-
Cureus Feb 2024, an anaerobic bacterium, has been associated with various infections, including prosthetic valve endocarditis, although its role in empyema remains uncommon. This...
, an anaerobic bacterium, has been associated with various infections, including prosthetic valve endocarditis, although its role in empyema remains uncommon. This abstract presents a case report of a patient diagnosed with empyema, highlighting the clinical presentation, diagnostic challenges, and successful treatment strategies. The case underscores the importance of considering unusual pathogens in the context of empyema. We discuss the clinical management, microbiological identification, and outcomes of this rare infection to contribute valuable insights for healthcare practitioners encountering similar cases.
PubMed: 38558678
DOI: 10.7759/cureus.55156 -
Microbiology Spectrum Mar 2023The Integrative Human Microbiome Project and other cohort studies have indicated that inflammatory bowel disease is accompanied by dysbiosis of gut microbiota, decreased...
The Integrative Human Microbiome Project and other cohort studies have indicated that inflammatory bowel disease is accompanied by dysbiosis of gut microbiota, decreased production of secondary bile acids, and increased levels of primary bile acids. Secondary bile acids, such as ursodeoxycholic acid (UDCA) and lithocholic acid (LCA), have been reported to be anti-inflammatory, yet it remains to be studied whether introducing selected bacteria strains to restore bile acid metabolism of the gut microbiome can alleviate intestinal inflammation. In this study, we screened human gut bacterial strains for bile acid metabolism and designed a consortium of three species, including AP sp000509125, Bacteroides ovatus, and Eubacterium limosum, and named it BAC (bile acid consortium). We showed that the three-strain gut bacterial consortium BAC is capable of converting conjugated primary bile acids taurochenodeoxycholic acid and glycochenodeoxycholic acid to secondary bile acids UDCA and LCA . Oral gavage treatment with BAC in mice resulted in protective effects against dextran sulfate sodium (DSS)-induced colitis, including reduced weight loss and increased colon length. Furthermore, BAC treatment increased the fecal level of bile acids, including UDCA and LCA. BAC treatment enhanced intestinal barrier function, which may be attributed to the increased activation of the bile acid receptor TGR5 by secondary bile acids. Finally, we examined the remodeling of gut microbiota by BAC treatment. Taken together, the three-strain gut bacterial consortium BAC restored the dysregulated bile acid metabolism and alleviated DSS-induced colitis. Our study provides a proof-of-concept demonstration that a rationally designed bacterial consortium can reshape the metabolism of the gut microbiome to treat diseases. Secondary bile acids have been reported to be anti-inflammatory, yet it remains to be studied whether introducing selected bacteria strains to restore bile acid metabolism of the gut microbiome can alleviate intestinal inflammation. To address this gap, we designed a consortium of human gut bacterial strains based on their metabolic capacity to produce secondary bile acids UDCA and LCA, and we evaluated the efficacy of single bacterial strains and the bacterial consortium in treating the murine colitis model. We found that oral gavage of the bacterial consortium to mice restored secondary bile acid metabolism to increase levels of UDCA and LCA, which induced the activation of TGR5 to improve gut-barrier integrity and reduced the inflammation in murine colitis. Overall, our study demonstrates that rationally designed bacterial consortia can reshape the metabolism of the gut microbiome and provides novel insights into the application of live biotherapeutics for treating IBD.
PubMed: 36943054
DOI: 10.1128/spectrum.03330-22 -
Toxins Sep 2020C3 protein toxins produced by and are mono-ADP-ribosyltransferases, which specifically modify the GTPases Rho A/B/C in the cytosol of monocytic cells, thereby...
C3 protein toxins produced by and are mono-ADP-ribosyltransferases, which specifically modify the GTPases Rho A/B/C in the cytosol of monocytic cells, thereby inhibiting Rho-mediated signal transduction in monocytes, macrophages, and osteoclasts. C3 toxins are selectively taken up into the cytosol of monocytic cells by endocytosis and translocate from acidic endosomes into the cytosol. The C3-catalyzed ADP-ribosylation of Rho proteins inhibits essential functions of these immune cells, such as migration and phagocytosis. Here, we demonstrate that C3 toxins enter and intoxicate dendritic cells in a time- and concentration-dependent manner. Both immature and mature human dendritic cells efficiently internalize C3 exoenzymes. These findings could also be extended to the chimeric fusion toxin C2IN-C3lim. Moreover, stimulated emission depletion (STED) microscopy revealed the localization of the internalized C3 protein in endosomes and emphasized its potential use as a carrier to deliver foreign proteins into dendritic cells. In contrast, the enzyme C2I from the binary C2 toxin was not taken up into dendritic cells, indicating the specific uptake of C3 toxins. Taken together, we identified human dendritic cells as novel target cells for clostridial C3 toxins and demonstrated the specific uptake of these toxins via endosomal vesicles.
Topics: ADP Ribose Transferases; Botulinum Toxins; Dendritic Cells; Dose-Response Relationship, Drug; Endocytosis; Endosomes; HeLa Cells; Humans; Protein Transport; Time Factors
PubMed: 32883045
DOI: 10.3390/toxins12090563 -
Microbiology Resource Announcements Jan 2020can be found in soil and the intestinal tract of animals. In 2014, was isolated from a suspected blackleg outbreak in cattle in Schleswig-Holstein, Germany. We present...
can be found in soil and the intestinal tract of animals. In 2014, was isolated from a suspected blackleg outbreak in cattle in Schleswig-Holstein, Germany. We present a complete genome sequence of a strain represented by a circular chromosome and three plasmids.
PubMed: 31919152
DOI: 10.1128/MRA.01487-19 -
Archives of Toxicology Jan 2018Bacterial protein toxins became valuable molecular tools for the targeted modulation of cell functions in experimental pharmacology and attractive therapeutics because...
Bacterial protein toxins became valuable molecular tools for the targeted modulation of cell functions in experimental pharmacology and attractive therapeutics because of their potent and specific mode of action in human cells. C2IN-C3lim, a recombinant fusion toxin (~50 kDa) of the Rho-inhibiting C3lim from Clostridium (C.) limosum and a non-toxic portion of the C. botulinum C2 toxin (C2IN), is selectively internalized into the cytosol of monocytic cells where C3lim specifically ADP-ribosylates Rho A and -B, thereby inhibiting Rho-mediated signaling. Thus, we hypothesized that these unique features make C2IN-C3lim an attractive molecule for the targeted pharmacological down-regulation of Rho-mediated functions in monocytes. The analysis of the actin structure and the Rho ADP-ribosylation status implied that C2IN-C3lim entered the cytosol of primary human monocytes from healthy donors ex vivo within 1 h. Moreover, it inhibited the fMLP-induced chemotaxis of human monocytes in a Boyden chamber model ex vivo. Similarly, in a 3-dimensional ex vivo model of extravasation, single cell analysis revealed that C2IN-C3lim-treated cells were not able to move. In a clinically relevant mouse model of blunt chest trauma, the local application of C2IN-C3lim into the lungs after thorax trauma prevented the trauma-induced recruitment of monocytes into the lungs in vivo. Thus, C2IN-C3lim might be an attractive lead compound for novel pharmacological strategies to avoid the cellular damage response caused by monocytes in damaged tissue after trauma and during systemic inflammation. The results suggest that the pathophysiological role of clostridial C3 toxins might be a down-modulation of the innate immune system.
Topics: ADP Ribose Transferases; Animals; Botulinum Toxins; Cell Movement; Cells, Cultured; Chemotaxis; Disease Models, Animal; Humans; Lung; Macrophages; Male; Mice, Inbred C57BL; Monocytes; Recombinant Fusion Proteins; Thoracic Injuries; Wounds, Nonpenetrating; rho GTP-Binding Proteins
PubMed: 28924833
DOI: 10.1007/s00204-017-2058-y -
Acta Veterinaria Scandinavica Sep 2016An outbreak of sudden death of pregnant farmed mink in Finland occurred during the busiest whelping period in the spring of 2013. The affected farms were all located in...
BACKGROUND
An outbreak of sudden death of pregnant farmed mink in Finland occurred during the busiest whelping period in the spring of 2013. The affected farms were all located in western Finland in a rather narrow geographic area, Ostrobothnia. Dead mink from 22 farms were submitted for laboratory diagnostics to the Finnish Food Safety Authority (Evira). The carcasses were necropsied and tissue specimens were prepared for histology. Samples of internal organs and peritoneal fluid were cultured bacteriologically.
RESULTS
Major pathological findings included hemorrhagic vaginal discharge, severely inflamed uteri with luminal hemorrhagic exudate and dead fetuses. Dead fetuses were present in the peritoneal cavity and associated severe peritonitis occurring as sequela of uterine rupture were found in most minks. Histological findings included hemorrhages, neutrophil infiltrations, degenerative inflammatory cells, edema, fibrin and rod-shaped bacteria on all layers of the uterine wall. In most samples abundant and pure anaerobic bacterial growth of Clostridium limosum was found.
CONCLUSIONS
This is the first report of C. limosum associated metritis in farmed mink. Disease was only observed in pregnant females and the uterus was the primary site of infection. The source of infection and the route of transmission remained unclear, but feed borne transmission was suspected.
Topics: Animals; Animals, Domestic; Clostridium; Clostridium Infections; Disease Outbreaks; Endometritis; Female; Finland; Mink; Pregnancy; Uterus
PubMed: 27600916
DOI: 10.1186/s13028-016-0230-7 -
Frontiers in Immunology 2015The C3 enzymes from Clostridium (C.) botulinum (C3bot) and Clostridium limosum (C3lim) are single chain protein toxins of about 25 kDa that mono-ADP-ribosylate Rho-A,... (Review)
Review
The C3 enzymes from Clostridium (C.) botulinum (C3bot) and Clostridium limosum (C3lim) are single chain protein toxins of about 25 kDa that mono-ADP-ribosylate Rho-A, -B, and -C in the cytosol of mammalian cells. We discovered that both C3 proteins are selectively internalized into the cytosol of monocytes and macrophages by an endocytotic mechanism, comparable to bacterial AB-type toxins, while they are not efficiently taken up into the cytosol of other cell types including epithelial cells and fibroblasts. C3-treatment results in disturbed macrophage functions, such as migration and phagocytosis, suggesting a novel function of clostridial C3 toxins as virulence factors, which selectively interfere with these immune cells. Moreover, enzymatic inactive C3 protein serves as a transport system to selectively deliver pharmacologically active molecules into the cytosol of monocytes/macrophages without damaging these cells. This review addresses also the generation of C3-based molecular tools for experimental macrophage pharmacology and cell biology as well as the exploitation of C3 for development of novel therapeutic strategies against monocyte/macrophage-associated diseases.
PubMed: 26175735
DOI: 10.3389/fimmu.2015.00339 -
PloS One 2013The C3 toxins from Clostridium botulinum (C3bot) and Clostridium limosum (C3lim) as well as C3-derived fusion proteins are selectively taken up into the cytosol of...
The C3 toxins from Clostridium botulinum (C3bot) and Clostridium limosum (C3lim) as well as C3-derived fusion proteins are selectively taken up into the cytosol of monocytes/macrophages where the C3-catalyzed ADP-ribosylation of Rho results in inhibition of Rho-signalling and characteristic morphological changes. Since the fusion toxin C2IN-C3lim was efficiently taken up into and inhibited proliferation of murine macrophage-like RAW 264.7 cells, its effects on RAW 264.7-derived osteoclasts were investigated. C2IN-C3lim was taken up into differentiated osteoclasts and decreased their resorption activity. In undifferentiated RAW 264.7 cells, C2IN-C3lim-treatment significantly decreased their differentiation into osteoclasts as determined by counting the multi-nucleated, TRAP-positive cells. This inhibitory effect was concentration- and time-dependent and most efficient when C2IN-C3lim was applied in the early stage of osteoclast-formation. A single-dose application of C2IN-C3lim at day 0 and its subsequent removal at day 1 reduced the number of osteoclasts in a comparable manner while C2IN-C3lim-application at later time points did not reduce the number of osteoclasts to a comparable degree. Control experiments with an enzymatically inactive C3 protein revealed that the ADP-ribosylation of Rho was essential for the observed effects. In conclusion, the results indicate that Rho-activity is crucial during the early phase of osteoclast-differentiation. Other bone cell types such as pre-osteoblastic cells were not affected by C2IN-C3lim. Due to their cell-type selective and specific mode of action, C3 proteins and C3-fusions might be valuable tools for targeted pharmacological manipulation of osteoclast formation and activity, which could lead to development of novel therapeutic strategies against osteoclast-associated diseases.
Topics: Adenosine Diphosphate Ribose; Animals; Botulinum Toxins; Cell Differentiation; Cell Line; Clostridium botulinum; Dose-Response Relationship, Drug; Mice; Osteoclasts; Protein Processing, Post-Translational; Time Factors; rho GTP-Binding Proteins
PubMed: 24386487
DOI: 10.1371/journal.pone.0085695 -
Toxins Jan 2013Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are the causative agent of the C. difficile-associated diarrhea (CDAD) and its severe form, the pseudomembranous... (Comparative Study)
Comparative Study
Difference in F-actin depolymerization induced by toxin B from the Clostridium difficile strain VPI 10463 and toxin B from the variant Clostridium difficile serotype F strain 1470.
Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are the causative agent of the C. difficile-associated diarrhea (CDAD) and its severe form, the pseudomembranous colitis (PMC). TcdB from the C. difficile strain VPI10463 mono-glucosylates (thereby inactivates) the small GTPases Rho, Rac, and Cdc42, while Toxin B from the variant C. difficile strain serotype F 1470 (TcdBF) specifically mono-glucosylates Rac but not Rho(A/B/C). TcdBF is related to lethal toxin from C. sordellii (TcsL) that glucosylates Rac1 but not Rho(A/B/C). In this study, the effects of Rho-inactivating toxins on the concentrations of cellular F-actin were investigated using the rhodamine-phalloidin-based F-actin ELISA. TcdB induces F-actin depolymerization comparable to the RhoA-inactivating exoenzyme C3 from C. limosum (C3-lim). In contrast, the Rac-glucosylating toxins TcdBF and TcsL did not cause F-actin depolymerization. These observations led to the conclusion that F-actin depolymerization depends on the toxin's capability of glucosylating RhoA. Furthermore, the integrity of focal adhesions (FAs) was analyzed using paxillin and p21-activated kinase (PAK) as FA marker proteins. Paxillin dephosphorylation was observed upon treatment of cells with TcdB, TcdBF, or C3-lim. In conclusion, the Rho-inactivating toxins induce loss of cell shape by either F-actin depolymerization (upon RhoA inactivation) or the disassembly of FAs (upon Rac1 inactivation).
Topics: Actins; Animals; Bacterial Proteins; Bacterial Toxins; Biomarkers; Bridged Bicyclo Compounds, Heterocyclic; Cell Line, Tumor; Cell Shape; Clostridioides difficile; Enzyme-Linked Immunosorbent Assay; Female; Glycosylation; HeLa Cells; Hepatocytes; Humans; Mice; NIH 3T3 Cells; Paxillin; Polymerization; Serotyping; Species Specificity; Thiazolidines; p21-Activated Kinases; rhoA GTP-Binding Protein
PubMed: 23344455
DOI: 10.3390/toxins5010106 -
Journal of Applied Microbiology Jul 2009It has been investigated whether secoisolariciresinol (SECO) and anhydrosecoisolariciresinol (AHS), an acid degradation product of SECO, could be fermented in a similar...
AIMS
It has been investigated whether secoisolariciresinol (SECO) and anhydrosecoisolariciresinol (AHS), an acid degradation product of SECO, could be fermented in a similar way, and to a similar extent, by members of the intestinal microbiota.
METHODS AND RESULTS
AHS and SECO were demethylated by Peptostreptococcus productus, Eubacterium limosum and Clostridium methoxybenzovorans. These bacteria have been identified as members of the human intestinal flora or closely related species. Demethylated AHS and demethylated SECO were purified by preparative RP-HPLC, and subsequently subjected to fermentation with Eggerthella lenta, Clostridium scindens and Clostridium hiranonis. Eggerthella lenta efficiently dehydroxylated demethylated SECO to enterodiol, whereas the other bacteria showed no dehydroxylation activity.
CONCLUSIONS
The conversion of the diol structure of SECO into the furan ring in AHS did not influence the demethylation capability of the tested bacteria. The results also showed that the extent of dehydroxylation of demethylated AHS was much lower than that of demethylated SECO.
SIGNIFICANCE AND IMPACT OF THE STUDY
Plant lignans are converted into bioactive mammalian lignans by the human intestinal bacteria. This study showed that the modification of plant lignans resulted in the formation a new type of mammalian lignan.
Topics: Butylene Glycols; Chromatography, High Pressure Liquid; Clostridium; Eubacterium; Fermentation; Lignans; Mass Spectrometry; Peptostreptococcus; Time Factors
PubMed: 19302311
DOI: 10.1111/j.1365-2672.2009.04209.x