The bacterial cytoskeleton modulates motility, type 3 secretion, and colonization in Salmonella.

Although there have been great advances in our understanding of the bacterial cytoskeleton, major gaps remain in our knowledge of its importance to virulence. In this study we have explored the contribution of the bacterial cytoskeleton to the ability of Salmonella to express and assemble virulence factors and cause disease. The bacterial actin-like protein MreB polymerises into helical filaments and interacts with other cytoskeletal elements including MreC to control cell-shape. As mreB appears to be an essential gene, we have constructed a viable ΔmreC depletion mutant in Salmonella. Using a broad range of independent biochemical, fluorescence and phenotypic screens we provide evidence that the Salmonella pathogenicity island-1 type three secretion system (SPI1-T3SS) and flagella systems are down-regulated in the absence of MreC. In contrast the SPI-2 T3SS appears to remain functional. The phenotypes have been further validated using a chemical genetic approach to disrupt the functionality of MreB. Although the fitness of ΔmreC is reduced in vivo, we observed that this defect does not completely abrogate the ability of Salmonella to cause disease systemically. By forcing on expression of flagella and SPI-1 T3SS in trans with the master regulators FlhDC and HilA, it is clear that the cytoskeleton is dispensable for the assembly of these structures but essential for their expression. As two-component systems are involved in sensing and adapting to environmental and cell surface signals, we have constructed and screened a panel of such mutants and identified the sensor kinase RcsC as a key phenotypic regulator in ΔmreC. Further genetic analysis revealed the importance of the Rcs two-component system in modulating the expression of these virulence factors. Collectively, these results suggest that expression of virulence genes might be directly coordinated with cytoskeletal integrity, and this regulation is mediated by the two-component system sensor kinase RcsC.

The role of international support programmes in global health security capacity building: A scoping review.

Large scale public health emergencies such as COVID-19 demonstrate the importance of Global Health Security (GHS) and highlight the necessity of resilient public health systems capable of preparing for, detecting, managing, and recovering from such emergencies. Many international programmes support low- and middle-income countries (LMICs) to strengthen public health capabilities for compliance with the International Health Regulations (IHR). This narrative review seeks to identify key characteristics and factors necessary for effective and sustainable IHR core capacity development, establishing roles for international support and some principles of good practice. We reflect on the "what" and the "how" of international support approaches, highlighting the importance of equitable partnerships and bi-directional learning, and inviting global introspection and re-framing of what capable and developed public health systems look like.

Uptake of monoaromatic hydrocarbons during biodegradation by FadL channel-mediated lateral diffusion.

In modern societies, biodegradation of hydrophobic pollutants generated by industry is important for environmental and human health. In Gram-negative bacteria, biodegradation depends on facilitated diffusion of the pollutant substrates into the cell, mediated by specialised outer membrane (OM) channels. Here we show, via a combined experimental and computational approach, that the uptake of monoaromatic hydrocarbons such as toluene in Pseudomonas putida F1 (PpF1) occurs via lateral diffusion through FadL channels. Contrary to classical diffusion channels via which polar substrates move directly into the periplasmic space, PpF1 TodX and CymD direct their hydrophobic substrates into the OM via a lateral opening in the channel wall, bypassing the polar barrier formed by the lipopolysaccharide leaflet on the cell surface. Our study suggests that lateral diffusion of hydrophobic molecules is the modus operandi of all FadL channels, with potential implications for diverse areas such as biodegradation, quorum sensing and gut biology.

Improving Management of Respiratory Tract Infections in Community Pharmacies and Promoting Antimicrobial Stewardship: A Cluster Randomised Control Trial with a Self-Report Behavioural Questionnaire and Process Evaluation.

In England, 81% of all antibiotic prescriptions originate in primary care/community settings, of which up to 20% are thought to be inappropriate. Community pharmacies are often the first point of community contact for patients with suspected infections; providing an opportunity for community pharmacy teams to promote antimicrobial stewardship (AMS). The objective of the study was to improve the management of infections and antimicrobial stewardship in community pharmacies. The study methodology included a non-blinded cluster randomised control trial with pharmacy staff in 272 community pharmacies in England. The intervention arm received an AMS webinar and a patient facing respiratory tract infection (RTI) leaflet (TARGET TYI-RTI) for use in everyday practice for four weeks. The control arm received a webinar on how to participate in the study. The primary outcome was self-reported referrals to general practitioners (GPs). The secondary outcomes were; provision of self-care advice/ written information to patients, referrals to pharmacists, sign-posting to non-prescription medicines and common barriers and facilitators to advice-giving in community pharmacies. Ethics approval was granted by the Public Health England Research Ethics and Governance Group. 66.91% (182 of 272) of pharmacies provided 3649 patient consultation data reports across both arms. Use of the leaflet was associated with a lower likelihood of referrals to GPs for certain RTIs (p < 0.05) and a more frequent provision of self-care advice than the control (p = 0.06). Opportunities to deliver self-care advice were limited due to lack of time. Pharmacy staff had good motivation and capability for managing self-limiting infections but the opportunity to do so was a perceived barrier. Use of the TARGET leaflet facilitated pharmacy staff to give more self-care advice and decreased referrals to GPs.

Antimicrobial Stewardship Programmes in Community Healthcare Organisations in England: A Cross-Sectional Survey to Assess Implementation of Programmes and National Toolkits.

OBJECTIVE: The aim of this study was to assess antimicrobial stewardship activities in Community Healthcare Organisations (CHOs) with focus on the implementation of the two national antimicrobial stewardship toolkits, TARGET (Treat Antibiotics Responsibly, Guidance, Education, Tools) and SSTF (Start Smart, then Focus). The study utilised a web-based survey comprising 34 questions concerning antimicrobial policies and awareness and implementation of antimicrobial stewardship toolkits. This was distributed to pharmacy teams in all 26 CHOs in England. Twenty CHOs (77%) responded. An antimicrobial stewardship (AMS) committee was active in 50% of CHOs; 25% employed a substantive pharmacist post and 70% had a local antibiotic policy. Fourteen of the responding CHOs were aware of both AMS toolkits, five organisations were aware of either SSTF or TARGET, and one organisation was not aware of either toolkit. Of the organisations aware of SSTF and TARGET, eight had formally reviewed both toolkits, though three had not reviewed either. Less than half of the respondents had developed local action plans for either toolkit. National guidance in England has focused attention on initiatives to improve AMS implementation in primary and secondary care; more work is required to embed AMS activities and the implementation of national AMS toolkit recommendations within CHOs.