Effect of long-term starvation on the survival, recovery, and carbon utilization profiles of a bovine Escherichia coli O157:H7 isolate from New Zealand

The ability to maintain a dual lifestyle of colonizing the ruminant gut and surviving in nonhost environments once shed is key to the success of Escherichia coli O157:H7 as a zoonotic pathogen. Both physical and biological conditions encountered by the bacteria are likely to change during the transition between host and nonhost environments. In this study, carbon starvation at suboptimal temperatures in nonhost environments was simulated by starving a New Zealand bovine E. coli O157:H7 isolate in phosphate-buffered saline at 4 and 15°C for 84 days. Recovery of starved cells on media with different nutrient availabilities was monitored under aerobic and anaerobic conditions. We found that the New Zealand bovine E. coli O157:H7 isolate was able to maintain membrane integrity and viability over 84 days and that the level of recovery depended on the nutrient level of the recovery medium as well as the starvation temperature. In addition, a significant difference in carbon utilization was observed between starved and nonstarved cells

Effect of long-term starvation on the survival, recovery, and carbon utilization profiles of a bovine Escherichia coli O157:H7 isolate from New Zealand

The ability to maintain a dual lifestyle of colonizing the ruminant gut and surviving in nonhost environments once shed is key to the success of Escherichia coli O157:H7 as a zoonotic pathogen. Both physical and biological conditions encountered by the bacteria are likely to change during the transition between host and nonhost environments. In this study, carbon starvation at suboptimal temperatures in nonhost environments was simulated by starving a New Zealand bovine E. coli O157:H7 isolate in phosphate-buffered saline at 4 and 15°C for 84 days. Recovery of starved cells on media with different nutrient availabilities was monitored under aerobic and anaerobic conditions. We found that the New Zealand bovine E. coli O157:H7 isolate was able to maintain membrane integrity and viability over 84 days and that the level of recovery depended on the nutrient level of the recovery medium as well as the starvation temperature. In addition, a significant difference in carbon utilization was observed between starved and nonstarved cells

Study of the B-site ion behaviour in the multiferroic perovskite bismuth iron chromium oxide

A simple, near-ambient pressure solid-state method was developed to nominally synthesize BiFe0.5Cr0.5O3. The procedure allowed the gram-scale production of multiferroic samples with appreciable purity and large amounts of Cr incorporation that were suitable for systematic structural investigation by neutron, X-ray, and electron diffraction in tandem with physical characterization of magnetic and ferroelectric properties. The rhombohedrally distorted perovskite phase was assigned to the space group R3c by way of X-ray and neutron powder diffraction analysis. Through a combination of magnetometry and muon spin relaxation, it is evident that there is magnetic ordering in the BFCO phase consistent with G-type antiferromagnetism and a TN 400 K. There is no clear evidence for chemical ordering of Fe and Cr in the B-site of the perovskite structure and this result is rationalized by density functional theory and bond valence simulations that show a lowered energy associated with a B-site disordered structure. We believe that our contribution of a new, low-complexity method for the synthesis of BFO type samples, and dialogue about realising certain types of ordering in oxide perovskite systems, will assist in the further development of multiferroics for next-generation devices. Published by AIP Publishing. https://doi.org/10.1063/1.5020305B.R.M., J.L., A.B., D.L.C., T.L., R.L.W., N.N., and Y.L. acknowledge the support of the Australian Research Council (ARC) in the form of Discovery Projects (No. DP160104780). A.B., D.L.C., N.N., D.Y. and authors thank the Australian Nuclear Science and Technology Organisation (ANSTO) for facilities and financial support and also thank the Echidna instrument scientists for their expertise

A malaria parasite subtilisin propeptide-like protein is a potent inhibitor of the egress protease SUB1.

Subtilisin-like serine peptidases (subtilases) play important roles in the life cycle of many organisms, including the protozoan parasites that are the causative agent of malaria, Plasmodium spp. As with other peptidases, subtilase proteolytic activity has to be tightly regulated in order to prevent potentially deleterious uncontrolled protein degradation. Maturation of most subtilases requires the presence of an N-terminal propeptide that facilitates folding of the catalytic domain. Following its proteolytic cleavage, the propeptide acts as a transient, tightly bound inhibitor until its eventual complete removal to generate active protease. Here we report the identification of a stand-alone malaria parasite propeptide-like protein, called SUB1-ProM, encoded by a conserved gene that lies in a highly syntenic locus adjacent to three of the four subtilisin-like genes in the Plasmodium genome. Template-based modelling and ab initio structure prediction showed that the SUB1-ProM core structure is most similar to the X-ray crystal structure of the propeptide of SUB1, an essential parasite subtilase that is discharged into the parasitophorous vacuole (PV) to trigger parasite release (egress) from infected host cells. Recombinant Plasmodium falciparum SUB1-ProM was found to be a fast-binding, potent inhibitor of P. falciparum SUB1, but not of the only other essential blood-stage parasite subtilase, SUB2, or of other proteases examined. Mass-spectrometry and immunofluorescence showed that SUB1-ProM is expressed in the PV of blood stage P. falciparum, where it may act as an endogenous inhibitor to regulate SUB1 activity in the parasite

Understanding the Needs and Priorities of People Living with Persistent Pain and Long-Term Musculoskeletal Conditions during the COVID-19 Pandemic—A Public Involvement Project

Background: Critiques of public involvement (PI) are associated with failing to be inclusive of under-represented groups, and this leads to research that fails to include a diversity of perspectives. Aim: The aim of this PI project was to understand the experiences and priorities of people from three seldom-heard groups whose musculoskeletal pain may have been exacerbated or treatment delayed due to COVID-19. Engaging representatives to report diverse experiences was important, given the goal of developing further research into personalised and integrated care and addressing population health concerns about access and self-management for people with musculoskeletal pain. Methods: The project was approved via Sheffield Hallam University Ethics but was exempt from further HRA approval. A literature review was conducted, followed by informal individual and group discussions involving professionals and people with lived experience of (a) fibromyalgia pain, (b) those waiting for elective surgery and (c) experts associated with the care home sector. Findings from the literature review were combined with the insights from the public involvement. Resulting narratives were developed to highlight the challenges associated with persistent pain and informed the creation of consensus statements on the priorities for service improvement and future research. The consensus statements were shared and refined with input from an expert steering group. Results: The narratives describe pain as a uniformly difficult experience to share with professionals; it is described as exhausting, frustrating and socially limiting. Pain leads to exclusion from routine daily activities and often resigns people to feeling and being unwell. In all cases, there are concerns about accessing and improving services and critical issues associated with optimising physical activity, functional wellbeing and managing polypharmacy. Exercise and/or mobilisation are important and commonly used self-management strategies, but opportunity and advice about safe methods are variable. Services should focus on personalised care, including self-management support and medication management, so that people’s views and needs are heard and validated by health professionals. Conclusions: More research is needed to explore the most effective pain management strategies, and public involvement is important to shape the most relevant research questions. Health and care systems evaluation is also needed to address the scale of the population health need. The pandemic appears to have highlighted pre-existing shortcomings in holistic pain management

Future agriculture with minimized phosphorus losses to waters: research needs and direction

The series of papers in this issue of AMBIO represent technical presentations made at the 7th International Phosphorus Workshop (IPW7), held in September, 2013 in Uppsala, Sweden. At that meeting, the 150 delegates were involved in round table discussions on major, predetermined themes facing the management of agricultural phosphorus (P) for optimum production goals with minimal water quality impairment. The six themes were (1) P management in a changing world; (2) transport pathways of P from soil to water; (3) monitoring, modeling, and communication; (4) importance of manure and agricultural production systems for P management; (5) identification of appropriate mitigation measures for reduction of P loss; and (6) implementation of mitigation strategies to reduce P loss. This paper details the major challenges and research needs that were identified for each theme and identifies a future roadmap for catchment management that cost-effectively minimizes P loss from agricultural activities

Association of resilience and psychological flexibility with surgeons' mental wellbeing.

BACKGROUND: Existing research highlights the link between certain personality traits and mental health in surgeons. However, little research has explored the important role of psychological skills and qualities in potentially explaining this link. A cross-sectional survey of UK-based surgeons was used to examine whether two such skills (psychological flexibility and resilience) helped to explain why certain personality traits might be linked to mental health in surgeons. METHOD: An online survey comprising measures of personality (neuroticism, extraversion and conscientiousness), psychological skills/qualities (psychological flexibility and resilience) and mental health (depression, anxiety, stress and burnout) was sent to surgeons practising in the UK. Mediation analyses were used to examine the potential mediating role of psychological flexibility and resilience in explaining the relationship between personality factors and mental health. RESULTS: A total of 348 surgeons completed the survey. In all 12 mediation models, psychological flexibility and/or resilience played a significant role in explaining the relationship between personality traits (neuroticism, extraversion and conscientiousness) and mental health (depression, anxiety and burnout). CONCLUSION: Findings suggest that it is not only a surgeon's personality that is associated with their mental health, but the extent to which a surgeon demonstrates specific psychological qualities and skills (psychological flexibility and resilience). This has important implications for improving surgeons' mental wellbeing, because psychological flexibility and resilience are malleable, and can be successfully targeted with interventions in a way that personality traits cannot

AMPK is essential for energy homeostasis regulation and glucose sensing by POMC and AgRP neurons

Hypothalamic AMP-activated protein kinase (AMPK) has been suggested to act as a key sensing mechanism, responding to hormones and nutrients in the regulation of energy homeostasis. However, the precise neuronal populations and cellular mechanisms involved are unclear. The effects of long-term manipulation of hypothalamic AMPK on energy balance are also unknown. To directly address such issues, we generated POMC alpha 2KO and AgRP alpha 2KO mice lacking AMPK alpha 2 in proopiomelanocortin- (POMC-) and agouti-related protein-expressing (AgRP-expressing) neurons, key regulators of energy homeostasis. POMC alpha 2KO mice developed obesity due to reduced energy expenditure and dysregulated food intake but remained sensitive to leptin. in contrast, AgRPa2KO mice developed an age-dependent lean phenotype with increased sensitivity to a melanocortin agonist. Electrophysiological studies in AMPK alpha 2-deficient POMC or AgRP neurons revealed normal leptin or insulin action but absent responses to alterations in extracellular glucose levels, showing that glucose-sensing signaling mechanisms in these neurons are distinct from those pathways utilized by leptin or insulin. Taken together with the divergent phenotypes of POMC alpha 2KO and AgRP alpha 2KO mice, our findings suggest that while AMPK plays a key role in hypothalamic function, it does not act as a general sensor and integrator of energy homeostasis in the mediobasal hypothalamus