Mutators can drive the evolution of multi-resistance to antibiotics.

Antibiotic combination therapies are an approach used to counter the evolution of resistance; their purported benefit is they can stop the successive emergence of independent resistance mutations in the same genome. Here, we show that bacterial populations with 'mutators', organisms with defects in DNA repair, readily evolve resistance to combination antibiotic treatment when there is a delay in reaching inhibitory concentrations of antibiotic-under conditions where purely wild-type populations cannot. In populations of Escherichia coli subjected to combination treatment, we detected a diverse array of acquired mutations, including multiple alleles in the canonical targets of resistance for the two drugs, as well as mutations in multi-drug efflux pumps and genes involved in DNA replication and repair. Unexpectedly, mutators not only allowed multi-resistance to evolve under combination treatment where it was favoured, but also under single-drug treatments. Using simulations, we show that the increase in mutation rate of the two canonical resistance targets is sufficient to permit multi-resistance evolution in both single-drug and combination treatments. Under both conditions, the mutator allele swept to fixation through hitch-hiking with single-drug resistance, enabling subsequent resistance mutations to emerge. Ultimately, our results suggest that mutators may hinder the utility of combination therapy when mutators are present. Additionally, by raising the rates of genetic mutation, selection for multi-resistance may have the unwanted side-effect of increasing the potential to evolve resistance to future antibiotic treatments.

IVEN: A quantitative tool to describe 3D cell position and neighbourhood reveals architectural changes in FGF4-treated preimplantation embryos.

Architectural changes at the cellular and organism level are integral and necessary to successful development and growth. During mammalian preimplantation development, cells reduce in size and the architecture of the embryo changes significantly. Such changes must be coordinated correctly to ensure continued development of the embryo and, ultimately, a successful pregnancy. However, the nature of such transformations is poorly defined during mammalian preimplantation development. In order to quantitatively describe changes in cell environment and organism architecture, we designed Internal Versus External Neighbourhood (IVEN). IVEN is a user-interactive, open-source pipeline that classifies cells into different populations based on their position and quantifies the number of neighbours of every cell within a dataset in a 3D environment. Through IVEN-driven analyses, we show how transformations in cell environment, defined here as changes in cell neighbourhood, are related to changes in embryo geometry and major developmental events during preimplantation mammalian development. Moreover, we demonstrate that modulation of the FGF pathway alters spatial relations of inner cells and neighbourhood distributions, leading to overall changes in embryo architecture. In conjunction with IVEN-driven analyses, we uncover differences in the dynamic of cell size changes over the preimplantation period and determine that cells within the mammalian embryo initiate growth phase only at the time of implantation.

Decolonizing drug-resistant E. coli with phage and probiotics: breaking the frequency-dependent dominance of residents.

Widespread antibiotic resistance in commensal bacteria creates a persistent challenge for human health. Resident drug-resistant microbes can prevent clinical interventions, colonize wounds post-surgery, pass resistance traits to pathogens or move to more harmful niches following routine interventions such as catheterization. Accelerating the removal of resistant bacteria or actively decolonizing particular lineages from hosts could therefore have a number of long-term benefits. However, removing resident bacteria via competition with probiotics, for example, poses a number of ecological challenges. Resident microbes are likely to have physiological and numerical advantages and competition based on bacteriocins or other secreted antagonists is expected to give advantages to the dominant partner, via positive frequency dependence. Since a narrow range of Escherichia coli genotypes (primarily those belonging to the clonal group ST131) cause a significant proportion of multidrug-resistant infections, this group presents a promising target for decolonization with bacteriophage, as narrow-host-range viral predation could lead to selective removal of particular genotypes. In this study we tested how a combination of an ST131-specific phage and competition from the well-known probiotic E. coli Nissle strain could displace E. coli ST131 under aerobic and anaerobic growth conditions in vitro. We showed that the addition of phage was able to break the frequency-dependent advantage of a numerically dominant ST131 isolate. Moreover, the addition of competing E. coli Nissle could improve the ability of phage to suppress ST131 by two orders of magnitude. Low-cost phage resistance evolved readily in these experiments and was not inhibited by the presence of a probiotic competitor. Nevertheless, combinations of phage and probiotic produced stable long-term suppression of ST131 over multiple transfers and under both aerobic and anaerobic growth conditions. Combinations of phage and probiotic therefore have real potential for accelerating the removal of drug-resistant commensal targets.

Perceived discrimination and medication adherence in black hypertensive patients: the role of stress and depression.

OBJECTIVE: To examine the relationship between perceived discrimination and medication adherence among black people with hypertension and the role of stress and depressive symptoms in this relationship. Perceived racial discrimination has been associated with poor health outcomes in blacks; its relationship to medication adherence among hypertensive patients remains untested. METHODS: We measured perceived racial discrimination at baseline, stress and depressive symptoms at 6 months, and medication adherence at 12 months among patients enrolled in a 30-site cluster-randomized controlled trial testing a patient and physician-targeted intervention to improve blood pressure. A mediational method with bootstrapping (stratified by site) confidence intervals was used to estimate the indirect association between perceived discrimination and medication adherence through stress and depression. RESULTS: Of 1056 patients from 30 sites enrolled in the trial, 463 had complete data on all four measures at 6 and 12 months and were included in the analyses. Adjusting for clustering, perceived discrimination was associated with poor medication adherence (B = 0.138, p = .011) at 12 months, and with stress (B = 2.24, p = .001) and depression (B = 1.47, p = .001) at 6 months. When stress and depression were included in the model, there was a 65% reduction in the total association of perceived discrimination with medication adherence, and the relationship was no longer significant (B = 0.049, p = .35). CONCLUSIONS: Perceived discrimination is associated with poor medication adherence among hypertensive blacks, and stress and depressive symptoms may account for this relationship. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00233220.

The relationship between racial identity status attitudes, racism-related coping, and mental health among Black Americans.

To date, few studies have examined how different strategies for coping with racism affect the mental health of Black Americans, and none have explored how racial identity status attitudes and racism-related coping affect mental health. This study sought to examine the relationship between racial identity status attitudes, the specific strategies used by Black Americans to cope with racism, and mental health outcomes. Participants were 233 Black adults, and cluster analysis identified four cluster groups that differed significantly with respect to the patterns of racial identity attitudes and racism-related coping strategies employed. Although the groups did not differ significantly in well-being, the group with predominantly high Internalization status attitudes and that used primarily Empowered Resistance racism-related coping strategies had the least psychological symptoms. Implications for mental health and research are discussed.

HIV testing in emergency departments in the United States: a national survey.

OBJECTIVES: In 2006, the Centers for Disease Control and Prevention (CDC) published recommendations for HIV testing in health care settings, calling for nontargeted opt-out rapid HIV screening in most settings, including emergency departments (EDs). Although a number of ED-based testing strategies exist, it is unclear to what extent they are used. The objective of this study is to survey academic and community EDs throughout the United States to determine ED-based HIV testing practices. METHODS: This was a cross-sectional survey study of all academic EDs and a weighted random sample of all community-based EDs in the United States. A standardized survey instrument was developed and administered with an Internet-based survey platform, followed by direct contact and mail. The survey included domains related to perceived HIV testing barriers, whether HIV testing was performed and methods used, and familiarity with the CDC recommendations and whether they had been adopted. RESULTS: Of the 131 total academic sites and the 435 community sites, 99 (76%) and 150 (35%) completed the survey, respectively. A larger proportion of academic sites believed HIV testing was needed (P=.02) and a larger proportion actually provided HIV testing (65% versus 50%; P=.04). Among the academic and community EDs that provided testing, 74% and 62% performed diagnostic testing, 26% and 22% performed targeted screening, and 16% and 6% performed nontargeted screening, respectively. A larger proportion of academic EDs reported receiving external funding to support testing (23% versus 4%; P=.001), whereas a large proportion of community sites considered costs a significant barrier to testing (P=.03). A larger proportion of academic EDs reported being familiar with the 2006 CDC recommendations (64% versus 40%; P<.001), although only 26% and 37% reported having implemented any part of them, respectively. CONCLUSION: Academic EDs only make up approximately 3% of all EDs in the United States. Significant differences exist between academic and community EDs as they relate to performing HIV testing. Increased efforts should be made to improve the ability of community EDs to provide this service.

Application of the National Institute for Health and Care Excellence Evidence Standards Framework for Digital Health Technologies in Assessing Mobile-Delivered Technologies for the Self-Management of Type 2 Diabetes Mellitus: Scoping Review.

BACKGROUND: There is a growing role of digital health technologies (DHTs) in the management of chronic health conditions, specifically type 2 diabetes. It is increasingly important that health technologies meet the evidence standards for health care settings. In 2019, the National Institute for Health and Care Excellence (NICE) published the NICE Evidence Standards Framework for DHTs. This provides guidance for evaluating the effectiveness and economic value of DHTs in health care settings in the United Kingdom. OBJECTIVE: The aim of this study is to assess whether scientific articles on DHTs for the self-management of type 2 diabetes mellitus report the evidence suggested for implementation in clinical practice, as described in the NICE Evidence Standards Framework for DHTs. METHODS: We performed a scoping review of published articles and searched 5 databases to identify systematic reviews and primary studies of mobile device-delivered DHTs that provide self-management support for adults with type 2 diabetes mellitus. The evidence reported within articles was assessed against standards described in the NICE framework. RESULTS: The database search yielded 715 systematic reviews, of which, 45 were relevant and together included 59 eligible primary studies. Within these, there were 39 unique technologies. Using the NICE framework, 13 technologies met best practice standards, 3 met minimum standards only, and 23 technologies did not meet minimum standards. CONCLUSIONS: On the assessment of peer-reviewed publications, over half of the identified DHTs did not appear to meet the minimum evidence standards recommended by the NICE framework. The most common reasons for studies of DHTs not meeting these evidence standards included the absence of a comparator group, no previous justification of sample size, no measurable improvement in condition-related outcomes, and a lack of statistical data analysis. This report provides information that will enable researchers and digital health developers to address these limitations when designing, delivering, and reporting digital health technology research in the future.

Routine opt-out rapid HIV screening and detection of HIV infection in emergency department patients.

CONTEXT: The Centers for Disease Control and Prevention (CDC) recommends routine (nontargeted) opt-out HIV screening in health care settings, including emergency departments (EDs), where the prevalence of undiagnosed infection is 0.1% or greater. The utility of this approach in EDs remains unknown. OBJECTIVE: To determine whether nontargeted opt-out rapid HIV screening in the ED was associated with identification of more patients with newly diagnosed HIV infection than physician-directed diagnostic rapid HIV testing. DESIGN, SETTING, AND PATIENTS: Quasi-experimental equivalent time-samples design in an urban public safety-net hospital with an approximate annual ED census of 55,000 patient visits. Patients were 16 years or older and capable of providing consent for rapid HIV testing. INTERVENTIONS: Nontargeted opt-out rapid HIV screening and physician-directed diagnostic rapid HIV testing alternated in sequential 4-month time intervals between April 15, 2007, and April 15, 2009. MAIN OUTCOME MEASURES: Number of patients with newly identified HIV infection and the association between nontargeted opt-out rapid HIV screening and identification of HIV infection. RESULTS: In the opt-out phase, of 28,043 eligible ED patients, 6933 patients (25%) completed HIV testing (6702 patients were screened; 231 patients were diagnostically tested). Ten of 6702 patients (0.15%; 95% CI, 0.07%-0.27%) who did not decline HIV screening in the opt-out phase had new HIV diagnoses, and 5 of 231 patients (2.2%; 95% CI, 0.7%-5.0%) who were diagnostically tested during the opt-out phase had new HIV diagnoses. In the diagnostic phase, of 29,925 eligible patients, 243 (0.8%) completed HIV testing. Of these, 4 patients (1.6%; 95% CI, 0.5%-4.2%) had new diagnoses. The prevalence of new HIV diagnoses in the opt-out phase (including those diagnostically tested) and in the diagnostic phase was 15 in 28,043 (0.05%; 95% CI, 0.03%-0.09%) and 4 in 29,925 (0.01%; 95% CI, 0.004%-0.03%), respectively. Nontargeted opt-out HIV screening was independently associated with new HIV diagnoses (risk ratio, 3.6; 95% CI, 1.2-10.8) when adjusting for patient demographics, insurance status, and whether diagnostic testing was performed in the opt-out phase. The median CD4 cell count for those with new HIV diagnoses in the opt-out phase (including those diagnostically tested) and in the diagnostic phase was 69/microL (IQR, 17-430) and 13/microL (IQR, 11-15) , respectively (P = .02). CONCLUSION: Nontargeted opt-out rapid HIV screening in the ED, vs diagnostic testing, was associated with identification of a modestly increased number of patients with new HIV diagnoses, most of whom were identified late in the course of disease.

A single administration of 'microbial' D-alanine to healthy volunteers augments reaction to negative emotions: A comparison with D-serine.

BACKGROUND: Activation of the glutamate N-methyl-D-aspartate receptor with its co-agonist D-serine has been shown to improve subjective mood in healthy volunteers. D-alanine is another potent N-methyl-D-aspartate receptor co-agonist which arises from the natural breakdown of host gut microbes, and is predominantly sequestered in the pituitary. This may suggest that D-alanine influences the neuroendocrine stress response which may then impact on emotion. AIMS: The current study explored the effects of D-serine and D-alanine on emotional processing, cognition and the levels of the stress hormone cortisol in healthy volunteers. METHODS: In a double-blind, placebo-controlled randomised study, participants (n=63) received a single oral dose of either D-serine, D-alanine (60 mg/kg) or placebo and then performed the Emotional Test Battery and N-back task (two hours post-administration) and provided saliva samples at fixed intervals. RESULTS: Subjects administered with D-alanine were faster at identifying facial expressions of fear, surprise and anger, and at categorising negative self-referential words. Participants on D-alanine also showed a trend to recall more words than placebo in a memory task. D-serine did not have any meaningful effects in any of the tasks. Neither amino acid had a significant effect on salivary cortisol or working memory. CONCLUSION: This study is the first to suggest that D-alanine can modulate emotional cognitive processing after a single dose. The lack of findings for D-serine nevertheless contrasts a previous study, emphasising a need for further investigation to clarify discrepancies. A better understanding of the physiological actions of D-amino acids would be beneficial in evaluating their therapeutic potential.

A guide to the forensic assessment of race-based traumatic stress reactions.

A large body of empirical evidence has accumulated over the past decade documenting the psychiatric and emotional consequences of racism and racial discrimination. Still, little has been written in the legal or psychiatric assessment literature that is focused on describing the direct and specific effects of racism and offering guidance to forensic psychiatrists in understanding, assessing, and treating the race-based stress reactions that may occur as a result of exposure to racial discrimination or harassment. This article uses the analysis of a case study to illustrate and extend previous work on the evaluation of racial discrimination by providing a guide to the forensic assessment of the psychiatric and emotional impact of race-based encounters--a guide that can be used both in preparing expert reports and in developing treatment approaches.

Negative frequency dependent selection on plasmid carriage and low fitness costs maintain extended spectrum ß-lactamases in Escherichia coli.

Plasmids may maintain antibiotic resistance genes in bacterial populations through conjugation, in the absence of direct selection pressure. However, the costs and benefits of conjugation for plasmid and bacterial fitness are not well understood. Using invasion and competition experiments with plasmid mutants we explicitly tested how conjugation contributes to the maintenance of a plasmid bearing a single extended-spectrum ß-lactamase (ESBL) gene (blaCTX-M-14). Surprisingly, conjugation had little impact on overall frequencies, although it imposed a substantial fitness cost. Instead, stability resulted from the plasmid conferring fitness benefits when rare. Frequency dependent fitness did not require a functional blaCTX-M-14 gene, and was independent of culture media. Fitness benefits when rare are associated with the core plasmid backbone but are able to drive up frequencies of antibiotic resistance because fitness burden of the blaCTX-M-14 gene is very low. Negative frequency dependent fitness can contribute to maintaining a stable frequency of resistance genes in the absence of selection pressure from antimicrobials. In addition, persistent, low cost resistance has broad implications for antimicrobial stewardship.

Cluster Randomized Clinical Trial of FAITH (Faith-Based Approaches in the Treatment of Hypertension) in Blacks.

BACKGROUND: Therapeutic lifestyle change (TLC) is a recommended treatment for patients with hypertension, but its effectiveness in community-based settings remains untested, particularly in black churches-an influential institution for health promotion in black communities. METHODS AND RESULTS: The FAITH study (Faith-Based Approaches in the Treatment of Hypertension) evaluated the comparative effectiveness of a TLC intervention plus motivational interviewing (MINT) sessions versus health education (HE) alone, on blood pressure (BP) reduction among blacks with uncontrolled hypertension. Data were collected on 373 participants meeting eligibility criteria (self-identification as black, age ≥18 years, self-reported diagnosis of hypertension, and uncontrolled BP [BP ≥140/90 or ≥130/80 mm Hg with diabetes mellitus or chronic kidney disease]) from 32 New York City churches. The MINT-TLC intervention plus motivational interviewing treatment comprised 11 weekly group sessions on TLC plus 3 MINT sessions delivered monthly by lay health advisors. The HE control group received 1 TLC session plus 10 sessions on health topics delivered by local experts. The outcomes were BP reduction at 6 months (primary) and BP control and BP reduction at 9 months (secondary). The sample mean age was 63 years; 76% women, with mean BP of 153/87 mm Hg. Using linear mixed-effects regression models, the MINT-TLC intervention plus motivational interviewing group had a significantly greater systolic BP reduction of 5.79 mm Hg compared with the HE group at 6 months ( P=0.029). The treatment effect on systolic BP persisted at 9 months but had reduced significance (5.21 mm Hg; P=0.068). The between-group differences in diastolic BP reduction (0.41 mm Hg) and mean arterial pressure (2.24 mm Hg) at 6 months were not significant. Although the MINT-TLC intervention plus motivational interviewing group had greater BP control than the HE group at 9 months, the difference was not statistically significant (57.0% versus 48.8%; odds ratio, 1.43; 95% CI, 0.90-2.28). CONCLUSIONS: A community-based lifestyle intervention delivered in churches led to significantly greater reduction in systolic BP in hypertensive blacks compared with HE alone. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01065831.

Youth preferences for prenatal and parenting teen services.

STUDY OBJECTIVE: Parenting teens served by a teen-tot program and teens from a prenatal clinic participated in focus groups to explore their perceptions of medical care, social services, and psycho-educational parenting groups. DESIGN: The teens met in four focus groups, two prenatal and two postnatal. SETTING: Teens receiving care from a teen-tot program and associated prenatal clinic in a large metropolitan area in New England. PARTICIPANTS: A total of 16 pregnant (n=6) and parenting (n=10) teens ages ranging from 16 to 21 years (13 African American, 2 Latina, and 1 Haitian) participated in the four focus groups. METHODS: A qualitative focus group study was performed. Structured, culturally sensitive questions guided the discussion based on a hypothetical case scenario. Themes were identified through grounded theory with three coders and differences were reconciled. RESULTS: The groups revealed prenatal and postnatal mothers valued medical and social services provided in a teen-focused hospital clinic. Prenatal teens looked to providers for health education services and group support. Parenting teens requested consistent doctors for their children and social supports for themselves. Both groups desired assistance with social services, education, housing, and finances as well as educational services for fathers. CONCLUSIONS: Teen parents' perceptions and suggestions for services are critical to program development that meets the needs of participants.

Perceived racial discrimination and adoption of health behaviors in hypertensive Black Americans: the CAATCH trial.

BACKGROUND: Few studies examine psychosocial factors influencing the adoption of healthy behaviors among hypertensive patients. The effect of discrimination on health behaviors remains untested. PURPOSE: To examine the influence of discrimination on adoption of healthy behaviors among low-income Black hypertensive patients. METHODS: Black patients (N = 930) in community-based primary care practices enrolled in the CAATCH trial. Mixed effects regressions examined associations between perceived discrimination and change in medication adherence, diet, and physical activity from baseline to 12 months, controlling for intervention, gender, age, income, and education. RESULTS: Patients were low-income, high-school-educated, with a mean age of 57 years. Greater discrimination was associated with worse diet and lower medication adherence at baseline. Discrimination was associated with greater improvement in healthy eating behaviors over the course of the 12-month trial. CONCLUSIONS: Prior exposure to discrimination was associated with unhealthy behaviors at baseline, but did not negatively influence the adoption of health behaviors over time.