scholarly journals Transfer of Plasmid DNA to Clinical Coagulase-Negative Staphylococcal Pathogens by Using a Unique Bacteriophage

2015 ◽  
Vol 81 (7) ◽  
pp. 2481-2488 ◽  
Author(s):  
Volker Winstel ◽  
Petra Kühner ◽  
Bernhard Krismer ◽  
Andreas Peschel ◽  
Holger Rohde

ABSTRACTGenetic manipulation of emerging bacterial pathogens, such as coagulase-negative staphylococci (CoNS), is a major hurdle in clinical and basic microbiological research. Strong genetic barriers, such as restriction modification systems or clustered regularly interspaced short palindromic repeats (CRISPR), usually interfere with available techniques for DNA transformation and therefore complicate manipulation of CoNS or render it impossible. Thus, current knowledge of pathogenicity and virulence determinants of CoNS is very limited. Here, a rapid, efficient, and highly reliable technique is presented to transfer plasmid DNA essential for genetic engineering to important CoNS pathogens from a uniqueStaphylococcus aureusstrain via a specificS. aureusbacteriophage, Φ187. Even strains refractory to electroporation can be transduced by this technique once donor and recipient strains share similar Φ187 receptor properties. As a proof of principle, this technique was used to delete the alternative transcription factor sigma B (SigB) via allelic replacement in nasal and clinicalStaphylococcus epidermidisisolates at high efficiencies. The described approach will allow the genetic manipulation of a wide range of CoNS pathogens and might inspire research activities to manipulate other important pathogens in a similar fashion.

2015 ◽  
Vol 22 (2) ◽  
pp. 93-114 ◽  
Author(s):  
Michelle Liu ◽  
Pramila Rao

Purpose – This research paper aims to showcase current knowledge management (KM) practices via social media that is being adopted by organizations in India and China. India and China are considered leading economies in today’s global market. Any understanding of management practices in these countries will help practitioners in doing businesses in these nations. Design/methodology/approach – This conceptual paper analyzes KM practices in India and China using an in-depth analysis of the extant literature to provide a comparative perspective of KM policies in these two economies. This paper has used a wide range of scholarly and non-scholarly databases from ABI Global Inform to Business Source Complete to Google Scholar among others. Findings – This research offers valuable insights into characteristic KM trends followed by Indian and Chinese firms. This paper also highlights different approaches adopted by these two cultures in managing their KM practices. The study also provides hypotheses that can be tested by potential scholars. This paper also offers theoretical models to understand this concept better. Practical implications – This paper also provides implications for practice by identifying guidelines for global managers. These frameworks might serve as preliminary parameters for practitioners planning to establish KM practices in India and China. Originality/value – This paper compares and contrasts KM practices in one of the two largest BRIC (Brazil, Russia, India and China) economies which have not been addressed in the literature before. It also combines two theoretical frameworks from different fields (information technology and human resource management) providing a richer viewpoint on the subject.


Author(s):  
Robert Bogue

Purpose This paper aims to illustrate the growing role robots are playing in recycling and product disassembly and provide an insight into recent research activities. Design/methodology/approach Following a short introduction, this first considers robotic waste sorting systems and then describes two systems for the disassembly of electronic products. It then provides details of some recent research activities. Finally, brief conclusions are drawn. Findings Robotic systems exploiting artificial intelligence combined with various sensing and machine vision technologies are playing a growing role in the sorting of municipal and industrial waste, prior to recycling. These are mostly based on delta robots and can achieve pick rates of 60-70 items/min and be configured to recognise and select a wide range of different materials and items from moving conveyors. Electronic waste recycling is yet to benefit significantly from robotics although a limited number of systems have been developed for product disassembly. Disassembly techniques are the topic of a concerted research effort which often involves robots and humans collaborating and sharing disassembly tasks. Originality/value This provides an insight into the present-day uses and potential future role of robots in recycling which has traditionally been a highly labour-intensive industry.


2017 ◽  
Vol 199 (16) ◽  
Author(s):  
Stephen K. Costa ◽  
Niles P. Donegan ◽  
Anna-Rita Corvaglia ◽  
Patrice François ◽  
Ambrose L. Cheung

ABSTRACT Staphylococcus epidermidis is the leading cause of infections on indwelling medical devices worldwide. Intrinsic antibiotic resistance and vigorous biofilm production have rendered these infections difficult to treat and, in some cases, require the removal of the offending medical prosthesis. With the exception of two widely passaged isolates, RP62A and 1457, the pathogenesis of infections caused by clinical S. epidermidis strains is poorly understood due to the strong genetic barrier that precludes the efficient transformation of foreign DNA into clinical isolates. The difficulty in transforming clinical S. epidermidis isolates is primarily due to the type I and IV restriction-modification systems, which act as genetic barriers. Here, we show that efficient plasmid transformation of clinical S. epidermidis isolates from clonal complexes 2, 10, and 89 can be realized by employing a plasmid artificial modification (PAM) in Escherichia coli DC10B containing a Δdcm mutation. This transformative technique should facilitate our ability to genetically modify clinical isolates of S. epidermidis and hence improve our understanding of their pathogenesis in human infections. IMPORTANCE Staphylococcus epidermidis is a source of considerable morbidity worldwide. The underlying mechanisms contributing to the commensal and pathogenic lifestyles of S. epidermidis are poorly understood. Genetic manipulations of clinically relevant strains of S. epidermidis are largely prohibited due to the presence of a strong restriction barrier. With the introductions of the tools presented here, genetic manipulation of clinically relevant S. epidermidis isolates has now become possible, thus improving our understanding of S. epidermidis as a pathogen.


2014 ◽  
Vol 114 (3) ◽  
pp. 421-437 ◽  
Author(s):  
Kai-Tang Fan ◽  
Yuan-Ho Chen ◽  
Ching-Wen Wang ◽  
Minder Chen

Purpose – Virtual teams are becoming a norm in current knowledge-based society and offer a wide range of organizational benefits. This paper aims to investigate the effects of leaders’ motivating language (ML) and feedback approach on virtual team members’ creativity performance. Design/methodology/approach – A 2×2 with pre-test and post-test experimental design was employed to explore how to stimulate virtual team members’ creativity performance using a group decision support system. Findings – The results show that leaders’ ML and feedback approach via e-mail instructions have different interaction effects on members’ creativity and idea generation performance. Team members receiving direction-giving instructions generate more ideas under the demanding feedback approach and team member receiving instructions with more empathetic language exhibit higher creativity performance under the encouraging feedback approach. Research limitations/implications – Shortcomings of virtual environment and leadership remain the major factors influencing such findings. Since the results are also restrained by the functionality of the utilized software tool, tools for virtual teams are recommended to include features that can support the effective use of team leaders’ motivational language. Social implications – Virtual team leaders should provide proper guidance to members using understanding and empathetic wording approach. For task-oriented work, leaders should consider giving more specific instructions and provide constant feedback for completed work. For creative work, leaders should give positive encouragement as feedback or even challenge team members to stimulate their creativity. Additionally, facilitation rules can be set up in advance so that the intelligent agent can timely send out follow-up instructions/feedback. Originality/value – The gained insights beneficially help tool developers for virtual teams build/enhance their tools based on the need of team leaders. This paper also usefully offers important implications regarding how to motivate virtual team members’ creative thinking.


mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Ian R. Monk ◽  
Jai J. Tree ◽  
Benjamin P. Howden ◽  
Timothy P. Stinear ◽  
Timothy J. Foster

ABSTRACTStaphylococcus aureusis a prominent global nosocomial and community-acquired bacterial pathogen. A strong restriction barrier presents a major hurdle for the introduction of recombinant DNA into clinical isolates ofS. aureus. Here, we describe the construction and characterization of the IMXXB series ofEscherichia colistrains that mimic the type I adenine methylation profiles ofS. aureusclonal complexes 1, 8, 30, and ST93. The IMXXB strains enable direct, high-efficiency transformation and streamlined genetic manipulation of majorS. aureuslineages.IMPORTANCEThe genetic manipulation of clinicalS. aureusisolates has been hampered due to the presence of restriction modification barriers that detect and subsequently degrade inappropriately methylated DNA. Current methods allow the introduction of plasmid DNA into a limited subset ofS. aureusstrains at high efficiency after passage of plasmid DNA through the restriction-negative, modification-proficient strain RN4220. Here, we have constructed and validated a suite ofE. colistrains that mimic the adenine methylation profiles of different clonal complexes and show high-efficiency plasmid DNA transfer. The ability to bypass RN4220 will reduce the cost and time involved for plasmid transfer intoS. aureus. The IMXXB series ofE. colistrains should expedite the process of mutant construction in diverse genetic backgrounds and allow the application of new techniques to the genetic manipulation ofS. aureus.


2012 ◽  
Vol 78 (15) ◽  
pp. 5093-5103 ◽  
Author(s):  
Dandan Chen ◽  
Qi Zhang ◽  
Qinglin Zhang ◽  
Peilin Cen ◽  
Zhinan Xu ◽  
...  

ABSTRACTFK506 is a potent immunosuppressant that has a wide range of clinical applications. Its 23-member macrocyclic scaffold, mainly with a polyketide origin, features two methoxy groups at C-13 and C-15 and one allyl side chain at C-21, due to the region-specific incorporation of two unusual extender units derived from methoxymalonyl-acyl carrier protein (ACP) and allylmalonyl-coenzyme A (CoA), respectively. Whether their intracellular formations can be a bottleneck for FK506 production remains elusive. In this study, we report the improvement of FK506 yield in the producing strainStreptomyces tsukubaensisby the duplication of two sets of pathway-specific genes individually encoding the biosyntheses of these two extender units, thereby providing a promising approach to generate high-FK506-producing strains via genetic manipulation. Taking advantage of the fact thatS. tsukubaensisis amenable to two actinophage (ΦC31 and VWB) integrase-mediated recombination systems, we genetically enhanced the biosyntheses of methoxymalonyl-ACP and allylmalonyl-CoA, as indicated by transcriptional analysis. Together with the optimization of glucose supplementation, the maximal FK506 titer eventually increased by approximately 150% in comparison with that of the original strain. The strategy of engineering the biosynthesis of unusual extender units described here may be applicable to improving the production of other polyketide or nonribosomal peptide natural products that contain pathway-specific building blocks.


2018 ◽  
Vol 38 (6) ◽  
pp. 1433-1466 ◽  
Author(s):  
Neil Turner ◽  
James Aitken ◽  
Cecil Bozarth

PurposeThe purpose of this paper is to examine the nature of supply chain complexity and extend this with literature developed within the project domain. The authors use the lens of ambidexterity (the ability both to exploit and explore) to analyse responses to complexity, since this enables the authors to understand the application of known solutions in conjunction with innovative ones to resolve difficulties. This research also seeks to investigate how managers respond to supply chain complexities that can either be operationally deleterious or strategically beneficial.Design/methodology/approachThe authors develop a descriptive framework based on the project management (PM) literature to understand response options to complexity, and then use interviews with supply chain managers in six organisations to examine the utility of this framework in practice. The authors ask the research question “How do managers in supply chains respond to complexities”?FindingsThe case study data show first that managers faced with structural, socio-political, or emergent supply chain complexities use a wide range of responses. Second, over a third of the instances of complexity coded were actually accommodated, rather than reduced, by the study firms, suggesting that adapting to supply chain complexity in certain instances may be strategically appropriate. Third, the lens of ambidexterity allows a more explicit assessment of whether existing PM solutions can be considered or if novel methods are required to address supply chain complexities.Practical implicationsThe descriptive framework can aid managers in conceptualising and addressing supply chain complexity. Through exploiting current knowledge, managers can lessen the impact of complexity while exploring other innovative approaches to solve new problems and challenges that evolve from complexity growth driven by business strategy.Originality/valueThis study addresses a gap in the literature through the development of a framework which provides a structure on ways to address supply chain complexity. The authors evaluate an existing project complexity concept and demonstrate that it is both applicable and valuable in non-project, ongoing operations. The authors then extend it using the lens of ambidexterity, and develop a framework that can support practitioners in analysing and addressing both strategically necessary supply complexities, together with unwanted, negative complexities within the organisation and across the supply chain.


2021 ◽  
Vol 12 ◽  
Author(s):  
Judith Naamala ◽  
Donald L. Smith

Sustainable agriculture remains a focus for many researchers, in an effort to minimize environmental degradation and climate change. The use of plant growth promoting microorganisms (PGPM) is a hopeful approach for enhancing plant growth and yield. However, the technology faces a number of challenges, especially inconsistencies in the field. The discovery, that microbial derived compounds can independently enhance plant growth, could be a step toward minimizing shortfalls related to PGPM technology. This has led many researchers to engage in research activities involving such compounds. So far, the findings are promising as compounds have been reported to enhance plant growth under stressed and non-stressed conditions in a wide range of plant species. This review compiles current knowledge on microbial derived compounds, taking a reader through a summarized protocol of their isolation and identification, their relevance in present agricultural trends, current use and limitations, with a view to giving the reader a picture of where the technology has come from, and an insight into where it could head, with some suggestions regarding the probable best ways forward.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Claudia Maria Cacovean ◽  
Alessandro M. Peluso ◽  
Ioan Plăiaș

PurposeThe aim of the study is to explore the chain of relationships between service attributes, consumers' perceived benefits, fulfilment of personal goals, satisfaction judgements and future intentions.Design/methodology/approachThis research proposes and implements a model of consumer satisfaction in the performing arts. The model is based on means-end chain theory and incorporates consumer involvement as a moderator. The paper is a quantitative study using a questionnaire administered in Romanian theatres, the country chosen because of its post-communist profile.FindingsA partial least squares structural equation modelling analysis revealed that both core and peripheral attributes' evaluations were positively related to perceived benefits, which in turn were positively related to goal fulfilment. Acting as a mediator, goal fulfilment predicts satisfaction, which positively influences a series of intentions regarding supportive behaviours such as recommendation, donation, subscribing and repurchasing. Consumer involvement partially moderates the relationships within the proposed model.Research limitations/implicationsThe limitations of this research offer opportunities for future studies. First, as this study was conducted in Romania, the obtained results are not easily generalisable to other geographical or cultural contexts. Second, future studies could extend the proposed model to include other constructs that may be connected to satisfaction in performing arts. They could also apply the model (or an extended alternative) to adjacent fields such as opera, or live jazz, in order to explore whether the patterns of results which emerged here hold in other situations.Practical implicationsFrom a practical perspective, the research has implications for performing arts managers by offering actions to improve cultural consumption. First, the results support the idea that satisfaction is a key construct to investigate, even in the field of performing arts, as it can predict future positive intentions. Thus, arts managers should strive to maximise consumer satisfaction. From a marketing perspective, consumer satisfaction could be increased by improving core and peripheral service attributes, but especially the latter. The research provides means for audience segmentation in terms of consumer goals, benefits, and involvement. Arts managers should devote special attention to increasing consumer involvement in services provided.Social implicationsThe research provides a different view on the performing arts evaluation considering the theatregoers' perceptions. This type of evaluation is useful to understand the specificities of the audiences and to respond to their needs accordingly, contributing from a social point of view to audience development and making arts accessible to a wide range of people in a variety of ways: physically, geographically, socially and psychologically.Originality/valueThis research explores a new model of customer satisfaction in performing arts in a post-communist country, such as Romania, and the findings have implications at both theoretical and practical level. From a theoretical perspective, it contributes to a better understanding of the cognitive and emotional processes underlying the formation of satisfaction judgements in performing arts. The obtained findings are particularly useful for expanding current knowledge of how consumers think and behave with respect to performing arts. From a practical perspective, the findings have implications for arts managers deciding how to develop marketing strategies aimed at increasing satisfaction, and the consequential supportive behaviours towards performing arts.


2011 ◽  
Vol 193 (22) ◽  
pp. 6187-6196 ◽  
Author(s):  
Yefei Zhu ◽  
Renu Nandakumar ◽  
Marat R. Sadykov ◽  
Nandakumar Madayiputhiya ◽  
Thanh T. Luong ◽  
...  

Staphylococcus aureusis a medically important pathogen that synthesizes a wide range of virulence determinants. The synthesis of many staphylococcal virulence determinants is regulated in part by stress-induced changes in the activity of the tricarboxylic acid (TCA) cycle. One metabolic change associated with TCA cycle stress is an increased concentration of ribose, leading us to hypothesize that a pentose phosphate pathway (PPP)-responsive regulator mediates some of the TCA cycle-dependent regulatory effects. Using bioinformatics, we identified three potential ribose-responsive regulators that belong to the RpiR family of transcriptional regulators. To determine whether these RpiR homologues affect PPP activity and virulence determinant synthesis, therpiRhomologues were inactivated, and the effects on PPP activity and virulence factor synthesis were assessed. Two of the three homologues (RpiRB and RpiRC) positively influence the transcription of the PPP genesrpiAandzwf, while the third homologue (RpiRA) is slightly antagonistic to the other homologues. In addition, inactivation of RpiRC altered the temporal transcription of RNAIII, the effector molecule of theagrquorum-sensing system. These data confirm the close linkage of central metabolism and virulence determinant synthesis, and they establish a metabolic override for quorum-sensing-dependent regulation of RNAIII transcription.


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