Anderson R C, Callaway T R, Buckley S A, Anderson T J, Genovese K J, Sheffield C L, Nisbet D J
USDA/ARS, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, TX 77845, USA.
Int J Food Microbiol. 2001 Dec 30;71(2-3):125-30. doi: 10.1016/s0168-1605(01)00562-1.
Strategies are sought to reduce pathogenic Escherichia coli concentrations in food animals. Because E. coli possess respiratory nitrate reductase activity, which also reduces chlorate to cytotoxic chlorite, we tested and found that oral sodium chlorate administration reduced gut concentrations of E. coli O157:H7 in experimentally infected pigs and wildtype E. coli concentrations in nonchallenged pigs. Mean +/- S.E. concentrations (log10 CFU/g) of E. coli O157:H7 in ileal, cecal, colonic and rectal contents from placebo-treated pigs were 4.03 +/- 0.66, 3.82 +/- 0.24, 4.42 +/- 0.25 and 4.03 +/- 0.16, respectively. In contrast, E. coli O157:H7 concentrations were reduced (P < 0.05) in ileal (1.56 +/- 0.22) cecal (2.65 +/- 0.38), colonic (3.05 +/- 0.38) and rectal (3.00 +/- 0.29) contents from pigs orally administered three successive (8 h apart) 10-ml doses of 100 mM chlorate. Wildtype E. coli concentrations in gut contents of non-E. coli O157:H7-challenged pigs likewise treated with chlorate were reduced by 1.1 to 4.5 log10 units compared to concentrations in placebo-treated pigs, which exceeded 6.0 log10 CFU/g. As before, the reductions were greater in anterior regions of the gut than regions more caudal. Similar treatment of E. coli O157:H7-challenged pigs with 200 mM chlorate caused reductions in gut concentrations of E. coli O157:H7; however, the reductions were not necessarily greater than those achieved with the 100 mM chlorate treatment.
人们一直在寻找降低食用动物体内致病性大肠杆菌浓度的策略。由于大肠杆菌具有呼吸硝酸盐还原酶活性，该活性也会将氯酸盐还原为具有细胞毒性的亚氯酸盐，我们进行了测试并发现，口服氯酸钠可降低实验感染猪肠道中O157:H7大肠杆菌的浓度以及未受感染猪肠道中野生型大肠杆菌的浓度。接受安慰剂处理的猪的回肠、盲肠、结肠和直肠内容物中O157:H7大肠杆菌的平均浓度（log10 CFU/g）±标准误分别为4.03±0.66、3.82±0.24、4.42±0.25和4.03±0.16。相比之下，连续三次（间隔8小时）口服10 ml 100 mM氯酸盐的猪，其回肠（1.56±0.22）、盲肠（2.65±0.38）、结肠（3.05±0.38）和直肠（3.00±0.29）内容物中O157:H7大肠杆菌的浓度降低了（P<0.05）。同样用氯酸盐处理的未感染O157:H7大肠杆菌的猪的肠道内容物中野生型大肠杆菌的浓度，与接受安慰剂处理的猪相比，降低了1.1至4.5个log10单位，后者超过6.0 log10 CFU/g。和之前一样，肠道前部区域的减少幅度大于更靠后的区域。用200 mM氯酸盐对感染O157:H7大肠杆菌的猪进行类似处理，可使肠道中O157:H7大肠杆菌的浓度降低；然而，降低幅度不一定大于100 mM氯酸盐处理的效果。
