Experimental use of 2-nitropropanol for reduction of Salmonella Typhimurium in the ceca of broiler chicks.

The effect of 2-nitropropanol (2NPOH) administration on Salmonella enterica serovar Typhimurium in experimentally infected chicks was determined. Chicks orally challenged with 10(6) CFU/ml of a novobiocin- and naladixic acid-resistant Salmonella Typhimurium at 6 days of age were divided into three groups receiving 0 (control), 6.5, and 13 mg 2NPOH per bird (experiment 1) or four groups receiving 0 (control), 13, 65, and 130 mg 2NPOH per bird (experiment 2). Treatments were administered orally 1 day post-Salmonella challenge. Cecal contents collected at necropsy 24 and 48 h after treatment were subjected to bacterial and volatile fatty acid (VFA) analysis. In experiment 1, concentrations (mean+/-SD log CFU per g) of Salmonella were reduced (P < 0.05) in the group administered 13 mg 2NPOH per bird at both the 24- and 48-h samplings compared with the controls (2.58+/-2.10 versus 4.64+/-1.79 and 2.88+/-2.78 versus 5.03+/-2.42 at 24 and 48 h, respectively). In experiment 2, mean+/-SD populations of Salmonella were reduced (P < 0.05) in all groups receiving 2NPOH compared with untreated controls (3.65+/-2.01, 3.39+/-2.42, and 3.47+/-1.55 at 13, 65, and 130 mg, respectively, versus 6.09+/-1.02). Propionate concentrations were reduced (P < 0.05) by the 13-mg 2NPOH per bird treatment. Total VFA concentrations from the group treated with 13 mg 2NPOH per bird were lower (P < 0.05) by 48, but not 24, hours posttreatment than those from the group treated with 6.5 mg 2NPOH per bird. These results demonstrate the inhibitory activity of 2NPOH against Salmonella Typhimurium in vivo.