Molecular characteristics and genetic evolution analysis of CRISPR loci in Listeria monocytogenes
- Author:
DU Bo
;
WU Ying
;
CAI Nannan
;
REN Yanyan
;
XIU Min
;
LIU Wenxin
- Publication Type:Journal Article
- Keywords:
Listeria monocytogenes;
CRISPR;
repeat sequence;
spacer sequence;
phage
- From:
China Tropical Medicine
2025;25(3):343-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To detect clustered regularly interspaced short palindromic repeats (CRISPR) in Listeria monocytogenes, and analyze the structure and homology of CRISPR loci. Methods Totally 34 strains of Listeria monocytogenes isolated in our laboratory were identified, PCR amplified and sequenced. The repeat sequence structure and spacer sequence homology in CRISPR loci were analyzed by bioinformatics software. Results A total of 7 CRISPR loci were detected in 34 strains. The mutation rate of the first 2 and last 2 bases of the Repeat sequence of CRISPR loci was higher, while the mutation rate of the middle part was lower. Seven CRISPR sites form eight CRISPR structural types, among which the Repeat sequences of CRISPR1 and CRISPR2 are relatively conserved, while the Repeat sequences of CRISPR1 and CRISPR5 can form dumbbell shaped secondary structures. The number of Spacer sequences contained in each CRISPR site ranges from 2 to 15, with an average of 2.43. The 136 Spacer sequences detected were not only homologous to Listeria plasmids and bacteriophages, but also homologous to uncultured virus sequences, staphylococcal bacteriophages, and Listeria innocua. The same CRISPR genotype did not show large-scale clustering, but some strains in the same year were in the same evolutionary cluster with close genetic relationships. Conclusion The CRISPR structure of Listeria monocytogenes in this study exhibits high specificity, and its homology with bacteriophages provides a theoretical basis for the application of bacteriophages in the control and prevention of Listeria monocytogenes.
- Full text:202511191645167668515.Molecular characteristics and genetic evolution analysis of CRISPR loci in Listeria monocytogenes.pdf
