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Streptolysin O

Vikesh Chhabria, Steve Beeton
AIM: To produce mammalian biomimetic nanosponges from mammalian erythrocyte ghosts. Biomimetic nanosponges were studied in vitro as treatment platforms against exotoxin-related sepsis. METHODS: Ovine blood was treated with hypotonic buffer to create erythrocyte ghosts and then subjected to sonication to produce erythrocyte vesicles of nonuniform size. Vesicles were then serially extruded through 400-nm and 100-nm polycarbonate membranes. Nanosponges were prepared by fusing poly(d,l-lactic-co-glycolic acid) cores with ovine erythrocyte vesicles...
October 21, 2016: Nanomedicine
Z Birsin Özçakar, Suat Fitöz, Adalet Elçin Yıldız, Fatoş Yalçınkaya
There is limited number of publications about the use of non-invasive imaging modalities in the diagnosis of childhood polyarteritis nodosa (cPAN). The aim of this study was to present the clinical and imaging findings of the patients with cPAN who were diagnosed with non-invasive imaging techniques. Files of patients who had been diagnosed as cPAN in our department from 2005 to 2015 were reviewed, retrospectively. Demographic, clinical, laboratory, and imaging findings of the patients were evaluated. Nine patients (8M, 1F; age at disease onset: 12...
October 5, 2016: Clinical Rheumatology
Otilia V Vieira
Disruption of the cell plasma membrane can occur due to mechanical damage, pore forming toxins, etc. Resealing or plasma membrane repair (PMR) is the emergency response required for cell survival. It is triggered by Ca(2+) entering through the disruption, causing organelles such as lysosomes located underneath the plasma membrane to fuse rapidly with the adjacent plasma membrane. We have recently identified some of the molecular traffic machinery that is involved in this vital process. Specifically, we showed that 2 members of the Rab family of small GTPases, Rab3a and Rab10, are essential for lysosome exocytosis and PMR in cells challenged with a bacterial toxin, streptolysin-O (SLO)...
September 29, 2016: Small GTPases
Nigus Zegeye, Daniel Asrat, Yimtubezinash Woldeamanuel, Abebe Habte, Etsegenet Gedlu, Tone Tønjum, Abraham Aseffa
BACKGROUND: Among children diagnosed to have chronic rheumatic valvular heart disease (RHD) in Ethiopia, many have been observed to develop recurrence of rheumatic fever (RF) despite secondary prophylaxis. This study determined the throat culture positivity rate and drug susceptibility pattern of beta hemolytic streptococci (BHS) isolated from children attending a specialized cardiac clinic in Ethiopia. METHODS: Throat swabs were collected from 233 children receiving benzathine penicillin injection as secondary prophylaxis for RHD and cultured...
September 23, 2016: BMC Infectious Diseases
M S Sahin, M U Yalcin, D Kocyigit
INTRODUCTION: Patients with elevated anti-streptolysin O (ASO) titers (ASOT) and recurrent tonsillitis episodes are known to be at higher risk for rheumatic heart disease (RHD). However, there is no data regarding prevalence of RHD in this high risk population. In this study, we aimed to screen ambulatory patients with elevated ASOT and recurrent tonsillitis episodes using echocardiography for identification of RHD. We hypothesized that prevalence of RHD is higher in this patient group compared to general population...
October 2016: International Journal of Pediatric Otorhinolaryngology
María F Quevedo, Ornella Lucchesi, Matías A Bustos, Cristian A Pocognoni, Paola X De la Iglesia, Claudia N Tomes
At the final stage of exocytotis, a fusion pore opens between the plasma and a secretory vesicle membranes; typically, when the pore dilates the vesicle releases its cargo. Sperm contain a large dense-core secretory granule (the acrosome) whose contents are secreted by regulated exocytosis at fertilization. Minutes after the arrival of the triggering signal, the acrosomal and plasma membranes dock at multiple sites and fusion pores open at the contact points. It is believed that immediately afterwards, fusion pores dilate spontaneously...
September 9, 2016: Journal of Biological Chemistry
Trevor W Stone, L Gail Darlington, Caroline M Forrest
The serine protease subtilisin induces a form of long-term depression (LTD) which is accompanied by a reduced expression of the axo-dendritic guidance molecule Unco-ordinated-5C (Unc-5C). One objective of the present work was to determine whether a loss of Unc-5C function contributed to subtilisin-induced LTD by using Unc-5C antibodies in combination with the pore-forming agents Triton X-100 (0.005%) or streptolysin O in rat hippocampal slices. In addition we have assessed the effect of subtilisin on the related dependence receptor Deleted in Colorectal Cancer (DCC) and used antibodies to this protein for functional studies...
November 12, 2016: Neuroscience
Yoshihide Fujigaki, Yosuke Kawamorita, Hiromi Yamaguchi, Shigeyuki Arai, Yoshifuru Tamura, Tatsuru Ota, Shigeru Shibata, Fukuo Kondo, Yutaka Yamaguchi, Shunya Uchida
We report a 32-year-old man with nephrotic syndrome and preceding symptom of infection. He had renal insufficiency, hypocomplementemia, and elevated titer of anti-streptolysin O. Renal biopsy showed mesangial hypercellularity and focal segmental endocapillary hypercellularity with double contour of the glomerular basement membrane (GBM). Immunofluorescence study showed granular C3 staining on the mesangial areas and glomerular capillary walls (GCWs) and linear immunoglobulin G (IgG) staining on GCWs. Electron microscopy revealed sporadic subepithelial humps, discontinuous small and thin deposits in the endothelial side of the GBM and mesangial deposits...
September 2016: Pathology International
Sevda Erer Özbek, Zuhal Yapıcı, Erdem Tüzün, Murat Giriş, Selcen Duran, Özlem Taşkapılıoğlu, Mehmet Okan
Encephalitis associated with leucine-rich glioma inactivated 1 (LGI1) antibodies is often encountered in elderly male patients and may infrequently present with isolated syndromes. A 6-year-old boy was admitted with acute onset severe oral and facial stereotypic and choreiform movements. On his neurologic examination, he had repetitive and rhythmic movements in orolingual muscles including tongue protrusion, limb chorea and minimal facial stereotypic movements. Anti-streptolysin O (ASO) titers were found severely elevated in several measurements...
September 2015: Turkish Journal of Pediatrics
Atsushi Shoji, Kana Ikeya, Miki Aoyagi, Ryutaro Takatsuji, Akio Yanagida, Yoichi Shibusawa, Masao Sugawara
Streptolysin O (SLO), which recognizes sterols and forms nanopores in lipid membranes, is proposed as a sensing element for monitoring cholesterol oxidation in a lipid bilayer. The structural requirements of eight sterols for forming nanopores by SLO confirmed that a free 3-OH group in the β-configuration of sterols is required for recognition by SLO in a lipid bilayer. The extent of nanopore formation by SLO in lipid bilayers increased in the order of cholestanol<cholesterol<25-OH cholesterol and in a sterol concentration-dependent manner...
September 5, 2016: Journal of Pharmaceutical and Biomedical Analysis
Kazuo Ebine, Makoto Hirai, Miako Sakaguchi, Kazuhide Yahata, Osamu Kaneko, Yumiko Saito-Nakano
BACKGROUND: Rab5 GTPase regulates membrane trafficking between the plasma membrane and endosomes and harbours a conserved C-terminal isoprenyl modification that is necessary for membrane recruitment. Plasmodium falciparum encodes three Rab5 isotypes, and one of these, Rab5b (PfRab5b), lacks the C-terminal modification but possesses the N-terminal myristoylation motif. PfRab5b was reported to localize to the parasite periphery. However, the trafficking pathway regulated by PfRab5b is unknown...
2016: Malaria Journal
Tania Rivera-Hernandez, Manisha Pandey, Anna Henningham, Jason Cole, Biswa Choudhury, Amanda J Cork, Christine M Gillen, Khairunnisa Abdul Ghaffar, Nicholas P West, Guido Silvestri, Michael F Good, Peter M Moyle, Istvan Toth, Victor Nizet, Michael R Batzloff, Mark J Walker
UNLABELLED: Group A Streptococcus (GAS) is an important human pathogen responsible for both superficial infections and invasive diseases. Autoimmune sequelae may occur upon repeated infection. For this reason, development of a vaccine against GAS represents a major challenge, since certain GAS components may trigger autoimmunity. We formulated three combination vaccines containing the following: (i) streptolysin O (SLO), interleukin 8 (IL-8) protease (Streptococcus pyogenes cell envelope proteinase [SpyCEP]), group A streptococcal C5a peptidase (SCPA), arginine deiminase (ADI), and trigger factor (TF); (ii) the conserved M-protein-derived J8 peptide conjugated to ADI; and (iii) group A carbohydrate lacking the N-acetylglucosamine side chain conjugated to ADI...
2016: MBio
Alan F Garcia, Karen M Yamaga, Leigh Anne Shafer, Oana Bollt, Elizabeth K Tam, Madeleine W Cunningham, David K Kurahara
BACKGROUND: Acute rheumatic fever (ARF) is an autoimmune disorder associated with Streptococcus pyogenes infection. A prevailing hypothesis to account for this disease is that epitopes of self-antigens, such as cardiac myosin react to antibodies against S. pyogenes. The goal of our study was to confirm disease epitopes of cardiac myosin, identify immunodominant epitopes and to monitor the epitope response pattern in acute and convalescent rheumatic fever. METHODS: Enzyme-linked immunosorbant assays were used to determine epitopes immunodominant in acute disease and to track the immune response longitudinally to document any changes in the epitope pattern in convalescent sera...
September 2016: Pediatric Infectious Disease Journal
A Joshi, R P B Shrestha, P S Shrestha, S Dangol, N C Shrestha, P Poudyal, A Shrestha
Sydenham's chorea is the most common type of acquired chorea in childhood which is a major neurological manifestation of rheumatic fever. We describe a 13 years old girl who presented with weakness and purposeless involuntary movements of upper and lower limbs. The symptoms slightly affected the child's daily activities and had an unstable gait on walking which was aggravated during stress. Grade II ejection systolic murmur was noticed on cardiovascular examination. Echocardiography evaluation showed thickened aortic and mitral valve leaflets with mild to moderate degree of mitral regurgitation...
July 2015: Kathmandu University Medical Journal (KUMJ)
Luchang Zhu, Randall J Olsen, Nicola Horstmann, Samuel A Shelburne, Jia Fan, Ye Hu, James M Musser
Variable-number tandem-repeat (VNTR) polymorphisms are ubiquitous in bacteria. However, only a small fraction of them has been functionally studied. Here, we report an intergenic VNTR polymorphism that confers an altered level of toxin production and increased virulence in Streptococcus pyogenes The nature of the polymorphism is a one-unit deletion in a three-tandem-repeat locus upstream of the rocA gene encoding a sensor kinase. S. pyogenes strains with this type of polymorphism cause human infection and produce significantly larger amounts of the secreted cytotoxins S...
July 2016: Infection and Immunity
Alan M O'Neill, Teresa L M Thurston, David W Holden
UNLABELLED: As key components of innate immune defense, macrophages are essential in controlling bacterial pathogens, including group A Streptococcus(GAS). Despite this, only a limited number of studies have analyzed the recovery of GAS from within human neutrophils and macrophages. Here, we determined the intracellular fate of GAS in human macrophages by using several quantitative approaches. In both U937 and primary human macrophages, the appearance over time of long GAS chains revealed that despite GAS-mediated cytotoxicity, replication occurred in viable, propidium iodide-negative macrophages...
2016: MBio
Bryan P Hurley, Waheed Pirzai, Alex D Eaton, Marc Harper, Jason Roper, Cindi Zimmermann, Gregory S Ladics, Raymond J Layton, Bryan Delaney
Human intestinal epithelial cell lines (T84, Caco-2, and HCT-8) grown on permeable Transwell™ filters serve as models of the gastrointestinal barrier. In this study, this in vitro model system was evaluated for effectiveness at distinguishing between hazardous and non-hazardous proteins. Indicators of cytotoxicity (LDH release, MTT conversion), monolayer barrier integrity ([(3)H]-inulin flux, horseradish peroxidase flux, trans-epithelial electrical resistance [TEER]), and inflammation (IL-8, IL-6 release) were monitored following exposure to hazardous or non-hazardous proteins...
June 2016: Food and Chemical Toxicology
M A Kim, A V Labushkina, E N Simovanian, G G Kharseeva
The Rostovskii state medical university of Minzdrav of Russia, 344022 Rostov-on-Don, Russia The analysis is applied concerning significance of laboratory techniques of verification of streptococcus infection (bacteriological analysis, detection of anti-streptolysin O in pair serums) in 148 patients with infectious mononucleosis aged from 3 to 15 years. The content of anti-streptolysin O exceeded standard in 41 ± 4.8% of patients with concomitant in acute period and in 49.5 ± 4.9% during period of re-convalescence...
November 2015: Klinicheskaia Laboratornaia Diagnostika
Onkar Sharma, Maghnus O'Seaghdha, Jorge J Velarde, Michael R Wessels
A global increase in invasive infections due to group A Streptococcus (S. pyogenes or GAS) has been observed since the 1980s, associated with emergence of a clonal group of strains of the M1T1 serotype. Among other virulence attributes, the M1T1 clone secretes NAD+-glycohydrolase (NADase). When GAS binds to epithelial cells in vitro, NADase is translocated into the cytosol in a process mediated by streptolysin O (SLO), and expression of these two toxins is associated with enhanced GAS intracellular survival...
March 2016: PLoS Pathogens
Clara Gutiérrez, María Chacón, Luis Pérez-Ybarra, Hilary Rivero, Sheryl Straga, Juan Luis-León
INTRODUCTION: β-hemolytic streptococci (Streptococcus pyogenes) groups A, C or G, secretes streptolysin O, toxin which causes in the infected individual an adaptive humoral immune response with production of serum antibodies called anti-streptolysin O (ASO). OBJECTIVES: To determine the reference value of ASO in a sample of 159 individuals aged 16-72 years from municipality Francisco Linares Alcántara, Aragua state, applying indirect (passive) agglutination test...
December 2015: Revista Chilena de Infectología: órgano Oficial de la Sociedad Chilena de Infectología
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