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Suis Serotype (sui + serotype)
Kinds of Suis Serotype Selected AbstractsStreptococcus suis outbreak investigation using multiple-locus variable tandem repeat number analysisMICROBIOLOGY AND IMMUNOLOGY, Issue 7 2010Wei Li ABSTRACT Two outbreaks of Streptococcus suis ST7 occurred in humans in 1998 and 2005 in China. PFGE of chromosome restriction fragments found all ST7 isolates to be indistinguishable. Due to the genetic homogeneity of ST7 isolates, development of a rapid sub-typing method with high discriminatory power for ST7 isolates is required. In this study, a novel method, MLVA, was developed to type S. suis serotype 2 strains. Further, this method was used to analyze outbreak-associated ST7 strains in China. A total of 144 ST7 S. suis isolates were sub-typed into 34 MLVA types. Among these, eight isolates from the 1998 outbreak were sub-typed into five MLVA types, of which four MLVA types were also detected in Sichuan in 2005. These data indicate that the pathogens responsible for the two outbreaks had the same origin. In addition, some observations also provided molecular evidence for the transmission route, possibly indicating that the MLVA method has usefulness in epidemiology. The developed MLVA scheme for S. suis has greater discriminative power than PFGE. The method described here may be useful for identifying the source of S. suis infection and monitoring its spread. [source] Identification of immunogenic cell wall-associated proteins of Streptococcus suis serotype 2PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 17 2008Anding Zhang Abstract Streptococcus suis serotype 2 (SS2) is a porcine and human pathogen with adhesive and invasive properties. The absence of suitable vaccine or virulent marker can be the bottleneck to control SS2 infection. An immunoproteome-based approach was developed to identify candidate antigens of SS2 for vaccine development. Hyperimmune sera, convalescent sera, and control sera were analyzed for reactivity by Western Blot against SS2 cell wall-associated proteins (WAPs) separated by 2-DE. A total of 34 proteins were identified by immunoproteomic analysis, of which 15 were recognized by both hyperimmune sera and convalescent sera, including most WAPs currently characterized as SS2 vaccine candidate antigens: muramidase-released protein (MRP), surface protein SP1 (Sao), and glyceraldehyde-3-phosphate dehydrogenase (GapdH). The novel immunogenic proteins may be developed as alternative antigens for further study of SS2 vaccine and diagnostics. [source] Aerogenous infection of microbiologically defined minipigs with Streptococcus suis serotype 2APMIS, Issue 6 2001A new model Streptococcus suis serotype 2 is the cause of serious infections in animals and humans, but certain aspects of the infection pathogenesis still remain unclear. In this study an experimental model of aerogenous infection and induction of septicemia with S. suis serotype 2 was established in microbiologically defined Göttingen minipigs. Ten animals were exposed to aerosolized S. suis after previous exposure to mild acetic acid in aerosol. Six of the animals were immunosuppressed with prednisolone acetate on different days. All the animals were monitored clinically until euthanasia on days 6 to 13 after exposure. Necropsy was performed and samples were taken for microbiology, histopathology, and immunohistochemistry. Three out of four animals immunosuppressed on days 5 to 7 after exposure developed S. suis septicemia, and S. suis could be detected in the tonsil of the soft palate and/or the nasal cavity of all exposed animals. Thus, using the presented model, local as well as systemic infection with S. suis serotype 2 was established in the Göttingen minipig. Since this breed is defined as free of S. suis and a range of other endemic porcine pathogens, the experimental model could prove useful in the study of this infection. [source] Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of SAICAR synthase from Streptococcus suis serotype 2ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2010Xia Cheng Phosphoribosylaminoimidazole-succinocarboxamide synthase (SAICAR synthase) plays an essential role in the de novo biosynthesis of purine nucleotides. In this study, the SAICAR synthase from Streptococcus suis was cloned and overexpressed in Escherichia coli. The subsequent product was purified and crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to 2.8,Å resolution and belonged to space group P2, with unit-cell parameters a = 70.2, b = 52.2, c = 153.9,Å, , = 102.8°. [source] Mitogenic effect contributes to increased virulence of Streptococcus suis sequence type 7 to cause streptococcal toxic shock-like syndromeCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2008H. Zheng Summary Streptococcus suis serotype 2 sequence type 7 strains emerged in 1996 and caused a streptococcal toxic shock-like syndrome in 1998 and 2005 in China. Evidence indicated that the virulence of S. suis sequence type 7 had increased, but the mechanism was unknown. The sequence type 7 strain SC84, isolated from a patient with streptococcal toxic shock-like syndrome during the Sichuan outbreak, and the sequence type 1 strain 31533, a typical highly pathogenic strain isolated from a diseased pig, were used in comparative studies. In this study we show the mechanisms underlying cytokine production differed between the two types of strains. The S. suis sequence type 7 strain SC84 possesses a stronger capacity to stimulate T cells, naive T cells and peripheral blood mononuclear cell proliferation than does S. suis sequence type 1 strain 31533. The T cell response to both strains was dependent upon the presence of antigen-presenting cells. Histo-incompatible antigen-presenting cells were sufficient to provide the accessory signals to naive T cell stimulated by the two strains, indicating that both sequence type 7 and 1 strains possess mitogens; however, the mitogenic effect was different. Therefore, we propose that the difference in the mitogenic effect of sequence type 7 strain SC84 compared with the sequence type 1 strain 31533 of S. suis may be associated with the clinical, epidemiological and microbiological difference, where the ST 7 strains have a larger mitogenic effect. [source] |