title: Aflatoxin, fumonisin and Shiga toxin-producing Escherichia coli infections in calves and the effectiveness of Celmanax®/Dairyman's Choice™ applications to eliminate morbidity and mortality losses.
abstract: Mycotoxin mixtures are associated with Shiga toxin-producing Escherichia coli (STEC) infections in mature cattle. STEC are considered commensal bacteria in mature cattle suggesting that mycotoxins provide a mechanism that converts this bacterium to an opportunistic pathogen. In this study, we assessed the mycotoxin content of hemorrhaged mucosa in dairy calves during natural disease outbreaks, compared the virulence genes of the STECs, evaluated the effect of the mucosal mycotoxins on STEC toxin expression and evaluated a Celmanax®/Dairyman's Choice™ application to alleviate disease. As for human infections, the OI-122 encoded nleB gene was common to STEC genotypes eliciting serious disease. Low levels of aflatoxin (1-3 ppb) and fumonisin (50-350 ppb) were detected in the hemorrhaged mucosa. Growth of the STECs with the mycotoxins altered the secreted protein concentration with a corresponding increase in cytotoxicity. Changes in intracellular calcium indicated that the mycotoxins increased enterotoxin and pore-forming toxin activity. A prebiotic/probiotic application eliminated the morbidity and mortality losses associated with the STEC infections. Our study demonstrates: the same STEC disease complex exists for immature and mature cattle; the significance of the OI-122 pathogenicity island to virulence; the significance of mycotoxins to STEC toxin activity; and, finally, provides further evidence that prebiotic/probiotic applications alleviate STEC shedding and mycotoxin/STEC interactions that lead to disease.
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403 1 Avenue South, Lethbridge, AB T1J 4B1, Canada. danica.baines@agr.gc.ca.
authors.forename: Danica
authors.initials: D
authors.lastname: Baines
authors.forename: Mark
authors.initials: M
authors.lastname: Sumarah
authors.forename: Gretchen
authors.initials: G
authors.lastname: Kuldau
authors.forename: Jean
authors.initials: J
authors.lastname: Juba
authors.forename: Alberto
authors.initials: A
authors.lastname: Mazza
authors.forename: Luke
authors.initials: L
authors.lastname: Masson
mesh_terms: D000348:Aflatoxins / Q000032:analysis; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000628:therapy*; D002460:Cell Line; D024881:Drug Resistance, Bacterial; D004927:Escherichia coli Infections / Q000382:microbiology / Q000628:therapy* / Q000662:veterinary; D005260:Female; D037341:Fumonisins / Q000032:analysis; D005658:Fungi / Q000302:isolation & purification / Q000378:metabolism; D007413:Intestinal Mucosa / Q000737:chemistry / Q000382:microbiology; D056692:Prebiotics; D019936:Probiotics / Q000627:therapeutic use*; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
chemical_list: D000348:Aflatoxins; D000900:Anti-Bacterial Agents; D037341:Fumonisins; D056692:Prebiotics