Wang Gang, Song Guobin, Xu Yuanhong
Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui Province, People's Republic of China.
Infect Drug Resist. 2020 Jun 23;13:1929-1935. doi: 10.2147/IDR.S253380. eCollection 2020.
is a common opportunistic pathogen and its production of extended-spectrum β-lactamases (ESBL) and carbapenemases leads to drug resistance. Clustered regularly interspaced short palindromic repeats (CRISPRs) and their associated genes (Cas) are widespread in the genome of many bacteria and are a defense mechanism against foreign invaders such as plasmids and viruses.
To investigate the prevalence of the CRISPR/Cas system in wild type strains of in the hospital and its association with drug resistance.
A total of 136 strains were collected and characterized their susceptibility to antimicrobial agents. The prevalence of CRISPR/Cas system was detected by PCR and DNA sequencing was analyzed by CRISPRFinder. The statistical analysis of the results was performed by SPSS.
We found that 50/136 (37%) isolates produced ESBL and 30/136 (22%) isolates were resistant to carbapenems. These isolates were liable to be multidrug resistant against β-lactams, quinolones, and aminoglycosides. Among the carbapenem-resistant isolates, was the main drug resistance-associated gene and different types of ESBL and AmpC genes were present. Resistance to β-lactams, quinolones, aminoglycosides, tetracyclines, and β-lactams/enzyme inhibitor were higher in absence of the CRISPR/Cas system. Eighteen spacers within the CRISPR arrays matched with the genomes of plasmids or phages, some of which carried drug resistance genes.
ESBL-producing and carbapenem-resistant are more likely to develop multidrug resistance and show an inverse correlation between drug resistance and CRISPR/Cas system. Absence of CRISPR/Cas modules allow for the acquisition of external drug resistance genes.
是一种常见的机会致病菌，其产生的超广谱β-内酰胺酶（ESBL）和碳青霉烯酶导致耐药性。成簇规律间隔短回文重复序列（CRISPRs）及其相关基因（Cas）广泛存在于许多细菌的基因组中，是抵御质粒和病毒等外来入侵者的防御机制。
调查医院内野生型菌株中CRISPR/Cas系统的流行情况及其与耐药性的关系。
共收集136株菌株，测定其对抗菌药物的敏感性。通过PCR检测CRISPR/Cas系统的流行情况，并用CRISPRFinder分析DNA序列。结果采用SPSS进行统计分析。
我们发现50/136（37%）的分离株产生ESBL，30/136（22%）的分离株对碳青霉烯类耐药。这些分离株易对β-内酰胺类、喹诺酮类和氨基糖苷类产生多重耐药。在耐碳青霉烯类分离株中，是主要的耐药相关基因，还存在不同类型的ESBL和AmpC基因。在没有CRISPR/Cas系统的情况下，对β-内酰胺类、喹诺酮类、氨基糖苷类、四环素类和β-内酰胺类/酶抑制剂的耐药性更高。CRISPR阵列中的18个间隔序列与质粒或噬菌体的基因组匹配，其中一些携带耐药基因。
产ESBL和耐碳青霉烯类的更易产生多重耐药，且耐药性与CRISPR/Cas系统呈负相关。缺乏CRISPR/Cas模块会导致获取外部耐药基因。
