Edmiston A L, Russell S M
Department of Poultry Science, University of Georgia, Athens 30602-2772, USA.
J Food Prot. 1998 Oct;61(10):1375-7. doi: 10.4315/0362-028x-61.10.1375.
Experiments were conducted to evaluate a rapid method for enumerating Escherichia coli from broiler chicken carcasses. In three separate trials, carcasses were obtained from a commercial processing plant, temperature abused at 37 degrees C for 0, 3, 6, 9, or 12 h, and then rinsed. E. coli were enumerated from carcass rinses using Petrifilm E. coli count plates (PC) and by placing the rinse into double-strength colifiform medium supplemented with 2% dextrose (CMD). The CMD mixture was placed into a Bactometer module and conductance was measured at 44 degrees C. Once a detection time (DT) was recorded, the sample was immediately recovered from the module well, diluted, and spread onto plate count agar. Colonies on plates at the highest dilution from each module well were randomly selected and identified. After 0, 3, 6, 9, and 12 h of temperature abuse, E. coli was the bacterial species identified 97, 92, 88, 87, and 61% of the time, respectively. These results indicate that the medium/temperature combination was excellent for enumerating E. coli from samples that contain mixed microflora using conductance. Significant linear correlations were observed between time of abuse (TA) and log10 PC (LPC) or DT (R2 = 0.86 and R2 = -0.90, respectively). A significant linear correlation was observed between LPC and DT (R2 = -0.92). This rapid method (1 to 7.6 h) for enumeration of E. coli on chicken should provide a way to determine E. coli levels before a product is shipped, and it should aid the poultry industry in meeting the E. coli testing requirement of the U.S. Department of Agriculture Food Safety and Inspection Service pathogen reduction regulation.
进行了多项实验以评估一种从肉鸡胴体中快速计数大肠杆菌的方法。在三项独立试验中，从一家商业加工厂获取胴体，在37摄氏度下进行0、3、6、9或12小时的温度滥用处理，然后进行冲洗。使用Petrifilm大肠杆菌计数平板（PC）并将冲洗液放入添加2%葡萄糖的双倍强度大肠菌群培养基（CMD）中，从胴体冲洗液中计数大肠杆菌。将CMD混合物放入Bactometer模块中，在44摄氏度下测量电导率。一旦记录到检测时间（DT），立即从模块孔中取出样品，稀释并涂布在平板计数琼脂上。从每个模块孔中最高稀释度平板上的菌落中随机选择并进行鉴定。在温度滥用0、3、6、9和12小时后，分别有97%、92%、88%、87%和61%的时间鉴定出大肠杆菌为优势菌种。这些结果表明，该培养基/温度组合对于使用电导率从含有混合微生物群落的样品中计数大肠杆菌非常有效。在滥用时间（TA）与log10 PC（LPC）或DT之间观察到显著的线性相关性（R2分别为0.86和-0.90）。在LPC与DT之间观察到显著的线性相关性（R2 = -0.92）。这种用于在鸡肉上快速计数大肠杆菌的方法（1至7.6小时）应能提供一种在产品发货前确定大肠杆菌水平的方法，并应有助于家禽行业满足美国农业部食品安全与检验局病原体减少规定中的大肠杆菌检测要求。
