超广谱β-内酰胺酶表型检测与CTX-M型酶基因型检测的相关性分析  

Correlation Between Detection of Extended-spectrum β-lactamases Phenotype and CTX-M-enzymes Genotype

作　　者：刘文恩[1] 陈腊梅[1] 郭婧婧[1] 

机构地区：[1]中南大学湘雅医院检验科,湖南长沙410008

出　　处：《实用预防医学》2007年第2期341-343,共3页Practical Preventive Medicine

摘　　要：目的了解采用双纸片协同法进行CTX-M酶的表型检测与多重PCR法检测基因型的相关性。方法按CLSI/NCCLS所推荐的方法进行ESBLs表型确证试验,多重PCR法对ESBLs表型阳性株进一步进行CTX-M酶基因型的检测。结果233株多重耐药革兰阴性杆菌中136株ESBLs表型阳性,经多重PCR扩增证实99株携带CTX-M型ESBL,CTX-M型ESBL检出率占ESBLs72.8%(99/136)。根据多重PCR检测结果再回顾性地观察表型检测结果,发现以头孢他啶和头孢他啶/棒酸这对纸片进行试验,产CTX-M型ESBLs细菌检出数为0;以头孢噻肟纸片及头孢噻肟/棒酸这对纸片进行试验,产CTX-M型ESBLs细菌检出率72.8%(99/136),其中用上述两对纸片共同检出产CTX-M型ESBLs细菌检出率41.7%(58/136)。结论以头孢噻肟,头孢噻肟/克拉维酸这对纸片可达到有效进行CTX-M酶的表型检测的目的;用头孢噻肟,头孢噻肟/克拉维酸、头孢他啶,头孢他啶/克拉维酸这两对纸片同时进行筛检超广谱β-内酰胺酶,可有效降低ESBLs漏检率。Objective To investigate the correlation between phenotypic confirmatory by double disc test and genotype of CTX - M - enzymes detected by multiplex polymerase chain reaction （PCR）. Methods ESBLs producing isolates were confirmed by means of phenotypic confirmatory tests as recommended by the CLSI/NCCLS. Multiplex PCR was used to determine the genotype of the CTX- M enzymes. Results Of the 233 clinical isolates of multidrug resistant gram - negative bacilli, 136 ESBL - producing clinical strains were identified, 99 isolates were confirmed to possess blaOTX - M genes by multi- plex PCR. The rate of ESBLs- producing strains carrying CTX - M - type β - lactamases was 72.8%. According to the re- sults of genotype of CTX - M - enzymes, retrospective analysis of the data of phenotypic confirmatory was conducted. The results suggested that none of CTX - M - producing isolate was detected by CAZ and CAZ/Olavulanic acid; 72.8 % CTX - M- producing isolates were detected by OTX and OTX/ Olavulanic acid; 41.7 % OTX- M- producing isolates were detected by both of doubledisk methods simultaneously. Conclusions The phenotypic confirmatory tests for OTX- M enzymes can be detected only by OTX and OTX/Olavulanic acid effectively. Using both OTX, OTX/Olavulanic acid and OAZ, OAZ/Olavulanic acid simultaneously can reduce the missing rate of ESBLs.

关 键 词：CTX—M型超广谱β-内酰胺酶 ESBLs表型确证试验 多重PCR 相关性 

分 类 号：R446[医药卫生—诊断学]