title: [Detection of CRISPR and its relationship to drug resistance in Shigella].
abstract: OBJECTIVE
  To detect clustered regularly interspaced short palindromic repeats (CRISPR) in Shigella, and to analyze its relationship to drug resistance.
  
  
  METHODS
  Four pairs of primers were used for the detection of convincing CRISPR structures CRISPR-S2 and CRISPR-S4, questionable CRISPR structures CRISPR-S1 and CRISPR-S3 in 60 Shigella strains. All primers were designed using sequences in CRISPR database. CRISPR Finder was used to analyze CRISPR and susceptibilities of Shigella strains were tested by agar diffusion method. Furthermore, we analyzed the relationship between drug resistance and CRISPR-S4.
  
  
  RESULTS
  The positive rate of convincing CRISPR structures was 95%. The four CRISPR loci formed 12 spectral patterns (A-L), all of which contained convincing CRISPR structures except type K. We found one new repeat and 12 new spacers. The multi-drug resistance rate was 53. 33% . We found no significant difference between CRISPR-S4 and drug resistant. However, the repeat sequence of CRISPR-S4 in multi- or TE-resistance strains was mainly R4.1 with AC deletions in the 3' end, and the spacer sequences of CRISPR-S4 in multi-drug resistance strains were mainly Sp5.1, Sp6.1 and Sp7.
  
  
  CONCLUSIONS
  CRISPR was common in Shigella. Variations df repeat sequences and diversities of spacer sequences might be related to drug resistance in Shigella.
authors.forename: Linlin
authors.initials: L
authors.lastname: Wang
authors.forename: Yingfang
authors.initials: Y
authors.lastname: Wang
authors.forename: Guangcai
authors.initials: G
authors.lastname: Duan
authors.forename: Zerun
authors.initials: Z
authors.lastname: Xue
authors.forename: Xiangjiao
authors.initials: X
authors.lastname: Guo
authors.forename: Pengfei
authors.initials: P
authors.lastname: Wang
authors.forename: Yuanlin
authors.initials: Y
authors.lastname: Xi
authors.forename: Haiyan
authors.initials: H
authors.lastname: Yang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D024881:Drug Resistance, Bacterial; D004405:Dysentery, Bacillary / Q000382:microbiology; D006801:Humans; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012760:Shigella / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents