Figure 4. Colonizing V. cholerae bacteria fill specific colonization vacancies.
(A) Schematic of a size estimation of the luminal surface area compared to an agar surface. (B) Mean conjugation efficiency of J13 between C6706 strains was determined for different bacterial densities at the time of recovery from either the DSI (in vivo) at 3 hr post infection or in vitro (LB Agar) 3 hr after being spotted onto a surface area equivalent to 1 cm intestine. Each column is the mean of 4 to 5 biological replicates. (C) Conjugation efficiency of the SXT element from donor strain KW3 to recipient C6706 lacZ::Tn after 18 hr was determined for the DSI, cecum and in vitro. Initial in vivo inoculum was 108 CFU with an equal number of donors and recipients. For in vitro conjugation, the indicated CFU were spotted on the agar surface. Significance was determined by t test. Bars represent the mean and standard error. (D and E) 6 rabbits were infected with Peru-NT J13. After 6 hours, wild type C6706 was used to superinfect the same animals. CFU counts and conjugation efficiency was determined from bacteria recovered from MSI, DSI, and cecum 24 hours after the initial inoculation. In the control group, no bacteria were present in the initial inoculation. Peru-NT J13 and C6706 were then inoculated together at the 6 hr time point. (D) Each column is the mean CFU/cm tissue recovered for Peru-NT J13 (Black) and C6706 (Gray) with error bars indicating standard error. Significance with determined by t test with * - p < 0.05, *** - p < 10−3, **** - p < 10−4. (E) Data points represent the conjugation efficiency of bacteria in each experimental animal with bars indicating mean and standard error. Significance with respect to the control group was determined by t test **** - p < 10−4.