摘要
目的了解CLSI 2010(S20)及2009(S19)头孢他啶(CAZ)、头孢噻肟(CTX)新旧折点变化对本地区肺炎克雷伯菌药物敏感性及产超广谱β-内酰胺酶(ESBLs)菌株分布的影响。方法收集安徽医科大学第一附属医院临床分离的50株肺炎克雷伯菌;纸片扩散法测定菌株对CTX及CAZ的敏感性,CLSI表型确证试验确定产ESBLs菌株,改良三维试验检测CTX和/或CAZ耐药、非产ESBLs菌株的产酶情况。结果在S19折点下,CTX和CAZ耐药率分别为54.0%、30.0%;在S20折点下,耐药率分别为68.0%、42.0%。产ESBLs菌株总检出率为64.0%(32/50)。旧折点下,分别有81.3%、43.8%的产ESBLs菌株分布在CTX和CAZ耐药菌株中;新折点下,升高至100%、62.5%。2株对CTX和/CAZ耐药、非产ESBL菌株中,1株同时产ESBLs和AmpC酶,1株仅产AmpC酶。结论根据S20,肺炎克雷伯菌对CTX和CAZ的耐药率较S19均有所增高;并提高了耐药表型与产ESBLs菌株的一致性。产AmpC酶可影响表型确证试验对产ESBLs菌株的检出。
Objective To evaluate the influences of CLSI 2009 （S19） and 2010 （$20） breakpoints of cefotaxime （CTX） and cefiazidime （CAZ） on the antimicrobial susceptibility interpretation and distribution of extended-spectrum β-1actamases （ESBLs） producers in Klebsiella pneumonia isolates. Method Fifty K. pneumonia isolates were collected from the First Affiliated Hospital of Anhui Medical University in 2008. Antimicrobial susceptibility of those isolates were tested by disk diffusion method, and ESBLs producers were confirmed by the CLSI phenotypic confirmatory test. Susceptibility of K. pneumonia to CTX and CAZ as well as the distribution of ESBLs producers were analyzed according to the breakpoints of the S19 and S20, respectively. The modified three-dimensional extract test was used to detect the ESBLs-negative isolates with resistance to CTX and/or CAZ. Result According to the S19, the resistance rate to CTX and CAZ was 54.0% and 30.0%, respectively, while to the S20, the resistance rate was 68% and 42% , respectively. ESBLs producers were detected in 64.0% （32/50） of K. pneumonia. According to S19/S20 breakpoints, the distribution of ESBLs producers in CTX or CAZ resistant isolates was 81.3%/100.0% and 43.8%/62.5%, respectively. In ESBLs-negative producers, two were resistant to CTX and/or CAZ. One produced AmpC enzyme and ESBLs, the other only produced AmpC enzyme. Conclusion The resistance rate of CTX and CAZ increases according to new breakpoints （S20）, and the consistency of the drug resistance and ESBLs phenotype is improved. Detection rate of ESBLs producers is influenced by AmpC-producing capability of those isolates.
出处
《中国微生态学杂志》
CAS
CSCD
2012年第3期251-253,256,共4页
Chinese Journal of Microecology
基金
教育部科学研究重点项目(209059)
安徽省高等学校省级自然科学研究项目(KJ2011A180)
安徽省人社厅
卫生厅人才基金
