化妆品中铜绿假单胞菌的酶底物快速测定法

Rapid detection of Pseudomonas aeruginosa in cosmetics with enzyme substrate technique

目的比较酶底物定量法(Pseudlert法)与标准平板计数法用于化妆品中铜绿假单胞菌检测的等效性。方法选用乳剂、霜剂、粉剂3种不同性状的检测合格的送检化妆品,用铜绿假单胞菌分别加标于3种化妆品中,用生理盐水和添加Pseudlert试剂的生理盐水进行稀释后检测,结果采用《化妆品卫生规范》(2007)中规定的化妆品菌落总数的检验方法进行计数分析。结果铜绿假单胞菌两种稀释液检测计数结果差异虽有统计学意义(P<0.01),但计数结果差异较小(扩展不确定度为2.8%),且相关性较高(r=0.99,P<0.05),依据ISO 17994—2004《水质微生物方法等效性的确定准则》,认为Pseudlert试剂对铜绿假单胞菌的生长无影响;乳剂化妆品中,铜绿假单胞菌两种稀释液检测计数结果差异无统计学意义(P>0.05);霜剂化妆品中,铜绿假单胞菌两种稀释液检测计数结果差异虽有统计学意义(P<0.01),但计数结果差异较小(扩展不确定度为7.2%),依据ISO17994—2004,认为霜剂化妆品中,Pseudlert试剂对铜绿假单胞菌的生长无影响;粉剂化妆品中,铜绿假单胞菌两种稀释液检测计数结果差异无统计学意义(P>0.05)。结论铜绿假单胞菌酶底物定量法具备快速、灵敏等优点,可以用作评价化妆品中铜绿假单胞菌污染的一种快检方法,但后续研究应加大样本量及试验重复次数并着重对两种方法最低检出限的比较研究。

Objective To compare the equivalence of enzyme substrate method and standard plate count method for Pseudomonas aeruginosa detection in cosmetics. Methods Three different traits of qualified cosmetics were selected, and mixed with Pseudomonas aeruginosa and respectively diluted with saline and Pseudlert reagent saline, and were detected and analyzed according to the method of aerobic bacterial count based on Hygienic Standard for Cosmetics（2007）. Results The results of Levene test for equality of variances indicated that the difference of count results between saline diluted solution and Pseudlert diluted solution was not significant, Pearson correlation coefficient approximately was 0.99. In emulsion cosmetics, the difference of count results between saline diluted solution and Pseudlert diluted solution was not significant. In cream cosmetics, count results（lgx） indicated that there was little variation between saline diluted solution and Pseudlert diluted solution（1.39 and 1.19）. In powder cosmetics, the difference of count results between saline diluted solution and Pseudlert diluted solution was not significant. Conclusion The enzyme substrate detection system IDEXX Pseudalert can identify Pseudomonas aeruginosa in cosmetics rapidly and specifically, and it can be used as a standard method for cosmetics safety evaluation.