Enterotoxigenic Escherichia coli Pathogenic for Man: Biological and Immunological Aspects of Fimbrial Colonization Factor Antigens
This chapter is concerned with work stimulated by the idea that Colonization Factor Antigens (CFA)/I and CFA/II may play the most important role as Enterotoxigenic Escherichia coli (ETEC)-specific antigens in terms of immune responses protective against ETEC infection in man. In vivo production of CFAs has been evidenced by confirmation of seroconversion in naturally occurring and artificially induced ETEC diarrhea and by the serological detection of CFAs directly in diarrheal stool specimens. One major goal is to develop the methodology for preventing ETEC diarrhea by vaccination with ETEC-specific antigens. Since ETEC diarrhea is a major problem in developing countries, as reflected by the travelers’ diarrhea syndrome, and especially in infants and young children in these countries one area of concern is the potential of anti-CFA antibody in breast milk of mothers to protect their infants against ETEC diarrhea. Animal-associated ETEC produce fimbrial CFAs which have been characterized as K88, K99, and 987P.