Search results for "Clostridium"
showing 10 items of 128 documents
An Integrated Pharmacophore/Docking/3D-QSAR Approach to Screening a Large Library of Products in Search of Future Botulinum Neurotoxin A Inhibitors
2020
Botulinum toxins are neurotoxins produced by Clostridium botulinum. This toxin can be lethal for humans as a cause of botulism
Isolation of lactic acid-forming bacteria from biogas plants.
2017
Direct molecular approaches provide hints that lactic acid bacteria play an important role in the degradation process of organic material to methanogenetic substrates in biogas plants. However, their diversity in biogas fermenter samples has not been analyzed in detail yet. For that reason, five different biogas fermenters, which were fed mainly with maize silage and manure from cattle or pigs, were examined for the occurrence of lactic acid-forming bacteria. A total of 197 lactic acid-forming bacterial strains were isolated, which we assigned to 21 species, belonging to the genera Bacillus, Clostridium, Lactobacillus, Pediococcus, Streptococcus and Pseudoramibacter-related. A qualitative m…
Functional comparison of bacteria from the human gut and closely related non-gut bacteria reveals the importance of conjugation and a paucity of moti…
2016
International audience; The human GI tract is a complex and still poorly understood environment, inhabited by one of the densest microbial communities on earth. The gut microbiota is shaped by millennia of evolution to co-exist with the host in commensal or symbiotic relationships. Members of the gut microbiota perform specific molecular functions important in the human gut environment. This can be illustrated by the presence of a highly expanded repertoire of proteins involved in carbohydrate metabolism, in phase with the large diversity of polysaccharides originating from the diet or from the host itself that can be encountered in this environment. In order to identify other bacterial fun…
Lactic Acid Bacteria
2008
A typical lactic acid bacterium grown under standard conditions is aerotolerant, acid tolerant, organotrophic, and a strictly fermentative rod or coccus, producing lactic acid as a major end product. It lacks cytochromes and is unable to synthesize porphyrins. Its features can vary under certain conditions. Catalase and cytochromes may be formed in the presence of hemes and lactic acid can be further metabolized, resulting in lower lactic acid concentrations. Cell division occurs in one plane, except pediococci. The cells are usually nonmotile. They have a requirement for complex growth factors such as vitamins and amino acids. An unequivocal definition of LAB is not possible (Axelsson, Lac…
The Monoclonal Antitoxin Antibodies (Actoxumab–Bezlotoxumab) Treatment Facilitates Normalization of the Gut Microbiota of Mice with Clostridium diffi…
2016
Antibiotics have significant and long-lasting impacts on the intestinal microbiota and consequently reduce colonization resistance against Clostridium difficile infection (CDI). Standard therapy using antibiotics is associated with a high rate of disease recurrence, highlighting the need for novel treatment strategies that target toxins, the major virulence factors, rather than the organism itself. Human monoclonal antibodies MK-3415A (actoxumab–bezlotoxumab) to C. difficile toxin A and toxin B, as an emerging non-antibiotic approach, significantly reduced the recurrence of CDI in animal models and human clinical trials. Although the main mechanism of protection is through direct neutraliza…
Saccharomyces boulardii to Prevent Antibiotic-Associated Diarrhea: A Randomized, Double-Masked, Placebo-Controlled Trial.
2015
Antibiotic-associated diarrhea is an important clinical problem, associated with morbidity, mortality and healthcare costs. Our randomized, placebo controlled multicenter trial do not support the efficacy of Saccharomyces boulardii in the prevention of antibiotic-associated diarrhea.
Partial purification and characterization of an NAD-dependent 3 beta-hydroxysteroid dehydrogenase from Clostridium innocuum
1989
In nine strains of Clostridium innocuum, 3 beta-hydroxysteroid-dehydrogenating activities were detected. 3 beta, 7 alpha, 12 alpha-Trihydroxy- and 3 beta-hydroxy-12-keto-5 beta-cholanoic acids were identified as reduction products of the respective 3-keto bile acids by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. One strain was shown to contain a NAD-dependent 3 beta-hydroxysteroid dehydrogenase. Enzyme production was constitutive in the absence of added bile acids. The specific enzyme activity was significantly reduced by growth medium supplementation with 3-keto bile acids, with trisubstituted acids being more effective than disubstituted ones. A pH optimum o…
In Silico Conformational Features of Botulinum Toxins A1 and E1 According to Intraluminal Acidification
2022
International audience; Although botulinum neurotoxins (BoNTs) are among the most toxic compounds found in nature, their molecular mechanism of action is far from being elucidated. A key event is the conformational transition due to acidification of the interior of synaptic vesicles, leading to translocation of the BoNT catalytic domain into the neuronal cytosol. To investigate these conformational variations, homology modeling and atomistic simulations are combined to explore the internal dynamics of the sub-types BoNT/A1 (the most-used sub-type in medical applications) and BoNT/E1 (the most kinetically efficient sub-type). This first simulation study of di-chain BoNTs in closed and open s…
Safety and immunomodulatory effects of three probiotic strains isolated from the feces of breast-fed infants in healthy adults: SETOPROB study.
2013
We previously described the isolation and characterization of three probiotic strains from the feces of exclusively breast-fed newborn infants: Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036. These strains were shown to adhere to intestinal mucus in vitro, to be sensitive to antibiotics and to resist biliary salts and low pH. In the present study, a multicenter, randomized, double-blind, placebo-controlled trial with 100 healthy volunteers in three Spanish cities was carried out to evaluate the tolerance, safety, gut colonization and immunomodulatory effects of these three probiotics. Volunteers underwent a 15-day washout perio…
Induction of antitoxin responses in Clostridium-difficile-infected patients compared to healthy blood donors
2016
According to the literature Clostridium difficile antitoxins are present in up to 66% of humans. In a survey of ∼400 plasma samples from healthy blood donors we found that less than 6% were positive for anti-TcdA or anti-TcdB antitoxins. Using the same standard immunoassay protocol, we looked for IgG and IgA antitoxins in the blood and stool samples from 25 patients with C. difficile infection (CDI). Some patients with CDI had no antitoxin detected at all, while others had high levels of specific IgG- and IgA-antitoxins against both TcdA and TcdB in blood and IgA-anti-TcdA and -anti-TcdB antibodies in stool. Systemic responses to TcdB and mucosal responses to TcdA predominated. Among patien…