CRISPR-Cas systems in enterococci

Area of Science:

• Microbiology
• Genetics
• Molecular Biology

Background:

• Enterococci are common microbiota in humans and animals, prevalent in environments and healthcare settings.
• Widespread antimicrobial use drives resistance in enterococci, posing a significant public health challenge within the One Health framework.
• CRISPR-Cas systems offer prokaryotic defense against mobile genetic elements, potentially limiting antimicrobial resistance and virulence gene acquisition.

Purpose of the Study:

• To review CRISPR-Cas systems in enterococci, examining their prevalence, structure, function, and applications.
• To understand the role of CRISPR-Cas in enterococcal antimicrobial resistance and virulence.
• To explore the utility of CRISPR-Cas as a gene-editing technology in enterococci.

Main Methods:

• Literature review of studies on CRISPR-Cas systems in enterococci.
• Analysis of CRISPR system occurrence, structure (spacers, direct repeats), and organization.
• Examination of CRISPR-Cas mechanisms and applications in enterococcal gene editing.

Main Results:

• Type II-A CRISPR-Cas systems are most frequent in enterococci.
• The orphan CRISPR2 system is the most common (54.1%), particularly in Enterococcus faecalis.
• CRISPR systems exhibit variation in distribution, spacer count (1-20), spacer size (23-37 bp), and direct repeat length (25-37 bp).

Conclusions:

• CRISPR-Cas systems are present in enterococci with diverse characteristics.
• CRISPR-Cas technology offers a promising tool for targeting resistance and virulence genes in enterococci.
• Further research into CRISPR-Cas in enterococci can advance antimicrobial resistance and gene editing strategies.