A Mouse Model of Mild Infection for the Characterization of Natural Immune Responses.

(1) Background: We describe a model of primary mild- infection (CDI) in a naïve host, including gut microbiota analysis, weight loss, mortality, length of colonization. This model was used in order to describe the kinetics of humoral (IgG, IgM) and mucosal (IgA) immune responses against toxins (TcdA/TcdB) and surface proteins (SlpA/FliC). (2) Methods: A total of 10 CFU vegetative forms of 630Δ were used for challenge by oral administration after dysbiosis, induced by a cocktail of antibiotics.

Inulin prebiotic reinforces host cancer immunosurveillance ɣδ T cell activation.

The gut microbiota is now recognized as a key parameter affecting the host's anti-cancer immunosurveillance and ability to respond to immunotherapy. Therefore, optimal modulation for preventive and therapeutic purposes is very appealing. Diet is one of the most potent modulators of microbiota, and thus nutritional intervention could be exploited to improve host anti-cancer immunity.

Oral administration of viable Bifidobacterium pseudolongum strain Patronus modified colonic microbiota and increased mucus layer thickness in rat.

This study aimed at evaluating the alteration of the colonic microbiota and the changes in the mucus layer thickness induced by oral administration of living bifidobacteria in rats. The study was performed on rats fed with Bifidobacterium pseudolongum strain Patronus (1010 bacteria per day for 7 days). This bacterial administration led to a large increase of mucus thickness (57%, P < 0.

Contrasting effects of historical contingency on phenotypic and genomic trajectories during a two-step evolution experiment with bacteria.

Background: The impact of historical contingency, i.e. the past evolutionary history of a population, on further adaptation is mostly unknown at both the phenotypic and genomic levels.

Long-term changes in human colonic Bifidobacterium populations induced by a 5-day oral amoxicillin-clavulanic acid treatment.

The objective of this study was to assess the possible modifications due to amoxicillin-clavulanic acid (AMC) treatment on total bacteria and on Bifidobacterium species balance in human colonic microbiota. Eighteen healthy volunteers (19 to 36 years old) were given a 875/125 mg dose of AMC twice a day for 5 days. Fecal samples were obtained before and after antibiotic exposure.

Effect of dietary fibre of barley variety 'Rihane' on azoxymethane-induced aberrant crypt foci development and on colonic microbiota diversity in rats.

Many epidemiological and experimental studies have suggested an important role for dietary fibre (DF) of cereals in the prevention of colon cancer. The objective of the present study was to explain the effects of the DF of barley Rihane (BR) on azoxymethane (AOM)-induced aberrant crypt foci (ACF) and colonic bacterial diversity in rats. Following an acclimatisation period, rats were divided into four groups and fed a control (C) diet or experimental diet containing 30 % of BR.

Diversity of gut Bifidobacterium species is not altered between allergic and non-allergic French infants.

Some clinical studies have suggested a relationship between allergic diseases and gut microbiota. We aimed to study bifidobacterial colonization at species and strain levels in ten allergic French infants included at their first clinical consultation and 20 controls matching for age at sampling, mode of delivery, per partum antibiotics, type of feeding and antibiotics in the first weeks of life. The faecal microbiota was analyzed by culture methods and TTGE.

A fermented formula in pre-term infants: clinical tolerance, gut microbiota, down-regulation of faecal calprotectin and up-regulation of faecal secretory IgA.

Intestinal bacterial colonisation in pre-term infants is delayed compared with full-term infants, leading to an increased risk of gastrointestinal disease. Modulation of colonisation through dietary supplementation with probiotics or prebiotics could decrease such a risk. The present study evaluated clinical tolerance, the effects on gut microbiota, and inflammatory and immunological mucosal responses to an infant formula adapted for pre-term infants that included in its manufacturing process a fermentation step with two probiotic strains, Bifidobacterium breve C50 and Streptococcus thermophilus 065, inactivated by heat at the end of the process.

Faecal bifidobacteria in Indian neonates & the effect of asymptomatic rotavirus infection during the first month of life.

Background And Objectives: Bifidobacteria colonize the gut after the first week of life and remain an important component of the gut microbiota in infancy. This study was carried out to characterize the diversity and number of bifidobacteria colonizing the gut in Indian neonates and to investigate whether asymptomatic infection with rotavirus in the first month of life affected gut colonization by bifidobacteria.

Methods: DNA was isolated from faeces of 14 term-born neonates who were under surveillance for rotavirus infection.

Short-chain fatty acids and commensal microbiota in the faeces of severely malnourished children with cholera rehydrated with three different carbohydrates.

Background: Short-chain fatty acids (SCFAs) liberated by fermentation of complex carbohydrates might stimulate water and salt absorption, and provide energy. The aim of the study was to assess the number and proportion of faecal bacteria and the concentration of SCFAs of severely malnourished children with cholera receiving oral rehydration solution (ORS) containing glucose, amylase-resistant starch (ARS) or rice.

Methods: Serial faecal samples were collected from 30 malnourished children with cholera until rehydration and partial nutritional recovery.

Amoxicillin treatment modifies the composition of Bifidobacterium species in infant intestinal microbiota.

Objectives: Amoxicillin is a beta-lactam antibiotic largely used in childhood. However only few studies described its impact on composition of children gut microbiota, in particular on Bifidobacterium populations considered as beneficial microorganisms. In this study, the impact on faecal Bifidobacterium species of a seven-day amoxicillin treatment was quantitatively and qualitatively assessed in infants during an episode of acute respiratory infection.

Metronidazole effects on microbiota and mucus layer thickness in the rat gut.

Both mucus and mucosa-associated bacteria form a specific environment in the gut; their disruption may play a crucial role in the development of intestinal bowel disease (IBD). Metronidazole, an antibiotic used in the treatment of IBD, alters gut microbiota and reduces basal oxidative stress to proteins in colonic tissue of healthy rats. The aim of this study was to evaluate the impact of the altered microbiota due to the metronidazole on the thickness of the mucus layer.

Molecular analysis of intestinal microbiota of rainbow trout (Oncorhynchus mykiss).

The aim of this study was to evaluate different molecular tools based on the 16S rRNA gene, internal transcribed spacer, and the rpoB gene to examine the bacterial populations present in juvenile rainbow trout intestines. DNA was extracted from both pooled intestinal samples and bacterial strains. Genes were PCR-amplified and analysed using both temporal temperature gradient gel electrophoresis (TTGE) and restriction fragment length polymorphism methods.

Time course of bacterial diversity in stool samples of malnourished children with cholera receiving treatment.

Background: Recent nutritional interventions have targeted colonic functions in patients with infectious diarrhea during rehydration and during recovery from malnutrition, with the assumption that the effects will be influenced by metabolism of complex carbohydrates by colonic bacteria. However, the diversity of colonic bacteria in patients with cholera is not known.

Aim: To study the diversity of colonic bacteria in malnourished children with cholera before and during treatment with oral rehydration salt solutions containing 1 of these 3 substrates: glucose, rice, or amylase-resistant starch.

Differential effects of Bifidobacterium pseudolongum strain Patronus and metronidazole in the rat gut.

In the luminal contents of metronidazole-treated rats, there was a dominant Bifidobacterium species. A strain has been isolated, its 16S rRNA gene has been sequenced, and the strain has been named Bifidobacterium pseudolongum strain Patronus. In this study, using an experimental model of healthy rats, the effects of metronidazole treatment and B.

Effects on faecal microbiota of dietary and acidic oligosaccharides in children during partial formula feeding.

Objective: To test the safety and effect on faecal microbiota of a formula with prebiotic oligosaccharides alone or in combination with acidic oligosaccharides in infants at the age of partial formula feeding.

Patients And Methods: The study was a double-blind, placebo-controlled, randomised intervention trial in which 82 healthy, full-term, partially breast-fed children, from 1 week to 3 months old, were given 1 of the following formulae: whey-based formula (control group), whey-based formula with galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS group), or whey-based formula with galacto- and long-chain fructo-oligosaccharides added with pectin-derived acidic oligosaccharides (scGOS/lcFOS/pAOS group). Children were studied for the duration of the partial formula feeding period and every 2 weeks for 2 months after breast-feeding cessation.

Vascular emergencies in liver trauma.

The use of CT in the diagnosis and management of liver trauma is responsible for the shift from routine surgical versus non-surgical treatment in the management of traumatic liver injuries, even when they are of high grade. The main cause of complication and of death in liver trauma is related to vascular injury. The goal of this review focussed on the vascular complications of liver trauma is to describe the elementary lesions shown by CT in liver trauma including laceration, parenchymal hematoma and contusions, partial devascularisation, subcapsular hematomas, hemoperitoneum, active bleeding, pseudoaneurysm of the hepatic artery, bile leak, and periportal oedema, to illustrate the possible pitfalls in CT diagnosis of liver trauma and to underline the key-points which may absolutely be present in a CT report of liver trauma.

Conditions of bifidobacterial colonization in preterm infants: a prospective analysis.

Background: Premature birth results in a delayed and abnormal qualitative pattern of gut colonization. This abnormal pattern is thought to affect intestinal development and contribute to a higher risk of gastrointestinal infectious diseases such as neonatal necrotizing enterocolitis (NEC). In particular, bifidobacteria are thought to play a major role.

Patchy distribution of mucosal lesions in ileal Crohn's disease is not linked to differences in the dominant mucosa-associated bacteria: a study using fluorescence in situ hybridization and temporal temperature gradient gel electrophoresis.

Background: The mucosa-associated bacteria (MAB) are suspected of being involved in the pathogenesis of Crohn's disease. We analyzed and compared the MAB in noninflamed and inflamed ileal mucosa of Crohn's disease patients (n = 22).

Methods: Tissue samples from the inflamed ileal mucosa and from the adjacent noninflamed ileal mucosa were taken from surgical resection specimens.

A longitudinal study of infant faecal microbiota during weaning.

For infants, the introduction of food other than breast milk is a high risk period due to diarrheal diseases, and may be corroborated with a shift in the faecal microbiota. This longitudinal study was the first undertaken to understand the effect of the supplementation on the infant's faecal microbiota and particularly the bifidobacteria. Eleven infants were enrolled.

Low species diversity and high interindividual variability in faeces of preterm infants as revealed by sequences of 16S rRNA genes and PCR-temporal temperature gradient gel electrophoresis profiles.

Little information regarding the composition of the gut microbiota in preterm infants is available. The purpose of this study was to investigate the bacterial diversity in faeces of preterm infants, using analysis of randomly cloned 16S rRNA genes and PCR-TTGE (temporal temperature gradient gel electrophoresis) profiles, to determine whether noncultivated bacteria represented an important part of the community. The 288 clones obtained from faecal samples of 16 preterm infants were classified into 25 molecular species.

Characterization of human intestinal bifidobacteria using competitive PCR and PCR-TTGE.

In this study, a competitive PCR was developed to estimate the quantity of bifidobacteria in human faecal samples using two 16S rRNA gene Bifidobacterium genus-specific primers, Bif164f and Bif662r. A PCR-temporal temperature gradient gel electrophoresis (TTGE) with the same primers also allowed us to describe the Bifidobacterium species present in these faecal samples. The PCR product obtained from the competitor had 467 bp, and was 47 bp shorter than the PCR products obtained from Bifidobacterium strains.

Modulation of the fecal microbiota by the intake of a Lactobacillus johnsonii La1-containing product in human volunteers.

Lactobacillus johnsonii La1 (La1) is a probiotic strain capable of stimulating the immune system of the host and interfering with gastrointestinal pathogens. This study evaluates how the ingestion of different amounts of La1 influences the main bacterial populations of the fecal microbiota. Eight asymptomatic volunteers participated in the study.

Determination of an efficient and reliable method for DNA extraction from ticks.

Molecular detection of pathogenic microorganisms in ticks is based on DNA amplification of the target pathogen; therefore, extraction of DNA from the tick is a major step. In this study, we compared three different tick DNA extraction protocols based on an enzymatic digestion by proteinase K followed by DNA extraction by a commercial kit (method 1), or on mortar crushing, proteinase K digestion and phenol/chloroform DNA extraction (method 2) and fine crushing with a beads beater, proteinase K digestion and DNA extraction using a commercial kit (method 3). The absence of PCR inhibitors and the DNA quality were evaluated by PCR amplification of the tick mitochondrial 16S rRNA gene using tick-specific primers.