铜绿假单胞菌的耐药表型与耐药基因型研究

发布时间：2019-05-17 17:12

【摘要】：铜绿假单胞菌(Pseudomonas aeruginosa,PA)是一种常见的人畜共患机会致病菌,给人畜健康带来巨大威胁。本研究自临床分离PA 51株,并对其耐药表型、耐药基因型、外毒素及动物致病性进行了检测分析,以期为临床铜绿假单胞菌病的研究提供基础数据。自河北及周边地区2011年-2014年临床发病的鸡、猪体内分离并纯化,通过形态学及PCR技术进行鉴定后,获得PA野毒51株;采用Kirby-Bauer纸片扩散法(K-B法)进行3类17种抗菌药的药物敏感性试验,结果均表现为多重耐药性;对氨基糖苷类药物链霉素、阿米卡星、卡那霉素、新霉素、庆大霉素和大观霉素的耐药率依次为84.3%、84.3%、78.4%、78.4%、54.9%和25.2%;对喹诺酮类药物氧氟沙星、恩诺沙星、盐酸左氧、加替沙星、诺氟沙星和环丙沙星的耐药率依次94.1%、82.4%、80.4%、78.4%、62.7%和25.2%;对β-内酰胺类药物头孢拉定、青霉素、头孢曲松钠、头孢噻肟、头孢哌酮钠/舒巴坦钠的耐药率依次98.0%、98.0%、70.6%、2.0%和0.0%。本文对51株PA分离株相应的抗性基因进行了PCR检测。6种氨基糖苷类耐药基因(AMEs)的检测结果显示,ant(3′′)-Ia、aac(6′)-Ib、aac(3)-IIa、aph(3′′)-Ib(str A)、aph(6′)-Id(str B)、Aph(3′)-IIa的阳性率由高到低依次为98.0%、51.0%、43.1%、41.2%、31.4%、17.6%;其中有1株为所测AMEs基因阴性,3株为6种基因全携带者;16Sr RNA甲基化酶(arm A、rmt A、rmt B)的检测结果均为阴性;喹诺酮类耐药质粒的检测阳性率由高到低依次为aac(6′)-Ib-cr(13.7%)、qnr S(9.8%)、qnr B(5.9%);对gyr A基因中的氟喹诺酮耐药决定区(Quinolone-resisitant determining region,QRDR)进行PCR检测、测序、并进行序列分析,结果仅3株QRDR基因在其编码的第83位氨基酸发生突变,即83Thr→Ile;β-内酰胺类耐药基因的阳性率由高到低依次为OXA-3(7.8%)、OXA-1(2.0%)和OXA-5(0.0%)。PCR检测结果显示51株PA分离株细胞毒性外毒素A(Pseudomonas aeruginosa exo-toxin A,ETA)的阳性率为72.5%;动物致病性回归实验证明所分离的51株PA毒株均有较强的致病力。
[Abstract]:Pseudomonas aeruginosa (Pseudomonas aeruginosa,PA) is a common zoonosis opportunity pathogen, which brings great threat to human and animal health. In this study, 51 strains of PA were isolated from clinic, and their drug resistance phenotype, drug resistance genotype, exotoxin and animal pathogenicity were detected and analyzed in order to provide basic data for the study of clinical Pseudomonas aeruginosa disease. From Hebei and its surrounding areas from 2011 to 2014, pigs were isolated and purified in vivo. 51 strains of PA wild virus were obtained by morphology and PCR. The drug sensitivity test of three kinds of 17 kinds of antibiotics was carried out by Kirby-Bauer disk diffusion method (K 鈮，

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