FIG. 4.

NΔeps mutant does not survive the passage through the infant mouse gastrointestinal tract. Wild-type and NΔeps mutant strains of V. cholerae N16961 were separately inoculated into 4- to 5-day-old suckling mice as described in Materials and Methods. After 24 h postinoculation, the small intestines of the infected animals were removed and homogenized in LB broth, and serial dilutions were plated on LB agar supplemented with streptomycin to determine the number of CFU. The combined results of two independent experiments are presented. Datum points represent the CFU of wild-type N16961 (squares) and NΔeps mutant (circles) recovered from individual mice.