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Selection of Escherichia coli K88+ specific probiotic strains of E. coli from environmental isolates for post-weaning piglets.

Aim of this study was to select environmental E. coli isolates that produced colicins against the swine pathogen E. coli K88+. In initial evaluation using a modified plate method with 18 colicinogenic E. coli constructs, colicins E3, E4, E5, E9, Ia, K and N were found to possess inhibitory activity against 12 ETEC K88+ strains. A total of 463 environmental isolates from cattle rumen, cattle feces, pig feces and hog manure-amended soil were screened for colicin production by a modified plate test. Further, colicinogenic isolates were screened for five toxin genes LT, STa, STb, VT1 and VT2 as well as K88 (F4) fimbriae using PCR reactions. Fourteen non-pathogenic isolates were subjected to characterization of colicin genes by PCR using 9 new primer sequences, antibiotic susceptibilities and substrate utilization. Two potential probiotic strains of E. coli, UM-2 and UM-7 which produced colicins that could utilize potato starch and inulin were selected for in-vitro competition with E. coli K88+ strain 2-12. In vitro competition between the synbiotics and E. coli K88+ revealed inhibition of E. coli K88+. Based on the present in vitro studies it could be concluded that carefully selected potential synbiotics should be further studied for their role in protecting piglets from post-weaning diarrhea without antibiotics.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:MWU.1993/2456
Date12 June 2007
CreatorsSetia, Amit
ContributorsKrause, Denis O(Animal Science) House, James D (Animal Science), Nyachoti, Charles M (Animal Science) Holley, Rick A (Food Science)
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
Languageen_US
Detected LanguageEnglish

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