Enterococcus faecalis

Enterococcus faecalis – formerly classified as part of the group D Streptococcus, is a Gram-positive, commensal bacterium naturally inhabiting the gastrointestinal tracts of humans. Like other species in the genus Enterococcus, E. faecalis is found in healthy humans and can be used as a probiotic. The probiotic strains such as Symbioflor1 and EF-2001 are characterized by the lack of specific genes related to drug resistance and pathogenesis. Despite its commensal role, E. faecalis is an opportunistic pathogen that can cause severe infections, especially in nosocomial (hospital) settings. Enterococcus spp. is among the leading causes of healthcare-associated infections ranging from endocarditis to urinary tract infections (UTIs). Hospital-acquired UTIs are associated with catheterization because catheters provide an ideal surface for biofilm formation, allowing E. faecalis to adhere, persist, and evade both the immune response and antibiotic treatment. E. faecalis can grow in extreme environments due to its highly adaptive genome and lack of strong defense mechanisms. Its ability to easily acquire and transfer genes across species contributes to rising antibiotic resistance. E. faecalis exhibits intrinsic resistance to multiple antibiotics, including oxazolidinones, quinolones, and most β-lactams, such as cephalosporins. E.…

Enterococcus faecalis – formerly classified as part of the group D Streptococcus, is a Gram-positive, commensal bacterium naturally inhabiting the gastrointestinal tracts of humans. Like other species in the genus Enterococcus, E. faecalis is found in healthy humans and can be used as a probiotic. The probiotic strains such as Symbioflor1 and EF-2001 are characterized by the lack of specific genes related to drug resistance and pathogenesis. Despite its commensal role, E. faecalis is an opportunistic pathogen that can cause severe infections, especially in nosocomial (hospital) settings. Enterococcus spp. is among the leading causes of healthcare-associated infections ranging from endocarditis to urinary tract infections (UTIs). Hospital-acquired UTIs are associated with catheterization because catheters provide an ideal surface for biofilm formation, allowing E. faecalis to adhere, persist, and evade both the immune response and antibiotic treatment. E. faecalis can grow in extreme environments due to its highly adaptive genome and lack of strong defense mechanisms. Its ability to easily acquire and transfer genes across species contributes to rising antibiotic resistance. E. faecalis exhibits intrinsic resistance to multiple antibiotics, including oxazolidinones, quinolones, and most β-lactams, such as cephalosporins. E. faecalis has been frequently found in reinfected root canal-treated teeth, with a prevalence ranging from 30% to 90%. Re-infected root canal-treated teeth are about nine times more likely to harbor E. faecalis than cases of primary infections.

Survival and virulence factors

Endures prolonged periods of nutritional deprivation Binds to dentin and proficiently spreads into dentinal tubules via chain propagation Alters host responses Suppresses the action of lymphocytes Possesses lytic enzymes, cytolysin, aggregation substance, pheromones, and lipoteichoic acid Utilizes serum as a nutritional source Produces extracellular superoxide under selected growth conditions that can generate chromosomal instability in mammalian cells Resists intracanal medicaments (e.g. calcium hydroxide), although a study proposes elimination from root canals after using a mixture of a tetracycline isomer, an acid, and a detergent Maintains pH homeostasis Properties of dentin lessen the effect of calcium hydroxide Competes with other cells Forms a biofilm Activates the host protease plasminogen in a fashion that increases local tissue destruction

DNA repair

In human blood, E. faecalis is subjected to conditions that damage its DNA. This damage can be tolerated by the use of DNA repair processes. This damage tolerance depends, in part, on the two protein complex RexAB, encoded by the E. faecalis genome, that is employed in the recombinational repair of DNA double-strand breaks.

Biofilm formation

The ability of E. faecalis to form biofilms contributes to its capacity to survive in extreme environments. This facilitates its involvement in persistent bacterial infection, particularly multidrug-resistant strains. Biofilm formation in E. faecalis is associated with DNA release, and such release has emerged as a fundamental aspect of biofilm formation. Conjugative plasmid DNA transfer in E. faecalis is enhanced by the release of peptide sex pheromones.

Genome structure

The E. faecalis genome consists of 3.22 million base pairs and 3,113 protein-coding genes.

Treatment research

Glutamate racemase, hydroxymethylglutaryl-CoA synthase, diphosphomevalonate decarboxylase, topoisomerase DNA gyrase B, D-alanine—D-serine ligase, alanine racemase, phosphate acetyltransferase, NADH peroxidase, Phosphopantetheine adenylyltransferase (PPAT), acyl carrier protein, 3‐Dehydroquinate dehydratase and Deoxynucleotide triphosphate triphosphohydrolase are all potential molecules that may be used for treating EF infections. Bacillus haynesii CD223 and Advenella mimigardefordensis SM421 can inhibit the growth of Enterococcus faecalis. Type strain of Enterococcus faecalis at BacDive – the Bacterial Diversity Metadatabase

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