■CRISPR-Cas是一种原核适应性免疫系统,可保护细菌和古细菌免受移动遗传元件(MGE)的侵害,例如噬菌体质粒,和转座子。在这项研究中,我们旨在评估CRISPR-Cas系统的患病率及其与最具挑战性的细菌病原体之一的抗生素耐药性的关联。肺炎克雷伯菌。
方法:从各种临床感染中收集了105株肺炎克雷伯菌。超广谱β-内酰胺酶(ESBLs)的表型检测和ESBL的存在,氨基糖苷修饰酶(AME),使用PCR鉴定CRISPR-Cas系统亚型基因。此外,分离株的多样性通过肠杆菌重复基因间共有(ERIC)-PCR确定。
结果:表型,41.9%(44/105)的分离株被发现是ESBL生产者。肺炎克雷伯菌I-E亚型CRISPR-Cas系统的存在与ESBL产生之间存在显著的负相关。此外,ESBL基因blaCTX-M1的频率(3%),blaCTX-M9(12.1%),blaSHV(51.5%),和blaTEM(33.3%),在具有I-E亚型CRISPR-Cas系统的分离株中,aac(3)-Iva(21.2%)和ant(2\'\')-Ia(3%)等AME基因显着降低与CRISPR阴性分离株相比。ESBL和一些AME基因的存在与I-E亚型CRISPR-Cas系统之间存在显着负相关。
结论:I-E亚型CRISPR-Cas系统的存在与抗生素耐药基因(ARGs)相关。具有I-E亚型CRISPR-Cas系统的分离株的ESBL基因和某些AME基因的频率低于CRISPR阴性分离株。
UNASSIGNED: CRISPR-Cas is a prokaryotic adaptive immune system that protects bacteria and archaea against mobile genetic elements (MGEs) such as bacteriophages plasmids, and transposons. In this study, we aimed to assess the prevalence of the CRISPR-Cas systems and their association with antibiotic resistance in one of the most challenging bacterial pathogens, Klebsiella pneumoniae.
METHODS: A total of 105 K. pneumoniae isolates were collected from various clinical infections. Extended-spectrum β-lactamases (ESBLs) phenotypically were detected and the presence of ESBL, aminoglycoside-modifying enzymes (AME), and CRISPR-Cas system subtype genes were identified using PCR. Moreover, the diversity of the isolates was determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR.
RESULTS: Phenotypically, 41.9% (44/105) of the isolates were found to be ESBL producers. A significant inverse correlation existed between the subtype I-E CRISPR-Cas system\'s presence and ESBL production in K. pneumoniae isolates. Additionally, the frequency of the ESBL genes blaCTX-M1 (3%), blaCTX-M9 (12.1%), blaSHV (51.5%), and blaTEM (33.3%), as well as some AME genes such as aac(3)-Iva (21.2%) and ant(2\'\')-Ia (3%) was significantly lower in the isolates with the subtype I-E CRISPR-Cas system in comparison to CRISPR-negative isolates. There was a significant inverse correlation between the presence of ESBL and some AME genes with subtype I-E CRISPR-Cas system.
CONCLUSIONS: The presence of the subtype I-E CRISPR-Cas system was correlated with the antibiotic-resistant gene (ARGs). The isolates with subtype I-E CRISPR-Cas system had a lower frequency of ESBL genes and some AME genes than CRISPR-negative isolates.