- 期刊
利用沙門氏菌回復突變試驗評估基質輔助雷射脫附游離-飛行時間質譜基質(α-Cyano-4-Hydroxycinnamic Acid 溶於 50% Acetonitrile 與 2.5% Trifluoroacetic Acid)的致突變性
Salmonella Reversion Mutation Assay on ＂Saturated -Cyano-4-Hydroxycinnamic Acid in 50% Acetonitrile and 2.5% Trifluoroacetic Acid＂ Used as the Martrix in Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
摘要
基質輔助雷射脫附游離-飛行時間質譜儀(matrix-assisted laser desorption ionization-time of flight massspectrometry, MALDI-TOF MS)是近30 年來逐漸發展出的微生物鑑定方法，MALDI-TOF MS 基質以溶液型態與待測物進行作用，其中將飽和10 mg α-cyano-4-hydroxycinnamic acid (CHCA)加至50% acetonitrile與2.5% trifluoroacetic acid的溶液最常作為MALDI-TOF MS基質。本研究以沙門氏菌回復突變試驗(Amestest)評估MALDI-TOF MS 基質溶液對於操作人員是否會造成危險性。試驗分成三步驟：(i)突變型沙門氏菌株的特性鑑定、(ii)試驗物質對菌株的殺傷力測定及(iii)試驗物質的致突變性測試。其中(i)及(ii)步驟為預備試驗，主要是用以提升最後致突變試驗的可信度及準確度。菌株特性鑑定的試驗結果顯示5 株突變型沙門氏菌在histidine requirement、rfa mutation、uvrB mutation 與R factor 四項特性鑑定上均符合菌株該有的性狀；試驗物質的殺傷力的測試結果指出基質對5 株突變型沙門氏菌株不具有殺傷力。因此推論菌株及試驗物質不對致突變性測試的結果造成影響，吾等進一步操作致突變性試驗，結果顯示僅有陽性對照組與陰性對照組的菌落數具有顯著性差異，且試驗組菌落數皆不大於陰性對照組菌落數的2 倍，因此可判定MALDI-TOF MS 基質溶液呈現陰性反應，即基質溶液不會造成測試細菌的基因突變，推測對於哺乳類動物也不會產生基因突變性的危害。
並列摘要
Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been applied to microbial identification for the past three decades. The matrix used in MALDI-TOF MS is usually in liquid form. Saturated α-cyano-4-hydroxycinnamic acid in 50% acetonitrile and 2.5% trifluoroacetic acid solution (CHCA) is one of liquids most commonly used as the matrix in MALDI-TOF MS. This study applied the results obtained from a Salmonella reversion mutation assay (Ames test) to evaluate whether this particular matrix could cause any hazards to laboratory personnel. We divided the Ames test into three steps: (i) characterization of Salmonella mutant strains; (ii) determination of the bactericidal activity of the test material on the test strains and (iii) mutagenicity test of the test material. Among these steps, steps (i) and (ii) were viewed as serving as a preparatory test, inasmuch as their major purpose is to promote the precision of and, therefore, confidence in the mutageni city test. The results indicated that the properties of the 5 Salmonella strains tested were in compliance with the characters of histidine requirement, rfa mutation, uvrB mutation and R factor, respectively. In addition, the test matrix was not found to have any bactericidal effects on those 5 test strains. This implied both that the tested strains themselves and the test material would not affect the results of the mutagenicity test. Finally, the mutagenicity tests were conducted and the results showed that there were significant differences in the bacterial colony counts obtained between the positive and negative controls. Also, all of the bacterial colony counts in the test groups were not more than twice as high as the counts for the negative control. This implied the negative results of the Ames test on the test material, that is, the matrix (CHCA) of the MALDI-TOF MS. This means that the matrix will not cause gene mutations in the test bacteria and thus will not cause any hazards to mammals, including human beings.