Recombinant E. coli K99 pilus protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

The E. coli K99 pilus also known as F5 antigen is a surface structure of Escherichia coli bacteria. This pilus plays a critical role in the adhesion process facilitating the attachment of bacteria to host cells specifically in the intestines of newborn animals. The K99 pilus consists of protein subunits with a molecular mass around 18 kDa. These structures are expressed on the surface of enterotoxigenic E. coli particularly strains that infect livestock such as calves and piglets.

Biological function summary

The K99 pilus protein functions as an essential factor in the colonization and establishment of infections in the host. This protein aids in the initial adherence step which is necessary for bacterial aggregation and biofilm formation. The K99 pilus forms part of the broader adhesive structures composed of various protein complexes facilitating effective host-pathogen interactions and subsequent pathogenicity.

Pathways

The K99 E. coli pilus participates in adhesion pathways of enterotoxigenic E. coli. It functions alongside fimbrial proteins like F41 which work together to enhance the bacterial adherence ability. This interaction is important for the bacteria's infectious cycle involving pathways linked to bacterial mobility and host cell interaction. The pilus-related proteins assist the bacteria in resisting host defense mechanisms and establishing infections more effectively.

The K99 E. coli pilus is closely related to diarrheal diseases in livestock particularly neonatal diarrhea in calves and piglets. These diseases result from the bacterial colonization in the intestines leading to fluid imbalance and nutrient malabsorption. The K99 pilus in combination with other virulence factors such as the heat-stable enterotoxin ST contributes to these conditions. The pilus is a target for vaccine development aiming to reduce the incidence of intestinal infections caused by K99 E. coli.