Enterotoxigenic Escherichia coli colonization factor CS5 fimbrial adhesin (CS5)

The Enterotoxigenic Escherichia coli (ETEC) colonization factor CS5 fimbrial adhesin is a specialized proteinaceous appendage on the bacterial surface that facilitates the initial attachment of ETEC to the human intestinal epithelium [1]. CS5 is a member of the Class 5 fimbriae family and is frequently associated with the CFA/IV group of colonization factors, which are prevalent in ETEC strains causing moderate-to-severe diarrhea worldwide [2]. The assembly of CS5 involves a major subunit, CsfA, and several minor subunits that form a stalk-like structure capable of binding to specific host cell receptors [3]. By enabling stable colonization, CS5 allows the bacteria to effectively deliver enterotoxins that disrupt intestinal fluid balance, leading to clinical symptoms [4]. Consequently, CS5 is a primary component in several multivalent ETEC vaccine candidates, such as ETVAX, which are designed to elicit protective mucosal immune responses [5]. Targeting this adhesin represents a prophylactic strategy to prevent the onset of infection by blocking the essential first step of bacterial pathogenesis [6]. Clinical evaluation of these vaccines often monitors the induction of anti-CS5 secretory IgA antibodies as a correlate of protection [5]. Sources: [1] Qadri F, et al. (2005) Clin Microbiol Rev; [2] Wolf MK. (1997) Clin Microbiol Rev; [3] Madhavan TP, et al. (2015) J Bacteriol; [4] Fleckenstein JM, et al. (2014) Lancet Infect Dis; [5] Lundgren A, et al. (2014) Vaccine; [6] Svennerholm AM. (2011) Indian J Med Res.

Other names

CS5 fimbriaeColonization factor antigen 5CsfACFA/V

Inhibition of bacterial adhesion to intestinal epithelial cells via vaccine-induced mucosal antibodies