Vitek1、Vitek2和BD Phoenix系统对超广谱β-内酰胺酶的检测和评价
目的评价Vitek1、Vitek2和BDPhoenix3台微生物鉴定和药敏系统对超广谱β-内酰胺酶（ESBLs）的检测。方法收集浙江大学医学院附属第一和第二医院临床分离的67株产ESBLs大肠埃希菌和肺炎克雷伯菌，利用聚合酶链反应、克隆测序的方法明确其基因型，同时在3台自动微生物鉴定和药敏系统上进行检测和分析，并检测细菌的最低抑菌浓度（MIC）。结果67株细菌主要以产CTX-M型为主，CTX—M-14、CTX—M-22、CTX—M．24和CTX—M-54种最常见，用Vitek—AMS检出60株ESBLs（89、6％），Vitek2检出62株ESBLs（92、5％），BD Phoenix检出63株ESBLs（94．0％）。不能检测的7株菌基因型主要为SHV-12、CTX—M-14、CTX-M-22及SHV-28基因型。对其MIC的检测结果显示主要为对多种抗生素均高耐药，或者为在临界点附近。结论3台微生物鉴定和药敏系统对ESBLs的检出率均高于89％，但是对高耐药菌株或者混合有其他酶的菌株的检测有待进一步研究和改进。
Abstract:
Objective To compare the application of three automated microbiology identification and rapid susceptibility assessment systems, Vitek1, Viket2 and BD Phoenix, in detection of extended-spectrum beta-lactamases（ESBLs）. Methods The genotypes of 67 clinical isolates of ESBLs-producing E. coli and K. phneumoniae,which were collected from the 1st and 2nd Affiliated Hospital of Zhejiang University,were determined by PCR amplification and sequencing. Meanwhile,these isolates were analyzed by the three automatic microbiology identification system, and the minimum inhibitory concentration （MIC）s for antibiotics were determined. Results Majority of the 67 isolates produced CTX-M type of ESBL. Among them, CTX-M-14, CTX-M-22, CTX-M24 and CTX-M-3 were the most frequently detectable types. By using Vitek-AMS,60 isolates （89.6%）were detected to be ESBLs-producing. By using Vitek2, 62 isolates （92. 5% ） were ESBLs-producing. No SHV-12, CTX-M-14 and SHV-28 were detected by the 3 automatic systems. The results of MICs analysis indicated these isolates showed either high resistance for multiple antibiotics or around the boundary areas of MICs test. Conclusions The three automatic analysis systems are able to provide a detectable rate of more than 98% for ESBLs. However,it is needed to further improve the detection for high resistant strain or the strains carrying multiple resistant genes.
