Characterization of colonization of the rabbit gastrointestinal tract by Escherichia coli RDEC-1.
We have reported previously the isolation of an Escherichia coli strain (RDEC-1) that in rabbits is able to colonize the gut, adhere to mucosal epithelial cells of the ileum, cecum, and colon, and cause diarrhea by a novel mechanism. The purpose of the present study was to characterize more fully the colonization of the rabbit gut by strain RDEC-1. Colonization reached a maximum 3 to 4 days post-inoculation with strain RDEC-1 and did not decrease until 15 days post-inoculation. Diarrhea occurred 3 to 4 days after colonization reached its maximum intensity. Semiquantitative rectal swab cultures were found to be correlated with counts of colony-forming units of strain RDEC-1 per gram of ileum, cecum, and colon and their contents and were used to chart the course of colonization of the rabbit gut. The actual number of colony-forming units per gram was dependent on the stage of colonization and ranged from 4.0 X 10(3) to 2.4 X 20(6) in the ileum to 3.1 X 10(5) to 3.6 X 10(7) in the cecum. The number of colony-forming units per gram was not affected by the presence of diarrhea. E. coli RDEC-1 colonizes the ileum, cecum, and colon of rabbits heavily for a relatively long period of time.
D000818:Animals; D002432:Cecum / Q000382:microbiology; D003106:Colon / Q000382:microbiology; D003114:Colony-Forming Units Assay; D003967:Diarrhea / Q000382:microbiology; D004926:Escherichia coli / Q000254:growth & development* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D007082:Ileum / Q000382:microbiology; D007422:Intestines / Q000382:microbiology*; D011817:Rabbits; D012007:Rectum / Q000382:microbiology