A vaccine and diagnostic target for Clostridium bolteae, an autism-associated bacterium

• Discovery of the first Clostridium bolteae immunogen.
• C. bolteae expresses a conserved polysaccharide (PS).
• C. bolteae PS is immunogenic in rabbits.
• C. bolteae PS could be used as a vaccine against C. bolteae-associated autism.
• C. bolteae PS could be used as a diagnostic marker for C. bolteae infection.

Constipation and diarrhea are common in autistic patients. Treatment with antibiotics against bacteria appears to partially alleviate autistic-related symptoms. Clostridium bolteae is a bacterium that has been shown to be overabundant in the intestinal tract of autistic children suffering from gastric intestinal ailments, and as such is an organism that could potentially aggravate gastrointestinal symptoms. We set out to investigate the cell-wall polysaccharides of C. bolteae in order to evaluate their structure and immunogenicity. Our explorations revealed that C. bolteae produces a conserved specific capsular polysaccharide comprised of rhamnose and mannose units: [→3)-α-D-Manp-(1→4)-β-d-Rhap-(1→], which is immunogenic in rabbits. These findings are the first description of a C. bolteae immunogen and indicate the prospect of using this polysaccharide as a vaccine to reduce or prevent C. bolteae colonization of the intestinal tract in autistic patients, and as a diagnostic marker for the rapid detection of C. bolteae in a clinical setting.