Draft Genome Sequence of Enterococcus faecalis AS003, a Strain Possessing All Three Type II-a CRISPR Loci

Mulkerrins, Kevin B.; Lyons, Casandra; Shiaris, Michael P.

doi:10.1128/mra.01449-20

Cited by 1 publication

(1 citation statement)

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“…Studies have demonstrated a highly significant negative correlation between the presence of the CRISPR-Cas system in Enterococcus faecalis and acquired antibiotic resistance. 26 Several studies have proposed the potential of the CRISPR-Cas system to regulate bacterial virulence. However, some researchers have found no evidence by a statistical model that the CRISPR-Cas system can prevent the occurrence of HGT on the time scale of bacterial evolution.…”

Section: Introductionmentioning

confidence: 99%

Association of CRISPR-Cas System with the Antibiotic Resistance and Virulence Genes in Nosocomial Isolates of Enterococcus

Tao¹,

Chen²,

Li³

et al. 2022

IDR

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Purpose This study aimed to investigate the prevalence of the CRISPR-Cas system in nosocomial isolates of Enterococcus and their possible association with antibiotic resistance and virulence genes. Materials and Methods Identification and antimicrobial susceptibility of the microorganism were performed by the automatized VITEK 2 Compact system (bioMerieux, France). A total of 100 Enterococcus isolates were collected and identified by VITEK 2 Compact automatic microbial identification drug susceptibility analyzer. The prevalence of various CRISPR-Cas systems, antibiotic resistance genes and virulence genes were investigated by polymerase chain reaction (PCR). The prevalence of CRISPR-Cas systems associated with antibiotic resistance and virulence genes was performed by appropriate statistical tests. Results A total of 100 isolates of Enterococcus were identified and there were 62/100(62.0%) Enterococcus faecalis isolates and 38/100(38.0%) Enterococcus faecalis isolates. In total, 46 (46.0%) of 100 isolates had at least one CRISPR-Cas locus. CRISPR elements were more prevalent in Enterococcus faecalis isolates. The results of PCR demonstrated that CRISPR1-Cas, orphan CRISPR2, and CRISPR3-Cas were present in 23 (23.0%), 42 (42.0%) and 5 (5.0%) Enterococcus isolates, respectively. Compared with CRISPR-Casnegative isolates, the CRISPR-Cas positive isolates showed significant lower resistance rates against ampicillin, erythromycin, levofloxacin, tetracycline, vancomycin, gentamicin, streptomycin, and rifampicin. Presumably consistent with drug susceptibility, fewer CRISPR loci were identified in vanA, tetM, ermB, aac6’-aph(2”), aadE , and ant(6) positive isolates. There was a significant negative correlation between the CRISPR-Cas locus and the enterococcal virulence factors enterococcal surface protein ( esp ) gene. Conclusion In conclusion, the results indicated that the absence of the CRISPR-Cas system was negatively associated with some antibiotic resistance in clinical isolates of Enterococcus faecalis and Enterococcus faecium . Also, there was a negative correlation with the carriage of antibiotic resistance genes. Furthermore, CRISPR-Cas may prevent some isolates from acquiring certain virulence factors.

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Section: Introductionmentioning

confidence: 99%