bluuebunny/crossref_metadata_2025 huggingface dataset:
Charting the progress of technology adoption in tourism and hospitality in the era of industry 4.0
Authors: Buhalis Dimitrios , Efthymiou Leonidas , Uzunboylu Naziyet , Thrassou Alkis
Published: March 2024

Purpose

Amidst ongoing digital transformation, the current paper provides a 360-degree overview of technology-adoption in Tourism and Hospitality. By combining and consolidating a wide range of sources, mainly in the tourism literature, the analysis depicts how the complex technological ecosystem often enhances or hinders the successful adoption, integration and interoperability of different technologies.

Design/methodology/approach

The critical review method was used to assess, analyse and synthesise existing literature in the area of digitisation in tourism and hospitality. The critical review process included a thematic analysis of the literature, where recurring themes, patterns and trends were identified towards addressing the study’s research questions.

Findings

The analysis identifies current trends, opportunities, challenges and strategies for technology adoption in tourism and hospitality, the implications for theory, practicable executive directions and avenues for further research.

Originality/value

The paper’s main contribution lies in its comprehensive identification, consideration and incorporation of all primary contemporary technological elements, and the ensuing development of a corresponding conceptual charting framework, which illustrates a multifaceted process with practical implications for various stakeholders, including businesses, authorities, consumers and employees.
Career adaptability in the new normal world of work: exploring the post-pandemic research trends using bibliometric analysis
Authors: Parrey Aubid Hussain , Kour Gurleen
Published: March 2024

Purpose

Career adaptability is emerging as an important research area in today's uncertain, volatile world of work created by the COVID-19 pandemic. The present study focuses on career adaptability research post-COVID-19 by scientifically capturing the literature evolution, hotspots and future trends using bibliometric analysis.

Design/methodology/approach

The Scopus database, due to its vast and quality literature, was used to search the papers from the period 2020 to 2023. Bibliometric data were extracted and analyzed from the relevant literature. For further scientific mapping, VOSviewer and Biblioshiny software tools were used.

Findings

Findings of the analysis suggest a positive research trend related to career adaptability research post-Covid. Keyword analysis revealed noteworthy clusters and important themes. Bibliometric visual networks regarding authors, sources, citations, future themes, etc. are also presented from the 441 analyzed publications with comprehensive interpretation.

Research limitations/implications

The literature for carrying out the bibliometric analysis was confined to the Scopus database. Other databases in combination with different software can be used for future niche research. From the analysis, future research avenues and practical interventions are presented which have significant implications for future researchers, career counselors and managers.

Originality/value

The study summarizes the recent literature on career adaptability in the aftermath of the pandemic and makes a novel contribution to the existing literature. A reliable study has been provided by the authors using the scientific bibliometric technique. The study highlights emerging research trends post the pandemic. The results are concluded with further suggestions which can guide future research related to the topic.
Ultrasonic vibration cutting of advanced aerospace materials: a critical review of in-service functional performance
Authors: Peng Zhenlong , Han Aowei , Wang Chenlin , Jin Hongru , Zhang Xiangyu
Published: March 2024

Purpose

Unconventional machining processes, particularly ultrasonic vibration cutting (UVC), can overcome such technical bottlenecks. However, the precise mechanism through which UVC affects the in-service functional performance of advanced aerospace materials remains obscure. This limits their industrial application and requires a deeper understanding.

Design/methodology/approach

The surface integrity and in-service functional performance of advanced aerospace materials are important guarantees for safety and stability in the aerospace industry. For advanced aerospace materials, which are difficult-to-machine, conventional machining processes cannot meet the requirements of high in-service functional performance owing to rapid tool wear, low processing efficiency and high cutting forces and temperatures in the cutting area during machining.

Findings

To address this literature gap, this study is focused on the quantitative evaluation of the in-service functional performance (fatigue performance, wear resistance and corrosion resistance) of advanced aerospace materials. First, the characteristics and usage background of advanced aerospace materials are elaborated in detail. Second, the improved effect of UVC on in-service functional performance is summarized. We have also explored the unique advantages of UVC during the processing of advanced aerospace materials. Finally, in response to some of the limitations of UVC, future development directions are proposed, including improvements in ultrasound systems, upgrades in ultrasound processing objects and theoretical breakthroughs in in-service functional performance.

Originality/value

This study provides insights into the optimization of machining processes to improve the in-service functional performance of advanced aviation materials, particularly the use of UVC and its unique process advantages.
Contagious resilience – how leaders’ resilient behaviour promotes followers’ resilient behaviour
Authors: Caniëls Marjolein C.J. , Curseu Petru
Published: March 2024

Purpose

Leaders are role models and through social influence processes, they shape the behaviour of their followers. We build on social learning, social identity and person-environment (P-E) fit theories of leadership to explore the association between leaders’ and followers’ resilient behaviours.

Design/methodology/approach

In a three-wave, multisource study amongst 269 Dutch leaders and their followers, we investigate the mediating role of coaching in the relationship between leaders’ resilient behaviour and followers’ resilient behaviour and the moderating role of regulatory focus in this mediation path.

Findings

Our results show that coaching is a key relational vehicle through which leaders’ resilient behaviours shape employees’ resilient behaviours, and this indirect association is stronger for employees scoring low on promotion focus. In addition, our results show that resilient employees attract more coaching from their leaders, which further strengthens their resilient behaviours.

Originality/value

Existing studies have shown the occurrence of trickle-down effects of various leader behaviours, moods and work states on those of their followers. However, it remained obscure whether leaders’ resilient behaviour could trickle down to followers’ as well. Our study shows that such a link indeed exists and that coaching is a relational vehicle that embodies two key mechanisms to (1) foster social learning through behavioural entrainment and contagion and (2) facilitate support provision through which leaders promote resilient behaviour in their followers.
Attitude in a crisis: A new keystone concept in crisis communication leadership
Authors: Graffeo Jonathan , Jin Yan
Published: March 2024

‘When people's emotions are at stake, there is the constant need to be seen to engage and connect with them in their hours of need’. This study contributes to the literature on Integrated Crisis Mapping, a stakeholder‐centric crisis communication framework that attunes organisational leaders to the emotional responses and coping needs of their primary publics. Building on Weick's insight about the importance of an attitude of wisdom in making sense of a crisis, the study proposes crisis attitude as a keystone concept to help bridge the gap between theory and practice in crisis communication. The study illustrates the concept with an attitude of humility, explaining how it could be apposite to navigating the dynamics of a crisis and serve a sensegiving function that decreases stakeholders' negative emotions and fosters their trust in leadership.
What factors contribute to the formation of interorganizational collaboration networks: A longitudinal study in response to COVID‐19 emergency
Authors: Wang Fei , Hou Xiaorong , Feng Xianli
Published: March 2024

In the realm of addressing large‐scale emergencies, interorganizational collaboration emerges as a crucial strategy for effectively mitigating crises. However, the existence of institutional and procedural disparities poses significant challenges in establishing collaborative networks among diverse organizations. Moreover, the determinants influencing cooperative formations exhibit heterogeneity across distinct network structures. This research employs proximity theory and the Exponential Random Graph Model (ERGM) to comprehensively examine the dynamic evolution of interorganizational collaboration networks. Our primary objective is to investigate the effects of institutional proximity, organizational proximity, geographical proximity and social proximity on the formation of interorganizational collaboration networks. Textual data was meticulously collected from the Wisers database and official websites. The findings underscore the pivotal roles of institutional and organizational proximity in fostering interorganizational collaboration networks, while the impact of geographical proximity is relatively insignificant. Additionally, we delve into the driving factors that influence the formation of diverse structural networks. Social proximity emerges as a significant catalyst for horizontal collaborative networks but impedes the establishment of vertical collaborative relationships. Furthermore, we partition the entire emergency response process into six stages to explore the dynamic evolution characteristics of these networks. The results reveal an overall decentralized structure with a tendency toward clustering in the collaborative network. These findings hold substantial significance as they elucidate the influential factors driving the formation of diverse collaborative networks in a dynamic context. Therefore, this research bears implications for policymakers and practitioners aiming to enhance their emergency response capabilities with optimal efficiency.
Introduction of summer houses into semi‐natural habitats: impacts on ground‐nesting birds
Authors: Pálsdóttir Aldís E. , Alves José A. , Gill Jennifer A. , Pálsson Snæbjörn , Méndez Verónica , Gunnarsson Tómas G.
Published: March 2024

Degradation of natural and semi‐natural habitats is often initiated and facilitated by expansions in anthropogenic infrastructures. Identifying and reducing the impact of anthropogenic structures on the wildlife that these habitats support is vital for biodiversity conservation. In Iceland, the number of summer houses has increased over the past two decades, from ~10 000 to 15 000, and >7000 additional plots for summer house construction have been approved. Most of this housing infrastructure development is in the Icelandic lowlands, which support internationally important populations of several ground‐nesting bird species. To explore the effects of summer house infrastructure on the distribution of ground‐nesting birds, we conducted surveys at 292 points within 71 sites with varying density of houses and associated infrastructure (tracks, decking, etc). Significant reductions in abundance with increasing housing density occurred in five (Golden Plover (Pluvialis apricaria), Black‐tailed Godwit (Limosa limosa), Redshank (Tringa totanus), Whimbrel (Numenius phaeopus) and Meadow pipit (Anthus pratensis)) of the seven study species, while one species (Snipe (Gallinago gallinago)) showed no change and one (Redwing (Turdus iliacus)) increased. The differences in abundance between plots with no houses and plots with high house densities (>0.5 houses ha−1) ranged from 34 to 95%, despite the housing infrastructure covering only ~6% of the area of these plots. These findings suggest that even relatively low densities of anthropogenic structures in natural or semi‐natural areas can have substantial impacts on wildlife in the surrounding areas and highlight the urgent need for effective planning regulations to limit the expansion of anthropogenic structures into currently undisturbed habitats, particularly in areas of high biodiversity value.
Service evaluation suggests variation in clinical care provision in adults with congenital adrenal hyperplasia in the UK and Ireland
Authors: Doyle Lauren Madden , Ahmed S. Faisal , Davis Jessica , Elford Sue , Elhassan Yasir S. , James Lynette , Lawrence Neil , Llahana Sofia , Okoro Grace , Rees D. Aled , Tomlinson Jeremy W. , O'Reilly Michael W. , Krone Nils P.
Published: March 2024

Background

Congenital adrenal hyperplasia (CAH) encompasses a rare group of autosomal recessive disorders, characterised by enzymatic defects in steroidogenesis. Heterogeneity in management practices has been observed internationally. The International Congenital Adrenal Hyperplasia registry (I‐CAH, https://sdmregistries.org/) was established to enable insights into CAH management and outcomes, yet its global adoption by endocrine centres remains unclear.

Design

We sought (1) to assess current practices amongst clinicians managing patients with CAH in the United Kingdom and Ireland, with a focus on choice of glucocorticoid, monitoring practices and screening for associated co‐morbidities, and (2) to assess use of the I‐CAH registry.

Measurements

We designed and distributed an anonymised online survey disseminated to members of the Society for Endocrinology and Irish Endocrine Society to capture management practices in the care of patients with CAH.

Results

Marked variability was found in CAH management, with differences between general endocrinology and subspecialist settings, particularly in glucocorticoid use, biochemical monitoring and comorbidity screening, with significant disparities in reproductive health monitoring, notably in testicular adrenal rest tumours (TARTs) screening (p = .002), sperm banking (p = .0004) and partner testing for CAH (p < .0001). Adoption of the I‐CAH registry was universally low.

Conclusions

Differences in current management of CAH continue to exist. It appears crucial to objectify if different approaches result in different long‐term outcomes. New studies such as CaHASE2, incorporating standardised minimum datasets including replacement therapies and monitoring strategies as well as longitudinal data collection, are now needed to define best‐practice and standardise care.
Barriers to adopting digital contact tracing for COVID‐19: Experiences in New Zealand
Authors: Elers Phoebe , Emery Tepora , Derrett Sarah , Chambers Tim
Published: March 2024

Background

Digital contact tracing (DCT) was a central component of the global response to containing COVID‐19. Research has raised concerns that DCT could exacerbate inequities, yet the experiences of diverse communities at greater risk from COVID‐19 are typically underrepresented.

Methods

The present study aimed to understand the perceived barriers to the adoption of the app amongst Māori, Pasifika, and disabled people. Focus groups and interviews were undertaken with Māori, Pasifika, and disability sector stakeholders and community participants.

Results

Participants (n = 34) generally expressed willingness to utilise DCT and support its adoption within the communities. Simultaneously, participants revealed how the app could marginalise community members who struggled with the usability and those distrusting of the government's COVID‐19 interventions.

Conclusions

The findings highlight how addressing communication inequality can assist in the development of contact‐tracing responses that are both effective and equitable. The study provides insights about the role of information and communication technologies as health resources.

Patient or Public Contribution

Consulting with members of the target communities was central throughout the present study, including recommendations for potential participants, participation in interviews and sharing early findings for feedback. This study reports on focus groups and interviews with individuals from Māori and disability sectors.
Digital health technologies: Compounding the existing ethical challenges of the ‘right’ not to know
Authors: Armitage Richard C.
Published: March 2024

Introduction

Doctors hold a prima facie duty to respect the autonomy of their patients. This manifests as the patient's ‘right’ not to know when patients wish to remain unaware of medical information regarding their health, and poses ethical challenges for good medical practice. This paper explores how the emergence of digital health technologies might impact upon the patient's ‘right’ not to know.

Method

The capabilities of digital health technologies are surveyed and ethical implications of their effects on the ‘right’ not to know are explored.

Findings

Digital health technologies are increasingly collecting, processing and presenting medical data as clinically useful information, which simultaneously presents large opportunities for improved health outcomes while compounding the existing ethical challenges generated by the patient's ‘right’ not to know.

Conclusion

These digital tools should be designed to include functionality that mitigates these ethical challenges, and allows the preservation of their user's autonomy with regard to the medical information they wish to learn and not learn about.
Single measurement of bowel wall thickness using intestinal ultrasonography in children with ulcerative colitis
Authors: Otani Masano , Okuhira Takeru , Yoden Atsushi , Kaji Emiri , Inoue Keisuke , Aomatsu Tomoki , Takitani Kimitaka , Ashida Akira
Published: March 2024

Background

Endoscopic monitoring of disease activity in patients with ulcerative colitis (UC) is important. However, frequent colonoscopic examinations are difficult to perform because of their invasiveness, especially in children. Bowel wall thickness (BWT) measurement using intestinal ultrasonography and fecal calprotectin (FC) measurement are useful noninvasive evaluation methods.

Methods

We retrospectively analyzed BWT and FC levels and evaluated the Mayo endoscopic subscore (MES) using colonoscopy in pediatric patients with UC during the same period. The BWT was evaluated using the maximum BWT (mBWT), which was the maximum value of each colonic BWT; the sum of BWT (sBWT), which was the sum of each colonic BWT; and the sum of the adjusted BWT (saBWT), which was corrected using sBWT.

Results

In 54 procedures from 40 patients, FC, mBWT, sBWT, and saBWT were significantly different between MES 0–1 and MES 2. The agreement between BWT and MES 2 was 193 out of 216 segments (89.4%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FC were 68.8%, 84.2%, 64.7%, 86.5%, and 79.6% respectively, while those of saBWT were 81.2%, 89.5%, 76.5%, 91.9%, 87.0%, respectively.

Conclusions

BWT in each colonic segment, particularly saBWT, was more useful than FC for detecting moderate colonic inflammation (MES 2) in pediatric patients with UC. Therefore, intestinal ultrasonography may be helpful in the less invasive management of pediatric patients with UC.
Mitigating imported fuel dependency in agricultural production: Case study of an island nation's vulnerability to global catastrophic risks
Authors: Boyd Matt , Ragnarsson Sam , Terry Simon , Payne Ben , Wilson Nick
Published: March 2024

A major global catastrophe would likely disrupt trade in liquid fuels. Countries dependent on imported oil products might struggle to sustain industrial agriculture. Island nations importing 100% of refined fuels are particularly vulnerable. Our case study aimed to estimate the agricultural land area and biofuel volumes needed to feed the population of New Zealand in the absence of trade. Results showed that stored diesel would quickly be exhausted with ordinary use (weeks) and even with strict rationing (months). To preserve fuel, we found that farming wheat (requiring as little as 5.4 million liters [L] of diesel per annum) was more fuel‐efficient than potatoes (12.3) or dairy (38.7) to feed the national population under a climate‐as‐usual scenario. In a nuclear winter scenario, with reduced agricultural yields, proportionately greater diesel is needed. The wheat would require 24% of current grain‐cropped land, and the canola crop used as feedstock for the required biofuel would occupy a further 1%–7%. Investment in canola biodiesel or renewable diesel refineries could ensure supply for the bare minimum agricultural liquid fuel needs. Were subsequent analysis to favor this option as part of a fuels resilience response and as a tradeoff for routine food use, expansion in refining and canola cropping before a catastrophe could be encouraged through market mechanisms, direct government investment, or a combination of these. Logistics of biofuel refining scale‐up, post‐catastrophe, should also be analyzed. Further, biodiesel produced in normal times would help the nation meet its emissions reduction targets. Other countries should conduct similar analyses.
Rage against the machine? Framing societal threat and efficacy in YouTube videos about artificial intelligence
Authors: Schwarz Andreas , Unselt Janina Jacqueline
Published: March 2024

Artificial intelligence (AI) has become a part of the mainstream public discourse beyond expert communities about its risks, benefits, and need for regulation. In particular, since 2014, the news media have intensified their coverage of this emerging technology and its potential impact on most domains of society. Although many studies have analyzed traditional media coverage of AI, analyses of social media, especially video‐sharing platforms, are rare. In addition, research from a risk communication perspective remains scarce, despite the widely recognized potential threats to society from many AI applications. This study aims to detect recurring patterns of societal threat/efficacy in YouTube videos, analyze their main sources, and compare detected frames in terms of reach and response. Using a theoretical framework combining framing and risk communication, the study analyzed the societal threat/efficacy attributed to AI in easily accessible YouTube videos published in a year when public attention to AI temporarily peaked (2018). Four dominant AI frames were identified: the balanced frame, the high‐efficacy frame, the high‐threat frame, and the no‐threat frame. The balanced and no‐threat frames were the most prevalent, with predominantly positive and neutral AI narratives that neither adequately address the risks nor the necessary societal response from a normative risk communication perspective. The results revealed the specific risks and benefits of AI that are most frequently addressed. Video views and user engagement with AI videos were analyzed. Recommendations for effective AI risk communication and implications for risk governance were derived from the results.
Can species endure massive introgression? Genomic evidence of asymmetric gene flow in Melitaea butterflies
Authors: Hinojosa Joan C. , Marques Valéria , Mesa Luis Sánchez , Dapporto Leonardo , Dincă Vlad , Vila Roger
Published: March 2024

Hybridisation and introgression are increasingly seen as important drivers of the evolution of organisms, particularly in Lepidoptera. One group that is gaining attention due to recently published cases of interspecific gene flow is the genus Melitaea Fabricius (Nymphalidae). In this study, we used genomics to investigate the role of hybridisation in the evolution of the western Palearctic species of the Melitaea phoebe group M. ornata Christoph, the recently described M. pseudornata Muñoz Sariot & Sánchez Mesa, M. phoebe (Denis & Schiffermüller), M. punica Oberthür, and M. telona (Fruhstorfer). We provide evidence of asymmetric gene flow from M. phoebe to both M. ornata and M. pseudornata. Gene flow from M. phoebe to M. pseudornata was very high (25.0%–31.9%), widespread throughout the distribution of the latter, and not equally distributed along the genome. The Z chromosome showed patterns compatible with the large‐Z effect, which were mimicked by two autosomes. Melitaea pseudornata endured massive introgression while remaining a separate entity from M. phoebe, although gene flow may have altered its phenotype, including its voltinism and the morphology of the adults and caterpillars. These findings suggest that hybridisation may be pervasive in this genus and highlight its key role in the evolution of butterflies, emphasising the need for further research on this topic.
KU70 and CAF‐1 in Arabidopsis: Divergent roles in rDNA stability and telomere homeostasis
Authors: Závodník Michal , Pavlištová Veronika , Machelová Adéla , Lyčka Martin , Mozgová Iva , Caklová Karolína , Dvořáčková Martina , Fajkus Jiří
Published: March 2024

Deficiency in chromatin assembly factor‐1 (CAF‐1) in plants through dysfunction of its components, FASCIATA1 and 2 (FAS1, FAS2), leads to the specific and progressive loss of rDNA and telomere repeats in plants. This loss is attributed to defective repair mechanisms for the increased DNA breaks encountered during replication, a consequence of impaired replication‐dependent chromatin assembly. In this study, we explore the role of KU70 in these processes. Our findings reveal that, although the rDNA copy number is reduced in ku70 mutants when compared with wild‐type plants, it is not markedly affected by diverse KU70 status in fas1 mutants. This is consistent with our previous characterisation of rDNA loss in fas mutants as a consequence part of the single‐strand annealing pathway of homology‐dependent repair. In stark contrast to rDNA, KU70 dysfunction fully suppresses the loss of telomeres in fas1 plants and converts telomeres to their elongated and heterogeneous state typical for ku70 plants. We conclude that the alternative telomere lengthening pathway, known to be activated in the absence of KU70, overrides progressive telomere loss due to CAF‐1 dysfunction.
Some convexity criteria for differentiable functions on the 2‐Wasserstein space
Authors: Parker Guy
Published: March 2024

We show that a differentiable function on the 2‐Wasserstein space is geodesically convex if and only if it is also convex along a larger class of curves which we call ‘acceleration‐free’. In particular, the set of acceleration‐free curves includes all generalised geodesics. We also show that geodesic convexity can be characterised through first‐ and second‐order inequalities involving the Wasserstein gradient and the Wasserstein Hessian. Subsequently, such inequalities also characterise convexity along acceleration‐free curves.
Signed permutohedra, delta‐matroids, and beyond
Authors: Eur Christopher , Fink Alex , Larson Matt , Spink Hunter
Published: March 2024

We establish a connection between the algebraic geometry of the type permutohedral toric variety and the combinatorics of delta‐matroids. Using this connection, we compute the volume and lattice point counts of type generalized permutohedra. Applying tropical Hodge theory to a new framework of “tautological classes of delta‐matroids,” modeled after certain vector bundles associated to realizable delta‐matroids, we establish the log‐concavity of a Tutte‐like invariant for a broad family of delta‐matroids that includes all realizable delta‐matroids. Our results include new log‐concavity statements for all (ordinary) matroids as special cases.
Distinct electrophysiological properties of long‐range GABAergic and glutamatergic neurons from the lateral amygdala to the auditory cortex of the mouse
Authors: Bertero Alice , Apicella Alfonso junior
Published: March 2024

Differentiating between auditory signals of various emotional significance plays a crucial role in an individual's ability to thrive and excel in social interactions and in survival. Multiple approaches, including anatomical studies, electrophysiological investigations, imaging techniques, optogenetics and chemogenetics, have confirmed that the auditory cortex (AC) impacts fear‐related behaviours driven by auditory stimuli by conveying auditory information to the lateral amygdala (LA) through long‐range excitatory glutamatergic and GABAergic connections. In addition, the LA provides glutamatergic projections to the AC which are important to fear memory expression and are modified by associative fear learning. Here we test the hypothesis that the LA also sends long‐range direct inhibitory inputs to the cortex. To address this fundamental question, we used anatomical and electrophysiological approaches, allowing us to directly assess the nature of GABAergic inputs from the LA to the AC in the mouse. Our findings elucidate the existence of a long‐range inhibitory pathway from the LA to the AC (LAC) via parvalbumin‐expressing (LAC‐Parv) and somatostatin‐expressing (LAC‐SOM) neurons. This research identifies distinct electrophysiological properties for genetically defined long‐range GABAergic neurons involved in the communication between the LA and the cortex (LAC‐Parv inhibitory projections → AC neurons; LAC‐Som inhibitory projections → AC neurons) within the lateral amygdala cortical network.

image

Key points

The mouse auditory cortex receives inputs from the lateral amygdala.

Retrograde viral tracing techniques allowed us to identify two previously undescribed lateral amygdala to auditory cortex (LAC) GABAergic projecting neurons.

Extensive electrophysiological, morphological and anatomical characterization of LAC neurons is provided here, demonstrating key differences in the three populations.

This study paves the way for a better understanding of the growing complexity of the cortico‐amygdala‐cortico circuit.
Murepavadin promotes the killing efficacies of aminoglycoside antibiotics against
Pseudomonas aeruginosa
by enhancing membrane potential
Authors: Wei Xiaoya , Gao Jiacong , Zhou Dandan , Xu Congjuan , Chen Ping , Chen Shuiping , Zhang Yanhong , Liu Xuehua , Li Guanxian , Zhu Guangbo , Liu Huimin , Li Jinjin , Geng Bin , Gao Linlin , Cheng Zhihui , Lamont Iain L. , Pletzer Daniel , Jin Yongxin , Jin Shouguang , Wu Weihui
Published: March 2024

Murepavadin is a peptidomimetic that specifically targets the lipopolysaccharide transport protein LptD of
Pseudomonas aeruginosa
. Here, we found that murepavadin enhances the bactericidal efficacies of tobramycin and amikacin. We further demonstrated that murepavadin enhances bacterial respiration activity and subsequent membrane potential, which promotes intracellular uptake of aminoglycoside antibiotics. In addition, the murepavadin-amikacin combination displayed a synergistic bactericidal effect in a murine pneumonia model.
Efficacy and effect on lipid profiles of switching to ainuovirine-based regimen versus continuing efavirenz-based regimen in people with HIV-1: 24-week results from a real-world, retrospective, multi-center cohort study
Authors: Wang Chunmei , Yu Xiaoli , Ke Yingchun , Fu Yanhua , Luo Yanhe , Li Ying , Bi Yanmei , Chen Xingqiong , Li Linghua , Zhao Xiuhong , Chen Zhong
Published: March 2024

Ainuovirine (ANV), a novel non-nucleoside reverse-transcriptase inhibitor (NNRTI), was approved in China in 2021. In a previous randomized phase 3 trial, ANV demonstrated non-inferior efficacy relative to efavirenz (EFV) and was associated with lower rates of dyslipidemia. In this study, we aimed to explore lipid changes in treatment-experienced people with human immunodeficiency virus (HIV)-1 (PWH) switching to ANV from EFV in real world. At week 24, 96.65% of patients in the ANV group and 93.25% in the EFV group had HIV-1 RNA levels below the limit of quantification (LOQ). Median changes from baseline in CD4 +T cell counts (37.0 vs 36.0 cells/µL,
P
= 0.886) and CD4+/CD8 +ratio (0.03 vs 0.10,
P
= 0.360) were similar between the two groups. The ANV group was superior to the EFV group in mean changes in total cholesterol (TC, −0.06 vs 0.26 mmol/L,
P
= 0.006), triglyceride (TG, −0.6 vs 0.14 mmol/L,
P
< 0.001), high-density lipoprotein cholesterol (HDL-C, 0.09 vs 0.08 mmol/L,
P
= 0.006), and low-density lipoprotein cholesterol (LDL-C, −0.18 vs 0.29 mmol/L,
P
< 0.001) at week 24. We also observed that a higher proportion of patients demonstrated improved TC (13.55% vs 4.45%,
P
= 0.015) or LDL-C (12.93% vs 6.89%,
P
= 0.017), and a lower proportion of patients showed worsened LDL-C (5.57% vs 13.52%,
P
= 0.017) with ANV than with EFV at week 24. In conclusion, we observed good efficacy and favorable changes in lipids in switching to ANV from EFV in treatment-experienced PWH in real world, indicating a promising switching option for PWH who may be more prone to metabolic or cardiovascular diseases.
Deciphering the molecular and functional basis of TMexCD1: the plasmid-encoded efflux pump of resistance-nodulation-division superfamily
Authors: Shang Yan , Zhang Ye , Wang Ruimin , Peng Yishu , Ding Bo , Liu Yuanxiang , Li Chongzhou , Feng Luhua , Liu Honglei , Yang Chunyu , Tang Yajie
Published: March 2024

Horizontal gene transfer has been demonstrated to be an important driver for the emergency of multidrug-resistant pathogens. Recently, a transferable gene cluster
tmexCD1-toprJ1
of the resistance-nodulation-division (RND) superfamily was identified in the plasmids of animal-derived
Klebsiella pneumoniae
strains, with a higher efflux capacity for various drugs than the
Escherichia coli
AcrAB-TolC homolog system. In this study, we focused on the differences in the inner membrane pump of these two systems and identified some key residues that contribute to the robust efflux activity of the TMexCD1 system. With the aid of homologous modeling and molecular docking, eight residues from the proximal binding pocket (PBP) and nine from the distal binding pocket (DBP) were selected and subjected to site-directed mutagenesis. Several of them, such as S134, I139, D181, and A290, were shown to be important for substrate binding in the DBP region, and all residues in PBP and DBP showed certain substrate preferences. Apart from the conservative switch loop (L613–623
TMexD1
) previously identified in the
E. coli
AcrB (EcAcrB), a relatively unconservative loop (L665–675
TMexD1
) at the bottom of PBP was proposed as a critical element for the robust activity of TMexD1, due to variations at sites E669, G670, N673, and S674 compared to EcAcrAB, and the significantly altered efflux activity due to their mutations. The conservation and flexibility of these key factors can contribute to the evolution of the RND efflux pumps and thus serve as potential targets for developing inhibitors to block the widespread of the TMexCD1 system.
Pseudomonas aeruginosa
ventricular assist device infections: findings from ineffective phage therapies in five cases
Authors: Aslam Saima , Roach Dwayne , Nikolich Mikeljon P. , Biswas Biswajit , Schooley Robert T. , Lilly-Bishop Kimberley A. , Rice Gregory K. , Cer Regina Z. , Hamilton Theron , Henry Matthew , Luong Tiffany , Salabarria Ann-Charlott , Sisk-Hackworth Laura , Filippov Andrey A. , Lebreton Francois , Hall Lindsey , Nir-Paz Ran , Onallah Hadil , Livni Gilat , Shostak Eran , Wieder-Finesod Anat , Yahav Dafna , Yerushalmy Ortal , Alkalay-Oren Sivan , Braunstein Ron , Khalifa Leron , Rimon Amit , Gelman Daniel , Hazan Ronen
Published: March 2024

Left ventricular assist devices (LVAD) are increasingly used for management of heart failure; infection remains a frequent complication. Phage therapy has been successful in a variety of antibiotic refractory infections and is of interest in treating LVAD infections. We performed a retrospective review of four patients that underwent five separate courses of intravenous (IV) phage therapy with concomitant antibiotic for treatment of endovascular
Pseudomonas aeruginosa
LVAD infection. We assessed phage susceptibility, bacterial strain sequencing, serum neutralization, biofilm activity, and shelf-life of phage preparations. Five treatments of one to four wild-type virulent phage(s) were administered for 14–51 days after informed consent and regulatory approval. There was no successful outcome. Breakthrough bacteremia occurred in four of five treatments. Two patients died from the underlying infection. We noted a variable decline in phage susceptibility following three of five treatments, four of four tested developed serum neutralization, and prophage presence was confirmed in isolates of two tested patients. Two phage preparations showed an initial titer drop. Phage biofilm activity was confirmed in two. Phage susceptibility alone was not predictive of clinical efficacy in
P. aeruginosa
endovascular LVAD infection. IV phage was associated with serum neutralization in most cases though lack of clinical effect may be multifactorial including presence of multiple bacterial isolates with varying phage susceptibility, presence of prophages, decline in phage titers, and possible lack of biofilm activity. Breakthrough bacteremia occurred frequently (while the organism remained susceptible to administered phage) and is an important safety consideration.
Toward the development of a molecular toolkit for the microbial remediation of per-and polyfluoroalkyl substances
Authors: Hu Miao , Scott Colin
Published: March 2024

Per- and polyfluoroalkyl substances (PFAS) are highly fluorinated synthetic organic compounds that have been used extensively in various industries owing to their unique properties. The PFAS family encompasses diverse classes, with only a fraction being commercially relevant. These substances are found in the environment, including in water sources, soil, and wildlife, leading to human exposure and fueling concerns about potential human health impacts. Although PFAS degradation is challenging, biodegradation offers a promising, eco-friendly solution. Biodegradation has been effective for a variety of organic contaminants but is yet to be successful for PFAS due to a paucity of identified microbial species capable of transforming these compounds. Recent studies have investigated PFAS biotransformation and fluoride release; however, the number of specific microorganisms and enzymes with demonstrable activity with PFAS remains limited. This review discusses enzymes that could be used in PFAS metabolism, including haloacid dehalogenases, reductive dehalogenases, cytochromes P450, alkane and butane monooxygenases, peroxidases, laccases, desulfonases, and the mechanisms of microbial resistance to intracellular fluoride. Finally, we emphasize the potential of enzyme and microbial engineering to advance PFAS degradation strategies and provide insights for future research in this field.
Impacts of litter microbial community on litter decomposition in the absence of soil microorganisms
Authors: Liu Jiaying , Ding Changjun , Teng Chao , Zhang Weixi , Su Xiaohua , Zhu Wenxu
Published: March 2024

What is the effect of phyllosphere microorganisms on litter decomposition in the absence of colonization by soil microorganisms? Here, we simulated the litter standing decomposition stage in the field to study the differences in the composition and structure of the phyllosphere microbial community after the mixed decomposition of
Populus
×
canadensis
and
Pinus sylvestris
var.
mongolica
litter. After 15 months of mixed decomposition, we discovered that litters that were not in contact with soil had an antagonistic effect (the actual decomposition rate was 18.18%, which is lower than the expected decomposition rate) and the difference between the litters themselves resulted in a negative response to litter decomposition. In addition, there was no significant difference in bacterial and fungal community diversity after litter decomposition. The litter bacterial community was negatively responsive to litter properties and positively responsive to the fungal community. Importantly, we found that bacterial communities had a greater impact on litter decomposition than fungi. This study has enriched our understanding of the decomposition of litter itself and provided a theoretical basis for further exploring the “additive and non-additive effects” of litter decomposition and the mechanism of microbial drive.

IMPORTANCE

The study of litter decomposition mechanism plays an important role in the material circulation of the global ecosystem. However, previous studies have often looked at contact with soil as the starting point for decomposition. But actually, standing litter is very common in forest ecosystems. Therefore, we used field simulation experiments to simulate the decomposition of litters without contact with soil for 15 months, to explore the combined and non-added benefits of the decomposition of mixed litters, and to study the influence of microbial community composition on the decomposition rate while comparing the differences of microbial communities.
Pyoluteorin regulates the biosynthesis of 2,4-DAPG through the TetR family transcription factor PhlH in
Pseudomonas protegens
Pf-5
Authors: Luo Li-Ming , Xu Hang , Zhang Nannan , Ge Honghua , Xiang Yun , Yang Hao , He Yong-Xing
Published: March 2024

Soil and rhizosphere bacteria act as a rich source of secondary metabolites, effectively fighting against a diverse array of pathogens. Certain
Pseudomonas
species harbor biosynthetic gene clusters for producing both pyoluteorin and 2,4-diacetylphloroglucinol (2,4-DAPG), which are polyketides that exhibit highly similar antimicrobial spectrum against bacteria and fungi or oomycete. A complex cross talk exists between pyoluteorin and 2,4-DAPG biosynthesis, and production of 2,4-DAPG was strongly repressed by pyoluteorin, yet the underlying mechanism is still elusive. In this study, we find that the TetR family transcription factor PhlH is involved in the cross talk between pyoluteorin and 2,4-DAPG biosynthesis. PhlH binds to a palindromic sequence within the promoter of
phlG
(PphlG), which encodes a C-C bond hydrolase responsible for degrading 2,4-DAPG. As a signaling molecule, pyoluteorin disrupts the PhlH-PphlG complex by binding to PhlH, leading to decreased levels of 2,4-DAPG. Proteomics data suggest that pyoluteorin regulates multiple physiological processes including fatty acid biosynthesis and transportation of taurine, siderophore, and amino acids. Our work not only reveals a novel mechanism of cross talk between pyoluteorin and 2,4-DAPG biosynthesis, but also highlights pyoluteorin’s role as a messenger in the complex communication network of
Pseudomonas
.

IMPORTANCE

Antibiosis serves as a crucial defense mechanism for microbes against invasive bacteria and resource competition. These bacteria typically orchestrate the production of multiple antibiotics in a coordinated fashion, wherein the synthesis of one antibiotic inhibits the generation of another. This strategic coordination allows the bacterium to focus its resources on producing the most advantageous antibiotic under specific circumstances. However, the underlying mechanisms of distinct antibiotic production in bacterial cells remain largely elusive. In this study, we reveal that the TetR family transcription factor PhlH detects the secondary metabolite pyoluteorin and mediates the cross talk between pyoluteorin and 2,4-DAPG biosynthesis in the biocontrol strain
Pseudomonas protegens
Pf-5. These findings hold promise for future research, potentially informing the manipulation of these systems to enhance the effectiveness of biocontrol agents.
Comparison of the performance of multiple whole-genome sequence-based tools for the identification of
Bacillus cereus sensu stricto
biovar
Thuringiensis
Authors: Chung Taejung , Salazar Abimel , Harm Grant , Johler Sophia , Carroll Laura M. , Kovac Jasna
Published: March 2024

The
Bacillus cereus sensu stricto
(
s.s
.) species comprises strains of biovar
Thuringiensis
(
Bt
) known for their bioinsecticidal activity, as well as strains with foodborne pathogenic potential.
Bt
strains are identified (i) based on the production of insecticidal crystal proteins, also known as Bt toxins, or (ii) based on the presence of
cry
,
cyt
, and
vip
genes, which encode Bt toxins. Multiple bioinformatics tools have been developed for the detection of crystal protein-encoding genes based on whole-genome sequencing (WGS) data. However, the performance of these tools is yet to be evaluated using phenotypic data. Thus, the goal of this study was to assess the performance of four bioinformatics tools for the detection of crystal protein-encoding genes. The accuracy of sequence-based identification of
Bt
was determined in reference to phenotypic microscope-based screening for the production of crystal proteins. A total of 58 diverse
B. cereus sensu lato
strains isolated from clinical, food, environmental, and commercial biopesticide products underwent WGS. Isolates were examined for crystal protein production using phase contrast microscopy. Crystal protein-encoding genes were detected using BtToxin_Digger, BTyper3, IDOPS (identification of pesticidal sequences), and Cry_processor. Out of 58 isolates, the phenotypic production of crystal proteins was confirmed for 18 isolates. Specificity and sensitivity of
Bt
identification based on sequences were 0.85 and 0.94 for BtToxin_Digger, 0.97 and 0.89 for BTyper3, 0.95 and 0.94 for IDOPS, and 0.88 and 1.00 for Cry_processor, respectively. Cry_processor predicted crystal protein production with the highest specificity, and BtToxin_Digger and IDOPS predicted crystal protein production with the highest sensitivity. Three out of four tested bioinformatics tools performed well overall, with IDOPS achieving high sensitivity and specificity (>0.90).

IMPORTANCE

Strains of
Bacillus cereus sensu stricto
(
s.s
.) biovar
Thuringiensis
(
Bt
) are used as organic biopesticides
. Bt
is differentiated from the foodborne pathogen
Bacillus cereus s.s
. by the production of insecticidal crystal proteins. Thus, reliable genomic identification of biovar
Thuringiensis
is necessary to ensure food safety and facilitate risk assessment. This study assessed the accuracy of whole-genome sequencing (WGS)-based identification of
Bt
compared to phenotypic microscopy-based screening for crystal protein production. Multiple bioinformatics tools were compared to assess their performance in predicting crystal protein production. Among them, identification of pesticidal sequences performed best overall at WGS-based
Bt
identification.