title: Effects of sodium chlorate on toxin production by Escherichia coli O157:H7.
abstract: Chlorate kills E. coli O157:H7 and has been proposed as a feed additive to be included in cattle rations immediately prior to slaughter to reduce E. coli O157: H7 populations in the gut. Antibiotic usage is not recommended in cases of E. coil O157:H7-induced hemorrhagic colitis because some antibiotics stimulate increased toxin production. This study was undertaken to determine if chlorate treatment affected toxin production. Pure cultures of E. coil O157:H7 were treated with 1/4 MIC of antibiotics (ampicillin, tetracycline, ceftiofur, gentamicin, monensin, tylosin, penicillin, ciprofloxacin, and novobiocin); toxin production was significantly increased by some antibiotics, but not by chlorate. Studies with mixed fecal bacteria demonstrated that chlorate killed E. coli O157:H7, but again did not stimulate toxin production. Chlorate appears to be an effective method to reduce shiga toxin-producing E. coil (STEC) populations in food animals, but additional studies are warranted before it is used to control infections.
authors.affiliation: Feed and Food Safety Research Unit, Southern Plains Agricultural Research Center, 2881 F & B Rd., College Station, TX 77845, USA. callaway@ffsru.tamu.edu
authors.forename: T R
authors.initials: TR
authors.lastname: Callaway
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: T S
authors.initials: TS
authors.lastname: Edrington
authors.forename: Y S
authors.initials: YS
authors.lastname: Jung
authors.forename: K M
authors.initials: KM
authors.lastname: Bischoff
authors.forename: K J
authors.initials: KJ
authors.lastname: Genovese
authors.forename: T L
authors.initials: TL
authors.lastname: Poole
authors.forename: R B
authors.initials: RB
authors.lastname: Harvey
authors.forename: J A
authors.initials: JA
authors.lastname: Byrd
authors.forename: D J
authors.initials: DJ
authors.lastname: Nisbet
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism*; D002417:Cattle / Q000382:microbiology; D002704:Chlorates / Q000494:pharmacology*; D015169:Colony Count, Microbial / Q000662:veterinary; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D005516:Food Microbiology
chemical_list: D001427:Bacterial Toxins; D002704:Chlorates; C032706:sodium chlorate