- Cloning and characterization of genes encoding homologues of the B subunit of cholera toxin and the Escherichia coli heat-labile enterotoxin from clinical isolates of Citrobacter freundii and E. coli. Karasawa, T., Ito, H., Tsukamoto, T., Yamasaki, S., Kurazono, H., Faruque, S.M., Nair, G.B., Nishibuchi, M., Takeda, Y. Infect. Immun. (2002)









