Immunological characterization of antibody responses to Escherichia coli O antigens in bacteraemic patients

1988 ◽  
Vol 2 (4) ◽  
pp. 291-299 ◽  
Author(s):  
Annelie Brauner ◽  
Stefan B. Svenson ◽  
Bengt Wretlind
Keyword(s):  
Escherichia Coli ◽  
Antibody Responses ◽  
Immunological Characterization ◽  
O Antigens

scholarly journals Evaluation of applicability of DNA microarray–based characterization of bovine Shiga toxin–producing Escherichia coli isolates using whole genome sequence analysis

2017 ◽  
Vol 29 (5) ◽  
pp. 721-724 ◽  
Author(s):  
Stefanie A. Barth ◽  
Christian Menge ◽  
Inga Eichhorn ◽  
Torsten Semmler ◽  
Derek Pickard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Microarray ◽  
Shiga Toxin ◽  
In Silico ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Molecular Surveillance ◽  
Antimicrobial Resistance Genes ◽  
O Antigens

We assessed the ability of a commercial DNA microarray to characterize bovine Shiga toxin–producing Escherichia coli (STEC) isolates and evaluated the results using in silico hybridization of the microarray probes within whole genome sequencing scaffolds. From a total of 69,954 reactions (393 probes with 178 isolates), 68,706 (98.2%) gave identical results by DNA microarray and in silico probe hybridization. Results were more congruent when detecting the genoserotype (209 differing results from 19,758 in total; 1.1%) or antimicrobial resistance genes (AMRGs; 141 of 26,878; 0.5%) than when detecting virulence-associated genes (VAGs; 876 of 22,072; 4.0%). Owing to the limited coverage of O-antigens by the microarray, only 37.2% of the isolates could be genoserotyped. However, the microarray proved suitable to rapidly screen bovine STEC strains for the occurrence of high numbers of VAGs and AMRGs and is suitable for molecular surveillance workflows.

scholarly journals Characterization of Two β-1,3-Glucosyltransferases from Escherichia coli Serotypes O56 and O152

2008 ◽  
Vol 190 (14) ◽  
pp. 4922-4932 ◽  
Author(s):  
Inka Brockhausen ◽  
Bo Hu ◽  
Bin Liu ◽  
Kenneth Lau ◽  
Walter A. Szarek ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Clusters ◽  
Aliphatic Chain ◽  
Ph Optimum ◽  
Acceptor Substrate ◽  
C Terminus ◽  
Membrane Bound ◽  
O Antigens ◽  
Phosphate Groups

ABSTRACT The O antigens of outer membrane-bound lipopolysaccharides (LPS) in gram-negative bacteria are oligosaccharides consisting of repeating units with various structures and antigenicities. The O56 and O152 antigens of Escherichia coli both contain a Glc-β1-3-GlcNAc linkage within the repeating unit. We have cloned and identified the genes (wfaP in O56 and wfgD in O152) within the two O-antigen gene clusters that encode glucosyltransferases involved in the synthesis of this linkage. A synthetic substrate analog of the natural acceptor substrate undecaprenol-pyrophosphate-lipid [GlcNAc-α-PO3-PO3-(CH2)11-O-phenyl] was used as an acceptor and UDP-Glc as a donor substrate to demonstrate that both wfgD and wfaP encode glucosyltransferases. Enzyme products from both glucosyltransferases were isolated by high-pressure liquid chromatography and analyzed by nuclear magnetic resonance. The spectra showed the expected Glc-β1-3-GlcNAc linkage in the products, confirming that both WfaP and WfgD are forms of UDP-Glc: GlcNAc-pyrophosphate-lipid β-1,3-glucosyltransferases. Both WfaP and WfgD have a DxD sequence, which is proposed to interact with phosphate groups of the nucleotide donor through the coordination of a metal cation, and a short hydrophobic sequence at the C terminus that may help to associate the enzymes with the inner membrane. We showed that the enzymes have similar properties and substrate recognition. They both require a divalent cation (Mn2+ or Mg2+) for activity, are deactivated by detergents, have a broad pH optimum, and require the pyrophosphate-sugar linkage in the acceptor substrate for full activity. Substrates lacking phosphate or pyrophosphate linked to GlcNAc were inactive. The length of the aliphatic chain of acceptor substrates also contributes to the activity.

scholarly journals Escherichia coli O123 O antigen genes and polysaccharide structure are conserved in some Salmonella enterica serogroups

2009 ◽  
Vol 58 (7) ◽  
pp. 884-894 ◽  
Author(s):  
Clifford G. Clark ◽  
Andrew M. Kropinski ◽  
Haralambos Parolis ◽  
Christopher C. R. Grant ◽  
Keri M. Trout-Yakel ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Salmonella Enterica ◽  
Gene Clusters ◽  
E Coli ◽  
Antigen Gene ◽  
O Antigen ◽  
Antigenic Polysaccharide ◽  
O Antigens

The serotyping of O and H antigens is an important first step in the characterization of Salmonella enterica. However, serotyping has become increasingly technically demanding and expensive to perform. We have therefore sequenced additional S. enterica O antigen gene clusters to provide information for the development of DNA-based serotyping methods. Three S. enterica isolates had O antigen gene clusters with homology to the Escherichia coli O123 O antigen region. O antigen clusters from two serogroup O58 S. enterica strains had approximately 85 % identity with the E. coli O123 O antigen region over their entire length, suggesting that these Salmonella and E. coli O antigen regions evolved from a common ancestor. The O antigen cluster of a Salmonella serogroup O41 isolate had a lower level of identity with E. coli O123 over only part of its O antigen DNA cluster sequence, suggesting a different and more complex evolution of this gene cluster than those in the O58 strains. A large part of the Salmonella O41 O antigen DNA cluster had very close identity with the O antigen cluster of an O62 strain. This region of DNA homology included the wzx and wzy genes. Therefore, molecular serotyping tests using only the O41 or O62 wzx and wzy genes would not differentiate between the two serogroups. The E. coli O123 O-antigenic polysaccharide and its repeating unit were characterized, and the chemical structure for E. coli O123 was entirely consistent with the O antigen gene cluster sequences of E. coli O123 and the Salmonella O58 isolates. An understanding of both the genetic and structural composition of Salmonella and E. coli O antigens is necessary for the development of novel molecular methods for serotyping these organisms.

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