非发酵菌碳青霉烯酶检测及产酶菌株可移动遗传元件研究  

Detection of carbapenemases produced by non-fermenting bacteria and mobile genetic elements in enzyme-producing strains

作　　者：谷秀梅[1] 杨敏[2] 刘文恩[1] 彭婉婵[1] 李艳明[1] 李虹玲[1] 李艳华[1] 陈伟[1] 

机构地区：[1]中南大学湘雅医院检验科,湖南长沙410008 [2]中南大学湘雅医学院医学检验系,湖南长沙410013

出　　处：《中华医院感染学杂志》2013年第18期4341-4344,共4页Chinese Journal of Nosocomiology

基　　金：湖南省教育厅基金课题(湘教通[2012]594)

摘　　要：目的调查临床分离碳青霉烯类不敏感非发酵菌产碳青霉烯酶的情况,探讨产酶菌株可移动遗传元件分布,以了解产酶菌株分子流行病学特点及耐药机制。方法对某院2011年10月-2012年3月临床各类标本中非重复碳青霉烯类不敏感非发酵菌进行细菌培养、鉴定及药敏试验;采用两种改良Hodge试验进行碳青霉烯酶表型确证;聚合酶链式反应(PCR)检测主要碳青霉烯酶基因;对碳青霉烯酶基因扩增阳性菌株进行可移动遗传元件如整合子、转座子记、插入序列及接合性质粒等遗传标记的PCR扩增。结果分离的82株碳青霉烯类不敏感非发酵菌,包括27株铜绿假单胞菌和55株鲍氏不动杆菌,对多数抗菌药物耐药严重,耐药率大多>60.0%,而对阿米卡星和头孢哌酮/舒巴坦耐药率最低;采用大肠埃希菌ATCC 25922作为指示菌株的改良Hodge试验阳性菌株37株,不确定结果7株;采用肺炎克雷伯菌ATCC700603作为指示菌株的改良Hodge试验阳性菌株14株,不确定结果2株;1株铜绿假单胞菌携带VIM-2型基因,11株鲍氏不动杆菌携带blaOXA-23基因,这12株菌每株至少检出3种可移动遗传元件,最多检出5种可移动遗传元件,其中大部分受试菌携带4种可移动遗传元件,其他碳青霉烯酶基因未检出。结论某院碳青霉烯类不敏感非发酵菌以鲍氏不动杆菌为主,大部分为多药耐药菌株,仅对头孢哌酮/舒巴坦和阿米卡星较敏感,主要耐药机制为携带碳青霉烯酶基因blaOXA-23和blaVIM-2,且这些菌株易携带多种可移动遗传元件。OBJECTIVE To investigate the drug resistance and prevalence of carbapenemases in non-fermenting clinical isolates and study the distribution of mobile genetic elements in carbapenemase-producing isolates so as to study their molecular epidemiology and drug resistance mechanisms. METHODS From Oct 2011 to Mar 2012, various samples of non-repetitive carbapenem-non-susceptible non-fermenting bacteria were underwent a process of germ culture, identification, and drug susceptibility testing, then the non-fermenting bacteria resistant to carbap- enems were screened by disk diffusion method. Two kinds of modified Hodge tests were conducted to detect the carbapenemase-producing isolates. The carbapenemase genes were detected by specific PCR, and the amplified products were sequenced. PCR was used to amplify 11 types of mobile genetic elements such as integron genetic marks, transposon genetic marks, insertion sequence genetic marks and coniunction p].asmid genetic marks of the carbapenemase-producing isolates. RESULTS Totally 82 non-fermenting clinical isolates, including 27 strains of P. aeruginosa and 55 strains of A. baumannii, showed serious drug resistance to antimicrobial agents （more than 60.0%） ,while showed the lowest resistance to cefprazone-sulbactam and amikacin. By using the Escherichia coli ATCC 25922 as the indicator strain, there were 37 strains with modified Hodge test showing positive and 7 unknown strains; using the Klebsiella pneurnoniae ATCC700603 as the indicator strain, there were 14 strains with modified Hodge test showing positive and 2 unknown strains, one strain of P. aeruginosa isolate carried VIM-2 earbapenemase, 11 strains of A. baumannii carried OXA-23carbapenemase. At least 3 mobile genetic elements and at most 5 elements were found in these carbapenemase-produeing isolates, and most of them were detected to carry 4 kinds of mobile genetic elements, while the other earbapenemase genes were not found. CONCLUSION The A. baumannii is the predominant species among the carbapenem-resistant n

关 键 词：碳青霉烯酶 改良HODGE试验 可移动遗传元件 非发酵菌 

分 类 号：R978.1[医药卫生—药品]