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Streptolysin O

Yijie Chen, Mengchun Chen, Yue Zhang, Joo Hee Lee, Tamara Escajadillo, Hua Gong, Ronnie H Fang, Weiwei Gao, Victor Nizet, Liangfang Zhang
Neutralization of bacterial toxins has become a compelling approach to treating bacterial infections as it may pose less selective pressure for the development of bacterial resistance. Currently, the majority of toxin neutralization platforms act by targeting the molecular structure of the toxin, which requires toxin identification and customized design for different diseases. Therefore, their development has been challenged by the enormous number and complexity of bacterial toxins. Herein, biomimetic toxin nanosponges are formulated by coating membranes of human red blood cells (hRBCs) onto polymeric nanoparticles, which act as a toxin decoy to absorb and neutralize a broad-spectrum of hemolytic toxins regardless of their molecular structure...
February 13, 2018: Advanced Healthcare Materials
Heather Miller, Wenxia Song
B-lymphocytes have the ability to repair their plasma membranes following injury, such as by bacterial cholesterol-dependent cytolysins. The repair process includes the removal of the pore from the inflicted region of the plasma membrane via lipid raft-mediated internalization. Lipid rafts are critical for B cell receptor (BCR) activation. Cholesterol-dependent pore forming bacterial toxins provide a useful tool for examining the role of lipid rafts in B cell activation and the underlying cellular mechanisms...
2018: Methods in Molecular Biology
Masataka Murakami, Fumi Kano, Masayuki Murata
Cell-based assays have become increasingly important in the preclinical studies for biopharmaceutical products such as specialty peptides, which are of interest owing to their high substrate specificity. However, many of the latter are membrane impermeable and must be physically introduced into cells to evaluate their intracellular activities. We previously developed a "cell-resealing technique" that exploited the temperature-dependent pore-forming activity of the streptococcal toxin, streptolysin O (SLO), that enabled us to introduce various molecules into cells for evaluation of their intracellular activities...
January 31, 2018: Scientific Reports
Matías A Bustos, Ornella Lucchesi, María C Ruete, Claudia N Tomes
The acrosome reaction is the regulated exocytosis of mammalian sperm's single secretory granule, essential for fertilization. It relies on small GTPases, the cAMP binding protein Epac, and the SNARE complex, among other components. Here, we describe a novel tool to investigate Rab27-related signaling pathways: a hybrid recombinant protein consisting of human Rab27A fused to TAT, a cell penetrating peptide. With this tool, we aimed to unravel the connection between Rab3, Rab27 and Rap1 in sperm exocytosis and to deepen our understanding about how isoprenylation and guanine nucleotides influence the behaviour of Rab27 in exocytosis...
January 11, 2018: Cellular Signalling
Paria Motamen Salehi, Tahereh Foroutan, Arash Javeri, Masoumeh Fakhr Taha
Objectives: In some previous studies, the extract of embryonic carcinoma cells (ECCs) and embryonic stem cells (ESCs) have been used to reprogram somatic cells to more dedifferentiated state. The aim of this study was to investigate the effect of mouse ESCs extract on the expression of some pluripotency markers in human adipose tissue-derived stem cells (ADSCs). Materials and Methods: Human ADSCs were isolated from subcutaneous abdominal adipose tissue and characterized by flow cytometric analysis for the expression of some mesenchymal stem cell markers and adipogenic and osteogenic differentiation...
November 2017: Iranian Journal of Basic Medical Sciences
Narangerel Purevdorj, Yun Mu, Yajun Gu, Fang Zheng, Ran Wang, Jinwei Yu, Xuguo Sun
OBJECTIVE: To explore a panel of serum biomarkers for laboratory diagnosis of pediatric Henoch-Schönlein purpura (HSP). METHODS: The blood white blood cells (WBC) and serum levels of serum amyloid A (SAA), interleukin 6 (IL-6), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin E (IgE), C-reactive protein (CRP), complement component 3 (C3), complement component 4 (C4), and ASO (anti-streptolysin O) were detected in 127 patients with Henoch-Schonlein purpura (HSP), 110 cases of septicemia patients, and 121 healthy volunteers...
February 2018: Clinical Biochemistry
O V Blagova, Yu V Osipova, A V Nedostup, E A Kogan, V A Sulimov
AIM: To determine the diagnostic value of different clinical, laboratory, and instrumental signs in the diagnosis of myocarditis in patients with the picture of idiopathic arrhythmias, dilated cardiomyopathy (DCM) and in a comparison group when comparing with myocardial morphological examination. SUBJECTS AND METHODS: A study group included 100 patients (35 women; mean age, 44.7±12.5 years) with idiopathic arrhythmias (n=20) and DCM as a syndrome (n=100). All underwent myocardial morphological examination: endomyocardial biopsy (EMB) (n=71), intraoperative biopsy (n=13), study of the explanted heart (n=6), and autopsy (n=11)...
2017: Terapevticheskiĭ Arkhiv
Yudai Yamaoki, Ayaka Kiyoishi, Masayuki Miyake, Fumi Kano, Masayuki Murata, Takashi Nagata, Masato Katahira
In order to understand intracellular biological events, information on the structure, dynamics and interaction of proteins and nucleic acids in living cells is of crucial importance. In-cell NMR is a promising method to obtain this information. Although NMR signals of proteins in human cells have been reported, those of nucleic acids were reported only in Xenopus laevis oocytes, i.e., not in human cells. Here, DNA and RNA were introduced into human cells by means of pore formation by bacterial toxin streptolysin O and subsequent resealing...
October 12, 2017: Physical Chemistry Chemical Physics: PCCP
Sarita Das, T Dileepan, D R Johnson, E L Kaplan, P Patrick Cleary
Among the four known Streptococcal nucleases comprising of DNase A, B, C and D; DNase B is the most common, and determination of the levels of antibody to DNase B (ADB) is often used to confirm a clinical diagnosis of Streptococcus pyogenes/group A Streptococcal (GAS) infection. The commonly used assays for antibodies that neutralize DNase B or streptolysin O activity use partially purified antigens that often fail to detect antibody changes subsequent to culture documented infections. Therefore, an enzyme-linked immunosorbent assay (ELISA) was developed employing his-tagged recombinant DNase B as plate antigen for comparison to the commonly used DNA methyl green micromethod (DMGM)...
December 2017: Journal of Immunological Methods
Sopio Chochua, Ben J Metcalf, Zhongya Li, Joy Rivers, Saundra Mathis, Delois Jackson, Robert E Gertz, Velusamy Srinivasan, Ruth Lynfield, Chris Van Beneden, Lesley McGee, Bernard Beall
Group A streptococci (GAS) are genetically diverse. Determination of strain features can reveal associations with disease and resistance and assist in vaccine formulation. We employed whole-genome sequence (WGS)-based characterization of 1,454 invasive GAS isolates recovered in 2015 by Active Bacterial Core Surveillance and performed conventional antimicrobial susceptibility testing. Predictions were made for genotype, GAS carbohydrate, antimicrobial resistance, surface proteins (M family, fibronectin binding, T, R28), secreted virulence proteins (Sda1, Sic, exotoxins), hyaluronate capsule, and an upregulated nga operon (encodes NADase and streptolysin O) promoter (Pnga3)...
September 19, 2017: MBio
Yuko Saito, Susumu Ookawara, Hisataka Uchima, Takeshi Ishida, Masafumi Kakei, Hitoshi Sugawara
A 54-year-old Japanese man noticed painful swelling and redness of his left leg. He was admitted for treatment of cellulitis, which was accompanied with increased anti-streptolysin O and anti-streptokinase titers in his clinical course. After Piperacillin/Tazobactam administration, the skin lesion resolved. However, the patient then developed arthritis, palpable purpura, and intermittent abdominal pain, later found to be secondary to a severe duodenal ulcer. He was diagnosed with cellulitis-associated anaphylactoid purpura and was given prednisolone, which dramatically improved his symptoms...
2017: Case Reports in Medicine
Jorge J Velarde, Maghnus O'Seaghdha, Buket Baddal, Benedicte Bastiat-Sempe, Michael R Wessels
The globally dominant, invasive M1T1 strain of group A Streptococcus (GAS) harbors polymorphisms in the promoter region of an operon that contains the genes encoding streptolysin O (SLO) and NAD(+)-glycohydrolase (NADase), resulting in high-level expression of these toxins. While both toxins have been shown experimentally to contribute to pathogenesis, many GAS isolates lack detectable NADase activity. DNA sequencing of such strains has revealed that reduced or absent enzymatic activity can be associated with a variety of point mutations in nga, the gene encoding NADase; a commonly observed polymorphism associated with near-complete abrogation of activity is a substitution of aspartic acid for glycine at position 330 (G330D)...
September 12, 2017: MBio
Tamara Escajadillo, Joshua Olson, Brian T Luk, Liangfang Zhang, Victor Nizet
Group A Streptococcus (GAS), an important human-specific Gram-positive bacterial pathogen, is associated with a broad spectrum of disease, ranging from mild superficial infections such as pharyngitis and impetigo, to serious invasive infections including necrotizing fasciitis and streptococcal toxic shock syndrome. The GAS pore-forming streptolysin O (SLO) is a well characterized virulence factor produced by nearly all GAS clinical isolates. High level expression of SLO is epidemiologically linked to intercontinental dissemination of hypervirulent clonotypes and poor clinical outcomes...
2017: Frontiers in Pharmacology
Dóra Hancz, Elsa Westerlund, Benedicte Bastiat-Sempe, Onkar Sharma, Christine Valfridsson, Lena Meyer, John F Love, Maghnus O'Seaghdha, Michael R Wessels, Jenny J Persson
Group A Streptococcus (GAS) is a common human pathogen and the etiologic agent of a large number of diseases ranging from mild, self-limiting infections to invasive life-threatening conditions. Two prominent virulence factors of this bacterium are the genetically and functionally linked pore-forming toxin streptolysin O (SLO) and its cotoxin NAD(+)-glycohydrolase (NADase). Overexpression of these toxins has been linked to increased bacterial virulence and is correlated with invasive GAS disease. NADase can be translocated into host cells by a SLO-dependent mechanism, and cytosolic NADase has been assigned multiple properties such as protection of intracellularly located GAS bacteria and induction of host cell death through energy depletion...
July 18, 2017: MBio
Feng Xiao, Rui Zheng, Di Yang, Kejiang Cao, Shijiang Zhang, Bingruo Wu, Yongfeng Shao, Bin Zhou
BACKGROUND: Rheumatic heart disease is an autoimmune disease caused by group A streptococci infection and frequently affects the aortic valve. Sex differences are common in the disease progression, treatment, and outcome. However, little is known about the sex differences in the pathology of aortic valves in rheumatic heart disease. DESIGN: We studied the end-stage calcific aortic valves from male versus female patients to reveal the sex-dependent pathology differences and molecular changes associated with requiring valve replacement...
2017: PloS One
Koichi Ojima, Emi Ichimura, Yuya Yasukawa, Mika Oe, Susumu Muroya, Takahiro Suzuki, Jun-Ichi Wakamatsu, Takanori Nishimura
In striated muscles, approximately 300 myosin molecules form a single thick filament in myofibrils. Each myosin is continuously displaced by another myosin to maintain the thick filament structure. Our previous study using a fluorescence recovery after photobleaching (FRAP) technique showed that the myosin replacement rate is decreased by inhibition of protein synthesis, but myosin is still exchangeable. This result prompted us to examine whether myosin in the cytoplasm is involved in myosin replacement in myofibrils...
June 19, 2017: Animal Science Journal, Nihon Chikusan Gakkaihō
John Joseph, Neil Kent, Asha Bowen, Julie Hart, Meru Sheel, Robert Wardrop, Sam Abbs, Scott Bazely, Monika Rybak
This study was designed to determine the sensitivity and reproducibility of recovering anti-streptolysin O titres (ASOT) from dried blood spot (DBS) samples, a methodologic subcomponent of the penicillin pharmacokinetic studies in children receiving secondary prophylaxis with intramuscular benzathine penicillin for acute rheumatic fever.
September 2017: Journal of Immunological Methods
Glaucia Vanessa Novak, Koken Hayashi, Kohei Sampa, Yosuke Okumura, Gabriela Ribeiro Viola Ferreira, Clovis Artur Silva
Arthritis has been reported as an acute pattern, generally evanescent with oligoarthritis, mostly affecting knees and ankles in childhood systemic polyarteritis nodosa. However, chronic polyarthritis with morning stiffness mimicking juvenile idiopathic arthritis has not been reported. We describe the case of a 4-year old girl who had additive and chronic polyarthritis with edema, tenderness, pain on motion and morning stiffness for 2 months. After 45 days, she also presented painful subcutaneous nodules and erythematous-violaceous lesions in the extensor region of upper and lower limbs...
January 2017: Einstein
Werner Keenswijk, Johan Vande Walle
A 2-year-old boy presented with severe hypotension and acute kidney injury after a prodrome of non-bloody diarrhoea and fever in the preceding 3 days. He had a mild Ebstein cardiac anomaly but otherwise a normal past history and growth. On examination, he looked ill, his temperature was 37.5 °C, circulation was poor, and there were several purpuric lesions on the face, hands and scrotum. Haemoglobin was 7.8 g/dL (11-14), total white cell count 27 × 10(9)/L, platelets 62 × 10(9)/L, blood urea nitrogen 20...
April 20, 2017: Paediatrics and International Child Health
Rahul D Suryawanshi, Satya Veer Singh Malik, Bhushan Jayarao, Sandeep P Chaudhari, Emily Savage, Jess Vergis, Nitin V Kurkure, Sukhadeo B Barbuddhe, Deepak B Rawool
The present study for the first time evaluates the serodiagnostic efficacy of two recombinant antigens namely, listeriolysin O (rLLO) and phosphatidyl-inositol phospholipase C (rPI-PLC). Indirect ELISA with the above recombinant antigens was used on samples collected from bovines (n=106), goats (n=138) and pigs (n=92) having either a history of abortion, emaciation and/or apparently healthy animals. Isolation of Listeria was attempted from the blood samples using USDA-FSIS method. On screening of test sera by rLLO-based ELISA, antibodies against anti-listeriolysin O (ALLO) were observed in goats (22...
June 2017: Journal of Microbiological Methods
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