Disease relevance of flaB

• The first database comprised of flagellin gene (flaA) types of Campylobacter jejuni human clinical isolates from Greece [1].
• The strains were characterized by biotyping and PCR amplification of Campylobacter flaA/flaB and 16s-rRNA Arcobacter butzleri-specific genes [2].
• The flagellin proteins in pathogenic bacteria such as Campylobacter jejuni and Helicobacter pylori are heavily glycosylated with the nine-carbon alpha-keto acid, pseudaminic acid [3].
• The Cj1293 gene of C. jejuni encodes a putative UDP-GlcNAc C6-dehydratase/C4-reductase that is similar to a protein required for glycosylation of Caulobacter crescentus flagellin [4].
• A worldwide selected population of C. jejuni non-HS:19 strains associated with GBS and gastroenteritis was analyzed by use of multilocus enzyme electrophoresis, automated ribotyping, pulsed-field gel electrophoresis, and flagellin gene typing [5].

High impact information on flaB

• Mutants in which flaB but not flaA is inactivated remain motile [6].
• The most prominent was a cluster of six genes (cj1321 to cj1326) within the flagellin glycosylation locus, which were confirmed by PCR analysis as genetic markers in six additional chicken-associated strains [7].
• Mutation of six new genes, in addition to three previously reported, resulted in a non-motile phenotype, consistent with a role in synthesis of pseudaminic acid (PseAc) or transfer of PseAc to flagellin [8].
• Changes in flagellin glycosylation affect Campylobacter autoagglutination and virulence [8].
• Analysis of the complete flagellin glycosylation locus of Campylobacter jejuni strain 81-176 revealed a less complex genomic organization than the corresponding region in the genome strain, C. jejuni NCTC 11168 [8].

Chemical compound and disease context of flaB

• Twenty four Campylobacter jejuni and coli isolates obtained from Egyptian children were characterized using restriction fragment length polymorphism (RFLP) of flagellin genes and polyacrylamide gel electrophoresis of whole cell and glycine-extracted proteins [9].

Biological context of flaB

• METHODS: A total of 93 C. jejuni clinical isolates of known flagellin subunit A (flaA) genotype, serotype, and antimicrobial susceptibility pattern, were collected from a general hospital in the Attica region of Greece, between the years 2000 and 2003 [10].
• In most cases, the flaB gene displayed the same RFLP pattern as that of the flaA gene of the same strain, although some variability was observed [11].
• Using oligonucleotide primers based on the known DNA sequence of both the flaA and flaB genes from C. coli VC167 in the polymerase chain reaction, we have shown conservation of both fla genes among isolates within the LIO8 heat-labile serogroup by digestion of the amplified product with PstI and EcoRI restriction endonucleases [12].
• Complementation of a flaA flaB double mutant with a shuttle plasmid harboring either the flaA or flaB gene restored Cia protein secretion, suggesting that Cia export requires at least one of the two filament proteins [13].
• A recombinant was isolated in which the antibiotic-resistance gene had been repositioned into flaB, indicating that genetic information can be exchanged between the two flagellin genes of C. jejuni [14].

Anatomical context of flaB

• Mutants which lack flagella (flaA, flaB, and flbA) or common cell surface antigen (peb1A) were constructed in strain 81-176 by natural transformation-mediated allelic exchange [15].
• The shift in expression from flaA to flaB occurred not only during invasion assays but also under different conditions in the absence of eukaryotic cells [16].
• Isolates from the ceca, cloacae, and oviducts of 11 laying hens in three intensive egg-producing flocks were genotyped by Fla typing with the restriction fragment length polymorphism of the polymerase chain reaction product of the flaA and flaB genes (fla typing) and pulsed-field gel electrophoresis (PFGE) [17].
• Previous studies of Campylobacter jejuni have suggested that flagellin is an adhesin for epithelial cells and that motility is a virulence factor of this bacterium [18].
• These results show that the treatment of C. jejuni with heat produces a complex mixture of components, including cell wall lipopolysaccharide, the major outer membrane protein, and flagellin [19].

Associations of flaB with chemical compounds

• However, using mutants in genes affecting LAH serorecognition of flagellin it was demonstrated that sialic acid alone is not the LAH epitope [20].
• Post-translational modification has been suggested to be responsible for T1 and T2 epitopes, and, using mild periodate treatment and biotin hydrazide labelling, flagellin from both VC167-T1 and T2 were shown to be glycosylated [20].
• For example, the flagellin from the Gram-positive bacterium, L. monocytogenes showed O-linked GlcNAc residues at up to 6 sites/protein monomer [21].
• The internal epitopes were antigenically cross-reactive and linear, and in the case of C. jejuni flagellin were located on cyanogen bromide peptides of apparent Mr 22,400 and 11,000 [22].
• Three-day-old chicks were orally challenged with a motile wild-type strain of C. jejuni IN9 or with flagellar mutants created from IN9 by disrupting the flagellin genes with a kanamycin resistance cassette by using shuttle mutagenesis (A. Labigne-Roussel, P. Courcoux, and L. Tompkins, J. Bacteriol. 170:1704-1708, 1988) [23].

Other interactions of flaB

• FlaC is homologous to the N- and C-terminus of the C. jejuni flagellin proteins, FlaA and FlaB, but lacks the central portion of these proteins. flaC null mutants form a morphologically normal flagellum and are highly motile [24].
• Serum antibodies against flagellin, 40 kDa and 29 kDa antigens were still detectable in most patients up to a year postinfection, as were salivary antibodies to flagellin, the major outer-membrane protein and a 40 kDa antigen [25].

Analytical, diagnostic and therapeutic context of flaB

• Mutation of the ptm genes in C. coli VC167 can be detected by changes in apparent Mr of flagellin in SDS-PAGE gels, changes in isoelectric focusing (IEF) patterns and loss of immunoreactivity with antiserum LAH2 [26].
• Western blots (immunoblots) showed the absence of flagellin in the nonmotile form [27].
• Further characterization of IN1-NM showed that it produced a cytoplasmic 62K flagellin subunit protein, but this protein lacked six epitopes detected in IN1 and also differed in its two-dimensional gel electrophoresis pattern [28].
• In this study the genotyping techniques of flagellin typing (flaA typing), pulsed-field gel electrophoresis (PFGE), automated ribotyping, and amplified fragment length polymorphism (AFLP) fingerprinting were compared [29].
• The high-affinity antibody was used to immune blot purified flagellin from Pen 1 and Pen 3, as well as whole-cell preparations and acid-glycine extracts from the 60 reference strains of the thermostable antigen serotyping system [30].

References