Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo

BACKGROUND

Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39 °C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37 °C, by using RNAseq and physiological assays including in vivo experiments.

RESULTS

In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes in both species. Altered metabolic features at 39 °C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39 °C, they upregulated ethanol oxidation-related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα, and pmsβ genes at 39 °C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphyloxantin production, and a decrease in biofilm formation at 39 °C. On the side of PA monocultures, we observed an increase in extracellular lipase and protease and biofilm formation at 39 °C along with a decrease in the motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in vitro and in vivo. S. aureus monocultured at 39οC showed a decrease in cellular invasion and an increase in IL-8-but not in IL-6-production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39 °C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37 and 39 °C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39 °C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39 °C comparing with 37 °C.

CONCLUSIONS

Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

Unpacking the relationship between technological conflicts, dissatisfaction, and social media discontinuance intention: An integrated theoretical perspective

Previous research has largely overlooked the examination of the association between family, work, and personal (FWP) conflict, user dissatisfaction, and subsequent discontinuation intention in the context of social networking sites (SNS). Addressing this research gap, the present study aims to present an integrated theoretical perspective that combines Expectancy Disconfirmation Theory (EDT) and Merton's functions. By doing so, we seek to provide a comprehensive understanding of the factors influencing SNS withdrawal behavior. To achieve this objective, data were collected from 360 SNS users using a time-lag method across three waves, and Structural Equation Modeling (SEM) was employed for data analysis. The findings of our study reveal that all three disconfirmation-based factors (i.e., FWP conflicts) positively contribute to SNS user dissatisfaction, which subsequently leads to users' intention to discontinue their SNS usage. Additionally, we explored the moderating role of Merton's functions, specifically manifest and latent functions, in influencing users' decisions to discontinue SNS use. The results indicate that the manifest functions of social media weaken the relationship between dissatisfaction and discontinuation intention, whereas the latent functions do not exhibit a significant interaction effect. By proposing a dual theoretically integrated mechanism of SNS discontinuation intention, study contributes to the existing literature in the field of information systems. Furthermore, our findings provide valuable insights for managers regarding the timing and manner in which social media FWP conflicts can lead to user dissatisfaction. This knowledge can assist in the development of effective strategies aimed at retaining users in SNS and enhancing their overall user experience.

Fever-like temperature impacts on Staphylococcus aureus and Pseudomonas aeruginosa interaction, physiology, and virulence both in vitro and in vivo

Background

Staphylococcus aureus and Pseudomonas aeruginosa cause a wide variety of bacterial infections and coinfections, showing a complex interaction that involves the production of different metabolites and metabolic changes. Temperature is a key factor for bacterial survival and virulence and within the host, bacteria could be exposed to an increment in temperature during fever development. We analyzed the previously unexplored effect of fever-like temperatures (39°C) on S. aureus USA300 and P. aeruginosa PAO1 microaerobic mono- and co-cultures compared with 37°C, by using RNAseq and physiological assays including in-vivo experiments.

Results

In general terms both temperature and co-culturing had a strong impact on both PA and SA with the exception of the temperature response of monocultured PA. We studied metabolic and virulence changes on both species. Altered metabolic features at 39°C included arginine biosynthesis and the periplasmic glucose oxidation in S. aureus and P. aeruginosa monocultures respectively. When PA co-cultures were exposed at 39°C they upregulated ethanol oxidation related genes along with an increment in organic acid accumulation. Regarding virulence factors, monocultured SA showed an increase in the mRNA expression of the agr operon and hld, pmsα and pmsβ genes at 39°C. Supported by mRNA data, we performed physiological experiments and detected and increment in hemolysis, staphylxantin production and a decrease in biofilm formation at 39°C. On the side of PA monocultures, we observed increase in extracellular lipase and protease and biofilm formation at 39°C along with a decrease in motility in correlation with changes observed at mRNA abundance. Additionally, we assessed host-pathogen interaction both in-vitro and in-vivo . S. aureus monocultured at 39°C showed a decrease in cellular invasion and an increase in IL-8 -but not in IL-6- production by A549 cell line. PA also decreased its cellular invasion when monocultured at 39°C and did not induce any change in IL-8 or IL-6 production. PA strongly increased cellular invasion when co-cultured at 37°C and 39°C. Finally, we observed increased lethality in mice intranasally inoculated with S. aureus monocultures pre-incubated at 39°C and even higher levels when inoculated with co-cultures. The bacterial burden for P. aeruginosa was higher in liver when the mice were infected with co-cultures previously incubated at 39°C comparing with 37°C.

Conclusion

Our results highlight a relevant change in the virulence of bacterial opportunistic pathogens exposed to fever-like temperatures in presence of competitors, opening new questions related to bacteria-bacteria and host-pathogen interactions and coevolution.

How a Despotic Project Manager Jeopardizes Project Success: The Role of Project Team Members’ Emotional Exhaustion and Emotional Intelligence

Drawing on conservation of resources theory, our study investigates whether a project manager’s despotic leadership style influences project success directly and indirectly through the underlying mechanism of project team members’ emotional exhaustion. Additionally, the moderating role of project team members’ emotional intelligence (EI) between despotic leadership and emotional exhaustion is also examined. Data were collected from the project-based employees working in telecommunications organizations (n = 250) using a time-lagged survey in three waves. The result indicates that despotic leadership has a significant negative influence on project success, and emotional exhaustion partially mediates this relationship. Moreover, conforming to a rare line of inquiry that there is a dark side to being emotionally intelligent, our findings show that the effect of despotic leadership style on emotional exhaustion is stronger when a project team member is highly emotionally intelligent. We discuss the theoretical and practical implications of these findings.

Linking green supply chain management practices with competitiveness during covid 19: The role of big data analytics

Although the global green supply chain management (GSCM) practice has attracted considerable scholarly attention, its efficacy for environmental management systems (EMS) and market competitiveness during Covid-19 has not been fully capitalized. Therefore, the existing literature indicates that the important link between GSCM, EMS, and market competitiveness is missing as supply management is crucial to maintaining market competitiveness. To fill this research gap, the current study examines whether EMS affects the relationship between GSCM practices and market competitiveness. We also propose the moderating role of big data analytics and artificial intelligence (BDA-AI) and environmental visibility on these associations from a Covid-19 perspective. We tested a proposed model using the primary data (N = 283) from regression-based structural equation modeling (SEM). The results provide empirical support for the impact of GSCM on ESM and market competitiveness. Furthermore, the results show that BDA-AI and environmental visibility strengthen the positive relationship between GSCM-EMS and EMS and market competitiveness, respectively. Current research provides thoughtful insights for supply chain practitioners, policymakers, managers, and academics that organizations should opt for formal EMS, BDA-AI, and environmental visibility to achieve market competitiveness, even in times of crisis such as Covid-19.

Untangling the role of power in knowledge sharing and job performance: the mediating role of discrete emotions

Purpose

The purpose of this study is to empirically examine how psychological power explains dual conflicting emotions, influences and jeopardises knowledge sharing and eventually affects job performance. Specifically, this study argues that psychological power can induce feelings of pride and anxiety, which have opposite downstream effects on employees’ knowledge sharing and tasks, proactive and affiliative (TPA) performances.

Design/methodology/approach

This study tested the model using three waves of multi-source data from 46 teams and 357 respondents in the information technology and software industry in China. This study used multilevel structural equation modelling with Mplus 7.4 to examine the within-level team variance and thereby estimated the confidence intervals for the direct and indirect paths.

Findings

The results indicate that increased psychological power can cause contradictory emotions (i.e. pride and anxiety). Pride positively mediates the indirect influence of psychological power on knowledge sharing and TPA performance, while anxiety negatively mediates the above-mentioned indirect relationships.

Research limitations/implications

This study provides a novel perspective on how psychological forces shape people’s emotional experiences and subsequently their motivation to share knowledge and job performance. By integrating the existing power literature rooted in the approach/inhibition theory of power and cognitive appraisal theory of emotion, we identify two discrete emotions as underlying mechanisms between increased psychological power and motivation to share knowledge and job performance.

Practical implications

This research provides insights for managers regarding the ways in which psychological power can stimulate individuals to engage in negative behaviour towards others. Managers, in turn, must consider self-regulation to control this negative impact.

Originality/value

This study is among the earliest to examine the role of discrete positive and negative emotions caused by increased psychological power, which subsequently affect knowledge sharing and TPA performance.

Explore the mechanism for seafarers to reconnect with work after post-pandemic psychological distress (PAPIST19): The moderating role of health-supporting climate

Covid-19 has disrupted the lives of employees all over the world. After experiencing a prolonged yet ongoing destructive event (i.e. Covid-19), finding an effective and non-invasive way to get employees back and engage in work is a huge challenge for scholars. Few studies have focused on returning to work after a traumatic event (limited time), but the post-pandemic psychological stress caused by the Covid-19 (PAPIST₁₉) has not received much attention. Current research addresses this gap and uses a comprehensive model drawn from the transactional model of stress and the Kahn psychological framework to advance the work of predicting PAPIST₁₉. Specifically, the current research investigates how PAPIST₁₉ is related to job engagement, and emotional exhaustion and how job reattachment mediates the relationship. In addition, we use health support climate (HSC) as a boundary condition in our model, which can weaken the impact of PAPIST₁₉ and enhance the effectiveness of job reattachment in reducing emotional exhaustion and increasing job engagement. To test our model, we collected data in multiple waves from Chinese seaports, where seafarers came to work after the restrictions were lifted in China. The current research is one of the earliest scholarly contributions. It paved the way for the research to solve the problem of workers returning to work after large-scale destructive events, and discussed important implications.

Untangling the Adverse Effect of SNS Stressors on Academic Performance and Its Impact on Students’ Social Media Discontinuation Intention: The Moderating Role of Guilt

In recent research on information systems (IS), the advantages of social networking sites (SNS) in the education field have received widespread attention. However, excessive use of SNSs will negatively impact students academic performance, leading to the discontinuation intentions of social media. Therefore, this study aims to investigate an extended research model drawing on the stress-strain-outcome (SSO) theory and transactional model of stress to examine the adverse effect of SNS stressors on academic performance. The required data from the target population was collected through a structured questionnaire. The valid sample size of this study was n = 505 respondents. The data were analyzed using structural equation modeling (SEM) in AMOS (version 23.0) to examine the study hypotheses. The results confirmed that the SNS stressors, namely, social overload, information overload, and system feature overload, induce strain in terms of poor academic performance by generating feelings of guilt. It also unravels the effect of guilt feelings on discontinuance intention indirectly. This study offers imperative theoretical and practical implications.

Impact of big data analytics on sales performance in pharmaceutical organizations: The role of customer relationship management capabilities

In this era of technology development, every business wants to equip its salesforce with a sustainable salesforce automation system to improve sales performance and customer relationship management (CRM) capabilities. This study investigates the impact of big data analytics (BDA) on CRM capabilities and the sales performance of pharmaceutical organizations. A research model was tested based on 416 valid responses collected from pharmaceutical companies through a structured questionnaire. Structural equation modeling (SEM) was employed using Smart-PLS3 to confirm the contribution of BDA to improving CRM capabilities and sales performance. The study finds that individual characteristics such as self-efficacy, playfulness, and social norms, along with organizational characteristics such as voluntariness, user involvement, user participation, and management support, are positive predictors of salesforce perception of BDA. This positive perception of BDA increased the person-technology fit in the salesforce, which ultimately increased the CRM capabilities and sales performance.