scholarly journals Structural analysis of colanic acid from Escherichia coli by using methylation and base-catalysed fragmentation. Comparison with polysaccharides from other bacterial sources

1969 ◽  
Vol 115 (5) ◽  
pp. 947-958 ◽  
Author(s):  
C. J. Lawson ◽  
C. W. McCleary ◽  
Henry I. Nakada ◽  
D. A. Rees ◽  
I. W. Sutherland ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pyruvic Acid ◽  
Hydrolysis Product ◽  
Acid Methyl Ester ◽  
Extracellular Polysaccharide ◽  
Partial Hydrolysis ◽  
Capsular Polysaccharides ◽  
E Coli ◽  
Colanic Acid ◽  
Bacterial Sources

Essentially the same methanolysis products were obtained after methylation of the slime and capsular polysaccharides from Escherichia coli K12 (S53 and S53C sub-strains) and the slime polysaccharides from E. coli K12 (S61), Aerobacter cloacae N.C.T.C. 5290 and Salmonella typhimurium SL1543. These were the methyl glycosides of 2-O-methyl-l-fucose, 2,3-di-O-methyl-l-fucose, 2,3-di-O-methyl-d-glucuronic acid methyl ester, 2,4,6-tri-O-methyl-d-glucose, 2,4,6-tri-O-methyl-d-galactose and the pyruvic acid ketal, 4,6-O-(1′-methoxycarbonylethylidene)-2,3-O-methyl-d-galactose. All were identified as crystalline derivatives from an E. coli polysaccharide. The structure of the ketal was proved by proton-magnetic-resonance and mass spectrometry, and by cleavage to pyruvic acid and 2,3-di-O-methyl-d-galactose. All these polysaccharides are therefore regarded as variants on the same fundamental structure for which the name colanic acid is adopted. Although containing the same sugar residues, quite different methanolysis products were obtained after methylation of the extracellular polysaccharide from Klebsiella aerogenes (1.2 strain). The hydroxypropyl ester of E. coli polysaccharide, when treated with base under anhydrous conditions, underwent β-elimination at the uronate residues with release of a 4,6-O-(1′-alkoxycarbonylethylidene)-d-galactose. Together with the identification of 3-O-(d-glucopyranosyluronic acid)-d-galactose as a partial hydrolysis product, this establishes the nature of most, if not all, of the side chains as O-[4,6-O-(1′-carboxyethylidene)-d-galactopyranosyl]-(1→4)-O-(d-glucopyranosyluronic acid)-(1→3)-d-galactopyranosyl…

scholarly journals Identification of the Fucose Synthetase Gene in the Colanic Acid Gene Cluster of Escherichia coli K-12

1998 ◽  
Vol 180 (4) ◽  
pp. 998-1001 ◽  
Author(s):  
Kanella Andrianopoulos ◽  
Lei Wang ◽  
Peter R. Reeves
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Extracellular Polysaccharide ◽  
Surface Antigens ◽  
Bacterial Surface ◽  
E Coli ◽  
Colanic Acid ◽  
K 12

ABSTRACT GDP–l-fucose, the substrate for fucosyltransferases for addition of fucose to polysaccharides or glycoproteins in both procaryotes and eucaryotes, is made from GDP–d-mannose.l-Fucose is a component of bacterial surface antigens, including the extracellular polysaccharide colanic acid produced by most Escherichia coli strains. We previously sequenced theE. coli colanic acid gene cluster and identified one of the GDP–l-fucose biosynthetic pathway genes, gmd. We report here the identification of the gene (fcl), located downstream of gmd, encoding the fucose synthetase.

scholarly journals Functional Analysis of Conserved Gene Products Involved in Assembly of Escherichia coli Capsules and Exopolysaccharides: Evidence for Molecular Recognition between Wza and Wzc for Colanic Acid Biosynthesis

2005 ◽  
Vol 187 (15) ◽  
pp. 5470-5481 ◽  
Author(s):  
Anne N. Reid ◽  
Chris Whitfield
Keyword(s):  
Escherichia Coli ◽  
Chimeric Protein ◽  
Surface Expression ◽  
Capsular Polysaccharides ◽  
E Coli ◽  
Colanic Acid ◽  
Periplasmic Domain ◽  
Conserved Gene ◽  
K 12 ◽  
Group 1

ABSTRACT Group 1 capsular polysaccharides (CPSs) of Escherichia coli and some loosely cell-associated exopolysaccharides (EPSs), such as colanic acid, are assembled by a Wzy-dependent polymerization system. In this biosynthesis pathway, Wza, Wzb, and Wzc homologues are required for surface expression of wild-type CPS or EPS. Multimeric complexes of Wza in the outer membrane are believed to provide a channel for polymer export; Wzc is an inner membrane tyrosine autokinase and Wzb is its cognate phosphatase. This study was performed to determine whether the Wza, Wzb, and Wzc proteins for colanic acid expression in E. coli K-12 could function in the E. coli K30 prototype group 1 capsule system. When expressed together, colanic acid Wza, Wzb, and Wzc could complement a wza-wzb-wzc defect in E. coli K30, suggesting conservation in their collective function in Wzy-dependent CPS and EPS systems. Expressed individually, colanic acid Wza and Wzb could also function in K30 CPS expression. In contrast, the structural requirements for Wzc function were more stringent because colanic acid Wzc could restore translocation of K30 CPS to the cell surface only when expressed with its cognate Wza protein. Chimeric colanic acid-K30 Wzc proteins were constructed to further study this interaction. These proteins could restore K30 biosynthesis but were unable to couple synthesis to export. The chimeric protein comprising the periplasmic domain of colanic acid Wzc was functional for effective K30 CPS surface expression only when coexpressed with colanic acid Wza. These data highlight the importance of Wza-Wzc interactions in group 1 CPS assembly.

scholarly journals Escherichia coli Harboring a Natural IncF Conjugative F Plasmid Develops Complex Mature Biofilms by Stimulating Synthesis of Colanic Acid and Curli

2008 ◽  
Vol 190 (22) ◽  
pp. 7479-7490 ◽  
Author(s):  
Thithiwat May ◽  
Satoshi Okabe
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Three Dimensional ◽  
F Plasmid ◽  
Form Complex ◽  
Global Regulators ◽  
E Coli ◽  
Colanic Acid ◽  
Regulatory Systems ◽  
Initial Deposition

ABSTRACT It has been shown that Escherichia coli harboring the derepressed IncFI and IncFII conjugative F plasmids form complex mature biofilms by using their F-pilus connections, whereas a plasmid-free strain forms only patchy biofilms. Therefore, in this study we investigated the contribution of a natural IncF conjugative F plasmid to the formation of E. coli biofilms. Unlike the presence of a derepressed F plasmid, the presence of a natural IncF F plasmid promoted biofilm formation by generating the cell-to-cell mating F pili between pairs of F+ cells (approximately two to four pili per cell) and by stimulating the formation of colanic acid and curli meshwork. Formation of colanic acid and curli was required after the initial deposition of F-pilus connections to generate a three-dimensional mushroom-type biofilm. In addition, we demonstrated that the conjugative factor of F plasmid, rather than a pilus synthesis function, was involved in curli production during biofilm formation, which promoted cell-surface interactions. Curli played an important role in the maturation process. Microarray experiments were performed to identify the genes involved in curli biosynthesis and regulation. The results suggested that a natural F plasmid was more likely an external activator that indirectly promoted curli production via bacterial regulatory systems (the EnvZ/OmpR two-component regulators and the RpoS and HN-S global regulators). These data provided new insights into the role of a natural F plasmid during the development of E. coli biofilms.

scholarly journals Polysialic and colanic acids metabolism in Escherichia coli K92 is regulated by RcsA and RcsB

2013 ◽  
Vol 33 (3) ◽  
Author(s):  
Nicolás Navasa ◽  
Leandro Rodríguez-Aparicio ◽  
Miguel Ángel Ferrero ◽  
Andrea Monteagudo-Mera ◽  
Honorina Martínez-Blanco
Keyword(s):  
Escherichia Coli ◽  
Low Temperatures ◽  
Regulatory Mechanism ◽  
Polysialic Acid ◽  
Negative Regulators ◽  
Surface Appearance ◽  
E Coli ◽  
Colanic Acid

We have shown previously that Escherichia coli K92 produces two different capsular polymers known as CA (colanic acid) and PA (polysialic acid) in a thermoregulated manner. The complex Rcs phosphorelay is largely related to the regulation of CA synthesis. Through deletion of rscA and rscB genes, we show that the Rcs system is involved in the regulation of both CA and PA synthesis in E. coli K92. Deletion of either rcsA or rcsB genes resulted in decreased expression of cps (CA biosynthesis cluster) at 19°C and 37°C, but only CA production was reduced at 19°C. Concerning PA, both deletions enhanced its synthesis at 37°C, which does not correlate with the reduced kps (PA biosynthesis cluster) expression observed in the rcsB mutant. Under this condition, expression of the nan operon responsible for PA catabolism was greatly reduced. Although RcsA and RcsB acted as negative regulators of PA synthesis at 37°C, their absence did not reestablish PA expression at low temperatures, despite the deletion of rcsB resulting in enhanced kps expression. Finally, our results revealed that RcsB controlled the expression of several genes (dsrA, rfaH, h-ns and slyA) involved in the thermoregulation of CA and PA synthesis, indicating that RcsB is part of a complex regulatory mechanism governing the surface appearance in E. coli.

scholarly journals Role of Exopolysaccharides in the Survival and Pathogenesis of the Fire Blight Bacterium, Erwinia amylovora

1994 ◽  
Author(s):  
David Gutnick ◽  
David L. Coplin
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Erwinia Amylovora ◽  
Extracellular Polysaccharide ◽  
Gene Clusters ◽  
Site Directed Mutagenesis ◽  
E Coli ◽  
Erwinia Stewartii ◽  
Stewart's Wilt

Fireblight, a disease of apples and pears, is caused by Erwinia amylovora. Mutants of E. amylovora that do not produce the extreacellular polysaccharide (EPS), amylovoran, are avirulent. A similar EPS, stewartan, is produced by E. stewartii, which caused Stewart's wilt of corn, and which has also been implicated in the virulence of this strain. Both stewartan and amylovoran are type 1 capsular polysaccharides, typified by the colanic acid slime produced by Escherichia coli. Extracellular polysaccharide slime and capsules are important for the virulence of bacterial pathogens of plants and animals and to enhance their survival and dissemination outside of the host. The goals of this project were to examine the importance of polysaccharide structure on the pathogenicity and survival properties of three pathogenic bacteria: Erwinia amylovora, Erwinia stewartii and Escherichia coli. The project was a collaboration between the laboratories of Dr. Gutnick (PI, E. coli genetics and biochemistry), Dr. Coplin (co-PI, E. stewartii genetics) and Dr. Geider (unfunded collaborator, E. amylovora genetics and EPS analysis). Structural analysis of the EPSs, sequence analysis of the biosynthetic gene clusters and site-directed mutagenesis of individual cps and ams genes revealed that the three gene clusters shared common features for polysaccharide polymerization, translocation, and precursor synthesis as well as in the modes of transcriptional regulation. Early EPS production resulted in decreased virulence, indicating that EPS, although required for pathogenicity, is anot always advantageous and pathogens must regulate its production carefully.

Transfer and expression of the genetic determinants for O and K antigen synthesis in Escherichia coli O9:K(A)30 and Klebsiella sp. Ol:K20, in Escherichia coli K12

1988 ◽  
Vol 34 (8) ◽  
pp. 987-992 ◽  
Author(s):  
Dayle H. Laakso ◽  
Mary K. Homonylo ◽  
Sheila J. Wilmot ◽  
Chris Whitfield
Keyword(s):  
Escherichia Coli ◽  
Surface Antigens ◽  
Capsular Polysaccharides ◽  
Genetic Determinants ◽  
Cell Surface Antigens ◽  
E Coli ◽  
Close Proximity ◽  
Morphological Differences ◽  
Genetically Determined ◽  
K Antigen

Escherichia coli serotype O9:K(A)30 and Klebsiella O1:K20 produce thermostable capsular polysaccharides or K antigens, which are chemically and serologically indistinguishable. Plasmid pULB113 (RP4::mini-Mu) has been used to mediate chromosomal transfer from E. coli O9:K30 and Klebsiella O1:K20 to a multiply marked, unencapsulated, E. coli K12 recipient. Analysis of the cell surface antigens of the transconjugants confirmed previous reports that the genetic determinants for the E. coli K(A) antigens are located near the his and rfb (O antigen) loci on the E. coli linkage map. The Klebsiella K20 capsule genes were also found to be in close proximity to the his and rfb loci. Electron microscopy revealed significant differences in the structural organization of capsular polysaccharides in these two microorganisms and the morphological differences were also readily apparent in transconjugants expressing the respective K antigens. These results are consistent with the interpretation that at least some of the organizational properties of capsular polysaccharides may be genetically determined, rather than being a function of the outer membrane to which the capsular polysaccharides are ultimately attached.

scholarly journals Polysaccharides Cellulose, Poly-β-1,6-N-Acetyl-d-Glucosamine, and Colanic Acid Are Required for Optimal Binding of Escherichia coli O157:H7 Strains to Alfalfa Sprouts and K-12 Strains to Plastic but Not for Binding to Epithelial Cells

2008 ◽  
Vol 74 (8) ◽  
pp. 2384-2390 ◽  
Author(s):  
Ann G. Matthysse ◽  
Rajendar Deora ◽  
Meenu Mishra ◽  
Alfredo G. Torres
Keyword(s):  
Escherichia Coli ◽  
Mammalian Cells ◽  
Capsular Polysaccharide ◽  
Cellulose Synthase ◽  
Marginal Effect ◽  
Tomato Root ◽  
E Coli ◽  
Colanic Acid ◽  
Alfalfa Sprouts ◽  
K 12

ABSTRACT When Escherichia coli O157:H7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. In contrast, laboratory K-12 strains of E. coli do not bind to sprouts under similar conditions. The roles of E. coli O157:H7 lipopolysaccharide (LPS), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. An LPS mutant had no effect on the binding of the pathogenic strain. Cellulose synthase mutants showed a significant reduction in binding; colanic acid mutants were more severely reduced, and binding by poly-β-1,6-N-acetylglucosamine (PGA) mutants was barely detectable. The addition of a plasmid carrying a cellulose synthase gene to K-12 strains allowed them to bind to sprouts. A plasmid carrying the Bps biosynthesis genes had only a marginal effect on the binding of K-12 bacteria. However, the introduction of the same plasmid allowed Sinorhizobium meliloti and a nonbinding mutant of Agrobacterium tumefaciens to bind to tomato root segments. These results suggest that although multiple redundant protein adhesins are involved in the binding of E. coli O157:H7 to sprouts, the polysaccharides required for binding are not redundant and each polysaccharide may play a distinct role. PGA, colanic acid, and cellulose were also required for biofilm formation by a K-12 strain on plastic, but not for the binding of E. coli O157:H7 to mammalian cells.

Survival of Escherichia coli O157:H7 in Set Yogurt as Influenced by the Production of an Exopolysaccharide, Colanic Acid

2004 ◽  
Vol 67 (2) ◽  
pp. 252-255 ◽  
Author(s):  
SHIAO MEI LEE ◽  
JINRU CHEN
Keyword(s):  
Escherichia Coli ◽  
Culture Media ◽  
Starter Cultures ◽  
Escherichia Coli O157 ◽  
Acidic Polysaccharide ◽  
E Coli ◽  
Colanic Acid ◽  
Plate Counts ◽  
Processing And Storage ◽  
And Storage

Previous studies conducted in our laboratory revealed that Escherichia coli O157:H7 cells capable of producing colanic acid (CA), the acidic polysaccharide of mucoid slime, had increased tolerance to sublethal heat and the extreme pH of microbiological culture media. This study was undertaken to determine the effect of CA on the fate of E. coli O157:H7 during the processing and storage of an acid food: yogurt. Pasteurized and homogenized whole milk was inoculated with a wild-type E. coli O157:H7, its CA-deficient mutant, or a mixture (1:1) of the two strains. Set yogurt was processed from the contaminated milk and stored at 4° and 15°C for 3 weeks. Samples of milk and yogurt were withdrawn during processing and storage and analyzed for total plate counts and populations of E. coli O157:H7 and starter cultures. The results showed that E. coli O157: H7 survived longer in yogurt stored at 15°C than at 4°C. Cells of E. coli O157:H7 deficient in CA production died off more rapidly than those of the parent strain. This suggests that CA plays a role in protecting cells of E. coli O157:H7 from stress during the processing and storage of set yogurt.

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