Clinical Metagenomics Is Increasingly Accurate and Affordable to Detect Enteric Bacterial Pathogens in Stool.

Stool culture is the gold standard method to diagnose enteric bacterial infections; however, many clinical laboratories are transitioning to syndromic multiplex PCR panels. PCR is rapid, accurate, and affordable, yet does not yield subtyping information critical for foodborne disease surveillance. A metagenomics-based stool testing approach could simultaneously provide diagnostic and public health information. Here, we evaluated shotgun metagenomics to assess the detection of common enteric bacterial pathogens in stool. We sequenced 304 stool specimens from 285 patients alongside routine diagnostic testing for Salmonella spp., Campylobacter spp., Shigella spp., and shiga-toxin producing Escherichia coli. Five analytical approaches were assessed for pathogen detection: microbiome profiling, Kraken2, MetaPhlAn, SRST2, and KAT-SECT. Among analysis tools and databases compared, KAT-SECT analysis provided the best sensitivity and specificity for all pathogens tested compared to culture (91.2% and 96.2%, respectively). Where metagenomics detected a pathogen in culture-negative specimens, standard PCR was positive 85% of the time. The cost of metagenomics is approaching the current combined cost of PCR, reflex culture, and whole genome sequencing for pathogen detection and subtyping. As cost, speed, and analytics for single-approach metagenomics improve, it may be more routinely applied in clinical and public health laboratories.

Opioid and Cannabis Use During Pregnancy and Breastfeeding in Relation to Sociodemographics and Mental Health Status: A Descriptive Study.

OBJECTIVE: This study of Canadian women estimates the prevalence of opioid and cannabis use during pregnancy and cannabis use during the breastfeeding period and explores the sociodemographic and mental health characteristics associated with use. METHODS: A total of 13 000 women who gave birth between January and June 2018 were invited to participate in the Survey on Maternal Health by Statistics Canada; 7111 women participated for a response rate of 54.7%. Participants were asked about their mental health, supports during pregnancy, and substance use. Multivariable logistic regression was used to describe the relationship between sociodemographic and mental health characteristics and substance use during pregnancy and while breastfeeding. RESULTS: The prevalence of self-reported opioid use during pregnancy was 1.4% (95% confidence interval [CI] 1.1%-1.8%). A higher proportion of women reported using cannabis during pregnancy and while breastfeeding, at 3.1% (95% CI 2.5%-3.6%) and 2.6% (95% CI 2.1%-3.1%), respectively. Younger age, not being in a relationship, lower level of education, and thoughts of self-harm were significantly associated with cannabis use during pregnancy. Lower level of education and thoughts of self-harm were also significantly associated with cannabis use while breastfeeding, as were symptoms of postpartum depression and/or generalized anxiety. Lower level of education and symptoms of postpartum depression and/or generalized anxiety were also significantly associated with opioid use during pregnancy. CONCLUSION: The results of this survey show relatively low levels of opioid and cannabis use during pregnancy and cannabis use while breastfeeding in Canada. Different sociodemographic and mental health characteristics are associated with the use of these substances, and public health interventions and policies should take into account these factors.

Endogenous cortisol production and its relationship with feeding transitions in larval lake sturgeon (Acipenser fulvescens).

Our understanding of the importance of cortisol in the development of fishes largely stems from teleosts and in particular the zebrafish, Danio rerio. However, studies examining the ontogeny of the cortisol endocrine axis in acipenseriformes (sturgeon and paddlefish) have demonstrated similar general patterns during early development. Beginning with maternal deposition of cortisol in the egg, followed by development of de novo synthesis, a hypo-responsive period, and finally the ability of the fish to appropriately increase whole-body levels of cortisol in response to a stressor. In the present study, we demonstrate a similar pattern of ontogeny in the cortisol response in lake sturgeon over two-year classes. Whole-body levels of cortisol were examined over two cohorts and found to be different in both concentration and timing of endogenous production. The 2016 cohort were found to have relatively high levels of cortisol and developed to first feeding approximately six days faster than the 2017 cohort with lower levels of cortisol. In the 2017 cohort, mRNA expression of steroidogenic acute regulatory protein (StAR) and glucocorticoid receptor 1 (GR1) increased just prior to the increase in cortisol and associated onset of exogenous feeding. Treatment in metyrapone, an inhibitor of 11ß-hydroxylase, significantly inhibited cortisol production and resulted in the inability of the fish to appropriately transition to exogenous feeding. Data suggest a potential key role for cortisol in lake sturgeon as they transition between diets during early life history.

Novel glycolipid agents for killing cisplatin-resistant human epithelial ovarian cancer cells.

BACKGROUND: Chemotherapy resistance is one of the major factors contributing to mortality from human epithelial ovarian cancer (EOC). Identifying drugs that can effectively kill chemotherapy-resistant EOC cells would be a major advance in reducing mortality. Glycosylated antitumour ether lipids (GAELs) are synthetic glycolipids that are cytotoxic to a wide range of cancer cells. They appear to induce cancer cell death in an apoptosis-independent manner. METHODS: Herein, the effectiveness of two GAELs, GLN and MO-101, in killing chemotherapy-sensitive and -resistant EOC cells lines and primary cell samples was tested using monolayer, non-adherent aggregate, and non-adherent spheroid cultures. RESULTS: Our results show that EOC cells exhibit a differential sensitivity to the GAELs. Strikingly, both GAELs are capable of inducing EOC cell death in chemotherapy-sensitive and -resistant cells grown as monolayer or non-adherent cultures. Mechanistic studies provide evidence that apoptotic-cell death (caspase activation) contributes to, but is not completely responsible for, GAEL-induced cell killing in the A2780-cp EOC cell line, but not primary EOC cell samples. CONCLUSIONS: Studies using primary EOC cell samples supports previously published work showing a GAEL-induced caspase-independent mechanism of death. GAELs hold promise for development as novel compounds to combat EOC mortality due to chemotherapy resistance.

The temporal dynamics of chromosome instability in ovarian cancer cell lines and primary patient samples.

Epithelial ovarian cancer (EOC) is the most prevalent form of ovarian cancer and has the highest mortality rate. Novel insight into EOC is required to minimize the morbidity and mortality rates caused by recurrent, drug resistant disease. Although numerous studies have evaluated genome instability in EOC, none have addressed the putative role chromosome instability (CIN) has in disease progression and drug resistance. CIN is defined as an increase in the rate at which whole chromosomes or large parts thereof are gained or lost, and can only be evaluated using approaches capable of characterizing genetic or chromosomal heterogeneity within populations of cells. Although CIN is associated with numerous cancer types, its prevalence and dynamics in EOC is unknown. In this study, we assessed CIN within serial samples collected from the ascites of five EOC patients, and in two well-established ovarian cancer cell models of drug resistance (PEO1/4 and A2780s/cp). We quantified and compared CIN (as measured by nuclear areas and CIN Score (CS) values) within and between serial samples to glean insight into the association and dynamics of CIN within EOC, with a particular focus on resistant and recurrent disease. Using quantitative, single cell analyses we determined that CIN is associated with every sample evaluated and further show that many EOC samples exhibit a large degree of nuclear size and CS value heterogeneity. We also show that CIN is dynamic and generally increases within resistant disease. Finally, we show that both drug resistance models (PEO1/4 and A2780s/cp) exhibit heterogeneity, albeit to a much lesser extent. Surprisingly, the two cell line models exhibit remarkably similar levels of CIN, as the nuclear areas and CS values are largely overlapping between the corresponding paired lines. Accordingly, these data suggest CIN may represent a novel biomarker capable of monitoring changes in EOC progression associated with drug resistance.

Differential cellular responses induced by dorsomorphin and LDN-193189 in chemotherapy-sensitive and chemotherapy-resistant human epithelial ovarian cancer cells.

Inherent or acquired drug resistance is a major contributor to epithelial ovarian cancer (EOC) mortality. Novel drugs or drug combinations that produce EOC cell death or resensitize drug resistant cells to standard chemotherapy may improve patient treatment. After conducting drug tolerability studies for the multikinase inhibitors dorsomorphin (DM) and it is structural analogue LDN-193189 (LDN), these drugs were tested in a mouse intraperitoneal xenograft model of EOC. DM significantly increased survival, whereas LDN showed a trend toward increased survival. In vitro experiments using cisplatin (CP)-resistant EOC cell lines, A2780-cp or SKOV3, we determined that pretreatment or cotreatment with DM or LDN resensitized cells to the killing effect of CP or carboplatin (CB). DM was capable of blocking EOC cell cycle and migration, whereas LDN produced a less pronounced effect on cell cycle and no effect on migration. Subsequent analyses using primary human EOC cell samples or additional established EOC cells lines showed that DM or LDN induced a dose-dependent autophagic or cell death response, respectively. DM induced a characteristic morphological change with the appearance of numerous LC3B-containing acidic vacuoles and an increase in LC3BII levels. This was coincident with a decrease in cell growth and the altered cell cycle consistent with DM-induced cytostasis. By contrast, LDN produced a caspase 3-independent, reactive oxygen species-dependent cell death. Overall, DM and LDN possess drug characteristics suitable for adjuvant agents used to treat chemotherapy-sensitive and -resistant EOC.

Family structure, stress, and psychological distress: a demonstration of the impact of differential exposure.

In this article, we evaluate the relative power of differential exposure and differential vulnerability to stressors to account for variations in psychological distress between single and married mothers. The data for this assessment are derived from a longitudinal survey of 518 single mothers and 502 married mothers living in London, Ontario, Canada. Both cross-sectional and longitudinal analyses clearly reveal that the higher levels of psychological distress experienced by single mothers compared to married mothers are almost entirely related to their greater exposure to stress and strain rather than to any group differences in vulnerability to stressful experiences. Across a number of different dimensions of social stressors, single mothers are consistently more exposed to these stressors than married mothers are. Moreover, this differential exposure persists over time. In contrast, there is no evidence that single mothers are more vulnerable or reactive to stressors than are married mothers. We discuss these findings in terms of their implications for the sociology of mental health and for primary prevention.

Recent research on immigrant health from statistics Canada's population surveys.

This paper reviews recent research using Statistics Canada data to compare immigrant health with that of the Canadian-born. A number of Statistics Canada studies have been used for such comparisons, including the National Population Health Survey and the Canadian Community Health Survey. Across the range of indicators studied, compared to the Canadian-born, immigrants are generally in as good or better health, have similar or better health behaviours, and similar or less frequent health service use (the "healthy immigrant effect"). These indications appear to be strongest among recent and non-European immigrants. These studies have established baseline patterns and identified that important distinctions exist among immigrant subgroups. Future research on more detailed subgroups that uses longitudinal data and cross-culturally validated instruments is needed.