Search results for "rRNA"

Pyrosequencing survey of intestinal microbiota diversity in cultured sea bass (Dicentrarchus labrax) fed functional diets.

2014

The routine use of chemotherapy to control bacterial diseases in aquatic populations has resulted in the development and spread of antibiotic resistance. The inclusion of immunostimulants in fish diets (functional diets) is one of the main strategies to solve this threat. This study aimed to analyse the intestinal microbiota of cultured European sea bass (Dicentrarchus labrax) fed two functional diets applying pyrosequencing of PCR-amplified 16S rRNA gene. Quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. The autochthonous intestinal microbiota of sea bass consisted of two dominant bacterial genera: Dysgonomonas (Bacte…

Pole-to-Pole Connections : Similarities between Arctic and Antarctic Microbiomes and Their Vulnerability to Environmental Change

2017

The global biogeography of microorganisms remains poorly resolved, which limits the current understanding of microbial resilience toward environmental changes. Using high-throughput 16S rRNA gene amplicon sequencing, we characterized the microbial diversity of terrestrial and lacustrine biofilms from the Arctic, Antarctic and temperate regions. Our analyses suggest that bacterial community compositions at the poles are more similar to each other than they are to geographically closer temperate habitats, with 32% of all operational taxonomic units (OTUs) co-occurring in both polar regions. While specific microbial taxa were confined to distinct regions, representing potentially endemic popul…

Differential responses of bacterial and archaeal groups at high taxonomical ranks to soil management

2010

Little is known about abundances of the major bacterial taxa in agricultural soils and how they are affected by fertilization or other agricultural practices. Our aim was to determine the abundance and relative distribution of several bacterial phyla and one class, as well as the archaeal and crenarchaeal communities, and how they were affected by different fertilization regimes to examine whether specific responses of microorganisms could be identified at these high taxonomic ranks. We used real-time PCR with taxa specific primers to quantify the abundance of the Actinobacteria, Acidobacteria, Bacteriodetes, Firmicutes, Gemmatimonadetes, Verrucomicrobia, Alphaproteobacteria and Crenarchaeo…

Non-Coding RNA Networks as Potential Novel Biomarker and Therapeutic Target for Sepsis and Sepsis-Related Multi-Organ Failure.

2022

According to “Sepsis-3” consensus, sepsis is a life-threatening clinical syndrome caused by a dysregulated inflammatory host response to infection. A rapid identification of sepsis is mandatory, as the extent of the organ damage triggered by both the pathogen itself and the host’s immune response could abruptly evolve to multiple organ failure and ultimately lead to the death of the patient. The most commonly used therapeutic strategy is to provide hemodynamic and global support to the patient and to rapidly initiate broad-spectrum empiric antibiotic therapy. To date, there is no gold standard diagnostic test that can ascertain the diagnosis of sepsis. Therefore, once sepsis is suspected, t…

Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake

2019

Taxonomical and Functional Assessment of the Endometrial Microbiota in A Context of Recurrent Reproductive Failure: A Case Report

2019

Investigation of the microbial community in the female reproductive tract has revealed that the replacement of a community dominated by Lactobacillus with pathogenic bacteria may be associated with implantation failure or early spontaneous abortion in patients undergoing assisted reproductive technology (ART) treatment. Herein we describe taxonomically and functionally the endometrial microbiome of an infertile patient with repeated reproductive failures (involving an ectopic pregnancy and two clinical miscarriages). The microbiological follow-up is presented over 18-month in which the microbiota was evaluated in six endometrial fluid samples. The microbial profile of 16S rRNA gene sequenci…

The effect of peracetic acid on microbial community, water quality, nitrification and rainbow trout (Oncorhynchus mykiss) performance in recirculatin…

2020

Microbial biofilters control water quality and enable the overall function of recirculation aquaculture systems (RAS). Changes in environmental conditions can affect the abundance and interactions of the diverse microbial populations of the biofilter, affecting nitrification of harmful ammonium and thus fish health. Here, we examined the effect of different application frequencies (0, 1, 2 and 4 times per week) of a common disinfectant, peracetic acid (PAA, applied 1.1 mg l−1 twice per day), on biofilter microbial communities, focusing especially on nitrifying microbial groups and using a high throughput sequencing of 16S rRNA gene and quantitative PCR (qPCR). In addition, we measured biofi…

Variability of the human gut microbiota in space, time, and associated with the irritable bowel syndrome

2013

Esta tesis doctoral se centra en el estudio de una de las comunidades microbianas más complejas y de mayor interés biomédico: la microbiota asociada al intestino distal de humanos. El objetivo principal ha sido estudiar las alteraciones potenciales de la microbiota intestinal en relación con el síndrome del intestino irritable (SII), el desorden funcional del tracto gastrointestinal más común en sociedades occidentales. Nuestra aproximación forma parte de una visión actual sobre las relaciones entre microorganismos y hospedadores que trasciende la clásica y estrecha mirada sobre patógenos concretos y enfermedades infecciosas y la desplaza hacia una concepción más de conjunto, que valora los…

Response of microbial biomass and carbon dynamics to changing hydrological conditions in old peat deposits

2018

Peatlands play key roles in the global ecosystem carbon (C) balance, as important C-stores. Their efficiency as long-term C-stores or atmospheric C sink is affected by the rate of microbial mineralization. Most studies on the climate change effects on the microbial communities and C-cycling in peatlands have focused on the surface layers. This thesis compared microbial biomass, community composition and internal C cycling processes in drained vs. natural peat profiles with focus on deep old peat. Using the phospholipid fatty acid (PLFA) and rRNA gene analyses, the study particularly looked at the impact of long-term drainage and the short-term effects of temperature and water content on the…

Dinámica de la microbiota en niños, adolescentes y adultos

2022

La microbiota intestinal se implanta a lo largo del desarrollo del individuo y su composición y funciones difieren según la edad. Conocer los cambios que se producen en la microbiota intestinal a lo largo de la vida puede ayudar al diagnóstico, tratamiento y prevención de enfermedades relacionadas con alteraciones metabólicas e inmunitarias. Con este trabajo pretendemos contribuir a la comprensión del proceso de desarrollo de la microbiota intestinal, centrándonos en dos períodos que han recibido poca atención: los primeros años y la adolescencia. Hemos determinado la composición y la función de la microbiota a través de enfoques metagenómicos de genoma completo y basados ​​en ARN ribosómic…