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Genetic and Functional Diversity of Pseudomonas aeruginosa Lipopolysaccharide.

Lam JS, Taylor VL, Islam ST, Hao Y, Kocíncová D - Front Microbiol (2011)

Bottom Line: Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band), and the other a heteropolymer of three to five distinct (and often unique dideoxy) sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band).Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa.The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, University of Guelph Guelph, ON, Canada.

ABSTRACT
Lipopolysccharide (LPS) is an integral component of the Pseudomonas aeruginosa cell envelope, occupying the outer leaflet of the outer membrane in this Gram-negative opportunistic pathogen. It is important for bacterium-host interactions and has been shown to be a major virulence factor for this organism. Structurally, P. aeruginosa LPS is composed of three domains, namely, lipid A, core oligosaccharide, and the distal O antigen (O-Ag). Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band), and the other a heteropolymer of three to five distinct (and often unique dideoxy) sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band). Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa. The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa. The underlying factors contributing to this diversity will be thoroughly discussed and presented in the context of its contributions to host-pathogen interactions and the control/prevention of infection.

No MeSH data available.


Related in: MedlinePlus

Structures of uncapped and capped glycoforms. The structures of the uncapped core oligosaccharide (A), and capped core oligosaccharide (B) are depicted. All the sugars shown have α configuration unless otherwise indicated. Asterisks depict variable substitutions, acetylation sites are shown since they have not been precisely identified. Ala, alanine; Cm, carbamoyl; Etn, ethanolamine; GalN, 2-amino-2-deoxy-galactose (galactosamine); Glc, glucose; Hep, L-glycero-d-manno-heptose; Kdo, 3-deoxy-d-manno-oct-2-ulosonic acid; Rha, rhamnose. Adapted from King et al. (2009).
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Figure 4: Structures of uncapped and capped glycoforms. The structures of the uncapped core oligosaccharide (A), and capped core oligosaccharide (B) are depicted. All the sugars shown have α configuration unless otherwise indicated. Asterisks depict variable substitutions, acetylation sites are shown since they have not been precisely identified. Ala, alanine; Cm, carbamoyl; Etn, ethanolamine; GalN, 2-amino-2-deoxy-galactose (galactosamine); Glc, glucose; Hep, L-glycero-d-manno-heptose; Kdo, 3-deoxy-d-manno-oct-2-ulosonic acid; Rha, rhamnose. Adapted from King et al. (2009).

Mentions: Composition of the sugar constituents in inner core OS is identical among P. aeruginosa strains and it consists of two residues of 3-deoxy-D-manno-octulosonic acid (KdoI and KdoII) and two residues of L-glycero-D-manno-heptose (HepI and HepII; Figure 4). The inner core is highly conserved when compared to other Gram-negative bacteria. A distinguishing feature of the P. aeruginosa inner core is a high degree of phosphorylation that is essential for viability of P. aeruginosa, since mutation of either of the two genes (wapP and waaP) encoding kinases that are responsible for adding phosphate groups to the inner core heptoses is lethal (Walsh et al., 2000). In most P. aeruginosa strains, three phosphorylation sites have been identified; positions 2 and 4 on HepI and position 6 on HepII. In a CF isolate, HepII has been shown to possess an additional phosphorylation site on position 4 (Knirel et al., 2006). In theory, monophosphate, diphosphate, or triphosphate groups might occupy each of the phosphorylation sites (Kooistra et al., 2003; Choudhury et al., 2005; Bystrova et al., 2006). Some of the analyzed P. aeruginosa strains have shown the non-stoichiometric substitution of a phosphate group on position 2 of HepI by -ethanolamine-phosphate or ethanolamine-diphosphate (Bystrova et al., 2006). However, Knirel et al. (2006) suggested that the actual content of phosphates and ethanolamine-phosphates in the inner core might be higher, since these phosphate groups can be released from the core during preparation of LPS prior to structural analyses. In addition to phosphorylation, HepII is modified with another non-carbohydrate substituent, namely an O-carbamoyl group on position 7 (Beckmann et al., 1995).


Genetic and Functional Diversity of Pseudomonas aeruginosa Lipopolysaccharide.

Lam JS, Taylor VL, Islam ST, Hao Y, Kocíncová D - Front Microbiol (2011)

Structures of uncapped and capped glycoforms. The structures of the uncapped core oligosaccharide (A), and capped core oligosaccharide (B) are depicted. All the sugars shown have α configuration unless otherwise indicated. Asterisks depict variable substitutions, acetylation sites are shown since they have not been precisely identified. Ala, alanine; Cm, carbamoyl; Etn, ethanolamine; GalN, 2-amino-2-deoxy-galactose (galactosamine); Glc, glucose; Hep, L-glycero-d-manno-heptose; Kdo, 3-deoxy-d-manno-oct-2-ulosonic acid; Rha, rhamnose. Adapted from King et al. (2009).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108286&req=5

Figure 4: Structures of uncapped and capped glycoforms. The structures of the uncapped core oligosaccharide (A), and capped core oligosaccharide (B) are depicted. All the sugars shown have α configuration unless otherwise indicated. Asterisks depict variable substitutions, acetylation sites are shown since they have not been precisely identified. Ala, alanine; Cm, carbamoyl; Etn, ethanolamine; GalN, 2-amino-2-deoxy-galactose (galactosamine); Glc, glucose; Hep, L-glycero-d-manno-heptose; Kdo, 3-deoxy-d-manno-oct-2-ulosonic acid; Rha, rhamnose. Adapted from King et al. (2009).
Mentions: Composition of the sugar constituents in inner core OS is identical among P. aeruginosa strains and it consists of two residues of 3-deoxy-D-manno-octulosonic acid (KdoI and KdoII) and two residues of L-glycero-D-manno-heptose (HepI and HepII; Figure 4). The inner core is highly conserved when compared to other Gram-negative bacteria. A distinguishing feature of the P. aeruginosa inner core is a high degree of phosphorylation that is essential for viability of P. aeruginosa, since mutation of either of the two genes (wapP and waaP) encoding kinases that are responsible for adding phosphate groups to the inner core heptoses is lethal (Walsh et al., 2000). In most P. aeruginosa strains, three phosphorylation sites have been identified; positions 2 and 4 on HepI and position 6 on HepII. In a CF isolate, HepII has been shown to possess an additional phosphorylation site on position 4 (Knirel et al., 2006). In theory, monophosphate, diphosphate, or triphosphate groups might occupy each of the phosphorylation sites (Kooistra et al., 2003; Choudhury et al., 2005; Bystrova et al., 2006). Some of the analyzed P. aeruginosa strains have shown the non-stoichiometric substitution of a phosphate group on position 2 of HepI by -ethanolamine-phosphate or ethanolamine-diphosphate (Bystrova et al., 2006). However, Knirel et al. (2006) suggested that the actual content of phosphates and ethanolamine-phosphates in the inner core might be higher, since these phosphate groups can be released from the core during preparation of LPS prior to structural analyses. In addition to phosphorylation, HepII is modified with another non-carbohydrate substituent, namely an O-carbamoyl group on position 7 (Beckmann et al., 1995).

Bottom Line: Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band), and the other a heteropolymer of three to five distinct (and often unique dideoxy) sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band).Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa.The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cellular Biology, University of Guelph Guelph, ON, Canada.

ABSTRACT
Lipopolysccharide (LPS) is an integral component of the Pseudomonas aeruginosa cell envelope, occupying the outer leaflet of the outer membrane in this Gram-negative opportunistic pathogen. It is important for bacterium-host interactions and has been shown to be a major virulence factor for this organism. Structurally, P. aeruginosa LPS is composed of three domains, namely, lipid A, core oligosaccharide, and the distal O antigen (O-Ag). Most P. aeruginosa strains produce two distinct forms of O-Ag, one a homopolymer of D-rhamnose that is a common polysaccharide antigen (CPA, formerly termed A band), and the other a heteropolymer of three to five distinct (and often unique dideoxy) sugars in its repeat units, known as O-specific antigen (OSA, formerly termed B band). Compositional differences in the O units among the OSA from different strains form the basis of the International Antigenic Typing Scheme for classification via serotyping of different strains of P. aeruginosa. The focus of this review is to provide state-of-the-art knowledge on the genetic and resultant functional diversity of LPS produced by P. aeruginosa. The underlying factors contributing to this diversity will be thoroughly discussed and presented in the context of its contributions to host-pathogen interactions and the control/prevention of infection.

No MeSH data available.


Related in: MedlinePlus