The structural basis of serological specificity in Shigella flexneri O-antigens

1990 ◽  
Vol 18 (6) ◽  
pp. 1271-1272 ◽  
Author(s):  
D. ALASTAIR R. SIMMONS
Keyword(s):  
Shigella Flexneri ◽  
Structural Basis ◽  
O Antigens ◽  
Serological Specificity

scholarly journals Molecular Modeling of the Shigella flexneri Serogroup 3 and 5 O-Antigens and Conformational Relationships for a Vaccine Containing Serotypes 2a and 3a

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 643
Author(s):  
Jason Hlozek ◽  
Sara Owen ◽  
Neil Ravenscroft ◽  
Michelle M. Kuttel
Keyword(s):  
Diarrheal Disease ◽  
Shigella Flexneri ◽  
Quadrivalent Vaccine ◽  
Slight Effect ◽  
Work Support ◽  
O Antigen ◽  
The Common ◽  
O Antigens ◽  
Chain Conformations ◽  
Shared Epitopes

The pathogenic bacterium Shigella flexneri is a leading global cause of diarrheal disease. The O-antigen is the primary vaccine target and distinguishes the 30 serotypes reported. Except for serotype 6, all S. flexneri serotypes have a common backbone repeating unit (serotype Y), with variations in substitution creating the various serotypes. A quadrivalent vaccine containing serotypes 2a and 3a (as well as 6 and Shigella sonnei) is proposed to provide broad protection against non-vaccine S. flexneri serotypes through shared epitopes and conformations. Here we model the O-antigen (O-Ag) conformations of serogroups 3 and 5: a continuation of our ongoing systematic study of the S. flexneri O-antigens that began with serogroup 2. Our simulations show that S. flexneri serogroups 2, 3, and 5 all have flexible O-Ags, with substitutions of the backbone altering the chain conformations in different ways. Our analysis suggests three general heuristics for the effects of substitution on the Shigella O-Ag conformations: (1) substitution on rhamnose C reduces the extension of the O-Ag chain; (2) substitution at O-3 of rhamnose A restricts the O-Ags to predominantly helical conformations, (3) substitution at O-3 of rhamnose B has only a slight effect on conformation. The common O-Ag conformations across serotypes identified in this work support the assumption that a quadrivalent vaccine containing serotypes 2a and 3a could provide coverage against S. flexneri serotype 3b and serogroup 5.

scholarly journals Bacteriophage-encoded glucosyltransferase GtrII of Shigella flexneri: membrane topology and identification of critical residues

2005 ◽  
Vol 389 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Adele M. LEHANE ◽  
Haralambos KORRES ◽  
Naresh K. VERMA
Keyword(s):  
Sequence Similarity ◽  
Repeat Unit ◽  
Shigella Flexneri ◽  
Membrane Topology ◽  
Transmembrane Helices ◽  
O Antigen ◽  
Repeat Units ◽  
Related Group ◽  
Critical Residues ◽  
O Antigens

The Shigella flexneri serotypes differ in the nature of their O-antigens. The addition of glucosyl or O-acetyl groups to the common backbone repeat units gives rise to the different serotypes. GtrII glucosylates rhamnose III of the O-antigen repeat unit, thus converting serotype Y (which has no modifications to the basic O-antigen repeat unit) into serotype 2a, the most prevalent serotype. In the present study, the topology of GtrII has been determined. GtrII has nine transmembrane helices, a re-entrant loop and three large periplasmic regions. Four critical residues (Glu40, Phe414, Cys435 and Lys478) were identified in two of the periplasmic regions. Despite the lack of sequence similarity between GtrII and the Gtrs from other serotypes, three of the critical residues identified are conserved in the remaining Gtrs. This is consistent with some degree of mechanistic conservation in this functionally related group of proteins.

scholarly journals Structural Basis for the Recognition of Ubc13 by the Shigella flexneri Effector OspI

2013 ◽  
Vol 425 (15) ◽  
pp. 2623-2631 ◽  
Author(s):  
Akira Nishide ◽  
Minsoo Kim ◽  
Kenji Takagi ◽  
Ai Himeno ◽  
Takahito Sanada ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Structural Basis

scholarly journals Structural Studies of the Shigella flexneri Variant X, Type 5a and Type 5b O-Antigens

1977 ◽  
Vol 76 (2) ◽  
pp. 327-330 ◽  
Author(s):  
Lennart KENNE ◽  
Bengt LINDBERG ◽  
Kurt PETERSSON ◽  
Ewa KATZENELLENBOGEN ◽  
Elzbieta ROMANOWSKA
Keyword(s):  
Shigella Flexneri ◽  
Structural Studies ◽  
O Antigens

scholarly journals Molecular detection of all 34 distinct O-antigen forms of Shigella

2009 ◽  
Vol 58 (1) ◽  
pp. 69-81 ◽  
Author(s):  
Yayue Li ◽  
Boyang Cao ◽  
Bin Liu ◽  
Dan Liu ◽  
Qili Gao ◽  
...  
Keyword(s):  
Shigella Flexneri ◽  
Bacterial Species ◽  
Milk Powder ◽  
Shigella Dysenteriae ◽  
Detection Sensitivity ◽  
Clinical Samples ◽  
Shigella Boydii ◽  
O Antigen ◽  
Probe Concentration ◽  
O Antigens

Shigella is the cause of shigellosis or bacillary dysentery, the occurrence of which is estimated to be 165 million cases per year worldwide, resulting in 1.1 million deaths. Rapid and reliable assays for detecting and identifying Shigella in food, environmental and clinical samples are therefore necessary. Shigella species are traditionally identified by their O antigens. This study developed a DNA microarray targeting O-serotype-specific genes to detect all 34 distinct O-antigen forms of Shigella, including Shigella boydii types 1–18, Shigella dysenteriae types 1–13, Shigella flexneri types 1–5 and 6, and Shigella sonnei. A total of 282 strains were used to test the specificity of the microarray, including 186 Shigella and Escherichia coli representative strains, 86 Shigella clinical isolates and ten strains of other bacterial species that are commonly isolated from food or clinical stool specimens. The oligonucleotide probes were printed on the microarray in concentrations from 1 to 100 μM, and 10 μM proved to be the optimal probe concentration. The detection sensitivity for each serotype was 50 ng genomic DNA or 1 c.f.u. in 25 g milk powder sample following a 6 h enrichment in broth. The microarray is specific, sensitive and reproducible, and, to our knowledge, is the first report of a microarray for serotyping all O-antigen forms of Shigella.

scholarly journals IN VIVO CHANGE OF SEROLOGICAL SPECIFICITY IN SHIGELLA FLEXNERI

1958 ◽  
Vol 76 (1) ◽  
pp. 122-122
Author(s):  
C. David McGuire ◽  
Thomas M. Floyd
Keyword(s):  
Shigella Flexneri ◽  
Serological Specificity
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