CAJ | 학술논문

目的检测2011年江苏省分离的福氏志贺菌的耐药性和分子同源性,并分析整合子介导其耐药的机制.方法连续收集2011年1至12月江苏省8个城市72株福氏志贺菌.采用纸片扩散法检测菌株对抗菌药物的敏感性,采用脉冲场凝胶电泳(PFGE)进行分子同源性检测,PCR-限制性片段长度多态性(RFLP)进行整合子检测及分类,联合RFLP和DNA测序技术分析整合子携带的耐药基因.采用Fisher精确概率法对Ⅰ类整合子阳性和阴性菌株耐药情况进行比较.结果 72株福氏志贺菌对临床常用药物的耐药水平较高,对氨苄西林、萘啶酸和四环素的耐药率高达80.0％以上.菌株血清型以2a(31,43.1％)、1a(16,22.2％)和2b(15,20.8％)为主.PFGE聚类分析结果显示,72株福氏志贺菌中有18种为具有同源性的克隆,涉及47株菌,11种克隆在同一城市内传播,7种克隆在两个不同的城市传播.Ⅰ类、Ⅱ类和非典型Ⅰ类整合子广泛分布于福氏志贺菌中,检出率分别为77.8％(56/72),86.1％ (62/72)和90.3％ (65/72),未检测到Ⅲ类整合子.DNA测序显示Ⅰ类整合子中携带dfrA1-aadA1和aacA4-cmlA1基因盒,Ⅱ类和非典型Ⅰ类整合子可变区分别携带基因盒dfrA1-sat1-aadA1和bla oxa-30-aadA1.Ⅰ类整合子阳性组福氏志贺菌对氨苄西林、阿莫西林/克拉维酸、庆大霉素、萘啶酸、诺氟沙星、四环素和复方磺胺甲噁唑这7种抗菌药物的耐药率明显高于Ⅰ类整合子阴性组(P＜0.01).结论 2011年江苏省福氏志贺菌耐药严重,整合子在福氏志贺菌中广泛存在,并参与多重耐药的形成过程.
목적 검측2011년강소성분리적복씨지하균적내약성화분자동원성,병분석정합자개도기내약적궤제.방법 련속수집2011년1지12월강소성8개성시72주복씨지하균.채용지편확산법검측균주대항균약물적민감성,채용맥충장응효전영(PFGE)진행분자동원성검측,PCR-한제성편단장도다태성(RFLP)진행정합자검측급분류,연합RFLP화DNA측서기술분석정합자휴대적내약기인.채용Fisher정학개솔법대Ⅰ류정합자양성화음성균주내약정황진행비교.결과 72주복씨지하균대림상상용약물적내약수평교고,대안변서림、내정산화사배소적내약솔고체80.0％이상.균주혈청형이2a(31,43.1％)、1a(16,22.2％)화2b(15,20.8％)위주.PFGE취류분석결과현시,72주복씨지하균중유18충위구유동원성적극륭,섭급47주균,11충극륭재동일성시내전파,7충극륭재량개불동적성시전파.Ⅰ류、Ⅱ류화비전형Ⅰ류정합자엄범분포우복씨지하균중,검출솔분별위77.8％(56/72),86.1％ (62/72)화90.3％ (65/72),미검측도Ⅲ류정합자.DNA측서현시Ⅰ류정합자중휴대dfrA1-aadA1화aacA4-cmlA1기인합,Ⅱ류화비전형Ⅰ류정합자가변구분별휴대기인합dfrA1-sat1-aadA1화bla oxa-30-aadA1.Ⅰ류정합자양성조복씨지하균대안변서림、아막서림/극랍유산、경대매소、내정산、낙불사성、사배소화복방광알갑오서저7충항균약물적내약솔명현고우Ⅰ류정합자음성조(P＜0.01).결론 2011년강소성복씨지하균내약엄중,정합자재복씨지하균중엄범존재,병삼여다중내약적형성과정.
Objective To investigate the drug resistance and molecular homology of Shigella flexneri strains isolated from Jiangsu in 2011,and to study the mechanism of drug-resistance mediated by integrons.Methods A total of 72 strains of Shigella flexneri isolated from 8 cities in Jiangsu province during January and December 2011 were collected.The antibiotic susceptibility was tested by disk diffusion method.The molecular homology was analyzed by pulsed field gel electrophoresis (PFGE).The classification of integrons was performed by analyzing the positive PCR products using restriction fragment length polymorphism (RFLP).RFLP and DNA sequencing were used to analyze the resistance genes in integrons.Differences in drug resistance between class Ⅰ positive and negative strains were compared with Fisher exact test.Results Shigella flexneri strains were highly resistant to commonly used antibacterial agents in clinic service.Above 80.0％ strains were resistant to ampicillin,nalidixic acid and tetracycline.Shigella flexneri type 2a (31,43.1％),la (16,2.2％) and 2b (15,20.8％) were the predominant serotypes.PFGE analysis showed that there were 18 clones involved in 47 strains,in which 11 prevalent within the same city,7 prevalent in two different cities.Class Ⅰ,class Ⅱ and the atypical class Ⅰ integrons were positive in 77.8％ (56/72),86.1％ (62/72) and 90.3％ (65/72) strains,respectively,and no class Ⅲ integron was detected.Class Ⅰ integron-associated gene cassettes aacA4-cmlA1 and dfrA1aadA1DNA,class Ⅱ integron-associated gene cassette dfrA1-sat1-aadA1,and atypical class Ⅰ integronassociated gene cassette blaoxa-30-aadA1 were identified by DNA sequencing.Drug resistance rates to ampicillin,amoxicillin/clavulanate,gentamicin,nalidixic acid,norfloxacin,tetracycline and sulfamethoxazole in class Ⅰ positive strains were comparatively higher than those in class Ⅰ negative strains (P ＜ 0.01).Conclusions Shigella flexneri isolates from Jiangsu province in 2011 are highly resistant to commonly used antibacterial agents.Integrons are widely distributed and mediate the multi-drug resistance of these isolates.