Ugolini, S. | bioRxiv Science

bioRxiv2024

Dimalis: A complete standalone pipeline to analyse prokaryotic cell growth from time-lapse imaging

Real-time imaging of bacterial cell division, population growth and behaviour is essential for our understanding of microbial-catalyzed processes at the microscale. However, despite the relative ease by which high resolution imaging data can be acquired, the extraction of relevant cell features from images remains cumbersome. Here we present a versatile pipeline for automated extraction of bacterial cell features from standalone or time-resolved image series, with standardized data output for easy downstream processing. The input consist of phase-contrast images with or without additional fluorescence details, which are denoised to account for potential out-of-focus regions, and segmented to outline the morphologies of individual cells. Cells are then tracked over subsequent time frame images to provide genealogy or microcolony spatial information. We test the pipeline with eight different bacterial strains, cultured in microfluidics systems with or without nutrient flow, or on agarose miniature surfaces to follow microcolony growth. Examples of downstream processing in form of extraction of growth kinetic parameters or bistable cell differentiation are provided. The pipeline is wrapped in a Docker to facilitate installation, consistent processing and avoiding constant software updates.

microbiology↗

bioRxiv2023

Gut microbiota promotes pain chronicity in Myosin1A deficient male mice

Over the past decade, the gut microbiota has emerged as an important regulator of nervous systems health and disease states1. Yet, its contribution to the pathogenesis of chronic somatic pain remains poorly documented. Chronic pain is a heavily debilitating disease affecting more than 1.5 billion people worldwide that can manifest through a long-lasting hypersensitivity to mechanical and/or thermal stimulations2,3. Maladaptive responses of dorsal root ganglia (DRG) neurons and spinal cord (SC) interneurons to tissue injuries and also of non-neuronal cells including DRG macrophages and SC microglia are acknowledged as important drivers of sensory symptoms underlying chronic pain4,3,5-7. Recent evidence shows that signals from gut microbiota are required for the initiation of injury-induced sensory hypersensitivity, via the ability to interact with the immune system8-11. However, whether and how gut microbiota promotes pain chronicity remains unknown. Here, we report that male mice lacking Myosin1a (KO)12 raised under single genotype housing conditions (KO-SGH) are predisposed to develop chronic injury-induced mechanical pain. We demonstrate that this predisposition is caused by their dysbiotic gut microbiota, which sustains the immune response in the DRG following neuropathic injury. Parental antibiotic treatment modifies gut microbiota composition and completely rescues the injury-induced chronic pain and associated DRG inflammatory response in male KO-SGH offspring. Together, our data establish a causal relationship between a dysbiotic gut microbiota and the predisposition to injury-induced chronic pain.

neuroscience↗