Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 Contribute to Insect Killing.

Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whether these compounds also contribute to insecticidal activity. We tested mutants of the highly insecticidal strains Pseudomonas protegens CHA0, Pseudomonas chlororaphis PCL1391, and Pseudomonas sp. CMR12a, defective for individual or multiple antimicrobial compounds, for injectable and oral activity against lepidopteran insect larvae. Moreover, we studied expression of biosynthesis genes for these antimicrobial compounds for the first time in insects. Our survey revealed that hydrogen cyanide and different types of cyclic lipopeptides contribute to insecticidal activity. Hydrogen cyanide was essential to full virulence of CHA0 and PCL1391 directly injected into the hemolymph. The cyclic lipopeptide orfamide produced by CHA0 and CMR12a was mainly important in oral infections. Mutants of CMR12a and PCL1391 impaired in the production of the cyclic lipopeptides sessilin and clp1391, respectively, showed reduced virulence in injection and feeding experiments. Although virulence of mutants lacking one or several of the other antimicrobial compounds, i.e., 2,4-diacetylphloroglucinol, phenazines, pyrrolnitrin, or pyoluteorin, was not reduced, these metabolites might still play a role in an insect background since all investigated biosynthetic genes for antimicrobial compounds of strain CHA0 were expressed at some point during insect infection. In summary, our study identified new factors contributing to insecticidal activity and extends the diverse functions of antimicrobial compounds produced by fluorescent pseudomonads from the plant environment to the insect host

Generation of Enhanced Competitive Root-Tip-Colonizing Pseudomonas Bacteria through Accelerated Evolution

A recently published procedure to enrich for efficient competitive root tip colonizers (I. Kuiper, G. V. Bloemberg, and B. J. J. Lugtenberg, Mol. Plant-Microbe Interact. 14:1197-1205) after bacterization of seeds was applied to isolate efficient competitive root tip colonizers for both the dicotyledenous plant tomato and the monocotyledenous plant grass from a random Tn5luxAB mutant bank of the good root colonizer Pseudomonas fluorescens WCS365. Unexpectedly, the best-colonizing mutant, strain PCL1286, showed a strongly enhanced competitive root-tip-colonizing phenotype. Sequence analyses of the Tn5luxAB flanking regions showed that the transposon had inserted in a mutY homolog. This gene is involved in the repair of A · G mismatches caused by spontaneous oxidation of guanine. We hypothesized that, since the mutant is defective in repairing its mismatches, its cells harbor an increased number of mutations and therefore can adapt faster to the environment of the root system. To test this hypothesis, we constructed another mutY mutant and analyzed its competitive root tip colonization behavior prior to and after enrichment. As a control, a nonmutated wild type was subjected to the enrichment procedure. The results of these analyses showed (i) that the enrichment procedure did not alter the colonization ability of the wild type, (ii) that the new mutY mutant was strongly impaired in its colonization ability, but (iii) that after three enrichment cycles it colonized significantly better than its wild type. Therefore it is concluded that both the mutY mutation and the selection procedure are required to obtain an enhanced root-tip-colonizing mutant

Higher chances of survival to hospital admission after out-of-hospital cardiac arrest in patients with previously diagnosed heart disease

Aim This study aimed to determine whether patients suffering from out-of-hospital cardiac arrest (OHCA) with a pre-OHCA diagnosis of heart disease have higher survival chances than patients without such a diagnosis and to explore possible underlying mechanisms. Methods A retrospective cohort study in 3760 OHCA patients from the Netherlands (2010-2016) was performed. Information from emergency medical services, treating hospitals, general practitioner, resuscitation ECGs and civil registry was used to assess medical histories and the presence of pre-OHCA diagnosis of heart disease. We used multivariable regression analysis to calculate associations with survival to hospital admission or discharge, immediate causes of OHCA (acute myocardial infarction (AMI) vs non-AMI) and initial recorded rhythm. Results Overall, 48.1% of OHCA patients had pre-OHCA heart disease. These patients had higher odds to survive to hospital admission than patients without pre-OHCA heart disease (OR 1.25 (95%CI 1.05 to 1.47)), despite being older and more often having cardiovascular risk factors and some non-cardiac comorbidities. These patients also had higher odds of shockable initial rhythm (SIR) (OR 1.60 (1. 36 to 1.89)) and a lower odds of AMI as immediate cause of OHCA (OR 0.33 (0.25 to 0.42)). Their chances of survival to hospital discharge were not significantly larger (OR 1.16 (0.95 to 1.42)). Conclusion Having pre-OHCA diagnosed heart disease is associated with better odds to survive to hospital admission, but not to hospital discharge. This is associated with higher odds of a SIR and in a subgroup with available diagnosis a lower proportion of AMI as immediate cause of OHCA

ANTIMICROBIAL EFFECTS OF INDONESIAN MEDICINAL PLANTS EXTRACTS ON PLANKTONIC AND BIOFILM GROWTH OF PSEUDOMONAS AERUGINOSA AND STAPHYLOCOCCUS AUREUS

Objective: The increasing rates of antibiotic-resistant microbial infections requires continuous development of new antimicrobial agents. Moreover, microbial biofilms exhibit elevated resistance to most antimicrobial drugs and the host defense systems, which often results in persistent and difficult-to-treat infections. The discovery of anti-infective agents which are active against both planktonic and biofilm microbial are consequently required to deal with these biofilm-mediated infections. The aim of this study is to evaluate the activity of Indonesian medicinal plants extracts on planktonic and biofilm growth of Pseudomonas aeruginosa PAO1 and Staphylococcus aureus Cowan I.Methods: Fifty four (54) ethanol extracts were obtained from a variety of known Indonesian medicinal plants. The growth inhibitory concentration (MIC), effects on biofilm formation and biofilm breakdown, and biofilm architecture in the absence and presence of the extracts by confocal laser-scanning microscopy along with LIVE/DEAD staining was performed.Results: Plantextracts showed an inhibitory effect on planktonic growth of these bacteria and also on their biofilm formation. At a concentration as low as 0.12 mg/ml, biofilm formation of P. aeruginosa PAO1 and S. aureus Cowan I is inhibited by 5 plant ethanol extracts: Kaempferia rotunda L., Caesalpinia sappan L., Cinnamomum burmanii Nees ex Bl., C. sintoc and Nymphaea nouchali Burm. f. Limited bacteriostatic activity was evident.Conclusion: The results clearly indicate the extracts obtained are interesting sources of putative antibiofilm agents. This research can contribute to the development of new strategies to prevent and treat biofilm infections

Fusion of a family 1 carbohydrate binding module of Aspergillus niger to the Pycnoporus cinnabarinus laccase for efficient softwood kraft pulp biobleaching

International audiencePycnoporus cinnabarinus laccase was fused to the C-terminal linker and carbohydrate binding module (CBM) of Aspergillus niger cellobiohydrolase B (CBHB). The chimeric enzyme of molecular mass 100 kDa was successfully produced in A. niger. Laccase-CBM was further purified to determine its main biochemical properties. The Michaelis-Menten constant and pH activity profile were not modified, but the chimeric enzyme was less thermostable than either the P. cinnabarinus laccase or the recombinant laccase produced in the same strain. Laccase-CBM was able to bind to a cellulosic substrate and, to a greater extent, to softwood kraft pulp. Binding to the pulp was shown to be mainly time and temperature-dependent. Laccase-CBM was further investigated for its softwood kraft pulp biobleaching potential and compared with the P. cinnabarinus laccase. Addition of a CBM was shown to greatly improve the delignification capabilities of the laccase in the presence of 1-hydroxybenzotriazole (HBT). In addition, ClO2 reduction using 5 U of chimeric enzyme per gram of pulp was almost double than that observed using 20 U of P. cinnabarinus laccase per gram of pulp. We demonstrated that conferring a carbohydrate binding capability to the laccase could significantly enhance its biobleaching propertie

Developing a digital communication training tool on information-provision in oncology: Uncovering learning needs and training preferences

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Background: Adequate information-provision forms a crucial component of optimal cancer care. However, information-provision is particularly challenging in an oncology setting. It is therefore imperative to help oncological health care practitioners (HCP) optimise their information-giving skills. New forms of online education, i.e. e-learning, enable safe and time and location independent ways of learning, enhancing access to continuous learning for HCP. As part of a user-centred approach to developing an e-learning to improve information-giving skills, this study aims to: 1) uncover the learning needs of oncological healthcare providers related to information- provision, and 2) explore their training preferences in the context of clinical practice. Methods: Focus groups and interviews were organised with oncological HCP (medical specialists and clinical nurse specialists) addressing participants’ learning needs concerning information- provision and their training preferences with respect to a new digital training tool on this issue. All sessions were audiorecorded and transcribed verbatim. Using an inductive approach, transcripts were independently coded by three researchers and discussed to reach consensus. Main themes were summarised and discussed. Results: Four focus group sessions (total n = 13) and three interviews were conducted. The first theme concerned the patient outcomes HCP try to achieve with their information. We found HCP to mainly strive to promote patients’ understanding of information. The second theme concerned HCP reported strategies and challenges when trying to inform their patients. These entailed tailoring of information to patient characteristics, structuring of information, and dealing with patients’ emotions. Regarding HCP training preferences, an e-learning should be neatly connected to clinical practice. Moreover, participants desired a digital training to allow for feedback on their own (videotaped) information-giving skills from peers, communication experts, and/or patients; to monitor their progress and to tailored the training to individual learning needs. Conclusions: An e-learning for improvement of information-giving skills of oncological HCP should be aimed at the transfer of skills to clinical practice, rather than at enhancing knowledge. Moreover, an e-learning is probably most effective when the facilitates individual learning needs, supports feedback on competence level and improvement, and allows input from significant others (experts, peers, or patients).publishedVersio

Developing a digital communication training tool on information-provision in oncology: Uncovering learning needs and training preferences

Background: Adequate information-provision forms a crucial component of optimal cancer care. However, information-provision is particularly challenging in an oncology setting. It is therefore imperative to help oncological health care practitioners (HCP) optimise their information-giving skills. New forms of online education, i.e. e-learning, enable safe and time and location independent ways of learning, enhancing access to continuous learning for HCP. As part of a user-centred approach to developing an e-learning to improve information-giving skills, this study aims to: 1) uncover the learning needs of oncological healthcare providers related to information- provision, and 2) explore their training preferences in the context of clinical practice. Methods: Focus groups and interviews were organised with oncological HCP (medical specialists and clinical nurse specialists) addressing participants’ learning needs concerning information- provision and their training preferences with respect to a new digital training tool on this issue. All sessions were audiorecorded and transcribed verbatim. Using an inductive approach, transcripts were independently coded by three researchers and discussed to reach consensus. Main themes were summarised and discussed. Results: Four focus group sessions (total n = 13) and three interviews were conducted. The first theme concerned the patient outcomes HCP try to achieve with their information. We found HCP to mainly strive to promote patients’ understanding of information. The second theme concerned HCP reported strategies and challenges when trying to inform their patients. These entailed tailoring of information to patient characteristics, structuring of information, and dealing with patients’ emotions. Regarding HCP training preferences, an e-learning should be neatly connected to clinical practice. Moreover, participants desired a digital training to allow for feedback on their own (videotaped) information-giving skills from peers, communication experts, and/or patients; to monitor their progress and to tailored the training to individual learning needs. Conclusions: An e-learning for improvement of information-giving skills of oncological HCP should be aimed at the transfer of skills to clinical practice, rather than at enhancing knowledge. Moreover, an e-learning is probably most effective when the facilitates individual learning needs, supports feedback on competence level and improvement, and allows input from significant others (experts, peers, or patients)

Developing a digital training tool to support oncologists in the skill of information-provision: A user centred approach

Background: For patients with cancer, being well informed by their oncologist about treatment options and the implications thereof is highly relevant. Communication skills training (CST) programs have shown to be effective in improving clinicians' communication skills, yet CSTs are time-consuming, inconvenient to schedule, and costly. Online education enables new ways of accessible learning in a safe and personalised environment. Aim and methods: We describe the design of a digital CST-tool for information provision skills that meets oncologists' learning needs. We used the CeHRes Roadmap for user-centred design as a guiding framework. Phase 1 (Contextual Inquiry) involved consultation of the literature and a focus group interview study to uncover the learning needs and training preferences of clinicians' regarding a digital training for the skill of information-provision. In phase 2 (Value Specification), two multidisciplinary expert panels specified the learning content and format of a digital training. Phase 3 (Design) encompassed an iterative development process, including two user group assessment sessions and 5 individual user sessions in which prototypes were tested. All sessions were recorded and independently analyzed by two researchers. Results: Based on literature and consultation of the users in the inquiry phase of the development process, and on expert opinion in the value specification phase, relevant (sub) skills and user requirements were defined to consider for the digital training format. It was decided to develop a conventional e-learning and a chatbot. Personalization and interactivity were integrated in the prototypes by including features that allow for e.g., choosing text, video or animation; to upload video-recorded consultations to receive peer-feedback; and to consult a communication expert. Results revealed that, overall, participants expressed a willingness to use a digital training tool to acquire information-provision skills. Individual user testing (including junior clinicians), indicated a preference for the chatbot over the e-learning. Conclusion: We offer a description of extensive development work which was conducted in collaboration with multiple health care professionals to iteratively develop two innovative prototypes of digital tools that would appropriately engage oncologists in learning effective information giving skills. The resulting prototypes were well appreciated and thus provide a solid basis for further development and testing

Tailoring the amount of treatment information to cancer patients’ and survivors’ preferences: Effects on patient-reported outcomes

Objectives: Tailoring medical information to cancer patients’ needs is recommended, but there is little guidance on how to tailor, and limited research exists about its effects. Tailoring to the amount of preferred information may be easily implementable in clinic and is tested here. Methods: A video-vignette experiment was used to systematically vary video patients’ information preferences (limited/extensive) and amount of provided information (additional/no additional). N = 253 cancer patients/survivors evaluated these video-recorded consultations, serving as analogue patients (APs), and completed outcome measures. Results: Tailoring information to video patients’ preferences had no effect on APs’ evaluation of the consultation (satisfaction, trust). Yet, there was a main effect of APs’ own information preferences: Those preferring extensive information recalled (MΔ = 5.8%) and recognized (MΔ = 3.5%) more information than those preferring limited information. Moreover, information provision mattered among APs who preferred limited information: They recognized even less if provided with extensive information. Conclusions: Tailoring to the amount of video patient's information preferences did not affect APs’ evaluation of the consultation (satisfaction, trust), while APs’ personal information preferences determined their recall and recognition of medical information. Practice implications: Information preferences should be assessed and tailored to in clinical practice. Overwhelming patients/survivors, who prefer limited information, should be prevented