- The Escherichia coli K-12 gntP gene allows E. coli F-18 to occupy a distinct nutritional niche in the streptomycin-treated mouse large intestine. Sweeney, N.J., Klemm, P., McCormick, B.A., Moller-Nielsen, E., Utley, M., Schembri, M.A., Laux, D.C., Cohen, P.S. Infect. Immun. (1996)