Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (CAS) genes make up bacteria's adaptive immune system against bacteriophages. In this study, 675 isolates of the Lactiplantibacillus plantarum species were analyzed in terms of diversity, occurrence, and evolution of the CRISPR-Cas system. This study explored the presence and diversity of CRISPR-Cas systems, which act as adaptive defense mechanisms against phages, in 671 L. plantarum strains. The investigation includes a detailed examination of the structural variations, phylogenetic relationships, and diversity of CRISPR-Cas systems in L. plantarum. Moreover, targeting phages and plasmid diversity and phylogeny relationships between the predicted systems were dissected. The analysis reveals that 143 strains harbor confirmed CRISPR-Cas systems, with subtype II-A being predominant. Results also revealed that the predominant CRISPR-Cas system subtypes in L. plantarum strains were II-A and I-E. Notably, approximately 22% of the isolates with verified and complete CRISPR systems exhibited the coexistence of both subtypes II-A and I-E within their genomes. Additionally, the identified systems displayed a potential for targeting Lactobacillus phages. In conclusion, current findings offer a perspective on the prevalence and evolution of the CRISPR-Cas system in L. plantarum, contributing novel insights to the expanding field of CRISPR-Cas systems within lactobacillus strains. Moreover, this knowledge lays a foundation for future applied studies in this field.
