Effects of nitrate or nitro supplementation, with or without added chlorate, on Salmonella enterica serovar Typhimurium and Escherichia coli in swine feces.
The effects of coincubating the active agent of an experimental chlorate product with nitrate or select nitro compounds, possible inducers and competing substrates for the targeted respiratory nitrate reductase, on concentrations of experimentally inoculated Salmonella enterica serovar Typhimurium and indigenous Escherichia coli were determined. Studies were completed in swine fecal suspensions as a prelude to the administration of these inhibitors to pigs. Results confirmed the bactericidal effect of chlorate (5 to 10 mM) against these fecal enterobacteria, reducing (P < 0.05) concentrations by > 2 log CFU ml(-1) after 3 to 6 h of incubation. An effect (P < 0.05) of pH was observed, with considerable regrowth of Salmonella and E. coli occurring after 24 h of incubation in suspensions buffered to pH 7.1 but not in suspensions buffered to pH 6.5 or 5.6. A 24-h coincubation of fecal suspensions with 5 to 10 mM chlorate and as little as 2.5 mM nitrate or 10 to 20 mM 2-nitro-1-propanol, 2-nitroethanol, and, sometimes, nitroethane decreased (P < 0.05) Salmonella but not necessarily E. coli concentrations. 2-Nitro-1-propanol and 2-nitroethanol exhibited inhibitory activity against Salmonella and E. coli by an undetermined mechanism, even in the absence of added chlorate.
Anderson
Robin C
RC
U.S. Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, 2881 F&B Road, College Station, Texas, USA. anderson@ffsru.tamu.edu
Jung
Yong S
YS
Oliver
Christy E
CE
Horrocks
Shane M
SM
Genovese
Kenneth J
KJ
Harvey
Roger B
RB
Callaway
Todd R
TR
Edrington
Thomas S
TS
Nisbet
David J
DJ
D000818:Animals; D002704:Chlorates / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D005243:Feces / Q000382:microbiology; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009566:Nitrates / Q000494:pharmacology*; D009574:Nitro Compounds / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000254:growth & development; D013552:Swine
D002704:Chlorates; D009566:Nitrates; D009574:Nitro Compounds