Leica Science Lab - Tag : Bacteria https://www.leica-microsystems.com//science-lab/tag/bacteria/ Article tagged with Bacteria en-US https://www.leica-microsystems.com/19635 Fluorescence Microscopy Live-Cell Imaging Stereo Microscopy Widefield Microscopy Real Time Observation of Neutrophil White Blood Cell Recruitment to Bacterial Infection In Vivo The zebrafish (Danio rerio) is an emerging vertebrate model organism to study infection. The transparent larva comprises a fully functional innate immune system and enables live imaging of fluorescent immune cells in transgenic animals. Zebrafish infection models have been developed for both the human bacterial pathogen Shigella flexneri and the natural fish bacterial pathogen Mycobacterium marinum. Importantly, whilst S. flexneri causes acute infection and is typically used as an inflammatory paradigm, M. marinum causes a chronic disease similar to tuberculosis in humans. Here, we use real time fluorescence microscopy to image transgenic zebrafish larvae with neutrophils (granulocyte white blood cells) expressing the green fluorescent protein eGFP. https://www.leica-microsystems.com/science-lab/real-time-observation-of-neutrophil-white-blood-cell-recruitment-to-bacterial-infection-in-vivo/ Thu, 27 Jul 2017 11:20:00 +0000 MSc Alexandra R. Willis, MSc Vincenzo Torraca, PhD Serge Mostowy, PhD James DeRose https://www.leica-microsystems.com/19232 Fluorescence Microscopy CRISPR-Cas9 Five Big Mysteries about CRISPR’s Origins Francisco Mojica was not the first to see CRISPR, but he was probably the first to be smitten by it. He remembers the day in 1992 when he got his first glimpse of the microbial immune system that would launch a biotechnology revolution. He was reviewing genome-sequence data from the salt-loving microbe Haloferax mediterranei and noticed 14 unusual DNA sequences, each 30 bases long. https://www.leica-microsystems.com/science-lab/five-big-mysteries-about-crisprs-origins/ Mon, 20 Feb 2017 08:49:00 +0000 https://www.leica-microsystems.com/18008 CLEM Fluorescence Microscopy EM Sample Preparation Correlative Cryo-Fluorescence and Cryo-Scanning Electron Microscopy as a Straightforward Tool to Study Host-Pathogen Interactions Correlative light and electron microscopy is an imaging technique that enables identification and targeting of fluorescently tagged structures with subsequent imaging at near-to-nanometer resolution. We established a novel correlative cryo-fluorescence microscopy and cryo-scanning electron microscopy workflow, which enables imaging of the studied object of interest very close to its natural state, devoid of artifacts caused for instance by slow chemical fixation. This system was tested by investigating the interaction of the zoonotic bacterium Borrelia burgdorferi with two mammalian cell lines of neural origin in order to broaden our knowledge about the cell-association mechanisms that precedes the entry of the bacteria into the cell. https://www.leica-microsystems.com/science-lab/correlative-cryo-fluorescence-and-cryo-scanning-electron-microscopy-as-a-straightforward-tool-to-study-host-pathogen-interactions/ Tue, 13 Dec 2016 07:58:00 +0000 Martin Strnad https://www.leica-microsystems.com/18885 Fluorescence Microscopy CRISPR-Cas9 Gene Editing with CRISPR/Cas9 - Breakthrough in Genome Engineering The CRISPR/Cas9 system is one of several different bacterial systems for defense against viral attacks. It consists of two main components. One is a small piece of RNA which binds to the viral target sequence via Watson-Crick base pairing. It serves as a marker for the foreign nucleic acid. The second component is the Cas9 protein. It binds to the marked sequence and cuts it due to its nuclease activity. Because the base pairing RNA can be synthesized easily and then used to determine a target region, researchers have utilized this system in the laboratory for genome editing. https://www.leica-microsystems.com/science-lab/gene-editing-with-crisprcas9-breakthrough-in-genome-engineering/ Thu, 17 Nov 2016 18:54:00 +0000 Dr. Christoph Greb https://www.leica-microsystems.com/18106 EM Sample Preparation Nematode E. dianae - Critical Point Drying Protocol for SEM Application Note for Leica EM CPD300 - Critical point drying of nematode Eubostrichus dianae to detect the ectosymbiotic bacteria layer with subsequent gold coating ans SEM analysis. https://www.leica-microsystems.com/science-lab/nematode-e-dianae-critical-point-drying-protocol-for-sem/ Wed, 16 Nov 2016 11:05:00 +0000 Mag. Nikolaus Leisch https://www.leica-microsystems.com/18096 EM Sample Preparation Bacteria Protocol - Critical Point Drying of E. coli for SEM Application Note for Leica EM CPD300 - Critical point drying of E. coli with subsequent platinum / palladium coating and SEM analysis. Sample was inserted into a filter disc (Pore size: 16 - 40 μm) and placed into the filter discs and porous pots holder. Cultivate fungi and bacteria on agar containing growth medium for 3 days. https://www.leica-microsystems.com/science-lab/bacteria-protocol-critical-point-drying-of-e-coli-for-sem/ Thu, 13 Oct 2016 10:04:00 +0000 Dr. W. H. Mueller https://www.leica-microsystems.com/18115 Confocal Microscopy Contributions of Microbiome and Mechanical Deformation to Intestinal Bacterial Overgrowth and Inflammation in a Human Gut-on-a-Chip A human gut-on-a-chip microdevice was used to coculture multiple commensal microbes in contact with living human intestinal epithelial cells for more than a week in vitro and to analyze how gut microbiome, inflammatory cells, and peristalsis-associated mechanical deformations independently contribute to intestinal bacterial overgrowth and inflammation. This in vitro model replicated results from past animal and human studies, including demonstration that probiotic and antibiotic therapies can suppress villus injury induced by pathogenic bacteria. https://www.leica-microsystems.com/science-lab/contributions-of-microbiome-and-mechanical-deformation-to-intestinal-bacterial-overgrowth-and-inflammation-in-a-human-gut-on-a-chip/ Fri, 05 Aug 2016 16:29:00 +0000 https://www.leica-microsystems.com/18623 Fluorescence Microscopy CRISPR-Cas9 Video Talk: CRISPR-Cas – From a Bacterial Adaptive Immune System to a Genome Engineering Tool The CRISPR-Cas system was originally discovered as an adaptive immune system of bacteria and archaea to protect against viral attack. During this talk, given at Leica Microsystems in Wetzlar, Dr. Lennart Randau, MPI Marburg, presents this simple and fascinating system in detail. Furthermore, he introduces the adaption of the CRISPR-Cas system into a potent molecular biology tool, which is used heavily for genome editing. In addition to its influence on molecular biology, meanwhile the Cas9 nuclease also stimulates microscopy techniques e.g. to fluorescently label genomic loci in living cells. https://www.leica-microsystems.com/science-lab/video-talk-crispr-cas-from-a-bacterial-adaptive-immune-system-to-a-genome-engineering-tool/ Tue, 12 Jul 2016 04:13:00 +0000 Dr. Lennart Randau https://www.leica-microsystems.com/17382 CLEM Imaging of Host Cell-bacteria Interactions using Correlative Microscopy under Cryo-conditions Pathogenic bacteria have developed intriguing strategies to establish and promote infections in their respective hosts. Most bacterial pathogens initiate infectious diseases by adhering to host cells surface. Knowledge of the interplay between the pathogenic organism and the host cells can provide fundamental new insight into the underlying mechanisms of the infectious process and therefore of the disease. Various microscopy techniques have proven to be critical tools to study these events. https://www.leica-microsystems.com/science-lab/imaging-of-host-cell-bacteria-interactions-using-correlative-microscopy-under-cryo-conditions/ Tue, 01 Mar 2016 11:34:00 +0000 Martin Strnad https://www.leica-microsystems.com/15896 Stereo Microscopy Fluorescence Microscopy Infection of Zebrafish Embryos with Intracellular Bacterial Pathogens Transparent zebrafish embryos have proved useful model hosts to visualize and functionally study interactions between innate immune cells and intracellular bacterial pathogens, such as Salmonella typhimurium and Mycobacterium marinum. Micro-injection of bacteria and multi-color fluorescence imaging are essential techniques involved in the application of zebrafish embryo infection models. https://www.leica-microsystems.com/science-lab/infection-of-zebrafish-embryos-with-intracellular-bacterial-pathogens/ Fri, 05 Feb 2016 13:35:00 +0000 https://www.leica-microsystems.com/15596 EM Sample Preparation Transmission Electron Microscopy Sample Preparation Protocols for the Ultrastructural Study of Cysts of Free-living Protozoa Cysts of free-living protozoa have an impact on the ecology and epidemiology of bacteria because they may act as a transmission vector or shelter the bacteria against hash environmental conditions. Detection and localization of intracystic bacteria and examination of the en- and excystment dynamics is a major challenge because no detailed protocols for ultrastructural analysis of cysts are currently available. https://www.leica-microsystems.com/science-lab/transmission-electron-microscopy-sample-preparation-protocols-for-the-ultrastructural-study-of-cysts-of-free-living-protozoa/ Thu, 02 Jul 2015 17:25:00 +0000 https://www.leica-microsystems.com/14858 Confocal Microscopy Fluorescence Microscopy Influencing Factors and Applicability of the Viability EMA-qPCR for a Detection and Quantification of Campylobacter Cells from Water Samples In recent years, increasing numbers of human campylobacteriosis cases caused by contaminated water have been reported. As the culture-based detection of Campylobacter is time consuming and can yield false-negative results, the suitability of a quantitative real-time PCR method in combination with an ethidium monoazide pretreatment of samples (EMA-qPCR) for the rapid, quantitative detection of viable Campylobacter cells from water samples was investigated. https://www.leica-microsystems.com/science-lab/influencing-factors-and-applicability-of-the-viability-ema-qpcr-for-a-detection-and-quantification-of-campylobacter-cells-from-water-samples/ Tue, 06 Jan 2015 11:12:00 +0000 https://www.leica-microsystems.com/13917 Confocal Microscopy Live-Cell Imaging Analysis of Autofluorescence in Polymorphonuclear Neutrophils: A New Tool for Early Infection Diagnosis Diagnosing bacterial infection (BI) remains a challenge for the attending physician. An ex vivo infection model based on human fixed polymorphonuclear neutrophils (PMNs) gives an autofluorescence signal that differs significantly between stimulated and unstimulated cells. We took advantage of this property for use in an in vivo pneumonia mouse model and in patients hospitalized with bacterial pneumonia. https://www.leica-microsystems.com/science-lab/analysis-of-autofluorescence-in-polymorphonuclear-neutrophils-a-new-tool-for-early-infection-diagnosis/ Wed, 29 Oct 2014 12:21:00 +0000 https://www.leica-microsystems.com/12428 Confocal Microscopy Fluorescence Microscopy Colonization of Potato Rhizosphere by GFP-Tagged Bacillus subtilis MB73/2, Pseudomonas sp. P482 and Ochrobactrum sp. A44 Shown on Large Sections of Roots Using Enrichment Sample Preparation and Confocal Laser Scanning Microscopy The ability to colonize the host plants’ rhizospheres is a crucial feature to studyin the case of Plant Growth Promoting Rhizobacteria (PGPRs) with potential agricultural applications. In this work, we have created GFP-tagged derivatives of three candidate PGPRs: Bacillus subtilis MB73/2, Pseudomonas sp. P482 and Ochrobactrum sp. A44. https://www.leica-microsystems.com/science-lab/colonization-of-potato-rhizosphere-by-gfp-tagged-bacillus-subtilis-mb732-pseudomonas-sp-p482-and-ochrobactrum-sp-a44-shown-on-large-sections-of-roots-using-enrichment-sample-preparation-and-confocal-laser-scanning-microscopy/ Fri, 02 May 2014 15:04:00 +0000