Project description:<p>The study of antimicrobial resistance (AMR) in infectious diarrhea has generally been limited to cultivation, antimicrobial susceptibility testing and targeted PCR assays. When individual strains of significance are identified, whole genome shotgun (WGS) sequencing of important clones and clades is performed. Genes that encode resistance to antibiotics have been detected in environmental, insect, human and animal metagenomes and are known as "resistomes". While metagenomic datasets have been mined to characterize the healthy human gut resistome in the Human Microbiome Project and MetaHIT and in a Yanomani Amerindian cohort, directed metagenomic sequencing has not been used to examine the epidemiology of AMR. Especially in developing countries where sanitation is poor, diarrhea and enteric pathogens likely serve to disseminate antibiotic resistance elements of clinical significance. Unregulated use of antibiotics further exacerbates the problem by selection for acquisition of resistance. This is exemplified by recent reports of multiple antibiotic resistance in Shigella strains in India, in Escherichia coli in India and Pakistan, and in nontyphoidal Salmonella (NTS) in South-East Asia. We propose to use deep metagenomic sequencing and genome level assembly to study the epidemiology of AMR in stools of children suffering from diarrhea. Here the epidemiology component will be surveillance and analysis of the microbial composition (to the bacterial species/strain level where possible) and its constituent antimicrobial resistance genetic elements (such as plasmids, integrons, transposons and other mobile genetic elements, or MGEs) in samples from a cohort where diarrhea is prevalent and antibiotic exposure is endemic. The goal will be to assess whether consortia of specific mobile antimicrobial resistance elements associate with species/strains and whether their presence is enhanced or amplified in diarrheal microbiomes and in the presence of antibiotic exposure. This work could potentially identify clonal complexes of organisms and MGEs with enhanced resistance and the potential to transfer this resistance to other enteric pathogens.</p> <p>We have performed WGS, metagenomic assembly and gene/protein mapping to examine and characterize the types of AMR genes and transfer elements (transposons, integrons, bacteriophage, plasmids) and their distribution in bacterial species and strains assembled from DNA isolated from diarrheal and non-diarrheal stools. The samples were acquired from a cohort of pediatric patients and controls from Colombia, South America where antibiotic use is prevalent. As a control, the distribution and abundance of AMR genes can be compared to published studies where resistome gene lists from healthy cohort sequences were compiled. Our approach is more epidemiologic in nature, as we plan to identify and catalogue antimicrobial elements on MGEs capable of spread through a local population and further we will, where possible, link mobile antimicrobial resistance elements with specific strains within the population.</p>

Project description:Obesity and insulin resistance are two major risk factors underlying the metabolic syndrome. To gain more insight in the role of the small intestine in the etiology of these metabolic disorders, a microarray study was performed on small intestines (SI) of C57BL/6J mice that were fed a high fat diet mimicking the fatty acid composition of a Western-style human diet. The mice became obese and developed dietary fat-induced glucose intolerance. For gene expression profiling, the small intestines were subdivided in three equal parts along the longitudinal axis. The most pronounced effects of dietary fat were detected in part 2 of the small intestine. The biological processes that were most extensively modulated on a high fat diet were related to lipid metabolism, especially Î²- and Ï-fatty acid oxidation seemed to play an important role, cell cycle and inflammation/immune response. An additional secretome analysis revealed differentially expressed secreted proteins, such as Il18, Ffgf15, Mif, Igfbp3 and Angptl4, which might provoke systemic effects in peripheral organs by influencing their metabolic homeostasis. Furthermore, many of the dietary fat-modulated genes and biological processes in small intestine were previously already associated with obesity and/or insulin resistance. Together, the data of this exploratory study provided various leads for an essential role of the small intestine in development of obesity and/or insulin resistance. Experiment Overall Design: After a run-in period of 3 weeks on a low-fat diet, 9 weeks old mice were fed a high- (HF) or a low-fat (LF) purified diet for 2, 4, and 8 weeks (n=6 per diet, per time point). Body weight was recorded weekly and after 7 weeks of diet intervention an oral glucose tolerance test was performed. At the end of the experiment, mice were anaesthetized with a mixture of isofluorane (1.5%), nitrous oxide (70%) and oxygen (30%). The small intestines were excised and the adhering fat and pancreatic tissue were carefully removed. The small intestines were divided in three equal parts along the proximal to distal axis (SI 1, SI 2 and SI 3).

Dataset Information

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets