- 期刊
比較臺灣公告腸桿菌科之直接平板檢驗法與臺灣之大腸桿菌群MPN法及中國大陸國標大腸桿菌群直接平板法的檢測效能
Comparison of the Newly Published Enterobacteriaceae Direct Plate Test with the Coliform MPN and Direct Plate Methods for Detection of Hygiene Indicator Bacteria in Food
摘要
大腸桿菌群(coliform)多存在於溫血動物之糞便、人類活動之場所及有糞便污染的地方，常被作為食品被糞便汙染之指標。近年來，ISO機構提出以腸桿菌科傾注平板檢驗方法取代大部分食品的大腸桿菌群MPN法作為衛生指標菌，而台灣衛福部食品藥物管理署亦於2018年8月公告腸桿菌科檢驗方法之草案。為了評估新公告之草案與其它兩種大腸桿菌群檢驗方法（臺灣之大腸桿菌群MPN法及中國大陸國標大腸桿菌群直接平板法）之效能，本研究利用15件手搖飲料檢體及2件標準菌種的對照組進行三種方法檢驗結果的比較。利用不同稀釋濃度的檢液及培養基等進行評估，培養24小時後，計數及接續進一步鑑定。結果發現其中有5個檢體為未檢出和2件陽性飲料檢體MPN法超過1,100 MPN/g，因此，不能作為比較之用，本研究以介於未檢出及大量檢出中間的8件陽性檢體進行生長的菌數多寡比較，結果指出以新公告腸桿菌科草案所獲得的腸桿菌科菌數比其它兩種大腸桿菌群方法所獲得的菌數高，此說明衛福部新公告方法作為衛生指標菌有其意義及重要性。另外，本研究發現市售手搖飲料大腸桿菌群或腸桿菌科衛生指標菌檢測不合格率高達66.7% (10/15)，值得衛生主管單位作為稽核及加強從業人員衛生教育的參考。
並列摘要
Coliform bacteria (including Escherichia, Klebsiella, Enterobacter, and Citrobacter) are present in the feces of warm-blooded animals, places where there are human activities, and places where fecal contamination is common. The presence of coliform bacteria in food is a hygiene indicator of fecal contamination. In Taiwan, the commonly used method for the detection and enumeration of coliform bacteria is the MPN (most probable number) test as recommended by the Taiwan Bureau of Food and Drug Administration (TFDA). In China, two methods are used. The first one is the same MPN test as the one used in Taiwan. The second one is the direct plate method (DPM). The ISO (International Organization for Standardization) has recently proposed the use of the Enterobacteriaceae direct plate method to replace the MPN method. In August 2018, the TFDA announced a new method for detection of enteric bacteria based on the Enterobacteriaceae direct plate method of ISO. To compare the effectiveness of the new TFDA method with that of the other two methods (MPN and DPM), we examined 15 cold drink specimens and 2 standard coliform control strains. The specimens were serially diluted and cultured with the 3 different methods. At 24 hours after inoculation, coliform colonies on VRBA (violet red bile agar) and Enterobacteriaceae on VRBGA (violet red bile glucose agar) plates were enumerated. Five of the 15 samples showed negative results with all 3 methods. Two samples had more than 1,100 MPN/g of coliform bacteria. For the remaining 8 samples, the newly published TFDA Enterobacteriaceae method detected higher number of bacteria than the other 2 methods (MPN and DPM). Results of this study also indicated that 66.7% (10/15) of the cold drinks were unsatisfactory in food safety.