Effects of esculin and esculetin on the survival of Escherichia coli O157 in human faecal slurries, continuous-flow simulations of the rumen and colon and in calves.
The human pathogen Escherichia coli O157:H7 is thought to be spread by direct or indirect contact with infected animal or human faeces. The present study investigated the effects of the plant coumarin esculin and its aglycone esculetin on the survival of a strain of E. coli O157 under gut conditions. The addition of these compounds to human faecal slurries and in vitro continuous-flow fermenter models simulating conditions in the human colon and rumen caused marked decreases in the survival of an introduced strain of E. coli O157. When four calves were experimentally infected with E. coli O157 and fed esculin, the pathogen was detected in five of twenty-eight (18 %) of faecal samples examined post-inoculation, compared with thirteen of thirty-five (37 %) of faecal samples examined from five control calves not fed esculin. Coumarin compounds that occur naturally in dietary plants or when supplemented in the diet probably inhibit the survival of E. coli O157 in the gut.
Duncan
Sylvia H
SH
Gut Microbiology and Immunology Division, Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK. shd@rri.sari.ac.uk
Leitch
E Carol McWilliam
EC
Stanley
Karen N
KN
Richardson
Anthony J
AJ
Laven
Richard A
RA
Flint
Harry J
HJ
Stewart
Colin S
CS
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002417:Cattle; D003106:Colon / Q000382:microbiology; D015169:Colony Count, Microbial; D003470:Culture Media; D019453:Escherichia coli O157 / Q000187:drug effects*; D004929:Esculin / Q000494:pharmacology*; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D006801:Humans; D010945:Plants, Edible; D012417:Rumen / Q000382:microbiology; D014468:Umbelliferones / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D003470:Culture Media; D014468:Umbelliferones; D004929:Esculin; C007628:esculetin