Bactericidal effect of sodium chlorate on <i>Escherichia coli</i> O157:H7 and <i>Salmonella</i> typhimurium DT104 in rumen contents in vitro

作     者：Anderson, RC Buckley, SA Kubena, LF Stanker, LH Harvey, RB Nisbet, DJ 

作者机构：USDA Agr Res Serv So Plains Agr Res Ctr Food & Feed Res Unit College Stn TX 77845 USA 

出 版 物：《JOURNAL OF FOOD PROTECTION》 (食品保护杂志)

年 卷 期：2000年第63卷第8期

页      面：1038-1042页

核心收录：

学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 08[工学] 0836[工学-生物工程] 

主　　题：氯酸盐类/药理学 剂量效应关系 药物 大肠杆菌O157/药物作用 大肠杆菌O157/生长和发育 氢离子浓度 硝酸还原酶 硝酸盐还原酶类/代谢 瘤胃/微生物学 鼠伤寒沙门菌/药物作用 鼠伤寒沙门菌/生长和发育 动物 牛 

摘      要：Escherichia coli O157:H7 and Salmonella Typhimurium DT104 are important foodborne pathogens affecting the beef and dairy industries and strategies are sought to rid these organisms from cattle at slaughter Both pathogens possess respiratory nitrate reductase that also reduces chlorate to the lethal chlorite ion. Because most anaerobes lack respiratory nitrate reductase, we hypothesized that chlorate may selectively kill E. coli O157:1-17 and Salmonella Typhimurium DT104 but not potentially beneficial anaerobes. In support of this hypothesis, we found that concentrations of E. coli O157:H7 and Salmonella Typhimurium DT104 were reduced from approximately 1,000,000 colony forming units (CFU) to below our level of detection (less than or equal to 10 CFU) following in vitro incubation (24 h) in buffered ruminal contents (pH 6.8) containing 5 mM added chlorate. In contrast, chlorate had little effect on the most probable number (mean +/- SD) of total culturable anaerobes (ranging from 9.9 +/- 0.72 to 10.7 +/- 0.01 log(10) cells/ml). Thus, chlorate was bactericidal to E, coli O157:1-17 and Salmonella Typhimurium DT104 but not to potentially beneficial bacteria. The bactericidal effect of chlorate was concentration dependent (less at 1.25 mM) and markedly affected by pH (more bactericidal at pH 6.8 than pH 5.6).