human health and species of vaginal bacteria have been associated with reproductive disease. Strain-level variation is also thought to be important, ...but the diversity, structure and evolutionary history of vaginal strains is not as well characterized. We developed and validated an approach to measure strain variation from metagenomic data based on SNPs within the core genomes for six species of vaginal bacteria:
,
,
,
,
and
. Despite inhabiting the same environment, strain diversity and structure varies across species. All species except
are characterized by multiple distinct groups of strains. Even so, strain diversity is lower in the
species, consistent with a more recent colonization of the human vaginal microbiome. Both strain diversity and the frequency of multi-strain samples is related to species-level diversity of the microbiome in which they occur, suggesting similar ecological factors influencing diversity within the vaginal niche. We conclude that the structure of strain-level variation provides both the motivation and means of testing whether strain-level differences contribute to the function and health consequences of the vaginal microbiome.
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