Search results for "Clostridium"
showing 10 items of 128 documents
Liver infarction in a patient with Clostridium Difficile colitis. A possible connection?
2019
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Maitrise de la fermentation butyrique par la microflore lactique réductrice
2018
Clostridium tyrobutyricum, bactérie anaérobie stricte, endosporulée, est à l’origine de l’apparition du défaut appelé «gonflement tardif » lors de l’étape d’affinage de nombreux fromages à pâtes pressées non cuites et cuites. Selon d’Incecco et al. (2018), elle passerait de l’état spore à un état de cellule végétative à la fin de l’étape d’acidification. Par ailleurs dans le projet ANR FoodREDOX, il a été montré qu’un ensemencement dans le lait d’une microflore abaissant le potentiel d’oxydoréduction, ralentirait la consommation de lactates et la production de butyrate par C. tyrobutyricum lors de l’affinage des fromages. Ainsi, connaître et comprendre les mécanismes de germination, sporula…
Clostridium perfringens identificēšana un uzskaitīšana dzeramajā ūdenī ar fluorescentās in situ hibridizācijas metodi
2017
Sporu-veidojošā C. perfringens ir nozīmīgs organisms ūdens vidē, ko izmanto kā indikatororganismu dzeramā ūdens kvalitātes noteikšanai. Turklāt šī baktērija un tās sporas ir noderīgas, lai brīdinātu par citu stresa rezistento patogēnu iespējamo klātbūtni dzeramajā ūdenī. Atbilstoši Ministru kabineta noteikumiem Nr. 235, Clostridium perfringens noteikšanai un uzskaitei jāizmanto membrānfiltrācija un tālāka mikroorganismu kultivēšana. Tomēr izpētīts, ka kultivēšanas metodes nespēj identificēt ūdenī esošus nekultivējamus bet dzīvotspējīgus mikroorganismus (VBNC). Fluorescentā in situ hibridizācija (FISH), nodrošina baktēriju identificēšanu to dabiskā vidē, un var būt izmantojama, ka alternatīv…
Antibacterial activity of the enniatin B, produced by Fusarium tricinctum in liquid culture, and cytotoxic effects on Caco-2 cells.
2011
The enniatins (ENs) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium sp. The EN B was purified from extracts of Fusarium tricinctum growth on liquid culture of potato dextrose broth (PDB), using a semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (ESI-MS) study. The pure fraction of EN B was utilized to determine the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract: Escherichia coli, Enterococc…
Clostridium difficile IStron CdISt1: Discovery of a Variant Encoding Two Complete Transposase-Like Proteins
2004
ABSTRACT Screening a Clostridium difficile strain collection for the chimeric element Cd ISt1 , we identified two additional variants, designated Cd ISt1 -0 and Cd ISt1 -III. In in vitro assays, we could prove the self-splicing ribozyme activity of these variants. Structural comparison of all known Cd ISt1 variants led us to define four types of IStrons that we designated Cd ISt1 -0 through Cd ISt1 -III. Since Cd ISt1 -0 encodes two complete transposase-like proteins (TlpA and TlpB), we suggest that it represents the original genetic element, hypothesized before to have originated by fusion of a group I intron and an insertion sequence element.
The IStron CdISt1 of Clostridium difficile: molecular symbiosis of a group I intron and an insertion element
2003
Abstract The IStron CdISt1 was first discovered as an insertion into the tcdA gene of the clinical isolate C34. It combines structural and functional properties of a group I intron at its 5′-end with those of an insertion element at its 3′-end. Up to date four different types could be found, mainly differing in their IS-element portions. Contrasting classical group I introns, CdISt1 is always integrated in ORFs encoding bacterial protein. In case CdISt1 had only the IS-element function such insertion would inactivate the protein encoded by the host gene. It is only due to the self-splicing activity of the group I intron parts that CdISt1 integration does not abolish protein function. Both e…
Characterization of polymorphisms in the toxin A and B genes of Clostridium difficile.
2006
We have used six independent polymerase chain reactions (A1–A3 and B1–B3) for amplification of the entire sequence of the two toxin genes tcdA and tcdB of several Clostridium difficile strains. With this approach we have detected (1) restriction site polymorphisms which are distributed all over the genes, and (2) deletions that could be found only in tcdA. Characteristic differences between strains were mainly focused to the 5′ third of tcdB (B1 fragment) and/or the 3′ third of tcdA (A3 fragment). The possible use of our approach for typing of C. difficile toxin genes is discussed.
The second component of human complement: Use of glycosidases and glucosylation to distinguish the two forms
1988
Abstract The two forms of human plasma C2 that were described in the preceding report (1) were investigated for their functional and biochemical differences. Incubation with the neuraminidase (NAN'dase) of Clostridium perfringens at 37°C resulted in a four- to fivefold increase in the hemolytic activity of both forms. The increase in activity was different than the increase caused by treatment with iodine. The mechanism of increased activity of NAN'dase-treated C2 was the generation of increased molecules of activated C3 (C3b), resulting in more molecules of C5 binding to (C4b, 2a, 3b)n. Removal of N-acetyl-neuraminate from C2 did not alter its binding to a cationic exchanger. Nonenzymatic …
A novel cytotoxin from Clostridium difficile serogroup F is a functional hybrid between two other large clostridial cytotoxins.
1999
Abstract The large clostridial cytotoxins (LCTs) constitute a group of high molecular weight clostridial cytotoxins that inactivate cellular small GTP-binding proteins. We demonstrate that a novel LCT (TcdB-1470) from Clostridium difficile strain 1470 is a functional hybrid between “reference” TcdB-10463 andClostridium sordellii TcsL-1522. It bound to the same specific receptor as TcdB-10463 but glucosylated the same GTP-binding proteins as TcsL-1522. All three toxins had equal enzymatic potencies but were equally cytotoxic only when microinjected. When applied extracellularly TcdB-1470 and TcdB-10463 were considerably more potent cytotoxins than TcsL-1522. The small GTP-binding protein R-R…
FT-IR spectroscopic analysis for studying Clostridium cell response to conversion of enzymatically hydrolyzed hay
2013
Abstract Grass hay is one of assailable cellulose containing non-food agricultural wastes that can be used as a carbohydrate source by microorganisms producing biofuels. In this study three Clostridium strains Clostridium acetobutylicum, Clostridium beijerinckii and Clostridium tetanomorphum, capable of producing acetone, butanol and ethanol (ABE) were adapted to convert enzymatically hydrolyzed hay used as a growth media additive. The results of growth curves, substrate degradation kinetics and FT-IR analyses of bacterial biomass macromolecular composition showed diverse strain-specific cell response to the growth medium composition.