Analysis of CRISPR-Cas System in Streptococcus thermophilus and Its Application

Abstract

CRISPR-Cas (Clustered regularly interspaced short palindromic repeats-CRISPR associated proteins) loci, which provide a specific immunity against exogenous elements, are hypervariable among distinct prokaryotes. Based on previous researches, this review focuses on concluding systematical genome editing protocols in Streptococcus thermophilus. Firstly, its protocols and optimized conditions in gene editing are introduced. What’s more, classification and diversity analyses of S. thermophilus CRISPR-Cas benefit the further understanding of evolution relationship among Streptococcus. Ability of its foreign segment integration and spacer source analyses also indicate a new direction of phage resistance. Above all, all of these point out its potential to be regarded as another model system other than type II CRISPR-Cas in Streptococcus pyogenes.

Comparative Genomics of Streptococcus thermophilus Support Important Traits Concerning the Evolution, Biology and Technological Properties of the Species

“…The CRISPR-Cas systems are defense mechanisms widely distributed in prokaryotes, providing acquired immunity against foreign genetic elements like viruses and plasmids (Horvath and Barrangou, 2010). This immunity mechanism has been extensively studied in S. thermophilus, providing information concerning the environmental adaptability and the anti-phage activity of this microorganism (Sapranauskas et al, 2011;Louis et al, 2017;Hao et al, 2018). In addition, in certain studies spacers within CRISPR arrays in S. thermophilus were employed for assessing diversity among strains of the species (Horvath et al, 2008;Delorme et al, 2017).…”

“…As reported previously (Horvath and Barrangou, 2010), up to four distinct CRISPR-Cas loci, i.e., CRISPR1, CRISPR2, CRISPR3, and CRISPR4 were identified in our S. thermophilus strains (Supplementary Tables S8, S9A and Figure 7). CRISPR1 and CRISPR3 both belong to Class 2/subtype II-A CRISPR-Cas systems, while CRISPR2 and CRISPR4 belong to Class 1/subtype III-A and Class 1/subtype I-E CRISPR-Cas systems, respectively (Horvath et al, 2008;Makarova et al, 2015;Hao et al, 2018). Furthermore, one putative orphan CRISPR array structure was predicted by CRISPRFinder in strains JIM 8232 and LMG 18311, characterized by the absence of adjacent Cas proteins.…”

Genome Analysis and Physiological Characterization of Four Streptococcus thermophilus Strains Isolated From Chinese Traditional Fermented Milk

“…In the last two decades, a number of S. thermophilus genomes have been published, and the whole genome information has improved the understanding of metabolic activities of this bacterium at the molecular level, including the biosynthesis of EPS and folate (Iyer et al, 2010;Cui et al, 2017;Li et al, 2018;Xiong et al, 2019), resistance to bacteriophage (Hao et al, 2018), proteolytic system (Tian et al, 2018), and carbohydrate metabolism (Prajapati et al, 2013), etc. Furthermore, the comparative genomic analysis of different S. thermophilus strains with various technological properties has advanced the development of knowledge about the relationship between genetic characters and phenotypic traits (Rasmussen et al, 2008;Vendramin et al, 2017).…”

Study the Features of 57 Confirmed CRISPR Loci in 38 Strains of Staphylococcus aureus

“…At present, bioinformatics tools can help researchers expand their knowledge in different fields without the need for laborious laboratory experiments. Based on this method, there have been some studies on the CRISPR system in several bacteria (Hidalgo-Cantabrana et al, 2017 ; Negahdaripour et al, 2017 ; Tomida et al, 2017 ; Hao et al, 2018 ). Bioinformatics Analysis of CRISPR in foodborne pathogens is crucial for assessing the potential evolution of foodborne pathogens to predict the outbreak of food borne pathogens, which is of great importance to food safety.…”