The Putative Prenyltransferase Nus1 is Required for Filamentation in the Human Fungal Pathogen Candida albicans.

Candida albicans is a major fungal pathogen of humans that can cause serious systemic infections in vulnerable immunocompromised populations. One of its virulence attributes is its capacity to transition between yeast and filamentous morphologies, but our understanding of this process remains incomplete. Here, we analyzed data from a functional genomic screen performed with the C. albicans Gene Replacement And Conditional Expression (GRACE) collection to identify genes crucial for morphogenesis in host-relevant conditions. Through manual scoring of microscopy images coupled with analysis of each image using a deep learning-based method termed Candescence, we identified 307 genes important for filamentation in tissue culture medium at 37 °C with 5% CO2. One such factor was orf19.5963, which is predicted to encode the prenyltransferase Nus1 based on sequence homology to Saccharomyces cerevisiae. We further showed that Nus1 and its predicted interacting partner Rer2 are important for filamentation in multiple liquid filament-inducing conditions as well as for wrinkly colony formation on solid agar. Finally, we highlight that Nus1 and Rer2 likely govern C. albicans morphogenesis due to their importance in intracellular trafficking, as well as maintaining lipid homeostasis. Overall, this work identifies Nus1 and Rer2 as important regulators of C. albicans filamentation and highlights the power of functional genomic screens in advancing our understanding of gene function in human fungal pathogens.

Respiration supports intraphagosomal filamentation and escape of Candida albicans from macrophages.

IMPORTANCE: Candida albicans is a leading human fungal pathogen that often causes life-threatening infections in immunocompromised individuals. The ability of C. albicans to transition between yeast and filamentous forms is key to its virulence, and this occurs in response to many host-relevant cues, including engulfment by host macrophages. While previous efforts identified C. albicans genes required for filamentation in other conditions, the genes important for this morphological transition upon internalization by macrophages remained largely enigmatic. Here, we employed a functional genomic approach to identify genes that enable C. albicans filamentation within macrophages and uncovered a role for the mitochondrial ribosome, respiration, and the SNF1 AMP-activated kinase complex. Additionally, we showed that glucose uptake and glycolysis by macrophages support C. albicans filamentation. This work provides insights into the metabolic dueling that occurs during the interaction of C. albicans with macrophages and identifies vulnerabilities in C. albicans that could serve as promising therapeutic targets.

What are the barriers and facilitators to polio vaccination and eradication programs? A systematic review.

Global efforts to eradicate polio by the Global Polio Eradication Initiative agency partners and country-level stakeholders have led to the implementation of global polio vaccination programs. This study presents the findings of existing studies regarding the barriers and facilitators that countries face when implementing polio interventions. A comprehensive search was conducted in OVID Medline, OVID Embase, EBSCO CINAHL Plus, and Web of Science. Eligible studies underwent quality assessment. A qualitative evidence synthesis approach was conducted and aligned to the Consolidated Framework for Implementation Research (CFIR). The search identified 4147 citations, and following the removal of duplicates and screening according to our inclusion/exclusion criteria, 20 articles were eligible for inclusion in the review. Twelve countries were represented in this review, with India, Nigeria, Pakistan, Ethiopia, and Afghanistan having the most representation of available studies. We identified 36 barriers and 16 facilitators. Seven themes emerged from these barriers and facilitators: fear, community trust, infrastructure, beliefs about the intervention, influential opinions, intervention design, and geo-politics. The most frequently cited CFIR constructs for the facilitators and barriers were knowledge and beliefs about the intervention, followed by available resources. This study identified a wide range of barriers and facilitators to polio vaccination implementation across the globe, adding to the scarce body of literature on these barriers and facilitators from an implementation perspective and using a determinant framework. The diversity of factors among different groups of people or countries highlights the relevance of contexts. Implementers should be conversant with the contexts within which polio eradication programs boost intervention coverage and capacity. This study provides policymakers, practitioners, and researchers with a tool for planning and designing polio immunization programs. Trial registration: A protocol for this systematic review was developed and uploaded onto the PROSPERO international prospective register of systematic reviews database (Registration number: CRD42020222115).

Targeted genome editing in vivo corrects a Dmd duplication restoring wild-type dystrophin expression.

Tandem duplication mutations are increasingly found to be the direct cause of many rare heritable diseases, accounting for up to 10% of cases. Unfortunately, animal models recapitulating such mutations are scarce, limiting our ability to study them and develop genome editing therapies. Here, we describe the generation of a novel duplication mouse model, harboring a multi-exonic tandem duplication in the Dmd gene which recapitulates a human mutation. Duplication correction of this mouse was achieved by implementing a single-guide RNA (sgRNA) CRISPR/Cas9 approach. This strategy precisely removed a duplication mutation in vivo, restored full-length dystrophin expression, and was accompanied by improvements in both histopathological and clinical phenotypes. We conclude that CRISPR/Cas9 represents a powerful tool to accurately model and treat tandem duplication mutations. Our findings will open new avenues of research for exploring the study and therapeutics of duplication disorders.