scholarly journals High-resolution analysis of spatiotemporal virulence gene regulation during food-borne infection withEscherichia coliO157:H7 within a live host

2017 ◽  
Author(s):  
Daniel H Stones ◽  
Alexander GJ Fehr ◽  
Thekke P Madhavan ◽  
Kerstin Voelz ◽  
Anne Marie Krachler

ABSTRACTFood-borne infection with enterohemorrhagicEscherichia coli(EHEC) is a major cause of diarrheal illness in humans, and can lead to severe complications such as hemolytic uremic syndrome. Cattle and other ruminants are the main reservoir of EHEC, which enters the food-chain through contaminated meat, dairy, or vegetables. However, how EHEC transitions from the transmission vector to colonizing the intestinal tract, and how virulence-specific genes are regulated during this transition, is not well understood. Here, we describe the establishment of a vertebrate model for food-borne EHEC infection, using the protozoanParamecium caudatumas a vector and the zebrafish (Danio rerio) as a host. At 4 days post fertilization, zebrafish have a fully developed intestinal tract, yet are fully transparent. This allows us to follow intestinal colonization, microbe-host cell interactions, and microbial gene induction within the live host and in real time throughout the infection. Additionally, this model can be adapted to compare food- and water-borne infections, under gnotobiotic conditions or against the backdrop of an endogenous (and variable) host microbiota. Finally, the zebrafish allows for investigation of factors affecting shedding and transmission of bacteria to naïve hosts. High-resolution analysis of EHEC gene expression within the zebrafish host emphasizes the need for tight transcriptional regulation of virulence factors for within-host fitness.IMPORTANCEEnterohemorrhagicEscherichia coli(EHEC) is a food-borne pathogen which can cause diarrhea, vomiting and in some cases, severe complications such as kidney problems in humans. Up to 30% of cattle are colonized with EHEC, which can enter the food-chain through contaminated meat, dairy and vegetables. In order to control infections and stop transmission, it is important to understand what factors allow EHEC to colonize its hosts, cause virulence and aid transmission. Since this cannot be systematically studied in humans, it is important to develop animal models of infection and transmission. We developed a model which allows us to study food-borne infection in zebrafish, a vertebrate host that is transparent and genetically tractable. Using the zebrafish host, we can follow the bacterial infection cycle in real time, and gain important information regarding bacterial physiology and microbe-host interactions. This will allow us to identify potential new targets for infection control and prevention.

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 2139-P
Author(s):  
MIRZA MUHAMMAD FAHD QADIR ◽  
SILVIA ALVAREZ-CUBELA ◽  
JASMIJN VAN DIJK ◽  
JONATHAN WEITZ ◽  
SIRLENE CECHIN ◽  
...  

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.


2021 ◽  
Vol 13 (3) ◽  
pp. 1093
Author(s):  
Yunlong Zhao ◽  
Geng Kong ◽  
Chin Hao Chong ◽  
Linwei Ma ◽  
Zheng Li ◽  
...  

Controlling energy consumption to reduce greenhouse gas emissions has become a global consensus in response to the challenge of climate change. Most studies have focused on energy consumption control in a single region; however, high-resolution analysis of energy consumption and personalized energy policy-making, for multiple regions with differentiated development, have become a complicated challenge. Using the logarithmic mean Divisia index I (LMDI) decomposition method based on energy allocation analysis (EAA), this paper aims to establish a standard paradigm for a high-resolution analysis of multi-regional energy consumption and provide suggestions for energy policy-making, taking 29 provinces of China as the sample. The process involved three steps: (1) determination of regional priorities of energy consumption control by EAA, (2) revealing regional disparity among the driving forces of energy consumption growth by LMDI, and (3) deriving policy implications by comparing the obtained results with existing policies. The results indicated that 29 provinces can be divided into four groups, with different priorities of energy consumption control according to the patterns of coal flows. Most provinces have increasing levels of energy consumption, driven by increasing per capita GDP and improving living standards, while its growth is restrained by decreasing end-use energy intensity, improving energy supply efficiency, and optimization of industrial structures. However, some provinces are not following these trends to the same degree. This indicates that policy-makers must pay more attention to the different driving mechanisms of energy consumption growth among provinces.


2002 ◽  
Vol 70 (5) ◽  
pp. 1197-1214 ◽  
Author(s):  
Fulvio Cruciani ◽  
Piero Santolamazza ◽  
Peidong Shen ◽  
Vincent Macaulay ◽  
Pedro Moral ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aleksandar Antanasijevic ◽  
Leigh M. Sewall ◽  
Christopher A. Cottrell ◽  
Diane G. Carnathan ◽  
Luis E. Jimenez ◽  
...  

AbstractEngineered ectodomain trimer immunogens based on BG505 envelope glycoprotein are widely utilized as components of HIV vaccine development platforms. In this study, we used rhesus macaques to evaluate the immunogenicity of several stabilized BG505 SOSIP constructs both as free trimers and presented on a nanoparticle. We applied a cryoEM-based method for high-resolution mapping of polyclonal antibody responses elicited in immunized animals (cryoEMPEM). Mutational analysis coupled with neutralization assays were used to probe the neutralization potential at each epitope. We demonstrate that cryoEMPEM data can be used for rapid, high-resolution analysis of polyclonal antibody responses without the need for monoclonal antibody isolation. This approach allowed to resolve structurally distinct classes of antibodies that bind overlapping sites. In addition to comprehensive mapping of commonly targeted neutralizing and non-neutralizing epitopes in BG505 SOSIP immunogens, our analysis revealed that epitopes comprising engineered stabilizing mutations and of partially occupied glycosylation sites can be immunogenic.


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