Drug Applied Research Center, Tabriz University of Medical Sciences , Tabriz, I.R. Iran.
Immunology Research Center, Tabriz University of Medical Sciences , Tabriz, I.R. Iran.
Virulence. 2020 Dec;11(1):1257-1267. doi: 10.1080/21505594.2020.1809329.
is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of . Eighty-eight hospital-acquired and 73 dental-root canal isolates of were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as , and . Biofilm formation, gelatinase, and hemolysis activities were detected in 93.8%, 29.2%, and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was , which was followed by , whereas was the least identified. The presence of CRISPR1-, orphan CRISPR2, and CRISPR3- was determined in 13%, 55.3%, and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canal isolates. An inverse significant correlation was found between CRISPR- loci, and , while direct correlations were observed in the case of (among CRISPR-loci 1 and 3), , biofilm formation, and hemolysis activity. Findings, therefore, indicate that CRISPR- might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits. BHI: brain-heart infusion agar; CRISPRs: Clustered regularly interspaced short palindromic repeats; Esp: Cell wall-associated protein; ENT: ear-nose-throat; ICU: intensive care units; OD: optical densities; PCR: polymerase chain reaction; SDS: sodium dodecyl sulfate; UTI: urinary tract infection.
是人类医院获得性和危及生命感染的重要病原体之一。有几项研究表明，CRISPR 的存在与抗生素敏感性和缺乏毒力特征有关。在这项研究中，我们旨在评估与 CRISPR 元件相关的表型和基因型毒力决定因素，这些 CRISPR 元件来自牙科根管和医院获得的 分离株。在这项研究中，评估了 88 株医院获得性和 73 株牙科根管 分离株。使用 PCR 进行的基因型筛选进一步用于评估 CRISPR 元件和不同的毒力相关基因的存在，如 、 和 。生物膜形成、明胶酶和溶血活性在 93.8%、29.2%和 19.2%的分离株中检测到。最常见的毒力相关基因是 ，其次是 ，而 是最少识别的。CRISPR1-、孤儿 CRISPR2 和 CRISPR3-分别存在于 13%、55.3%和 17.4%的分离株中。CRISPR 元件在牙科根管分离株中更为普遍。CRISPR 位点与 之间存在显著的负相关，而与 之间存在直接相关，而在 CRISPR 位点 1 和 3 之间存在与 之间存在直接相关，与生物膜形成和溶血活性之间存在直接相关。因此，研究结果表明，CRISPR-可能阻止一些分离株获得某些相应的致病性因素，尽管并非全部；因此，选择压力不能影响致病特征。BHI：脑心浸液琼脂；CRISPRs：成簇的规则间隔的短回文重复序列；Esp：细胞壁相关蛋白；ENT：耳鼻喉科；ICU：重症监护病房；OD：光密度；PCR：聚合酶链反应；SDS：十二烷基硫酸钠；UTI：尿路感染。
