The multidrug efflux pump regulator AcrR directly represses motility in Escherichia coli.

Efflux and motility are two key biological functions in bacteria. Recent findings have shown that efflux impacts flagellum biosynthesis and motility in Escherichia coli and other bacteria. AcrR is known to be the major transcriptional repressor of AcrAB-TolC, the main multidrug efflux pump in E. coli and other Enterobacteriaceae. However, the underlying molecular mechanisms of how efflux and motility are co-regulated remain poorly understood. Here, we have studied the role of AcrR in direct regulation of motility in E. coli. By combining bioinformatics, electrophoretic mobility shift assays (EMSAs), gene expression, and motility experiments, we have found that AcrR represses motility in E. coli by directly repressing transcription of the flhDC operon, but not the other flagellum genes/operons tested. flhDC encodes the master regulator of flagellum biosynthesis and motility genes. We found that such regulation primarily occurs by direct binding of AcrR to the flhDC promoter region containing the first of the two predicted AcrR-binding sites identified in this promoter. This is the first report of direct regulation by AcrR of genes unrelated to efflux or detoxification. Moreover, we report that overexpression of AcrR restores to parental levels the increased swimming motility previously observed in E. coli strains without a functional AcrAB-TolC pump, and that such effect by AcrR is prevented by the AcrR ligand and AcrAB-TolC substrate ethidium bromide. Based on these and prior findings, we provide a novel model in which AcrR senses efflux and then co-regulates efflux and motility in E. coli to maintain homeostasis and escape hazards. IMPORTANCE Efflux and motility play a major role in bacterial growth, colonization, and survival. In Escherichia coli, the transcriptional repressor AcrR is known to directly repress efflux and was later found to also repress flagellum biosynthesis and motility by Kim et al. (J Microbiol Biotechnol 26:1824-1828, 2016, doi: 10.4014/jmb.1607.07058). However, it remained unknown whether AcrR represses flagellum biosynthesis and motility directly and through which target genes, or indirectly because of altering the amount of efflux. This study reveals that AcrR represses flagellum biosynthesis and motility by directly repressing the expression of the flhDC master regulator of flagellum biosynthesis and motility genes, but not the other flagellum genes tested. We also show that the antimicrobial, efflux pump substrate, and AcrR ligand ethidium bromide regulates motility via AcrR. Overall, these findings support a novel model of direct co-regulation of efflux and motility mediated by AcrR in response to stress in E. coli.

Masculine men do not like feminine wording: The effectiveness of gendered wording in health promotion leaflets in the UK.

Following mixed-methods sequential design and drawing on the message-audience congruence concept and homophily theory, across three studies in the UK, we examined the effect of gendered wording and endorser's gender on the effectiveness of leaflets promoting walking. In Study 1, a mall-intercept study achieved 247 completed questionnaires. Results demonstrated that men and women indicated the highest behavioural intentions for communal wording presented by a male endorser. However, pairwise comparisons revealed that when the wording of the advert was agentic and the endorser was male, males indicated significantly higher scores of behavioural intentions compared with females. Attitude towards the ad for women was highest for communal wording/female endorser; for men it was for agentic wording/male endorser. In Study 2, consumers' views towards the gendered content were explored in 20 semi-structured interviews. In study 3 we examined the impact of the respondent's gender role identity on gendered content effectiveness. Overall, when controlled for level of gender role identity, only masculine males evaluated leaflets featuring communal wording negatively which suggests that wording matters only for masculine males, but not for other men and women. Theoretically, we identified that gender-based message-respondent congruence is not a necessary aspect of communications to be effective, except for one group: masculine males. Our study identified dominant gender role identity as a factor that explained respondents' preferences for presented stimuli. Specifically, males who display masculine gender role identity differ in evaluations of communal wording from all other groups. Social and commercial marketers who target men and women with exercise-related services should consider the use of agentic wording endorsed by a male endorser when targeting masculine men to increase the likelihood of eliciting positive attitudes towards the communication. However, such distinctions should not be associated with differences in women's evaluations or men who do not report masculine gender role identity.

Variation in the timing of Covid-19 communication across universities in the UK.

During the Covid-19 pandemic, universities in the UK used social media to raise awareness and provide guidance and advice about the disease to students and staff. We explain why some universities used social media to communicate with stakeholders sooner than others. To do so, we identified the date of the first Covid-19 related tweet posted by each university in the country and used survival models to estimate the effect of university-specific characteristics on the timing of these messages. In order to confirm our results, we supplemented our analysis with a study of the introduction of coronavirus-related university webpages. We find that universities with large numbers of students are more likely to use social media and the web to speak about the pandemic sooner than institutions with fewer students. Universities with large financial resources are also more likely to tweet sooner, but they do not introduce Covid-19 webpages faster than other universities. We also find evidence of a strong process of emulation, whereby universities are more likely to post a coronavirus-related tweet or webpage if other universities have already done so.