摘要
目的了解某医院临床产超广谱β-内酰胺酶(ESBLs)细菌的耐药性与基因型,比较两种方法对ESBLs表型检测的效果。方法随机收集100株ESBLs阳性菌株(初筛试验阳性)为实验组,30株ESBLs阴性菌株(初筛试验阴性)为对照组。经Vitek2Compact自动化系统鉴定细菌,纸片扩散法进行药敏试验;采用改良Hodge试验检测耐碳青霉烯类药物菌株;美国临床实验室标准化研究所(CLSI)推荐的ESBLs表型确证试验和利用3-氨基苯酚硼酸改良的ESBLs表型确证试验进行表型检测;同时用聚合酶链反应(PCR)检测全部菌株的ESBLs基因。结果 ESBLs初筛试验阳性菌株均耐头孢噻肟,但对碳青霉烯类药物仍敏感;2株耐碳青霉烯类药物的菌株,改良Hodge试验阳性。ESBLs基因检出率为84.00%,基因型以SHV和CTX-M型为主。以PCR检测ESBLs基因结果为金标准,ESBLs表型确证试验和改良ESBLs表型确证试验的灵敏度、特异性、阴性预期值、阳性预期值分别为72.61%、100.00%、100.00%、66.67%和98.81%、100.00%、100.00%、97.87%,两种方法比较,差异有统计学意义(χ2=7.53,P=0.006)。结论 ESBLs初筛试验阳性菌株对碳青霉烯类药物具有较高的敏感性。利用3-氨基苯酚硼酸改良的ESBLs表型确证试验检测ESBLs表型,效果更好。
ObjectiveTo investigate antimicrobial resistance and genotypes of extendedspectrum β-lactamases （ESBLs）-producing strains isolated from clinic in a hospital, and to establish an effective method to analyze ESBL phenotypes.MethodsOne hundred ESBL positive isolates （initial screen test was positive） were randomly selected as experimental group, and 30 ESBL negative isolates （initial screen test was negative） was as control group. All strains were identified by Vitek2 Compact automatic system,and antimicrobial susceptibility test was performed by KirbyBauer disc diffusion method; Carbapenemresistant isolates were detected by modified Hodge test; β-lactamase phenotypes were detected by both ESBL phenotypic confirmatory test recommended by Clinical Laboratory Standard Institute（CLSI） and modified ESBL confirmatory test incorporating 3aminophenylboronic acid; ESBL genes of all isolates were detected by PCR and DNA sequencing. ResultsESBL screen positive isolates were all resistant to cefotaxime, but susceptible to carbapenems; the modified Hodge tests were positive in two carbapenemresistant isolates. The detection rate of ESBL genes was 84.00%, the dominant genes were SHV and CTXM type. PCR detection for ESBL genes was regarded as a golden standard,and the sensitivity,specificity,negative predictive value, as well as positive predictive value of ESBL phenotype confirmatory test and modified ESBL phenotype confirmatory test was 72.61%, 100.00%, 100.00%, 66.67% and 98.81%,100.00%,100.00%, 97.87% respectively, the difference was significant （χ2=7.53, P=0.006）. ConclusionESBL screen test positive isolates still have a high susceptible rate to carbapenems. ESBL phenotypes can be effectively detected by modified ESBL confirmatory test incorporating 3aminophenylboronic acid.
出处
《中国感染控制杂志》
CAS
2012年第5期336-340,共5页
Chinese Journal of Infection Control
基金
上海市浦东新区卫生局卫生科技发展专项基金资助(PW2011A-22)
关键词
超广谱Β-内酰胺酶
表型试验
耐药基因
抗药性
微生物
微生物敏感性试验
实验室技术和方法
extended-spectrumβ-lactamase
phenotypic test
drug-resistant gene
drug resistance, microbial
antimicrobial susceptibility testing
laboratory technique and method
作者简介
严育忠（1977-），男（汉族），上海市人，主管技师，主要从事临床微生物检验及细菌耐药性研究。
[通讯作者]陆燕春E-mail：huhua021@126．com
