Phylogenetic relationships ofCampylobacter jejunibased onporAsequences

2007 ◽  
Vol 53 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Clifford G Clark ◽  
Anne Beeston ◽  
Louis Bryden ◽  
Gehua Wang ◽  
Connie Barton ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Major Outer Membrane Protein ◽  
Campylobacter Coli ◽  
Functional Constraints ◽  
Antigenic Properties ◽  
Group 3 ◽  
Reference Strains

Campylobacter porins are the dominant major outer membrane protein (MOMP) of these bacteria. They are composed of hypervariable, surface-exposed, peptide loops and membrane-embedded, conserved peptide regions. Porins are functionally important and may also be useful for molecular subtyping methods but have not yet been well characterized. We therefore sequenced the porA gene from 39 Campylobacter isolates, including multilocus sequence type (MLST) reference strains, isolates from patients with the Guillain-Barré syndrome, other clinical isolates, and serotyping reference strains. These were compared with additional sequences available from GenBank. Three distinct porA lineages were observed after phylogenetic analysis. Both Campylobacter coli and Campylobacter jejuni were found with group 3 porA sequences, and this was the only group showing any evidence of recombination among porA genes. There was no recombination between porA genes from C. jejuni groups 1 and 2, suggesting there may be functional constraints on changes at this locus. Most of the amino acid differences among the three groups were present in surface-exposed loops, and dissimilar substitutions were found when groups 1 and 2 MOMP were compared. Different MOMP sequence groups may have different biological or antigenic properties, which in turn may be associated with survival in different environments, host adaptation, or virulence.Key words: Campylobacter, porin, major outer membrane protein, phylogenetic analysis.

Characterization of cross-reacting serotypes of Campylobacter jejuni

1989 ◽  
Vol 35 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Martin A. Preston ◽  
J. L. Penner
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Campylobacter Jejuni ◽  
Outer Membrane Protein ◽  
Antigenic Determinants ◽  
Protein Patterns ◽  
Cross Reactions ◽  
Antigenic Properties ◽  
Dna Restriction ◽  
Reference Strains

Some strains of Campylobacter jejuni react with more than one reference antiserum from the serotyping scheme based on heat-stable lipopolysaccharide antigens. To investigate the molecular basis of these cross-reactions, lipopolysaccharides from the reference strains for serotypes 4, 13, 16, 43, and 50 and isolates recovered during two different outbreaks of C. jejuni enteritis were analyzed by passive haemagglutination and sodium dodecyl sulphate – polyacrylamide gel electrophoresis coupled with silver staining or immunoblotting. The results showed that lipopolysaccharides from the reference strains and the isolates reacted with antisera prepared against heterologous strains in various combinations and that both silver-stainable, low Mr and non-silver-stainable, high Mr lipopolysaccharide components provided the antigenic determinants associated with the cross-reactions. There were strain-to-strain differences in the structural and antigenic properties of these macromolecules and shared antigenic determinants were not always provided by a common structure. Analysis of the silver-stained lipopolysaccharide profiles, outer membrane protein patterns, and chromosomal DNA restriction patterns indicated that strains with the same lipopolysaccharide profile could have the same outer membrane protein pattern and the same DNA restriction pattern. These results provided evidence for the presence of clones within this antigenic complex and implicated antigenic variation in some strains as the phenomenon responsible for the multiplicity of cross-reactions.Key words: Campylobacter, serotypes, cross-reaction.

scholarly journals Minor Nucleotide Substitutions in the omp31 Gene ofBrucella ovis Result in Antigenic Differences in the Major Outer Membrane Protein That It Encodes Compared to Those of the OtherBrucella Species

2001 ◽  
Vol 69 (11) ◽  
pp. 7020-7028 ◽  
Author(s):  
Nieves Vizcaı́no ◽  
Reinhold Kittelberger ◽  
Axel Cloeckaert ◽  
Clara M. Marı́n ◽  
Luis Fernández-Lago
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Western Blotting ◽  
Outer Membrane Protein ◽  
Recombinant Dna ◽  
Brucella Melitensis ◽  
Major Outer Membrane Protein ◽  
Nucleotide Substitutions ◽  
Diagnostic Antigen ◽  
Antigenic Properties

ABSTRACT The gene coding for the major outer membrane protein Omp31 was sequenced in five Brucella species and their biovars. Although the omp31 genes appeared to be highly conserved in the genus Brucella, nine nucleotide substitutions were detected in the gene of Brucella ovis compared to that ofBrucella melitensis. As shown by differential binding properties of monoclonal antibodies (MAbs) to the twoBrucella species, these nucleotide substitutions result in different antigenic properties of Omp31. The antigenic differences were also evidenced when sera from B. ovis-infected rams were tested by Western blotting with the recombinant B. melitensis or B. ovis Omp31 proteins. Twelve available sera reacted with recombinant B. ovis Omp31, but only four of them reacted with recombinant B. melitensisOmp31. These results validate previous evidence for the potential of Omp31 as a diagnostic antigen for B. ovis infection in rams and demonstrate that B. ovis Omp31, instead of B. melitensis Omp31, should be used to evaluate this point. The antigenic differences between the B. melitensis andB. ovis Omp31 proteins should also be taken into account when Omp31 is evaluated as a candidate for the development of subcellular vaccines against B. ovis infection. No reactivity against recombinant B. melitensis Omp31 was detected, by Western blotting, with sera from B. melitensis-infected sheep. Accordingly, Omp31 does not seem to be a good diagnostic antigen for B. melitensis infections in sheep. Two immunodominant regions were identified on the B. ovis Omp31 protein by using recombinant DNA techniques and specific MAbs. Sera from B. ovis-infected rams that reacted with the recombinant protein were tested by Western blotting against one of these immunodominant regions shown to be exposed at the bacterial surface. Only 4 of the 12 sera reacted, but with strong intensity.

scholarly journals Phylogenetic Analysis of the Chlamydia trachomatis Major Outer Membrane Protein and Examination of Potential Pathogenic Determinants

1998 ◽  
Vol 66 (8) ◽  
pp. 3618-3625 ◽  
Author(s):  
Diane R. Stothard ◽  
George Boguslawski ◽  
Robert B. Jones
Keyword(s):  
Phylogenetic Analysis ◽  
Chlamydia Trachomatis ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Cell Types ◽  
Major Outer Membrane Protein ◽  
Amino Acid Sequences ◽  
Tissue Tropism ◽  
Immune Pressure

ABSTRACT Phylogenetic analysis was utilized to investigate biological relationships (tissue tropism, disease presentation, and epidemiologic success), as evidenced by coevolution, among human strains ofChlamydia trachomatis. Nucleotide sequences ofomp1, the gene encoding the major outer membrane protein (MOMP) of C. trachomatis, were determined for 40 strains representing 11 serovars. These data were combined with availableomp1 sequences from GenBank for an analysis encompassing a total of 69 strains representing 17 serovars infecting humans. Phylogenetic analysis of the nucleotide and inferred amino acid sequences showed no evolutionary relationships among serovars that corresponded to biological or pathological phenotypes (tissue tropism, disease presentation, and epidemiologic success). In addition, no specific residues that may have evolved to play a role in determining biologically relevant characteristics of chlamydia, such as tissue specificity, disease presentation, and epidemiologic success, were apparent in the MOMP. These results suggest that variation in MOMP may have arisen from a need to be diverse in the presence of immune pressure rather than as a function of pathogenicity. Therefore, the role of MOMP in disease pathogenesis and infection may be passive, and it may not be the major ligand responsible for directing infection of various human cell types.

Monoclonal antibody binding to the major outer membrane protein of Campylobacter coli

2008 ◽  
Vol 339 (1) ◽  
pp. 104-113
Author(s):  
Hongliang Qian ◽  
Ervinna Pang ◽  
Jason Chang ◽  
Say Ling Toh ◽  
Fook Kheong Ng ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Antibody Binding ◽  
Major Outer Membrane Protein ◽  
Campylobacter Coli ◽  
Monoclonal Antibody Binding
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