三种检测铜绿假单胞菌AmpC酶方法的评价

To Evaluate the Three Methods Used in the Examination of AmpC Enzyme of Pseudomonas aeruginosa

目的探讨一种简便易行,适用于临床微生物实验室常规开展检测AmpCβ内酰胺酶(简称AmpC酶)的方法。方法对临床分离的150株铜绿假单胞菌用表型筛选试验作AmpC酶测定,对AmpC酶阳性菌株同时进行氯唑西林双纸片协同试验、氟氯西林(FCC)双抑制剂扩散协同试验、PCR基因检测。用基因检测来评价比较三种测定方法的检出率及差异。结果表型筛选试验AmpC酶阳性37株同时进行氯唑西林双纸片协同试验、氟氯西林双抑制剂扩散协同试验、基因检测,检测出阳性株分别为15、14、11株,阳性率分别是40.54%(15/37)、37.84%(14/37)、29.73%(11/37)。表型筛选试验与后三种方法比较差异有统计学意义(P<0.01),后三种方法结果比较差异无统计学意义(P>0.05)。结论氯唑西林双纸片协同试验、氟氯西林双抑制剂扩散协同试验检测AmpC酶特异性较表型筛选试验高,且操作简便、结果可靠,适合临床实验室常规检测应用。

Objective To evaluate the suitability of using phenotype screening test, cloxacillin double-disk synergy test and flucloxacillin double dose resistance test in the detection of AmpC enzyme. Methods 150 clinical isolates of Pseudomonas aeruginosa were used in this study. PCR was used for the species identification. Results AmpC was detected in 37 isolates by phenotype screening test.The percentage of detection of AmpC by cloxacillin double-disk synergy test, flucloxacillin double dose resistance test, and genetic method was 40.54% （15/37）, 37.83% （14/37）, and 29.7% （11/37）, respectively. Results from the phenotype screening test was significantly different from the other three methods （P〈0.01）. The difference among cloxacillin double-disk synergy test, flucloxacillin double dose resistance test, and genetic method was not significant. Conclusion Cloxacillin double-disk synergy test and flucloxacillin double dose resistance test are more specific then the phenotype screening test. These two tests are easy to perform and are suitable for use in clinical microbiology laboratories