Anderson R C, Buckley S A, Callaway T R, Genovese K J, Kubena L F, Harvey R B, Nisbet D J
US Department of Agriculture, Agricultural Research Service, Southern Plains Agricultural Research Center, Food and Feed Safety Research Unit, College Station, Texas 77845, USA.
J Food Prot. 2001 Feb;64(2):255-8. doi: 10.4315/0362-028x-64.2.255.
Salmonella cause economic losses to the swine industry due to disease and compromised food safety. Since the gut is a major reservoir for Salmonella, strategies are sought to reduce their concentration in pigs immediately before processing. Respiratory nitrate reductase activity possessed by Salmonella also catalyzes the intracellular reduction of chlorate (an analog of nitrate) to chlorite, which is lethal to the microbe. Since most gastrointestinal anaerobes lack respiratory nitrate reductase, we conducted a study to determine if chlorate may selectively kill Salmonella within the pig gut. Weaned pigs orally infected with 8 x 10(7) CFU of a novobiocin- and nalidixic acid-resistant strain of Salmonella Typhimurium were treated 8 and 16 h later via oral gavage (10 ml) with 0 or 100 mM sodium chlorate. Pigs were euthanized at 8-h intervals after receiving the last treatment. Samples collected by necropsy were cultured qualitatively and quantitatively for Salmonella and for most probable numbers of total culturable anaerobes. A significant (P < 0.05) chlorate treatment effect was observed on cecal concentrations of Salmonella, with the largest reductions occurring 16 h after receiving the last chlorate treatment. An observed treatment by time after treatment interaction suggests the chlorate effect was concentration dependent. Chlorate treatment may provide a means to reduce foodborne pathogens immediately before harvest.
沙门氏菌会因疾病和食品安全问题给养猪业造成经济损失。由于肠道是沙门氏菌的主要储存库，因此人们在寻求各种策略以在猪即将屠宰前降低其体内沙门氏菌的浓度。沙门氏菌所具有的呼吸硝酸盐还原酶活性还能催化细胞内将氯酸盐（硝酸盐的类似物）还原为亚氯酸盐，而亚氯酸盐对该微生物具有致死性。由于大多数胃肠道厌氧菌缺乏呼吸硝酸盐还原酶，我们开展了一项研究，以确定氯酸盐是否能在猪肠道内选择性地杀死沙门氏菌。用8×10⁷CFU对新生霉素和萘啶酸耐药的鼠伤寒沙门氏菌口服感染断奶仔猪，在8小时和16小时后通过口服灌胃（10毫升）给予0或100毫摩尔的氯酸钠。在接受最后一次治疗后，每隔8小时对猪实施安乐死。通过尸检采集的样本对沙门氏菌以及可培养厌氧菌的最可能数量进行定性和定量培养。观察到氯酸盐处理对盲肠中沙门氏菌的浓度有显著（P<0.05）影响，在接受最后一次氯酸盐处理16小时后减少最为明显。观察到的处理与处理后时间之间的相互作用表明氯酸盐的效果取决于浓度。氯酸盐处理可能提供一种在屠宰前立即减少食源性病原体的方法。
