Harmon S M, Kautter D A
Food and Drug Administration, Division of Microbiology, Washington, DC 20204.
J Assoc Off Anal Chem. 1987 Nov-Dec;70(6):994-6.
Enumeration of Clostridium perfringens spores was compared using 4 culture media. Duplicate 1 g portions of 35 stools (25 from C. perfringens food poisoning outbreaks and 10 from normal stools) were heat treated 20 min at 75 degrees C and tested on tryptose-sulfite-cycloserine (TSC) agar, trypticase-soy-blood (TSB) agar, lactose-sulfite (LS) medium, and iron milk (IM) medium. Dilutions were plated directly onto TSB and TSC, and a 3-tube most probable number determination was made with each specimen in LS and IM incubated at 45 degrees C. TSB was easiest to use and nonhemolytic food poisoning strains were readily differentiated from the normal hemolytic biotype on this medium. Confirmed counts on TSC and TSB were similar for all specimens, but counts of 8 of 25 outbreak specimens were 2-4 log units lower in LS and IM than on plating media; spores in specimens associated with 2 of 5 outbreaks were intolerant of the elevated temperatures. Results showed that elevated temperature MPN methods in LS and IM are inappropriate for the examination of outbreak stools.
使用4种培养基对产气荚膜梭菌芽孢进行计数比较。取35份粪便样本（25份来自产气荚膜梭菌食物中毒暴发事件，10份来自正常粪便），每份1 g，重复样本在75℃下热处理20分钟，然后在胰蛋白胨亚硫酸盐环丝氨酸（TSC）琼脂、胰蛋白酶大豆血（TSB）琼脂、乳糖亚硫酸盐（LS）培养基和铁乳（IM）培养基上进行检测。将稀释液直接接种到TSB和TSC上，对每份样本在45℃下孵育的LS和IM中进行3管最大可能数测定。TSB最易于使用，在此培养基上非溶血性食物中毒菌株很容易与正常溶血型生物型区分开来。所有样本在TSC和TSB上的确认计数相似，但25份暴发样本中有8份在LS和IM中的计数比平板培养基上低2 - 4个对数单位；与5次暴发中的2次相关的样本中的芽孢不耐受高温。结果表明，LS和IM中的高温最大可能数方法不适用于暴发粪便样本的检测。
