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Zygmunt Sidorczyk - One of the best experts on this subject based on the ideXlab platform.
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structure and serology of o antigens as the basis for classification of Proteus strains
Innate Immunity, 2011Co-Authors: Yuriy A. Knirel, Andrei V. Perepelov, Zygmunt Sidorczyk, Antoni Rozalski, Sofya N Senchenkova, Anna N. Kondakova, Wieslaw KacaAbstract:This review is devoted to structural and serological characteristics of the O-antigens (O-polysaccharides) of the lipopolysaccharides of various Proteus species, which provide the basis for classifying Proteus strains to Oserogroups. The antigenic relationships of Proteus strains within and beyond the genus as well as their O-antigenrelated bioactivities are also discussed.
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structure of the glycerol phosphate containing o polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis ccug 10704 oe and Proteus vulgaris tg 103 classified into a new Proteus serogroup o54
Fems Immunology and Medical Microbiology, 2006Co-Authors: Katarzyna Kolodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Agnieszka Zablotni, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structure of the glycerol phosphate‐containing O‐polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 classified into a new Proteus serogroup, O54
FEMS immunology and medical microbiology, 2006Co-Authors: Katarzyna Kołodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Agnieszka Zabłotni, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structures of the O-polysaccharides and classification of Proteus genomospecies 4, 5 and 6 into respective Proteus serogroups.
FEBS Journal, 2005Co-Authors: Krystyna Zych, Andrei V. Perepelov, Małgorzata Siwińska, Yuriy A. Knirel, Zygmunt SidorczykAbstract:An acidic branched O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide (LPS) of Proteus genomospecies 4 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and H-detected 1H,13C HSQC experiments. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established, which is unique among Proteus polysaccharide structures: where Qui3NAc stands for 3-acetamido-3,6-dideoxyglucose. Based on the O-polysaccharide structure and serological data, we propose classifying Proteus genomospecies 4 into a new, separate Proteus serogroup, O56. A weak cross-reactivity of Proteus genomospecies 4 antiserum with LPS of Providencia stuartii O18 and Proteus vulgaris OX2 was observed and is discussed in view of a similarity of the O-polysaccharide structures. Structural and serological investigations showed that Proteus genomospecies 5 and 6 should be classified into the existing Proteus serogroups O8 and O69, respectively.
Yuriy A. Knirel - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity of the O antigens of Proteus species and the development of a suspension array for molecular serotyping
PloS one, 2017Co-Authors: Agnieszka Torzewska, Dominika Drzewiecka, Antoni Rozalski, Yuriy A. Knirel, Xinjie Zhang, Zhiqiu Yin, Hengchun Cao, Bin Liu, Lei WangAbstract:Proteus species are well-known opportunistic pathogens frequently associated with skin wound and urinary tract infections in humans and animals. O antigen diversity is important for bacteria to adapt to different hosts and environments, and has been used to identify serotypes of Proteus isolates. At present, 80 Proteus O-serotypes have been reported. Although the O antigen structures of most Proteus serotypes have been identified, the genetic features of these O antigens have not been well characterized. The O antigen gene clusters of Proteus species are located between the cpxA and secB genes. In this study, we identified 55 O antigen gene clusters of different Proteus serotypes. All clusters contain both the wzx and wzy genes and exhibit a high degree of heterogeneity. Potential functions of O antigen-related genes were proposed based on their similarity to genes in available databases. The O antigen gene clusters and structures were compared, and a number of glycosyltransferases were assigned to glycosidic linkages. In addition, an O serotype-specific suspension array was developed for detecting 31 Proteus serotypes frequently isolated from clinical specimens. To our knowledge, this is the first comprehensive report to describe the genetic features of Proteus O antigens and to develop a molecular technique to identify different Proteus serotypes.
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structure and serology of o antigens as the basis for classification of Proteus strains
Innate Immunity, 2011Co-Authors: Yuriy A. Knirel, Andrei V. Perepelov, Zygmunt Sidorczyk, Antoni Rozalski, Sofya N Senchenkova, Anna N. Kondakova, Wieslaw KacaAbstract:This review is devoted to structural and serological characteristics of the O-antigens (O-polysaccharides) of the lipopolysaccharides of various Proteus species, which provide the basis for classifying Proteus strains to Oserogroups. The antigenic relationships of Proteus strains within and beyond the genus as well as their O-antigenrelated bioactivities are also discussed.
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structure of the glycerol phosphate containing o polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis ccug 10704 oe and Proteus vulgaris tg 103 classified into a new Proteus serogroup o54
Fems Immunology and Medical Microbiology, 2006Co-Authors: Katarzyna Kolodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Agnieszka Zablotni, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structure of the glycerol phosphate‐containing O‐polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 classified into a new Proteus serogroup, O54
FEMS immunology and medical microbiology, 2006Co-Authors: Katarzyna Kołodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Agnieszka Zabłotni, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structures of the O-polysaccharides and classification of Proteus genomospecies 4, 5 and 6 into respective Proteus serogroups.
FEBS Journal, 2005Co-Authors: Krystyna Zych, Andrei V. Perepelov, Małgorzata Siwińska, Yuriy A. Knirel, Zygmunt SidorczykAbstract:An acidic branched O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide (LPS) of Proteus genomospecies 4 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and H-detected 1H,13C HSQC experiments. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established, which is unique among Proteus polysaccharide structures: where Qui3NAc stands for 3-acetamido-3,6-dideoxyglucose. Based on the O-polysaccharide structure and serological data, we propose classifying Proteus genomospecies 4 into a new, separate Proteus serogroup, O56. A weak cross-reactivity of Proteus genomospecies 4 antiserum with LPS of Providencia stuartii O18 and Proteus vulgaris OX2 was observed and is discussed in view of a similarity of the O-polysaccharide structures. Structural and serological investigations showed that Proteus genomospecies 5 and 6 should be classified into the existing Proteus serogroups O8 and O69, respectively.
Dominika Drzewiecka - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity of the O antigens of Proteus species and the development of a suspension array for molecular serotyping
PloS one, 2017Co-Authors: Agnieszka Torzewska, Dominika Drzewiecka, Antoni Rozalski, Yuriy A. Knirel, Xinjie Zhang, Zhiqiu Yin, Hengchun Cao, Bin Liu, Lei WangAbstract:Proteus species are well-known opportunistic pathogens frequently associated with skin wound and urinary tract infections in humans and animals. O antigen diversity is important for bacteria to adapt to different hosts and environments, and has been used to identify serotypes of Proteus isolates. At present, 80 Proteus O-serotypes have been reported. Although the O antigen structures of most Proteus serotypes have been identified, the genetic features of these O antigens have not been well characterized. The O antigen gene clusters of Proteus species are located between the cpxA and secB genes. In this study, we identified 55 O antigen gene clusters of different Proteus serotypes. All clusters contain both the wzx and wzy genes and exhibit a high degree of heterogeneity. Potential functions of O antigen-related genes were proposed based on their similarity to genes in available databases. The O antigen gene clusters and structures were compared, and a number of glycosyltransferases were assigned to glycosidic linkages. In addition, an O serotype-specific suspension array was developed for detecting 31 Proteus serotypes frequently isolated from clinical specimens. To our knowledge, this is the first comprehensive report to describe the genetic features of Proteus O antigens and to develop a molecular technique to identify different Proteus serotypes.
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Significance and Roles of Proteus spp. Bacteria in Natural Environments
Microbial Ecology, 2016Co-Authors: Dominika DrzewieckaAbstract:Proteus spp. bacteria were first described in 1885 by Gustav Hauser, who had revealed their feature of intensive swarming growth. Currently, the genus is divided into Proteus mirabilis , Proteus vulgaris , Proteus penneri , Proteus hauseri , and three unnamed genomospecies 4, 5, and 6 and consists of 80 O-antigenic serogroups. The bacteria are known to be human opportunistic pathogens, isolated from urine, wounds, and other clinical sources. It is postulated that intestines are a reservoir of these proteolytic organisms. Many wild and domestic animals may be hosts of Proteus spp. bacteria, which are commonly known to play a role of parasites or commensals. However, interesting examples of their symbiotic relationships with higher organisms have also been described. Proteus spp. bacteria present in soil or water habitats are often regarded as indicators of fecal pollution, posing a threat of poisoning when the contaminated water or seafood is consumed. The health risk may also be connected with drug-resistant strains sourcing from intestines. Positive aspects of the bacteria presence in water and soil are connected with exceptional features displayed by autochthonic Proteus spp. strains detected in these environments. These rods acquire various metabolic abilities allowing their adaptation to different environmental conditions, such as high concentrations of heavy metals or toxic substances, which may be exploited as sources of energy and nutrition by the bacteria. The Proteus spp. abilities to tolerate or utilize polluting compounds as well as promote plant growth provide a possibility of employing these microorganisms in bioremediation and environmental protection.
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structure of the glycerol phosphate containing o polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis ccug 10704 oe and Proteus vulgaris tg 103 classified into a new Proteus serogroup o54
Fems Immunology and Medical Microbiology, 2006Co-Authors: Katarzyna Kolodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Agnieszka Zablotni, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structure of the glycerol phosphate‐containing O‐polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 classified into a new Proteus serogroup, O54
FEMS immunology and medical microbiology, 2006Co-Authors: Katarzyna Kołodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Agnieszka Zabłotni, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
Andreas Ulrich - One of the best experts on this subject based on the ideXlab platform.
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Genome-based phylogeny of the genera Proteus and Cosenzaea and description of Proteus terrae subsp. terrae subsp. nov. and Proteus terrae subsp. cibarius subsp. nov.
International journal of systematic and evolutionary microbiology, 2019Co-Authors: Undine Behrendt, Sonja Wende, Steffen Kolb, Andreas UlrichAbstract:The genera Proteus and Cosenzaea are closely related members of the family Morganellaceae. The genus Cosenzaea consists of the species Cosenzaea myxofaciens originally separated from the genus Proteus by rpoB gene analysis. Due to the high similarity of the 16S rRNA genes between species of both genera, the taxonomic status is here re-evaluated by a genome-based approach. Based on a core genome phylogeny and genome relatedness indices, it is shown that the taxonomy and nomenclature given for the basonym Proteus myxofaciens is more appropriate. Therefore, we propose to use this name in preference. Furthermore, the species status of Proteus terrae and Proteus cibarius was reassessed. Both species are related at subspecies level by digital DNA-DNA hybridization (dDDH) analysis. Additionally, average amino acid identity (AAI) and average nucleotide identity (ANI) do not support a separate species status, and therefore it is proposed to classify P. cibarius as a subspecies of P. terrae. Consequently, both species are being renamed Proteus terrae subsp. cibarius subsp. nov. and Proteus terrae subsp. terrae subsp. nov., respectively. The genome relatedness indices revealed a close relationship of the Proteus genomospecies 5 with P. terrae subsp. terrae. Thus, it has been assigned to the same subspecies.
Andrei V. Perepelov - One of the best experts on this subject based on the ideXlab platform.
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structure and serology of o antigens as the basis for classification of Proteus strains
Innate Immunity, 2011Co-Authors: Yuriy A. Knirel, Andrei V. Perepelov, Zygmunt Sidorczyk, Antoni Rozalski, Sofya N Senchenkova, Anna N. Kondakova, Wieslaw KacaAbstract:This review is devoted to structural and serological characteristics of the O-antigens (O-polysaccharides) of the lipopolysaccharides of various Proteus species, which provide the basis for classifying Proteus strains to Oserogroups. The antigenic relationships of Proteus strains within and beyond the genus as well as their O-antigenrelated bioactivities are also discussed.
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structure of the glycerol phosphate containing o polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis ccug 10704 oe and Proteus vulgaris tg 103 classified into a new Proteus serogroup o54
Fems Immunology and Medical Microbiology, 2006Co-Authors: Katarzyna Kolodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Agnieszka Zablotni, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structure of the glycerol phosphate‐containing O‐polysaccharides and serological studies of the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 classified into a new Proteus serogroup, O54
FEMS immunology and medical microbiology, 2006Co-Authors: Katarzyna Kołodziejska, Andrei V. Perepelov, Dominika Drzewiecka, Agnieszka Zabłotni, Sofya N Senchenkova, Yuriy A. Knirel, Krystyna Zych, Alexander S Shashkov, Zygmunt SidorczykAbstract:O-Polysaccharides were obtained from the lipopolysaccharides of Proteus mirabilis CCUG 10704 (OE) and Proteus vulgaris TG 103 and studied by chemical analyses and one- and two-dimensional 1H and 13C nuclear magnetic resonance spectroscopy, including rotating-frame nuclear Overhauser effect spectroscopy, H-detected 1H,13C heteronuclear single-quantum spectroscopy and 1H,31P heteronuclear multiple-quantum spectroscopy experiments. The Proteus mirabilis OE polysaccharide was found to have a trisaccharide repeating unit with a lateral glycerol phosphate group. The Proteus vulgaris TG 103 produces a similar O-polysaccharide, which differs in incomplete substitution with glycerol phosphate (c. 50% of the stoichiometric amount) and the presence of an O-acetyl group at position 6 of the 2-acetamido-2-deoxygalactose (GalNAc) residue. These structures are unique among the known bacterial polysaccharide structures. Based on the structural and serological data of the lipopolysaccharides, it is proposed to classify both strains studied into a new Proteus serogroup, O54, as two subgroups, O54a,54b and O54a,54c. The serological relatedness of the Proteus O54 and some other Proteus lipopolysaccharides is discussed.
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Structures of the O-polysaccharides and classification of Proteus genomospecies 4, 5 and 6 into respective Proteus serogroups.
FEBS Journal, 2005Co-Authors: Krystyna Zych, Andrei V. Perepelov, Małgorzata Siwińska, Yuriy A. Knirel, Zygmunt SidorczykAbstract:An acidic branched O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide (LPS) of Proteus genomospecies 4 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY and H-detected 1H,13C HSQC experiments. The following structure of the pentasaccharide repeating unit of the O-polysaccharide was established, which is unique among Proteus polysaccharide structures: where Qui3NAc stands for 3-acetamido-3,6-dideoxyglucose. Based on the O-polysaccharide structure and serological data, we propose classifying Proteus genomospecies 4 into a new, separate Proteus serogroup, O56. A weak cross-reactivity of Proteus genomospecies 4 antiserum with LPS of Providencia stuartii O18 and Proteus vulgaris OX2 was observed and is discussed in view of a similarity of the O-polysaccharide structures. Structural and serological investigations showed that Proteus genomospecies 5 and 6 should be classified into the existing Proteus serogroups O8 and O69, respectively.
