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Biochimica Et Biophysica Acta Sep 2016We demonstrate the use of tethered bilayer lipid membranes (tBLMs) as an experimental platform for functional and structural studies of membrane associated proteins by...
We demonstrate the use of tethered bilayer lipid membranes (tBLMs) as an experimental platform for functional and structural studies of membrane associated proteins by electrochemical techniques. The reconstitution of the cholesterol-dependent cytolysin (CDC) pyolysin (PLO) from Trueperella pyogenes into tBLMs was followed in real-time by electrochemical impedance spectroscopy (EIS). Changes of the EIS parameters of the tBLMs upon exposure to PLO solutions were consistent with the dielectric barrier damage occurring through the formation of water-filled pores in membranes. Parallel experiments involving a mutant version of PLO, which is able to bind to the membranes but does not form oligomer pores, strengthen the reliability of this methodology, since no change in the electrochemical impedance was observed. Complementary atomic force microscopy (AFM) and neutron reflectometry (NR) measurements revealed structural details of the membrane bound PLO, consistent with the structural transformations of the membrane bound toxins found for other cholesterol dependent cytolysins. In this work, using the tBLMs platform we also observed a protective effect of the dynamin inhibitor Dynasore against pyolysin as well as pneumolysin. An effect of Dynasore in tBLMs, which was earlier observed in experiments with live cells, confirms the biological relevance of the tBLMs models, as well as demonstrates the potential of the electrochemical impedance spectroscopy to quantify membrane damage by the pore forming toxins. In conclusion, tBLMs are a reliable and complementary method to explore the activity of CDCs in eukaryotic cells and to develop strategies to limit the toxic effects of CDCs.
Topics: Bacterial Proteins; Bacterial Toxins; Dielectric Spectroscopy; Erythrocyte Membrane; Hemolysin Proteins; Humans; Hydrazones; Lipid Bilayers; Microscopy, Atomic Force; Mutation
PubMed: 27211243
DOI: 10.1016/j.bbamem.2016.05.016 -
JMA Journal Sep 2019A 57-year-old man with untreated diabetes mellitus was admitted to our hospital due to an intrathoracic mass lesion infiltrating the vertebral body and mediastinum. The...
A 57-year-old man with untreated diabetes mellitus was admitted to our hospital due to an intrathoracic mass lesion infiltrating the vertebral body and mediastinum. The mass was suspected to be invasive lung cancer; however, percutaneous needle biopsy revealed that the mass was inflammatory granulation tissue caused by an infection. To the best of our knowledge, this is the first report of an intrathoracic mass lesion caused by an infection. When an intrathoracic mass lesion is suspected, clinicians should consider possible infections that cause granulation tissue, such as . This is particularly important in immunocompromized hosts such as patients with diabetes.
PubMed: 33615031
DOI: 10.31662/jmaj.2018-0036 -
New Microbes and New Infections Jun 2024
Expression of Concern: Arcanobacterium ihumii sp. nov., Varibaculum vaginae sp. nov. and Tessaracoccus timonensis sp. nov., isolated from vaginal swabs from healthy Senegalese women.
PubMed: 38799966
DOI: 10.1016/j.nmni.2024.101259 -
New Microbes and New Infections Sep 2019Culturomics studies the microbial variety of the human microbiome by combining diversified culture conditions, matrix-assisted laser desorption/ionization time-of-flight...
Culturomics studies the microbial variety of the human microbiome by combining diversified culture conditions, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene identification. This study identifies three putative new bacterial species: sp. nov. strain Marseille-P5647, sp. nov. strain Marseille-P5644 and sp. nov. strain Marseille-P5995, which we describe according to the concept of taxonogenomics.
PubMed: 31367386
DOI: 10.1016/j.nmni.2019.100585 -
The Medical Journal of Malaysia Oct 2018Systemic Arcanobacterium pyogenes is a rare bacterial infection in humans.1The diagnosis of thrombotic thrombocytopenic purpura (TTP)-like syndrome and infective...
Systemic Arcanobacterium pyogenes is a rare bacterial infection in humans.1The diagnosis of thrombotic thrombocytopenic purpura (TTP)-like syndrome and infective endocarditis (IE) is often elusive. We report a case of TTP-like syndrome associated with A. pyogenes endocarditis in a post-allogenic transplant patient.
Topics: Actinomycetales Infections; Arcanobacterium; Diagnosis, Differential; Endocarditis, Bacterial; Female; Hematopoietic Stem Cell Transplantation; Humans; Purpura, Thrombotic Thrombocytopenic; Young Adult
PubMed: 30350823
DOI: No ID Found -
Clinical Case Reports Aug 2016We report the first case of wound infection caused by Trueperella bernardiae after laparoscopic surgery. The patient was treated with oral amoxicillin/clavulanate which...
We report the first case of wound infection caused by Trueperella bernardiae after laparoscopic surgery. The patient was treated with oral amoxicillin/clavulanate which was continued for 1 week after discharge with a successful clinical response. There are few cases described but none related to wound infection after laparoscopic surgery.
PubMed: 27525092
DOI: 10.1002/ccr3.600 -
Radiology Case Reports Jul 2024, found as normal flora in healthy individuals, is an unusual culprit for pharyngitis and sinusitis in young adults, rarely leading to severe infections. Here, we...
, found as normal flora in healthy individuals, is an unusual culprit for pharyngitis and sinusitis in young adults, rarely leading to severe infections. Here, we present a singular case involving a 19-year-old immunocompetent male who experienced complications arising from sinusitis, leading to orbital and intracranial sinogenic complications. The patient developed severe cerebral vasospasm with delayed cerebral ischemia, necessitating aggressive management encompassing daily catheter-directed intra-arterial infusions, surgical source control, and maximal medical therapy. This case explores the challenging diagnostic and management aspects associated with cerebral artery vasospasm secondary to bacterial meningoencephalitis. The abrupt neurological decline in such patients presents a dilemma in recognizing the occurrence of cerebral vasospasm versus the progression of meningoencephalitis. By utilizing computed tomography brain perfusion scans, we were able to identify delayed cerebral ischemia due to cerebral vasospasm, acknowledging that this modality was not used to identify classical territorial stroke infarcts. This decision was made based on the understanding of the potential for bacterial-induced cerebral vasospasm to involve both hemispheres.
PubMed: 38645946
DOI: 10.1016/j.radcr.2024.03.029 -
New Microbes and New Infections Jul 2017Herein we report the main characteristics of strain Marseille-P3248 (=CSUR P3248) isolated from a urine sample of a 54-day-old girl with rotavirus gastroenteritis.
Herein we report the main characteristics of strain Marseille-P3248 (=CSUR P3248) isolated from a urine sample of a 54-day-old girl with rotavirus gastroenteritis.
PubMed: 28480045
DOI: 10.1016/j.nmni.2017.03.003 -
New Microbes and New Infections Jun 2024
PubMed: 38799916
DOI: 10.1016/j.nmni.2024.101260 -
New Microbes and New Infections Jun 2024
PubMed: 38799955
DOI: 10.1016/j.nmni.2024.101396