|Jung, Yong Soo|
Submitted to: Safepork
Publication Type: Proceedings
Publication Acceptance Date: 6/15/2005
Publication Date: 9/2/2005
Citation: Horrocks, S.M., Jung, Y., Ricke, S.C., Callaway, T.R., Edrington, T.S., Harvey, R.B., Anderson, R.C., Nisbet, D.J. 2005. Inhibitory effects of nitroethane and 2-nitropropanol against Campylobacter jejuni. Proceedings of SafePork 2005. p. 194-196.
Interpretive Summary: Campylobacter jejuni is an important food poisoning microorganism that colonizes the gut of swine. In this study, we tested two different chemicals, nitroethane and nitropropanol, to see if they may inhibit the growth of C. jejuni. Measurement of C. jejuni cell numbers at intervals during incubation revealed that nitroethane and nitropropanol significantly inhibited the growth of this pathogen. For instance, by 48 h of incubation, numbers of C. jejuni cells had increased almost 100-fold in control cultures containing no added nitrocompound but numbers of C. jejuni cells had decreased more than 10-fold in cultures incubated with nitroethane and had decreased more than 100,000-fold in cultures incubated with nitropropanol. A marked effect of acid level on the inhibitory activity of both compounds was observed, with greater activity observed in neutral or less acidic conditions than in more acidic conditions. These findings demonstrate the inhibitory activity of nitroethane and nitropropanol against C. jejuni and provide a basis for future research aimed at developing these compounds into feed additives to rid C. jejuni from food producing animals. This work will ultimately benefit producers and consumers by aiding the production of safe, wholesome pork products.
Technical Abstract: Campylobacter jejuni is an important foodborne pathogen that colonizes the gut of swine. In this study, the effects of nitroethane and 2-nitropropanol (0, 10 and 20 mM) on growth of C. jejuni were tested during culture in Bolton broth adjusted to pH of 5.6, 7.0, or 8.2. Viable cell counts of samples taken at intervals during incubation revealed main effects (P < 0.0001) of nitroethane or 2-nitropropanol on mean specific growth rates thus demonstrating that these were inhibitory to C. jejuni. By 48 h of incubation, C. jejuni concentrations had increased by 1.9 log10 CFU/ml or higher in cultures containing no added nitrocompound. In contrast, C. jejuni concentrations had decreased by > 1.8 and > 5.4 log10 CFU/ml after 48 h incubation with 20 mM nitroethane or 2-nitropropanol, respectively. A marked effect of pH on the inhibitory activity of both compounds was observed, with greater activity observed at higher pH.