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Streptococcal Toxic Shock Syndrome (streptococcal + toxic_shock_syndrome)
Selected AbstractsStructural features of a zinc binding site in the superantigen strepococcal pyrogenic exotoxin A (SpeA1): Implications for MHC class II recognitionPROTEIN SCIENCE, Issue 6 2001Matthew Baker Abstract Streptococcal pyrogenic exotoxin A (SpeA) is produced by Streptococcus pyogenes, and has been associated with severe infections such as scarlet fever and Streptococcal Toxic Shock Syndrome (STSS). In this study, the crystal structure of SpeA1 (the product of speA allele 1) in the presence of 2.5 mM zinc was determined at 2.8 Å resolution. The protein crystallizes in the orthorhombic space group P21212, with four molecules in the crystallographic asymmetric unit. The final structure has a crystallographic R -factor of 21.4% for 7,031 protein atoms, 143 water molecules, and 4 zinc atoms (one zinc atom per molecule). Four protein ligands,Glu 33, Asp 77, His 106, and His 110,form a zinc binding site that is similar to the one observed in a related superantigen, staphylococcoal enterotoxin C2. Mutant toxin forms substituting Ala for each of the zinc binding residues were generated. The affinity of these mutants for zinc ion confirms the composition of this metal binding site. The implications of zinc binding to SpeA1 for MHC class II recognition are explored using a molecular modeling approach. The results indicate that, despite their common overall architecture, superantigens appear to have multiple ways of complex formation with MHC class II molecules. [source] Detection of invasive protein profile of Streptococcus pyogenes M1 isolates from pharyngitis patientsAPMIS, Issue 3 2010TADAO HASEGAWA Hasegawa T, Okamoto A, Kamimura T, Tatsuno I, Hashikawa S-N, Yabutani M, Matsumoto M, Yamada K, Isaka M, Minami M, Ohta M. Detection of invasive protein profile of Streptococcus pyogenes M1 isolates from pharyngitis patients. APMIS 2010; 118: 167,78. Streptococcal toxic shock syndrome (STSS) is a re-emerging infectious disease in Japan and many other developed countries. Epidemiological studies have revealed that the M1 serotype of Streptococcus pyogenes is the most dominant causative isolate of STSS. Recent characterization of M1 isolates revealed that the mutation of covS, one of the two-component regulatory systems, plays an important role in STSS by altering protein expression. We analyzed the M1 S. pyogenes clinical isolates before or after 1990 in Japan, using two-dimensional gel electrophoresis (2-DE) and pulsed-field gel electrophoresis (PFGE). PFGE profiles were different between the isolates before and after 1990. Markedly different profiles among isolates after 1990 from STSS and pharyngitis patients were detected. Sequence analysis of two-component regulatory systems showed that covS mutations were detected not only in STSS but also in three pharyngitis isolates, in which proteins from the culture supernatant displayed the invasive type. The mutated CovS detected in the pharyngitis isolates had impaired function on the production of streptococcal pyrogenic exotoxin B (SpeB) analyzed by 2-DE. These results suggest that several covS mutations that lead to the malfunction of the CovS protein occurred even in pharyngeal infection. [source] Streptococcal toxic shock syndromeCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2002D. L. Stevens Perhaps more noteworthy than the emergence of Streptococcal toxic shock syndrome (StrepTSS) is its persistence for a period of more than 15 years in most geographical areas and an actual increase in incidence in some regions. Early diagnosis remains a problem, and aggressive surgery often cannot be avoided. The continuing rates of mortality and morbidity indicate the need for novel approaches to diagnosis and treatment. [source] Unusual presentation of necrotizing fasciitis in a patient who had achieved long-term remission after irradiation for testicular cancerINTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2005TOMOAKI MIYAGAWA Abstract, We report a case of a 60-year-old man with necrotizing fasciitis complicated by streptococcal toxic shock syndrome. The patient had received high-dose chemotherapy and radiotherapy to the pelvis for relapsed seminoma 7 years previously. He had been in long-term remission. He was admitted to the Tsukuba University Hospital, Tsukuba-City, Ibaraki, Japan, with complaints of fever and localized erythema over the foreskin. The patient suffered from septic shock and multiple organ failure. Despite intensive care, he died 18 h after admission. Streptococcus pyogenes was isolated from both the wound and blood culture. To our knowledge, this is the first description of necrotizing fasciitis primarily affecting the penile skin. [source] Group A streptococcal toxic shock syndrome with extremely aggressive course in the third trimesterJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2010Takashi Sugiyama Abstract Group-A-streptococcus-(GAS)-induced toxic shock syndrome (TSS) is uncommon, but carries a high risk of maternal mortality during pregnancy. The onset of gravidic GAS-TSS has been reported mostly during the puerperium. A 16-year-old woman, who was at 37 weeks of gestation, and without obstetrical care during the last 30 weeks, was referred to our hospital. She complained of fever for one day with headache and abdominal pain after the fever developed. On admission, her consciousness was drowsy, intrauterine fetal death was recognized, and she rapidly developed shock status with coma and hypotension, hemolysis, disseminated intravascular coagulation (DIC), and multi-organ failure. Although we had not obtained the results of a bacterial culture, we suspected sepsis with DIC with homolysis and multi-organ failure resulting from an infection. The patient was treated with antibiotics and intubation because of respiratory insufficiency. Twelve hours after admission to the intensive care unit in our hospital, she died. Cultures from blood, subcutaneous tissue, vaginal discharge, and pharynx all revealed GAS bacteria, and therefore she was diagnosed as having GAS-TSS. GAS-TSS in pregnancy is rare. However, once the infection occurs in a pregnant woman, it rapidly develops into sepsis with multi-organ failure. Therefore, early recognition and intensive treatment for GAS during pregnancy is recommended in women with high fever, muscular pain, hemolysis and DIC during pregnancy. [source] Crystal structure of a dimeric form of streptococcal pyrogenic exotoxin A (SpeA1)PROTEIN SCIENCE, Issue 9 2004Matthew D. Baker Abstract Streptococcal pyrogenic exotoxin A (SpeA1) is a bacterial superantigen associated with scarlet fever and streptococcal toxic shock syndrome (STSS). SpeA1 is found in both monomeric and dimeric forms, and previous work suggested that the dimer results from an intermolecular disulfide bond between the cysteines at positions 90 of each monomer. Here, we present the crystal structure of the dimeric form of SpeA1. The toxin crystallizes in the orthorhombic space group P212121, with two dimers in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.52% for 7248 protein atoms, 136 water molecules, and 4 zinc atoms (one zinc atom per molecule). The implications of SpeA1 dimer on MHC class II and T-cell receptor recognition are discussed. [source] Invasive group A, B, C and G streptococcal infections in Denmark 1999,2002: epidemiological and clinical aspectsCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2005K. Ekelund Abstract Group A streptococci (GAS) have been described frequently as an emerging cause of severe invasive infections in population-based surveillance studies, whereas the descriptions of group B, C and G streptococci (GBS, GCS and GGS) have been less frequent. Enhanced surveillance for invasive GAS, GBS, GCS and GGS was performed in Denmark in 1999,2002. A detailed questionnaire was completed for 1237 (98%) of 1260 invasive infections. GAS infections dominated (40%), followed by GGS (32%), GBS (23%) and GCS (6%). Most (74%) patients had predisposing factors, and there were no significant differences between the four serogroups when comparing the prevalence of cancer, diabetes mellitus, chronic heart or lung diseases, immunodeficiency or alcohol abuse. The overall case fatality rate at day 30 was 21%, increasing significantly to 59% for patients with streptococcal toxic shock syndrome (STSS). STSS was significantly more frequent in GAS patients (10%) than in GCS (4%), GBS (2%) and GGS (2%) patients. Regression analyses showed that, despite a younger median age among GAS patients, the probability of developing septic shock and mortality was significantly higher among GAS patients than among GBS and GGS patients. These analyses showed no significant differences between GAS and GCS infections. Invasive infections caused by GAS, GBS, GCS and GGS are still a major challenge for clinicians. Continued epidemiological and microbiological surveillance is important to assess the development of these infections and to improve preventative strategies. [source] | ||||||||||