Impact of resilience and environmental stress on burnout of students in public and private dental schools in Western Saudi Arabia

Background

Dental students' burnout has been repeatedly reported in the literature; however, there is little information about the contributing factors in different contexts and settings.

Aims

This study aimed to investigate the correlation between burnout among undergraduate dental students and sociodemographic (specifically gender), psychological (resilience), and structural factors (dental environment stress).

Subjects and Methods

An online cross-sectional survey questionnaire was distributed among a convenience sample of 500 undergraduate Saudi dental students. The survey included questions about sociodemographic factors (gender, level of education, academic achievement, type of school [public or private], and living arrangements). The study also included items that allowed assessment of students' burnout using the Maslach Burnout Inventory (MBI) and assessment of student environmental stress and resilience using the Dental Environment Stress Scale (DESS) and the Brief Resilience Scale (BRS). Descriptive statistics, univariate, and linear regression analyses were performed.

Results

The response rate was 67% (male = 119, female = 216). Univariable analysis showed that gender, level of education, and DESS and BRS scores correlated significantly (P <.05) with MBI scores. Adjusted multiple linear regression lends further support to that the MBI scores negatively correlated with the BRS score but positively correlated with the DESS score (β = -0.29, P <.001; β = 0.44, P <.001, respectively).

Conclusions

Within the limitations of this study, the findings demonstrated that increases in resilience correlated significantly with decreases in burnout and increases in environmental stress correlated significantly with increases in burnout among dental students. However, gender had no influence on burnout.

The Shigella ProU system is required for osmotic tolerance and virulence

To cope with hyperosmotic stress encountered in the environments and in the host, the pathogenic as well as non-pathogenic microbes use diverse transport systems to obtain osmoprotectants. To study the role of Shigella sonnei ProU system in response to hyperosmotic stress and virulence, we constructed deletion and complementation strains of proV and used an RNAi approach to silence the whole ProU operon. We compared the response between wild type and the mutants to the hyperosmotic pressure in vitro, and assessed virulence properties of the mutants using gentamicin protection assay as well as Galleria mellonella moth larvae model. In response to osmotic stress by either NaCl or KCl, S. sonnei highly up-regulates transcription of proVWX genes. Supplementation of betaine greatly elevates the growth of the wild type S. sonnei but not the proV mutants in M9 medium containing 0.2 M NaCl or 0.2 M KCl. The proV mutants are also defective in intracellular growth compared with the wild type. The moth larvae model of G. mellonella shows that either deletion of proV gene or knockdown of proVWX transcripts by RNAi significantly attenuates virulence. ProU system in S. sonnei is required to cope with osmotic stress for survival and multiplication in vitro, and for infection.

The Multivalent Adhesion Molecule SSO1327 plays a key role in Shigella sonnei pathogenesis

Shigella sonnei is a bacterial pathogen and causative agent of bacillary dysentery. It deploys a type III secretion system to inject effector proteins into host epithelial cells and macrophages, an essential step for tissue invasion and immune evasion. Although the arsenal of bacterial effectors and their cellular targets have been studied extensively, little is known about the prerequisites for deployment of type III secreted proteins during infection. Here, we describe a novel S. sonnei adhesin, SSO1327 which is a multivalent adhesion molecule (MAM) required for invasion of epithelial cells and macrophages and for infection in vivo. The S. sonnei MAM mediates intimate attachment to host cells, which is required for efficient translocation of type III effectors into host cells. SSO1327 is non-redundant to IcsA; its activity is independent of type III secretion. In contrast to the up-regulation of IcsA-dependent and independent attachment and invasion by deoxycholate in Shigella flexneri, deoxycholate negatively regulates IcsA and MAM in S. sonnei resulting in reduction in attachment and invasion and virulence attenuation in vivo. A strain deficient for SSO1327 is avirulent in vivo, but still elicits a host immune response.