Combining Signal Peptidase and Lipoprotein Processing Inhibitors Overcomes Ayr Resistance in Staphylococcus aureus.

Antibiotic resistance in bacterial pathogens is an ongoing public health concern. The arylomycins are a class of natural product antibiotics that target the type I signal peptidase, which carries out the terminal step in protein secretion. Here, we used transposon sequencing (Tn-Seq) to profile the effects of the optimized arylomycin derivative G0775 in Staphylococcus aureus. Our transposon libraries include both upregulation and inactivation mutants, allowing us to identify resistance mechanisms and targets for synergism. We identified several cell envelope pathways that, when inactivated, sensitize S. aureus to the arylomycin G0775. These pathways include the lipoprotein processing pathway, and we have shown that inhibitors of this pathway synergize with G0775 even though lipoprotein processing is nonessential in S. aureus. Moreover, we found that blocking this pathway completely reverses Ayr resistance, which is a major resistance mechanism to arylomycins, including G0775. Our Tn-Seq data also showed that upregulation of mprF and several other genes is protective against G0775. Because a subset of these genes was previously found in a Tn-Seq profile of the clinically important antibiotic daptomycin, we tested a set of daptomycin-nonsusceptible clinical isolates with gain-of-function mutations in mprF for susceptibility to arylomycin G0775. Despite structural and mechanistic differences between these antibiotics, we observed similar decreases in susceptibility. Taken together, our results highlight how Tn-Seq profiles that include both gene inactivation and upregulation can identify targets, antibiotic resistance mechanisms, and strategies to overcome resistance.

Staphylococcus aureus cell growth and division are regulated by an amidase that trims peptides from uncrosslinked peptidoglycan.

Bacteria are protected by a polymer of peptidoglycan that serves as an exoskeleton1. In Staphylococcus aureus, the peptidoglycan assembly enzymes relocate during the cell cycle from the periphery, where they are active during growth, to the division site where they build the partition between daughter cells2-4. But how peptidoglycan synthesis is regulated throughout the cell cycle is poorly understood5,6. Here, we used a transposon screen to identify a membrane protein complex that spatially regulates S. aureus peptidoglycan synthesis. This complex consists of an amidase that removes stem peptides from uncrosslinked peptidoglycan and a partner protein that controls its activity. Amidases typically hydrolyse crosslinked peptidoglycan between daughter cells so that they can separate7. However, this amidase controls cell growth. In its absence, peptidoglycan synthesis becomes spatially dysregulated, which causes cells to grow so large that cell division is defective. We show that the cell growth and division defects due to loss of this amidase can be mitigated by attenuating the polymerase activity of the major S. aureus peptidoglycan synthase. Our findings lead to a model wherein the amidase complex regulates the density of peptidoglycan assembly sites to control peptidoglycan synthase activity at a given subcellular location. Removal of stem peptides from peptidoglycan at the cell periphery promotes peptidoglycan synthase relocation to midcell during cell division. This mechanism ensures that cell expansion is properly coordinated with cell division.

Multi-strain Tn-Seq reveals common daptomycin resistance determinants in Staphylococcus aureus.

Antibiotic-resistant Staphylococcus aureus remains a leading cause of antibiotic resistance-associated mortality in the United States. Given the reality of multi-drug resistant infections, it is imperative that we establish and maintain a pipeline of new compounds to replace or supplement our current antibiotics. A first step towards this goal is to prioritize targets by identifying the genes most consistently required for survival across the S. aureus phylogeny. Here we report the first direct comparison of multiple strains of S. aureus via transposon sequencing. We show that mutant fitness varies by strain in key pathways, underscoring the importance of using more than one strain to differentiate between core and strain-dependent essential genes. We treated the libraries with daptomycin to assess whether the strain-dependent differences impact pathways important for survival. Despite baseline differences in gene importance, several pathways, including the lipoteichoic acid pathway, consistently promote survival under daptomycin exposure, suggesting core vulnerabilities that can be exploited to resensitize daptomycin-nonsusceptible isolates. We also demonstrate the merit of using transposons with outward-facing promoters capable of overexpressing nearby genes for identifying clinically-relevant gain-of-function resistance mechanisms. Together, the daptomycin vulnerabilities and resistance mechanisms support a mode of action with wide-ranging effects on the cell envelope and cell division. This work adds to a growing body of literature demonstrating the nuanced insights gained by comparing Tn-Seq results across multiple bacterial strains.

Factors influencing performance by contracted non-state providers implementing a basic package of health services in Afghanistan.

BACKGROUND: In 2002 Afghanistan's Ministry of Public Health (MoPH) and its development partners initiated a new paradigm for the health sector by electing to Contract-Out (CO) the Basic Package of Health Services (BPHS) to non-state providers (NSPs). This model is generally regarded as successful, but literature is scarce that examines the motivations underlying implementation and factors influencing program success. This paper uses relevant theories and qualitative data to describe how and why contracting out delivery of primary health care services to NSPs has been effective. The main aim of this study was to assess the contextual, institutional, and contractual factors that influenced the performance of NSPs delivering the BPHS in Afghanistan. METHODS: The qualitative study design involved individual in-depth interviews and focus group discussions conducted in six provinces of Afghanistan, as well as a desk review. The framework for assessing key factors of the contracting mechanism proposed by Liu et al. was utilized in the design, data collection and data analysis. RESULTS: While some contextual factors facilitated the CO (e.g. MoPH leadership, NSP innovation and community participation), harsh geography, political interference and insecurity in some provinces had negative effects. Contractual factors, such as effective input and output management, guided health service delivery. Institutional factors were important; management capacity of contracted NSPs affects their ability to deliver outcomes. Effective human resources and pharmaceutical management were notable elements that contributed to the successful delivery of the BPHS. The contextual, contractual and institutional factors interacted with each other. CONCLUSION: Three sets of factors influenced the implementation of the BPHS: contextual, contractual and institutional. The MoPH should consider all of these factors when contracting out the BPHS and other functions to NSPs. Other fragile states and countries emerging from a period of conflict could learn from Afghanistan's example in contracting out primary health care services, keeping in mind that generic or universal contracting policies might not work in all geographical areas within a country or between countries.

Genome-wide mutant profiling predicts the mechanism of a Lipid II binding antibiotic.

Identifying targets of antibacterial compounds remains a challenging step in the development of antibiotics. We have developed a two-pronged functional genomics approach to predict mechanism of action that uses mutant fitness data from antibiotic-treated transposon libraries containing both upregulation and inactivation mutants. We treated a Staphylococcus aureus transposon library containing 690,000 unique insertions with 32 antibiotics. Upregulation signatures identified from directional biases in insertions revealed known molecular targets and resistance mechanisms for the majority of these. Because single-gene upregulation does not always confer resistance, we used a complementary machine-learning approach to predict the mechanism from inactivation mutant fitness profiles. This approach suggested the cell wall precursor Lipid II as the molecular target of the lysocins, a mechanism we have confirmed. We conclude that docking to membrane-anchored Lipid II precedes the selective bacteriolysis that distinguishes these lytic natural products, showing the utility of our approach for nominating the antibiotic mechanism of action.

Human CHD1 is required for early DNA-damage signaling and is uniquely regulated by its N terminus.

CHD1 is a conserved chromatin remodeling enzyme required for development and linked to prostate cancer in adults, yet its role in human cells is poorly understood. Here, we show that targeted disruption of the CHD1 gene in human cells leads to a defect in early double-strand break (DSB) repair via homologous recombination (HR), resulting in hypersensitivity to ionizing radiation as well as PARP and PTEN inhibition. CHD1 knockout cells show reduced H2AX phosphorylation (γH2AX) and foci formation as well as impairments in CtIP recruitment to the damaged sites. Chromatin immunoprecipitation following a single DSB shows that the reduced levels of γH2AX accumulation at DSBs in CHD1-KO cells are due to both a global reduction in H2AX incorporation and poor retention of H2AX at the DSBs. We also identified a unique N-terminal region of CHD1 that inhibits the DNA binding, ATPase, and chromatin assembly and remodeling activities of CHD1. CHD1 lacking the N terminus was more active in rescuing the defects in γH2AX formation and CtIP recruitment in CHD1-KO cells than full-length CHD1, suggesting the N terminus is a negative regulator in cells. Our data point to a role for CHD1 in the DSB repair process and identify a novel regulatory region of the protein.

The Use of Family Rituals in Eating Behaviors in Hispanic Mothers.

Food rituals often abruptly change when Hispanic families migrate to the United States. This report describes changes in rituals of food procurement, preparation, and presentation (food-PPP) in Hispanic women following migration to the United States. Focus groups and face-to-face interviews were conducted with 13 low-income, overweight/obese Hispanic women 27 to 40 years of age. Content analysis was used to analyze cultural and contextual sources for food-PPP. Changes in rituals and traditions in food-PPP occurred, including materials and ingredients for traditional meals. Food rituals may play a role in healthful eating and could, therefore, serve as leverage points for interventions designed to promote healthy eating behaviors.

Reproductive Investment and Health Costs in Roma Women.

In this paper, we examine whether variation in reproductive investment affects the health of Roma women using a dataset collected through original anthropological fieldwork among Roma women in Serbia. Data were collected in 2014-2016 in several Roma semi-urban settlements in central Serbia. The sample consisted of 468 Roma women, averaging 44 years of age. We collected demographic data (age, school levels, socioeconomic status), risk behaviors (smoking and alcohol consumption), marital status, and reproductive history variables (the timing of reproduction, the intensity of reproduction, reproductive effort and investment after birth), in addition to self-reported health, height, and weight. Data analyses showed that somatic, short-term costs of reproduction were revealed in this population, while evolutionary, long-term costs were unobservable-contrariwise, Roma women in poor health contributed more to the gene pool of the next generation than their healthy counterparts. Our findings appear to be consistent with simple trade-off models that suggest inverse relationships between reproductive effort and health. Thus, personal sacrifice-poor health as an outcome-seems crucial for greater reproductive success.

The health of Romanian Gypsy women in Serbia.

Indigenous people are over-represented among the world's disadvantaged; their health is influenced by lack of access to critical resources including health care and by their cultural practices. We report on the health and the health practices of one group of indigenous women, the Roma/Gypsies of northern Serbia who live in poverty, reside in sub-standardized housing in segregated communities, and are poorly educated and stigmatized. We describe the environment in which they live, their health history, and the cultural practices that influence their health and health behaviors, including their sporadic utilization of health services that are provided by the state. We also present evidence supporting that, in the face of adversity, cultural practices, including those related to kinship and social support, can have significant benefits in shaping health status.

Spirituality, emotional distress, and post-traumatic growth in breast cancer survivors and their partners: an actor-partner interdependence modeling approach.

BACKGROUND: The association between spirituality and emotional health has been well documented in healthy individuals. A small literature has shown that spirituality plays a role in well-being for some breast cancer (BC) survivors; however, this link is virtually unexplored in partners/spouses of survivors. The current study aimed to assess the relationship between spirituality, emotional distress, and post-traumatic growth for BC survivors and their partners using a dyadic analyses approach. METHODS: A total of 498 couples who were 3-8 years post-BC diagnosis were recruited from the Eastern Oncology Group database. RESULTS: For BC survivors and their partners, greater levels of spirituality were associated with increases in their own post-traumatic growth. There was no relation between BC and partner spirituality and their own emotional distress, but partner's spirituality was associated with reduced occurrence of intrusive thoughts in the BC survivor. In contrast, BC survivors' spirituality was found to be wholly unrelated to partner's mental health and adjustment. CONCLUSIONS: Following diagnosis and treatment, spirituality appears to associate with positive growth in BC survivors and their partners. However, BC survivor and partner spirituality seem to be ineffective at impacting the other's post-traumatic growth or emotional distress, with the exception of intrusive thoughts. Dyadic analysis takes into account the reciprocal influence of close relationships on health and is an important and under-utilized methodology in behavioral oncology research and clinical practice. Copyright © 2016 John Wiley & Sons, Ltd.

Hair As a Barrier to Physical Activity among African American Women: A Qualitative Exploration.

BACKGROUND: African American (AA) women face unique sociocultural barriers to physical activity (PA) engagement. Such barriers may contribute to their low PA levels and high cardiometabolic disease burden. One particular barrier reported among AA women in recent research is that being physically active can have an undesirable effect on the hairstyles and hair maintenance of many AA women. However, the underlying mechanisms contributing to this barrier have not been fully elucidated. The purpose of this study is to explore hairstyle maintenance as a barrier to PA among AA women and to identify effective strategies to overcome this barrier in the design of a culturally relevant PA intervention. METHODS: A qualitative study design was used. Data were collected from the focus groups comprising 23 sedentary and obese AA women (median age = 38.1 years, median body mass index = 39.8 kg/m2). Content analysis was used to analyze these focus group data. RESULTS: Three key themes emerged from the qualitative narratives of participants: (1) impact of perspiration on hair and hairstyle maintenance, (2) image and social comparisons, and (3) solutions to overcome hair-related barriers to PA. For impact of perspiration and hairstyle maintenance, participants described how perspiring while engaging in PA negatively impacts many of their hairstyles. Participants further discussed how time and monetary burdens associated with PA-related hairstyle maintenance further contributed to this issue. Findings for the theme of image and social comparison focused on how an AA woman's hairstyle is an important part of the image and the social comparisons made by non-AAs regarding the hairstyles and maintenance practices of AA women. For solutions to hairstyle maintenance barriers, participant described a variety of potential styling techniques that may help alleviate PA-related maintenance concerns, including braids, locks, and natural hairstyles. However, no styling technique was uniformly endorsed by all study participants. CONCLUSION: Findings highlight the significance of hair in the AA community and provide further insight on appropriate intervention design strategies to overcome this sociocultural barrier to PA. Future research is needed to corroborate and further expand on our findings.

Sexting among singles in the USA: prevalence of sending, receiving, and sharing sexual messages and images.

Background: The transmission of sexual images and messages via mobile phone or other electronic media (sexting) has been associated with a variety of mostly negative social and behavioural consequences. Research on sexting has focussed on youth, with limited data across demographics and with little known about the sharing of private sexual images and messages with third parties. Methods: The present study examines sexting attitudes and behaviours, including sending, receiving, and sharing of sexual messages and images, across gender, age, and sexual orientation. A total of 5805 single adults were included in the study (2830 women; 2975 men), ranging in age from 21 to 75+ years. Results: Overall, 21% of participants reported sending and 28% reported receiving sexually explicit text messages; both sending and receiving 'sexts' was most common among younger respondents. Although 73.2% of participants reported discomfort with unauthorised sharing of sexts beyond the intended recipient, of those who had received sext images, 22.9% reported sharing them with others (on average with 3.17 friends). Participants also reported concern about the potential consequences of sexting on their social lives, careers, and psychosocial wellbeing. Conclusion: Views on the impact of sexting on reputation suggest a contemporary struggle to reconcile digital eroticism with real-world consequences. These findings suggest a need for future research into negotiations of sexting motivations, risks, and rewards.

Utility of Acculturation in Physical Activity Research in Latina Adults: An Integrative Review of Literature.

Latina adults in the United States have a disproportionately higher prevalence of chronic diseases related to low physical activity levels than non-Hispanic women. Literature indicates that acculturation may be a contributing factor to being physically active, but the extent of this association remains unclear. An integrative review of literature was conducted on studies that examined acculturation as it relates to physical activity in Latinas in the United States. Our review of 33 studies revealed inconsistent measurement and conceptualization of acculturation and physical activity across studies. Findings from this review reinforce the importance and continued use of acculturation by behavioral researchers; however, acculturation, as conceptualized in the studies reviewed, may not have had an influence on health as much as traditions, life patterns, and resources of Latinas.

The National Cancer Institute's Community Networks Program Initiative to Reduce Cancer Health Disparities: Outcomes and Lessons Learned.

BACKGROUND: We describe reach, partnerships, products, benefits, and lessons learned of the 25 Community Network Programs (CNPs) that applied community-based participatory research (CBPR) to reduce cancer health disparities. METHODS: Quantitative and qualitative data were abstracted from CNP final reports. Qualitative data were grouped by theme. RESULTS: Together, the 25 CNPs worked with more than 2,000 academic, clinical, community, government, faith-based, and other partners. They completed 211 needs assessments, leveraged funds for 328 research and service projects, trained 719 new investigators, educated almost 55,000 community members, and published 991 articles. Qualitative data illustrated how use of CBPR improved research methods and participation; improved knowledge, interventions, and outcomes; and built community capacity. Lessons learned related to the need for time to nurture partnerships and the need to attend to community demand for sustained improvements in cancer services. IMPLICATIONS: Findings demonstrate the value of government-supported, community-academic, CBPR partnerships in cancer prevention and control research.

Religion, kinship and health behaviors of African American women.

A positive relationship exists between functional health and religion. We present an empirical definition of religion and describe the key elements of religious behavior, building a model that can be used to explore the presumed relationship between religion and health. Semi-structured interactive interviews were conducted with 22 participants over a 6-month period. Head Start programs and churches located in the inner city of a large metropolitan area. Twenty-two African American women were aged from 21 to 45. We focus on social relationships and propose that prophet-created religions mimic kinship relationships and encourage kinship-like cooperation between members.

Addressing the demand for cultural relevance in intervention design.

This article describes the development of a model to promote physical activity in Hispanic women that embeds a life course perspective and culture to enhance comparative effectiveness in intervention design. When working with diverse cultural groups, researchers often struggle with intervention designs and strategies to enhance cultural relevance; they do so based on the assumption that this will enhance efficacy and make interventions more sustainable. In this article, the authors discuss how the model was used in two interventions designed for younger and older Hispanic women. These interventions were guided by a life course perspective, incorporated social support, and included salient elements from the women's culture. Three considerations underpinned the development of the model: (a) infusing concepts and values of a culture and tradition into the interventions, (b) viewing participants through a life course perspective to assess how an intervention can build on developmental transitions, and (c) determining how social support operates within two groups that, although sharing history and thus some cultural practices, diverge widely in those practices. The authors propose that by incorporating elements of this model into their interventions, researchers can increase program efficacy and effectiveness.

Inclusion of minorities and women in cancer clinical trials, a decade later: Have we improved?

BACKGROUND: Inclusion of diverse groups of participants in cancer clinical trials is an important methodological and clinical issue. The quality of the science and generalizability of results depends on the inclusion of study participants who represent all populations among whom these treatment and prevention approaches will be used. METHODS: We conducted a systematic review using OVID as the primary source of reports included. Based on 304 peer-reviewed publications, diversity in the inclusion and reporting of study participants during a decade of cancer treatment and prevention trials (2001-2010) is summarized. Recommendations are made for improvements in the science and reporting of cancer clinical trials. RESULTS: Of the 277 treatment trials and 27 prevention trials included in this report, more than 80% of participants were white and 59.8% were male. In the recent decade, race and sex are rarely used as selection criteria unless the trial is focused on a sex-specific cancer. CONCLUSIONS: Women and racial/ethnic minorities remain severely underrepresented in cancer clinical trials, thus limiting the generalizability of cancer clinical research.

Enhancing life after cancer in diverse communities.

BACKGROUND: Although large numbers of cancer survivors exist in every community, including minority communities, there is a significant gap in knowledge about best practices for these patients. METHODS: The Community Networks Program, funded by the National Cancer Institute Center to Reduce Cancer Health Disparities, has developed and tested unique services for these communities. These programs have used community-based participatory research techniques under a framework of diffusion of innovation and communications theory. RESULTS: This article describes some specifically tailored interventions that may be useful to a wide range of providers working with the underserved. CONCLUSIONS: Enhancing life after cancer can be achieved in underserved communities by supplementing local resources.

Promotoras' roles in integrative validity and treatment fidelity efforts in randomized controlled trials.

Promotoras from the communities in which interventions are implemented can be effective contributors to validity and fidelity efforts. This article describes a 48-week randomized controlled trial Madres para la Salud (Mothers for Health) and illustrates the use of promotoras as collaborative members of the research team to contribute to attaining integrative validity and treatment fidelity. Madres para la Salud implements a culturally tailored physical activity program to effect changes in body fat, systemic and fat tissue inflammation, and depression symptoms. The significance of Madres para la Salud treatment validity and fidelity processes includes cultural tailoring of a social support intervention, and a promotora model to incorporate initial and ongoing fidelity monitoring.