Genetic diversity of K-antigen gene clusters ofEscherichia coliand their molecular typing using a suspension array

Abstract

Capsular polysaccharides (CPSs), or K-antigens, are the major surface antigens of Escherichia coli. More than 80 serologically unique K-antigens are classified into 4 groups (Groups 1-4) of capsules. Groups 1 and 4 contain the Wzy-dependent polymerization pathway and the gene clusters are in the order galF to gnd; Groups 2 and 3 contain the ABC-transporter-dependent pathway and the gene clusters consist of 3 regions, regions 1, 2 and 3. Little is known about the variations among the gene clusters. In this study, 9 serotypes of K-antigen gene clusters (K2ab, K11, K20, K24, K38, K84, K92, K96, and K102) were sequenced and correlated with their CPS chemical structures. On the basis of sequence data, a K-antigen-specific suspension array that detects 10 distinct CPSs, including the above 9 CPSs plus K30, was developed. This is the first report to catalog the genetic features of E. coli K-antigen variations and to develop a suspension array for their molecular typing. The method has a number of advantages over traditional bacteriophage and serum agglutination methods and lays the foundation for straightforward identification and detection of additional K-antigens in the future.

Diversity and evolution of surface polysaccharide synthesis loci in Enterobacteriales

“…1a). The initial reference sequence database consisted of six sequences from E. coli [75]. Locus extraction was performed in the same way as with the cps locus, except that the locus was defined missing in the case of absence of any of the three genes kpsM, kpsT, kpsC, and the extended reference database had 106 sequences.…”

A link between zinc uptake, bile salts, and a capsule required for virulence of a mastitis-associated extraintestinal pathogenicEscherichia colistrain

“…ExPEC-associated virulence genes were also identified as potentially contributing to MG colonization. These included genes for group III capsule biosynthesis identical to those of the K96 serotype [18]. Elimination of the kpsCS capsule genes from strain M12 resulted in a modest decrease in fitness in mouse MG colonization.…”

Identification of Hypermutator Enterohemorrhagic Escherishia coli (EHEC) Using a High Throughput Screening Method to Inform Food Safety Investigations

“…identified O-groups, with more being discovered to this day (Lang et al, 2019). In addition, there are 53 H-groups (Fratamico et al, 2016), and over 80 K-groups (Yang et al, 2018). The O antigen is attached to the core oligosaccharide, making it the outermost portion of the LPS.…”

“…The K-antigen is found on the surface of the bacterium, under a thick, mucous-like capsule made of acidic polysaccharides (Whitfield, 2006). The importance of this molecule lies within the protection that it serves from environmental stress and desiccation (Yang et al, 2018).…”

“…These antigens can largely be subdivided into four groups; groups 1 and 4 K-antigens can sometimes be attached to the lipid-A core of the LPS and are only found with certain O-antigens (such as O8, O9, O20, and O101) (Whitfield, 2006). Group 2 and 3 K-antigens resemble those found on gram-positive bacteria and can be subdivided based on acidic constituents (Yang et al, 2018). These antigens have been associated with extraintestinal infections (Whitfield, 2006).…”