上海交通大学学报（医学版）

›› 2012, Vol. 32 ›› Issue (7): 866-.doi: 10.3969/j.issn.1674-8115.2012.07.010

• 论著（基础研究） • 上一篇    下一篇

鲍曼不动杆菌主动外排系统和NDM-1基因分布特征及与耐药表型的关系

李永丽, 应春妹   

  1. 上海交通大学 医学院附属仁济医院检验科, 上海 200127
  • 出版日期:2012-07-28 发布日期:2012-08-17
  • 通讯作者: 应春妹, 电子信箱: ycmzh@yahoo.com.cn。
  • 作者简介:李永丽（1987—）, 女, 硕士生；电子信箱: liyongliweifang@126.com。
  • 基金资助:

    上海市自然科学基金（11ZR1421200）

Resistance phenotype in relation to distribution of active efflux system gene and NDM-1 gene in Acinetobacter baumannii clinical isolates

LI Yong-li, YING Chun-mei   

  1. Department of Clinical Laboratory, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200127, China
  • Online:2012-07-28 Published:2012-08-17
  • Supported by:

    Natural Science Foundation of Shanghai, 11ZR1421200

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摘要：

目的 了解鲍曼不动杆菌主动外排系统(外排泵)基因和新德里金属β-内酰胺酶1（NDM-1）基因的分布情况，并分析其与细菌耐药表型的关系。方法 采用琼脂二倍稀释法检测13种抗生素对81株鲍曼不动杆菌临床分离株的最低抑菌浓度（MICs），根据外排泵抑制剂PAβN处理前后MICs的变化判定外排泵表型。利用PCR扩增技术检测外排泵基因adeABC、adeIJK和adeFGH以及NDM-1基因blaNDM-1在临床分离株中的分布特征，根据外排泵基因的检出情况将临床分离株进行分组并比较耐药率。结果 81株鲍曼不动杆菌对临床常用的13种抗生素普遍耐药，43株（53%）外排泵表型试验阳性，对米诺环素的耐药率最低（30.9%），其次为亚胺培南，对其余抗生素的耐药率均超过60%，对头孢西丁和复方新诺明的耐药率较高，分别为97.5%和93.8%。在AdeABC外排泵基因阳性的菌株中，adeB、adeS和adeR的检出率分别为78%、78%和74%；在AdeIJK和AdeFGH外排泵基因中，adeJ、adeL、adeF、adeG和adeH的检出率均>90%；外排泵基因adeB、adeJ和adeG全部阳性的60株鲍曼不动杆菌的多重耐药最为严重，耐药基因阳性组的耐药率明显高于相对基因阴性组。32株鲍曼不动杆菌被检测出携带blaNDM-1基因。结论 本地区鲍曼不动杆菌临床分离株多重耐药情况严重，存在blaNDM-1基因的克隆传播。AdeABC、AdeIJK和adeFGH外排泵基因在鲍曼不动杆菌临床分离株中的检出率较高。主动外排系统和NDM-1在鲍曼不动杆菌多重耐药性的形成中起重要作用。

关键词: 鲍曼不动杆菌, 主动外排系统, 耐药表型

Abstract:

Objective To investigate the relationship between resistance phenotype and distribution of active efflux system (efflux pump) genes as well as New Delhi metallo-β-lactamase (NDM-1) in Acinetobacter baumannii (A.baumannii). Methods The minimal inhibitory concentrations (MICs) of 13 antimicrobial agents against 81 A.baumannii clinical isolates were determined by agar dilution method. The phenotype of efflux pump was determined by the changes of MICs after treatment with efflux pump inhibitor PAβN. The distribution of efflux pump genes adeABC, adeIJK and adeFGH and NDM-1 gene blaNDM-1 in clinical isolates was detected by PCR, the clinical isolates were grouped according to the detection findings of efflux pump genes, and the resistance rates were compared among groups. Results Eighty-one A.baumannii clinical isolates were resistant to 13 common antimicrobial agents. There were active efflux pump in 43(53%) clinical isolated strains. The resistance rate was lowest (30.9%) to minocycline and second lowest to imipenem, and those to all the others were over 60%. The resstance rates to cefoxitin and co-trimoxazole were 97.5％and 93.8％ respectively, which were relatively higher. In clinical isolates with positive AdeABC efflux pump genes, the detection rates of adeB, adeS and adeR were 78%, 78%, 74% respectively. In AdeJ and AdeFGH efflux pump genes, the detection rates of adeJ, adeL, adeF, adeG and adeH were all over 90%. The multi-drug resistance of the 60 isolates with positive efflux pump genes adeB, adeJ and adeG were most serious, and the resistance rates of gene-positive groups were significantly higher than gene-negative groups. In addition, 32 A.baumannii clinical isolates were detected to carry blaNDM-1 gene. Conclusion The multi-drug resistance of A.baumannii clinical isolates in the region is serious, and there exists clonal spread of blaNDM-1 gene. The detection rates of efflux pump genes AdeABC, AdeIJK and AdeFGH in A.baumannii clinical isolates are relatively higher. Active efflux pump system and NDM-1 play an important role in the multi-drug resistance of A.baumannii.

Key words: Acinetobacter baumannii, active efflux system, resistance phenotype