Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems are one of the factors which can contribute to limiting the development and evolution of antibiotic resistance in bacteria. There are three genomic loci of CRISPR-Cas in Enterococcus faecalis. In this study, we aimed to assess correlation of the CRISPR-Cas system distribution with the acquisition of antibiotic resistance among E. faecalis isolates. A total of 151 isolates of E. faecalis were collected from urinary tract infections (UTI) and dental-root canal (DRC). All isolates were screened for phenotypic antibiotic resistance. In addition, antibiotic resistance genes and CRISPR loci were screened by using polymerase chain reaction. Genomic background of the isolates was identified by random amplified polymorphic DNA (RAPD)-PCR. The number of multidrug-resistant E. faecalis strains were higher in UTI isolates than in DRC isolates. RAPD-PCR confirmed that genomic background was diverse in UTI and DRC isolates used in this study. CRISPR loci were highly accumulated in gentamycin-, teicoplanin-, erythromycin-, and tetracycline-susceptible strains. In concordance with drug susceptibility, smaller number of CRISPR loci were identified in vanA, tetM, ermB, aac6’-aph(2”), aadE, and ant(6) positive strains. These data indicate a negative correlation between CRISPR-cas loci and antibiotic resistance, as well as, carriage of antibiotic resistant genes in both of UTI and DRC isolates.

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CRISPR-Cas系统对粪肠球菌抗生素耐药模式的作用

成簇的规则间隔短回文重复 (CRISPR)-Cas 系统是有助于限制细菌抗生素耐药性发展和进化的因素之一。CRISPR-Cas在粪肠球菌中有3个基因组位点。在本研究中，我们旨在评估 CRISPR-Cas 系统分布与粪肠球菌分离株中抗生素耐药性的获得之间的相关性。从尿路感染 (UTI) 和牙根管 (DRC) 中收集了总共 151 株粪肠球菌。筛选所有分离株的表型抗生素抗性。此外，还通过聚合酶链反应筛选了抗生素抗性基因和 CRISPR 基因座。通过随机扩增多态性 DNA (RAPD)-PCR 鉴定分离物的基因组背景。E.多重耐药菌数 UTI 分离株中的粪肠球菌菌株高于 DRC 分离株。RAPD-PCR 证实，本研究中使用的 UTI 和 DRC 分离株的基因组背景是不同的。CRISPR 基因座在庆大霉素、替考拉宁、红霉素和四环素敏感菌株中高度积累。与药物敏感性一致，在 vanA、tetM、ermB、aac6'-aph(2”)、aadE 和 ant(6) 阳性菌株中发现了较少数量的 CRISPR 基因座。这些数据表明 CRISPR-cas 基因座与抗生素抗性以及 UTI 和 DRC 分离株中抗生素抗性基因的携带之间呈负相关。红霉素和四环素敏感菌株。与药物敏感性一致，在 vanA、tetM、ermB、aac6'-aph(2”)、aadE 和 ant(6) 阳性菌株中发现了较少数量的 CRISPR 基因座。这些数据表明 CRISPR-cas 基因座与抗生素抗性以及 UTI 和 DRC 分离株中抗生素抗性基因的携带之间呈负相关。红霉素和四环素敏感菌株。与药物敏感性一致，在 vanA、tetM、ermB、aac6'-aph(2”)、aadE 和 ant(6) 阳性菌株中发现了较少数量的 CRISPR 基因座。这些数据表明 CRISPR-cas 基因座与抗生素抗性以及 UTI 和 DRC 分离株中抗生素抗性基因的携带之间呈负相关。