The heme sensing response regulator HssR in Staphylococcus aureus but not the homologous RR23 in Listeria monocytogenes modulates susceptibility to the antimicrobial peptide plectasin

<p>Abstract</p> <p>Background</p> <p>Host defence peptides (HDPs), also known as antimicrobial peptides (AMPs), have emerged as potential new therapeutics and their antimicrobial spectrum covers a wide range of target organisms. However, the mode of action and the genetics behind the bacterial response to HDPs is incompletely understood and such knowledge is required to evaluate their potential as antimicrobial therapeutics. Plectasin is a recently discovered HDP active against Gram-positive bacteria with the human pathogen, <it>Staphylococcus aureus </it>(<it>S. aureus</it>) being highly susceptible and the food borne pathogen, <it>Listeria monocytogenes </it>(<it>L. monocytogenes</it>) being less sensitive. In the present study we aimed to use transposon mutagenesis to determine the genetic basis for <it>S. aureus </it>and <it>L. monocytogenes </it>susceptibility to plectasin.</p> <p>Results</p> <p>In order to identify genes that provide susceptibility to plectasin we constructed bacterial transposon mutant libraries of <it>S. aureus </it>NCTC8325-4 and <it>L. monocytogenes </it>4446 and screened for increased resistance to the peptide. No resistant mutants arose when <it>L. monocytogenes </it>was screened on plates containing 5 and 10 fold Minimal Inhibitory Concentration (MIC) of plectasin. However, in <it>S. aureus</it>, four mutants with insertion in the heme response regulator (<it>hssR</it>) were 2-4 fold more resistant to plectasin as compared to the wild type. The <it>hssR </it>mutation also enhanced resistance to the plectasin-like defensin eurocin, but not to other classes of HDPs or to other stressors tested. Addition of plectasin did not influence the expression of <it>hssR </it>or <it>hrtA</it>, a gene regulated by HssR. The genome of <it>L. monocytogenes </it>LO28 encodes a putative HssR homologue, RR23 (in <it>L. monocytogenes </it>EGD-e lmo2583) with 48% identity to the <it>S. aureus </it>HssR, but a mutation in the <it>rr23 </it>gene did not change the susceptibility of <it>L. monocytogenes </it>to plectasin.</p> <p>Conclusions</p> <p><it>S. aureus </it>HssR, but not the homologue RR23 from <it>L. monocytogenes</it>, provides susceptibility to the defensins plectasin and eurocin. Our data suggest that a functional difference between response regulators HssR and RR23 is responsible for the difference in plectasin susceptibility observed between <it>S. aureus </it>and <it>L. monocytogenes</it>.</p

Resilience as a concept for understanding family caregiving of adults with Chronic Obstructive Pulmonary Disease (COPD): an integrative review

Abstract Aims: This paper was a report of the synthesis of evidence on examining the origins and definitions of the concept of resilience, investigating its application in chronic illness management and exploring its utility as a means of understanding family caregiving of adults with Chronic Obstructive Pulmonary Disease. Background: Resilience is a concept that is becoming relevant to understanding how individuals and families live with illness, especially long-term conditions. Caregivers of adults with Chronic Obstructive Pulmonary Disease must be able to respond to exacerbations of the condition and may themselves experience cognitive imbalances. Yet, resilience as a way of understanding family caregiving of adults with COPD is little explored. Design: Literature review – integrative review. Data sources: CINAHL, PubMed, Google Scholar and EBSCO were searched between 1989–2015. Review methods: The principles of rapid evidence assessment were followed. Results: We identified 376 relevant papers: 20 papers reported the presence of the concept of resilience in family caregivers of chronic diseases patients but only 12 papers reported the presence of the concept of resilience in caregivers of Chronic Obstructive Pulmonary Disease patients and have been included in the synthesis. The term resilience in Chronic Obstructive Pulmonary Disease caregiving is most often understood using a deficit model of health

Motivation, Barriers, and Suggestions for Intradialytic Exercise—A Qualitative Study among Patients and Nurses

Background: Intradialytic exercise is an effective intervention to reduce morbidity and mortality and increase quality of life among patients with chronic kidney disease undergoing dialysis. However, implementing and sustaining it in clinical practice has proved challenging. To identify how to best design an effective and sustainable intervention in clinical practice, we aimed to explore hemodialysis patients’ and nurses’ attitudes towards intradialytic exercise, including their motivation, anticipated barriers, and suggestions for the design of a proposed exercise program. Methods: Data were collected through qualitative semistructured interviews with patients and focus group interviews with nurses and analyzed inductively with content analysis. Results: Overall, patients’ and nurses’ attitudes towards intradialytic exercise were positive. Patients were motivated by their expectations about perceived benefits, such as improved quality of life and reduced musculoskeletal pain. Their main concern was triggering dialysis machine alarms and disturbing nurses. Nurses were more skeptical of intradialytic exercise and concerned about patient safety. Patients and nurses had several ideas on how to design a safe and motivating intradialytic exercise intervention. Conclusion: The analysis of patients’ and nurses’ experiences and attitudes generated recommendations for an intradialytic exercise program. Recommendations include individually tailored programs that are safe and that patients can do independently, continuous collaboration between patients, nurses, physicians, and physiotherapists, and educating nurses about the benefits and safety of intradialytic exercise

A qualitative study of integrated care from the perspectives of patients with chronic obstructive pulmonary disease and their relatives

BACKGROUND: Disease management programmes have been developed for chronic obstructive pulmonary disease (COPD) to facilitate the integration of care across healthcare settings. The purpose of the present study was to examine the experiences of COPD patients and their relatives of integrated care after implementation of a COPD disease management programme. METHODS: Seven focus groups and five individual interviews were held with 34 patients with severe or very severe COPD and two focus groups were held with eight of their relatives. Data were analysed using inductive content analysis. RESULTS: Four main categories of experiences of integrated care emerged: 1) a flexible system that provides access to appropriate healthcare and social services and furthers patient involvement; 2) the responsibility of health professionals to both take the initiative and follow up; 3) communication and providing information to patients and relatives; 4) coordination and professional cooperation. Most patients were satisfied with their care and raised few criticisms. However, patients with more unstable and severe disease tended to experience more problems. CONCLUSIONS: Participant suggestions for optimizing the integration of healthcare included assigning patients a care coordinator, telehealth solutions for housebound patients and better information technology to support interprofessional cooperation. Further studies are needed to explore these and other possible solutions to problems with integrated care among COPD patients. A future effort in this field should be informed by detailed knowledge of the extent and relative importance of the identified problems. It should also be designed to address variable levels of severity of COPD and relevant comorbidities and to deliver care in ways appropriate to the respective healthcare setting. Future studies should also take health professionals’ views into account so that interventions may be planned in the light of the experiences of all those involved in the treatment of COPD patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1472-6963-14-471) contains supplementary material, which is available to authorized users