Surface antigens of Extended-Spectrum Beta-Lactamase-producing Escherichia coli

Surface antigens on Extended-Spectrum Beta-Lactamase (ESBL)-producing Escherichia coli are structural components located on the bacterial outer membrane that serve as primary targets for the host immune system and novel therapeutic agents. These antigens include the O-antigen portion of lipopolysaccharides (LPS), capsular polysaccharides (K-antigens), flagellar proteins (H-antigens), and various outer membrane proteins (OMPs) like OmpA and fimbriae (Poolman & Wacker, 2016). In ESBL-producing strains, particularly the globally disseminated ST131 lineage, these surface structures are essential for mediating adhesion to host epithelia, biofilm formation, and resistance to serum-mediated killing (Pitout & Laupland, 2008). Because ESBL enzymes render standard beta-lactam therapies ineffective, these surface antigens are being utilized in the development of bioconjugate vaccines, such as ExPEC9V and ExPEC10V, which target the most prevalent O-serotypes associated with invasive disease (Frenck et al., 2022). Therapeutic strategies focusing on these antigens aim to induce opsonophagocytic antibodies that enhance bacterial clearance by neutrophils and macrophages, providing a narrow-spectrum approach that spares the commensal microbiome (Huttner et al., 2017).

Other names

ESBL E. coli surface antigensExPEC surface antigensOuter membrane antigens of Escherichia coliO-antigensK-antigensH-antigens

Induction of opsonophagocytic antibodies that facilitate bacterial clearance by host immune cells and inhibition of bacterial adhesion to host tissues (Frenck et al., 2022; Huttner et al., 2017).