Abstract
Enteric pathogens cause considerable public health concerns worldwide including the tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the functions of carbohydrates in infection by Salmonella enterica and several bacterial species that produce varieties of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infections by these microbes; however, the usage of carbohydrates by them varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tracts, various carbohydrate moieties are present and play crucial roles in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion processes of the microbes, carbohydrates function as receptors for various microbes, while they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking these interactions with carbohydrate. In addition, similarities in mode of infection may also be utilized. These findings we described are useful in development of the new drugs for treatments of enteric pathogens.
