Vibrio cholerae O139 O-specific polysaccharide (O139 OSP)

The Vibrio cholerae O139 O-specific polysaccharide (OSP) is a critical surface carbohydrate antigen found on the outer membrane of the O139 serogroup of Vibrio cholerae, which causes epidemic cholera. This polysaccharide is a key component of the lipopolysaccharide (LPS) and is unique to the O139 strain, which emerged in the early 1990s as a significant cause of cholera outbreaks (Johnson et al., 1994). Unlike the O1 serogroup, the O139 OSP is also associated with a capsular structure that contributes to the bacterium's virulence and ability to evade certain host immune responses (Waldor et al., 1994). In the context of vaccine development, O139 OSP is the primary target for inducing protective immunity, specifically through the generation of vibriocidal antibodies that correlate with protection against the disease (Qadri et al., 1995). It is a major constituent of bivalent oral cholera vaccines (OCVs) such as Shanchol and Euvichol, which provide protection against both O1 and O139 serogroups (WHO, 2017). Current research also explores the use of synthetic O139 OSP-protein conjugates to improve the immunogenicity and memory response of vaccines, particularly in pediatric populations (Sarkar et al., 2019).

Other names

O139 antigenO139 O-antigenVibrio cholerae O139 lipopolysaccharideVibrio cholerae O139 capsular polysaccharide

Induction of vibriocidal antibodies that mediate complement-dependent lysis of the bacteria and inhibit colonization of the small intestine