Pangloli Philipus, Dje Yobouet, Oliver S P, Mathew A, Golden D A, Taylor W J, Draughon F A
Food Safety Center of Excellence, Agricultural Experimental Station, The University of Tennessee, Knoxville, Tennessee 37996, USA.
J Food Prot. 2003 Nov;66(11):1987-95. doi: 10.4315/0362-028x-66.11.1987.
Current official methods for detection and isolation of Salmonella are mostly designed for foods. The objective of this study was to determine optimal methods for detection and isolation of Salmonella from animal and environmental samples of dairy, poultry, and swine farms. Preenrichment in lactose broth versus direct enrichment (no preenrichment) prior to selective enrichment in Rappaport-Vassiliadis, selenite cystine, and tetrathionate incubated at 35 and 42 degrees C and in four differential/selective plating media (brilliant green, bismuth sulfite, Hektoen enteric, and xylose-lysine-tergitol 4 agar base) were evaluated for their ability to recover Salmonella from artificially contaminated samples. The effects of pH adjustments to samples on Salmonella recovery were determined. A pH adjustment of the enrichment broth to 6.8 +/- 0.2 after addition of samples significantly improved recovery of Salmonella. The most effective medium combinations for isolation of Salmonella from farm samples depended on the type of samples. Generalizations of protocols for recovery of Salmonella from farm samples might result in poor recovery, increased recovery time, and increased sample processing costs.
当前检测和分离沙门氏菌的官方方法大多是针对食品设计的。本研究的目的是确定从奶牛场、家禽场和养猪场的动物及环境样本中检测和分离沙门氏菌的最佳方法。比较了在拉帕波特-瓦西里亚迪斯肉汤、亚硒酸盐胱氨酸肉汤和四硫磺酸盐肉汤中于35℃和42℃进行选择性增菌前，在乳糖肉汤中进行预增菌与直接增菌（无预增菌）的效果，并评估了在四种鉴别/选择性平板培养基（亮绿琼脂、亚硫酸铋琼脂、赫克托恩肠道琼脂和木糖赖氨酸脱氧胆酸盐4琼脂基础培养基）上从人工污染样本中回收沙门氏菌的能力。测定了对样本进行pH调节对沙门氏菌回收率的影响。在添加样本后将增菌肉汤的pH调节至6.8±0.2可显著提高沙门氏菌的回收率。从农场样本中分离沙门氏菌的最佳培养基组合取决于样本类型。从农场样本中回收沙门氏菌的方案一概而论可能会导致回收率低、回收时间延长和样本处理成本增加。
