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United States Department of Agriculture

Agricultural Research Service

Title: Survivability of Escherichia Coli O157:h7 in a Defined Mixed Competitive Exclusion Culture of Avian Microflora (Cf3) Maintained under Continuous Flow Anaerobic Conditions

item Nisbet, David
item Corrier, Donald
item Ricke, Steve - TEXAS A&M UNIVERSITY
item Deloach, John

Submitted to: World Congress on Anaerobic Bacteria and Infections
Publication Type: Abstract Only
Publication Acceptance Date: May 2, 1996
Publication Date: N/A

Technical Abstract: Escherichia coli O157:H7 has been associated with many outbreaks and cases of human hemorraghic colitis and hemolytic-uremic syndrome. Stavric et al. (1992 and 1993) demonstrated that colonization resistance against this potential human pathogen is increased when newly-hatched chicks are provided anaerobic bacteria obtained from the feces of healthy adult chickens. In this study, we document the survivability of E. coli O157:H7 in a anaerobic continuous-flow defined competitive-exclusion culture. The steady-state continuous-flow (CF) culture was inoculated with E. coli at concentrations of up to 10**4 CFU/ml. Samples were withdrawn directly from the culture post-inoculation until no E. coli O157:H7 could be detected or until the concentration of E. coli O157:H7 in the continuous- flow culture remained stable. When challenged with 10**1 E. coli CFU/ml, no E. coli could be detected in the CF-culture after 24 hr. When challenged with 10**2 or 10**3 CFU of E. coli/ml, no E. coli could be detected in the CF-culture after 72 hr and when challenged with 10**4 E. coli CFU/ml, no E. coli could be detected in the CF-culture after 96 hr. No changes in the fermentation profile of the CF-culture could be detected. Results indicate that the CF3 defined competitive exclusion culture inhibits growth of E. coli O157:7 in vitro.

Last Modified: 4/18/2015
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