【摘要】： 目的 了解本地區(qū)臨床分離鮑曼不動桿菌的臨床分布特征及對常用的抗菌藥物的耐藥特性;檢測鮑曼不動桿菌Ⅰ類整合子和三種主動外排系統(tǒng)的分布,探討Ⅰ類整合子和主動外排系統(tǒng)在介導(dǎo)細菌多重耐藥中的作用,為多重耐藥鮑曼不動桿菌感染的臨床治療提供重要的實驗依據(jù)。 方法 瓊脂二倍稀釋法檢測β-內(nèi)酰胺類、氨基糖苷類、氟喹諾酮類、四環(huán)素類、氯霉素類、多肽類、利福霉素類等20種抗菌藥物對112株鮑曼不動桿菌臨床分離株的MIC;PCR擴增檢測AdeABC-AdeSR、AdeIJK和AdeDE三種RND主動外排系統(tǒng)的結(jié)構(gòu)和調(diào)節(jié)基因,RT-PCR初步分析外排系統(tǒng)基因的表達;PCR擴增Ⅰ類整合酶基因,對部分Ⅰ類整合酶陽性菌株進行耐藥基因盒序列分析。 結(jié)果 112株鮑曼不動桿菌臨床分離株科室分布以ICU(37.5%)和呼吸內(nèi)科(17%)為主,標(biāo)本來源絕大部分為痰液(78.6%)。藥敏結(jié)果顯示鮑曼不動桿菌對IMP和MEM耐藥率分別為0.9%和1.8%,對CSL的耐藥率為37.2%,對其他抗菌藥物的耐藥率均大于60%,多重耐藥率為76.8%(86/112),但對PB和MIN均敏感。75.9%的菌株同時檢出adeABC-adeSR和adeIJK主動外排基因,6.3%僅檢出adeIJK,8%僅檢出adeE。同時檢出adeABC-adeSR和adeIJK的菌株耐藥率較高。使用RT-PCR在相對敏感株檢測到adeA和adeI,而adeE未擴出。Ⅰ類整合子陽性檢測率為80.4%,Ⅰ類整合子陽性株對13種抗菌藥物的耐藥率明顯高于Ⅰ類整合子陰性株;其多重耐藥率(90%)明顯高于Ⅰ類整合子陰性菌株(22.7%)。對部分Ⅰ類整合子陽性株進行整合子可變區(qū)擴增得到的片段均在2000bp左右,隨機選擇5個PCR產(chǎn)物進行測序分析,結(jié)果整合子可變區(qū)均含有aacA4, catB8和aadA1三個耐藥基因。 結(jié)論 1、本地區(qū)鮑曼不動桿菌臨床分離株多重耐藥情況嚴重,碳青霉烯類、PB和MIN是治療多重耐藥鮑曼不動桿菌感染的有效藥物。 2、adeABC和adeIJK在鮑曼不動桿菌臨床分離株有較高檢出率。adeABC主要存在于多重耐藥株,而adeIJK普遍存在于鮑曼不動桿菌。 3、Ⅰ類整合子在本地區(qū)鮑曼不動桿菌臨床分離株的檢出率較高,且Ⅰ類整合子陽性菌株大部分為多重耐藥株。 4、Ⅰ類整合子和AdeABC主動外排系統(tǒng)在鮑曼不動桿菌多重耐藥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，

本文編號：2321046