Analysis of the nucleotide sequence of fliC genes coding for flagellar antigens H7 and H6 revealed large sequence similarities between strains sharing the same H-type but different O-types. Typing of fliC genes by PCR was successfully employed for characterization of human pathogenic O157:H7 and O26:H11 strains. ![]() Therefore, alternative typing methods were developed including molecular characterization of genes coding for the O- and H-antigens in E. coli serotyping and the laborious typing procedure restricts its usage to a few reference laboratories. However, the large number of O- and H-antisera which are needed for E. coli which can occur in different combinations in wildtype isolates of strains. At present, 176 O- and 53 H-antigens are described for E. It was shown that the O:H serotype is a good marker for identification of strains belonging to clonal types of pathogenic E. coli populations by multilocus enzyme electrophoresis (MLEE) and multilocus sequence typing (MLST) allowed the detection of clonal types of strains which carry specific virulence markers and are associated with disease in humans. coli strains from both humans and animals. coli (EPEC) strains from stools of diarrhoeic infants and is successfully employed for characterization of pathogenic E. Serotyping proved to be widely useful for identification of enteropathogenic E. coli strains according to their O:H-types (serotypes). coli O- (lipopolysaccharide) and H-(flagellar) antigens which allowed the grouping of E. In 1944, Kauffmann established the method of serological typing for E. coli strains were agents of infantile gastroenteritis. coli strains were developed in the early 1940ies when it became evident that certain E. Typing systems for identification of related E. coli.īacterial strains belonging to the Enterobacteriaceae species Escherichia coli are common as commensals in the intestinal flora of humans and warm-blooded animals. ![]() Our expression studies show for the first time, that flagellins of different molecular weigth are functionally expressed and coassembled in the same flagellar filament in E. coli strainswhich were isolated at different time periods and geographical locations. The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. coli K-12 strain JM109 which encodes flagellar type H48. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. ![]() coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. Nucleotide sequencing of complete fliC genes of six E. coli strains reacting with H4 antiserum were investigated. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli reference strains U9-41 (O2:K1:H4) and P12b (O15:H17) was determined and both were found 99.3% (1043 of 1050 nucleotides) identical in their coding sequence. The complete nucleotide sequence of fliC genes present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. The flagellar antigen H4 is widely present in E. coli which occur in different combinations in the strains. Serotyping of O-(lipopolysaccharide) and H-(flagellar) antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli.
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