In vitro studies on the colonization of bovine colonic mucosa by Shiga-toxigenic Escherichia coli (STEC).
This study investigated host-related factors that influence intestinal colonization by Shiga-toxigenic E. coli (STEC). A quantitative colonization assay was developed to comparatively measure attachment of STEC to bovine colonic tissues maintained in vitro. No differences were determined in colonization susceptibility between tissues derived from weaning calves and adult cattle, or for tissues from cattle fed grain and forage-based rations. Substrate conditions designed to represent various intra-enteric environments were tested for their effect on STEC/mucosal interaction. Under conditions corresponding to a well-fed ruminant (high volatile fatty acid and lactate concentrations, low pH), significantly less STEC colonized the mucosal surface of colonic biopsies. These results may help explain why fasted, poorly or intermittently fed cattle and pre-ruminant calves excrete STEC to a greater degree. Studies on the ecology of STEC within the ruminant gut help identify mechanisms to reduce their threat to public health.
Department of Microbiology and Parasitology, University of Queensland, St Lucia, Queensland 4072, Australia.
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Desmarchelier
D000367:Age Factors; D000704:Analysis of Variance; D000821:Animal Feed; D000818:Animals; D000833:Animals, Suckling; D001422:Bacterial Adhesion; D001706:Biopsy; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology* / Q000473:pathology; D003106:Colon; D015169:Colony Count, Microbial; D004043:Dietary Fiber; D002523:Edible Grain; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000473:pathology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000145:classification; D005215:Fasting; D019084:Fluorescent Antibody Technique, Indirect; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000382:microbiology* / Q000473:pathology; D016014:Linear Models; D009924:Organ Culture Techniques; D012703:Serotyping; D022603:Shiga Toxins
D004043:Dietary Fiber; D022603:Shiga Toxins