以酵素免疫套組偵測米飯中之金黃色葡萄球菌腸毒素   全文下載

Detection of Staphylococcal Enterotoxins in Rice Using Enzyme Immunoassay Kits

以四種市售酵素免疫套組偵測由中毒食品中分離之金黃色葡萄球菌菌株19株，其毒素型別以A型最多（89.5%），C型次之（10.5%），B型及D型則未檢出，且不同型式之酵素免疫套組間檢驗結果一致。而於滅菌之米飯中添加1.7 × 103 CFU／g 金黃色葡萄球菌（產A型腸毒素），在37℃培養6小時菌數即達2.5 × 108 CFU／g 並可檢出0.11 ng腸毒素／g，而於22℃培養則需24小時可檢出0.25 ng 腸毒素／g，至於4℃貯存則延至48小時，亦未檢出腸毒素，菌數並維持於1.2～2.6 × 103 CFU／g。另以食品中常見之8株非金黃色葡萄球菌菌株測試四套市售套組，皆未產生交叉反應。

Four commercial enzyme immunoassay kits specific for the detection of staphylococcal enterotoxins(SE) were used to examine Staphylococcus, aureus strains isolated from samples of food poisoning outbreaks. Results showed that 89.5% and 10.5% of the strains tested could produce SEA and SEC, respectively. No SEB or SED producing strains were observed. A S. aureus strain which produces SEA was inoculated into some sterilized cooked rice at a concentration of 1.7 × 103 CFU/g. After 6 h incubation at 37°C, cell concentration reached 2.5 × 105 CFU/g and SEA reached 0.11 ng toxin/g. When the rice sample was kept at 4°C for 48 h, cell growth and toxin production was not detected. Using eight strains of non-S. aureus bacteria which may be commonly found in foods, was used as control to test the detection specificity of the four commercial available enzyme immunoassay kits. Results showed that no cross-reaction had occured indicating that the kits are highly specific for enterotoxin detection.