摘要
目的：研究成簇规律间隔短回文重复序列（CRISPR）相关蛋白基因cas1和cas2在志贺菌中的分布，并分析cas1和cas2基因突变与细菌耐药的关系。方法采用PCR扩增196株志贺菌cas1和cas2基因。对3株志贺菌（Z23、2003135、2008113）的cas2、cas1（a）和cas1（b）基因进行测序，分析其突变与耐药之间的关系。结果196株志贺菌均检出CRISPR相关蛋白基因cas1和cas2。测序结果显示，cas2的一致性为96.44%，cas1（a）的一致性为97.61%，cas1（b）的一致性为96.97%。菌株2003135的cas1（b）基因有2个突变位点：3177129位点（C→G）及3177126位点（G→C），Z23、2008113对应位置没有突变。药敏结果显示菌株2003135的耐抗生素种类和耐抗生素数目均大于菌株Z23、2008113。结论志贺菌中CRISPR基因广泛存在。cas1（b）基因突变菌株与未突变株比较，耐药性增强。cas1（b）基因突变可能是引起耐药程度不同的原因之一。
Objective To detect the distribution of clustered regularly interspaced short palindromic repeat（CRISPR）associated protein genes cas1 and cas2 in Shigella and to understand the characteristics of CRISPR with relationship between CRISPR and related characteristics on drug resistance. Methods CRISPR associated protein genes cas1 and cas2 in Shigella were detected by PCR,with its products sequenced and compared.Results The CRISPR-associated protein genes cas1 and cas2 were found in all the 196 Shigella isolates which were isolated at different times and locations in China. Consistencies showed through related sequencing appepared as follows：cas2,cas1 （a） and cas1（b）were 96.44%,97.61%and 96.97%,respectively. There were two mutations including 3177129 site（C→G）and 3177126 site（G→C）of cas1（b）gene in 2003135 strain which were not found in the corresponding sites of Z23 and 2008113. Results showed that in terms of both susceptibility and antibiotic-resistance,strain 2003135 was stronger than Z23 and 2008113. Conclusion CRISPR system widely existed in Shigella,with the level of drug resistance in cas1（b） gene mutant strains higher than in wild strains. Cas1（b）gene mutation might be one of the reasons causing the different levels of resistance.
出处
《中华流行病学杂志》
CAS
CSCD
北大核心
2014年第5期581-584,共4页
Chinese Journal of Epidemiology
关键词
志贺菌
成簇规律间隔短回文重复序列
耐药
Shigella
Clustered regularly interspaced short palindromic repeat
Resistance
