The Production of F41 Fimbriae by Piglet Strains of Enterotoxigenic Escherichia coli that Lack K88, K99 and 987P Fimbriae

Abstract

The enterotoxigenic Escherichia coli strains 1676,1706,175 1 and KEC96a, which do not produce fimbrial adhesive antigens of the K88, K99 or 987P antigen type reacted both in vitro and in vivo with antiserum to F41 fimbriae in an indirect immunofluorescent antibody technique. Antiserum used to demonstrate material B, an adhesive antigen thought to mediate the adhesive and mannose-resistant (MR) haemagglutinating properties of E. coli strains 1676, 1706 and 1751, reacted in vitro with an F41+ strain. The antiserum also inhibited the MR haemagglutinating activity of F41 antigen and gave an anionic precipitation line in immunoelectrophoresis experiments with an extract containing F41 antigen.The MR haemagglutinating properties of an antigen extract containing material B from E. coli strain 1706 was neutralized by antiserum to F41 fimbriae and by OK antisera to E. coli strains that produce both F41 and K99 fimbriae. These sera also gave an anionic precipitation line with the MR haemagglutinin from E . coli strain 1706 and the MR haemagglutinin gave a line of identity with F41 in gel diffusion experiments with antiserum to F41 fimbriae. OK antisera to K99+ F41-bacteria and OK antisera to K88+ bacteria and 987P+ bacteria did not react with this haemagglutinin.Transmission electron microscopy on the ileum of newborn gnotobiotic piglets infected with E. coli strain 1706 showed irregular, poorly defined filamentous material surrounding some, though not all, bacteria but regular fimbrial structures were not visible. Fine thread-like material was visible surrounding most of the bacteria in ultra thin sections from a piglet infected with an E. coli strain that produces both F41 and K99. Staining with ruthenium red suggested that this material was associated with polysaccharide.

F41 Antigen as a Virulence Factor in the Infant Mouse Model of Escherichia coli Diarrhoea

“…F41 antigen has been found in the bovine reference ETEC strain B41 (De Graaf & Roorda, 1982;Morris et al, 1983). It mediates bacterial adherence to intestinal epithelial cells (Morris et al, 1983), but its exact role in pathogenicity is not known.…”

“…It mediates bacterial adherence to intestinal epithelial cells (Morris et al, 1983), but its exact role in pathogenicity is not known. In this report, a genetic approach to the problem, especially by obtaining F41-variants, has shown that the F41 antigen is an important virulence factor in an infant mouse model.…”

Cloning of chromosomal DNA encoding the F41 adhesin of enterotoxigenic Escherichia coli and genetic homology between adhesins F41 and K88

“…Recently, F41 production has been demonstrated in non-K99-producing strains of ETEC of serogroup 0101 isolated from piglets with diarrhea (15). These strains have been demonstrated to be fully virulent in experimental infections in piglets and calves (1,15,21). This suggests that F41 is a virulence factor, since these strains produce no other known adhesin.…”

“…The F41 antigen was first recognized as a second mannoseresistant hemagglutinin produced by ETEC strains which also express the K99 adhesin (14). The F41 antigen is associated with K99-producing ETEC of serogroups 09 and 0101, but has not been reported among K99-producing strains of other serogroups (15). Recently, F41 production has been demonstrated in non-K99-producing strains of ETEC of serogroup 0101 isolated from piglets with diarrhea (15).…”

Detection of quantitative trait loci for porcine susceptibility to enterotoxigenic Escherichia coli F41 in a White Duroc × Chinese Erhualian resource population

“…ETEC strains with different fimbriae have been isolated from pigs with diarrhoea, including F4 (Jones and Rutter, 1972), F18 (Bertschinger et al, 1990), 987P , K99 and F41 (Morris et al, 1983). These bacteria adhere to brush borders of the intestinal epithelial cells through their surface fimbriae.…”