鲍曼不动杆菌耐药性及其多重耐药机制研究
发布时间：2018-11-09 17:07
【摘要】： 目的 了解本地区临床分离鲍曼不动杆菌的临床分布特征及对常用的抗菌药物的耐药特性;检测鲍曼不动杆菌Ⅰ类整合子和三种主动外排系统的分布,探讨Ⅰ类整合子和主动外排系统在介导细菌多重耐药中的作用,为多重耐药鲍曼不动杆菌感染的临床治疗提供重要的实验依据。 方法 琼脂二倍稀释法检测β-内酰胺类、氨基糖苷类、氟喹诺酮类、四环素类、氯霉素类、多肽类、利福霉素类等20种抗菌药物对112株鲍曼不动杆菌临床分离株的MIC;PCR扩增检测AdeABC-AdeSR、AdeIJK和AdeDE三种RND主动外排系统的结构和调节基因,RT-PCR初步分析外排系统基因的表达;PCR扩增Ⅰ类整合酶基因,对部分Ⅰ类整合酶阳性菌株进行耐药基因盒序列分析。 结果 112株鲍曼不动杆菌临床分离株科室分布以ICU(37.5%)和呼吸内科(17%)为主,标本来源绝大部分为痰液(78.6%)。药敏结果显示鲍曼不动杆菌对IMP和MEM耐药率分别为0.9%和1.8%,对CSL的耐药率为37.2%,对其他抗菌药物的耐药率均大于60%,多重耐药率为76.8%(86/112),但对PB和MIN均敏感。75.9%的菌株同时检出adeABC-adeSR和adeIJK主动外排基因,6.3%仅检出adeIJK,8%仅检出adeE。同时检出adeABC-adeSR和adeIJK的菌株耐药率较高。使用RT-PCR在相对敏感株检测到adeA和adeI,而adeE未扩出。Ⅰ类整合子阳性检测率为80.4%,Ⅰ类整合子阳性株对13种抗菌药物的耐药率明显高于Ⅰ类整合子阴性株;其多重耐药率(90%)明显高于Ⅰ类整合子阴性菌株(22.7%)。对部分Ⅰ类整合子阳性株进行整合子可变区扩增得到的片段均在2000bp左右,随机选择5个PCR产物进行测序分析,结果整合子可变区均含有aacA4, catB8和aadA1三个耐药基因。 结论 1、本地区鲍曼不动杆菌临床分离株多重耐药情况严重,碳青霉烯类、PB和MIN是治疗多重耐药鲍曼不动杆菌感染的有效药物。 2、adeABC和adeIJK在鲍曼不动杆菌临床分离株有较高检出率。adeABC主要存在于多重耐药株,而adeIJK普遍存在于鲍曼不动杆菌。 3、Ⅰ类整合子在本地区鲍曼不动杆菌临床分离株的检出率较高,且Ⅰ类整合子阳性菌株大部分为多重耐药株。 4、Ⅰ类整合子和AdeABC主动外排系统在鲍曼不动杆菌多重耐药性的形成中起重要作用。
[Abstract]:Objective to investigate the clinical distribution of Acinetobacter baumannii and its resistance to common antimicrobial agents. To detect the distribution of class I integron and three active efflux systems of Acinetobacter baumannii, and to explore the role of class I integron and active efflux system in mediating multidrug resistance of bacteria. To provide an important experimental basis for the clinical treatment of multidrug resistant Acinetobacter baumannii infection. Methods Agar double dilution assay was used to detect MIC; of 20 antimicrobial agents, including 尾 -lactams, aminoglycosides, fluoroquinolones, tetracyclines, chloramphenicol, polypeptides and rifamycin, against 112 clinical isolates of Acinetobacter baumannii. PCR amplification was used to detect the structure and regulatory genes of three kinds of RND active efflux systems, AdeABC-AdeSR,AdeIJK and AdeDE, and RT-PCR was used to analyze the gene expression of the efflux system. Class I integrase gene was amplified by PCR. Results the clinical isolates of Acinetobacter baumannii were mainly distributed in ICU (37.5%) and Department of Respiratory Medicine (17%). Most of the samples were from sputum (78.6%). The results showed that the resistance rates of Acinetobacter baumannii to IMP and MEM were 0.9% and 1.8%, to CSL were 37.2%, and to other antimicrobial agents were higher than 60%, the multidrug resistance rate was 76.8% (86 / 112). However, 75.9% of the strains were sensitive to both PB and MIN. 75.9% of the strains detected adeABC-adeSR and adeIJK active efflux genes at the same time, while 6.3% detected only adeIJK,8% and only adeE.. The resistant rate of adeABC-adeSR and adeIJK strains was higher than that of other strains. AdeA and adeI, were detected in relatively sensitive strains by RT-PCR, but adeE was not detected. The positive rate of class 鈪，
本文编号：2321046
[Abstract]:Objective to investigate the clinical distribution of Acinetobacter baumannii and its resistance to common antimicrobial agents. To detect the distribution of class I integron and three active efflux systems of Acinetobacter baumannii, and to explore the role of class I integron and active efflux system in mediating multidrug resistance of bacteria. To provide an important experimental basis for the clinical treatment of multidrug resistant Acinetobacter baumannii infection. Methods Agar double dilution assay was used to detect MIC; of 20 antimicrobial agents, including 尾 -lactams, aminoglycosides, fluoroquinolones, tetracyclines, chloramphenicol, polypeptides and rifamycin, against 112 clinical isolates of Acinetobacter baumannii. PCR amplification was used to detect the structure and regulatory genes of three kinds of RND active efflux systems, AdeABC-AdeSR,AdeIJK and AdeDE, and RT-PCR was used to analyze the gene expression of the efflux system. Class I integrase gene was amplified by PCR. Results the clinical isolates of Acinetobacter baumannii were mainly distributed in ICU (37.5%) and Department of Respiratory Medicine (17%). Most of the samples were from sputum (78.6%). The results showed that the resistance rates of Acinetobacter baumannii to IMP and MEM were 0.9% and 1.8%, to CSL were 37.2%, and to other antimicrobial agents were higher than 60%, the multidrug resistance rate was 76.8% (86 / 112). However, 75.9% of the strains were sensitive to both PB and MIN. 75.9% of the strains detected adeABC-adeSR and adeIJK active efflux genes at the same time, while 6.3% detected only adeIJK,8% and only adeE.. The resistant rate of adeABC-adeSR and adeIJK strains was higher than that of other strains. AdeA and adeI, were detected in relatively sensitive strains by RT-PCR, but adeE was not detected. The positive rate of class 鈪，
本文编号：2321046
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