Enterococcus faecalis

Enterococci were first mentioned in French literature in 1899 as germs found in the gastrointestinal tract with the potential to cause significant disease (Kasper 2015).

The first pathological description is found in the same year in a patient who died of endocarditis. The causative germs were termed "Micrococcus zymogenes" and later renamed "Streptococcus faecalis" (Kasper 2015).

"Streptococcus faecalis" was described as the first species of enterococci by Andrewes and Hoder in 1906 (Darai 2009).

In 1984, the generic name "Enterococcus" was proposed by Schleifer and Kilpper- Bälz for E. faecalis and E. faecium (Darai 2009).

E. faecalis is one of the enterococci and does not normally have adverse effects on healthy individuals (Lossouarn 2019). The germ is found in approximately 60-80% of the human gut microbiota in infants and 80% in adults. It is also part of the normal flora in the oral cavity (Kao 2019).

E. faecalis, on the other hand, is an opportunistic pathogen (Lossouarn 2019) and can cause severe infections, especially in immunocompromised patients (Chilambi 2021), transplanted patients, intensive care unit patients, and hematologic oncology wards (Mischnik 2019) (Gök 2020).

Enterococci are among the typical symbionts in the human intestine (Kasper 2015). They include various species. Of particular medical relevance are:

- E. faecalis

- E. faecium (Mischnik 2019).

E. faecium- group probably first emerged 75 years ago, at the time of the introduction of antimicrobial drugs (Kasper 2015).

The ratio between E. faecalis: E. faecium is reported to be 90: 10, although there are significant local differences (Schulz- Stübner 2017).

Enterococci are normally inhabitants of the adult colon and account for < 1% of the culturable intestinal microflora (Kasper 2015). E. faecalis is one of the gram-positive cocci (Kasper 2015) and is facultatively anaerobic (Lossouarn 2019).

E. faecalis can cause the following diseases:

- Native valve endocarditis (Herold 2022):

This is caused by E. faecalis in 97% of cases (Beganovic 2018).

- Late endocarditis after valve disruption (Herold 2022).

- peritonitis

- urinary tract infections

- Bacteremia (Lossouarn 2019)

- Endophthalmitis (Chilambi (2021)

- Wound infections (Chong 2017)

- Chronic prostatitis:

In chronic prostatitis, therapy is more difficult because effective drugs have difficulty penetrating the prostate. Chronic prostatitis, in turn, can be the cause of recurrent enterococcal bacteremia (Kasper 2015).

Enterococcus faecalis is sensitive to:

- Aminopenicillins such as ampicillin, amoxicillin (Herold 2022).

- Linezolid (Neumeister 2009)

- piperacillin

- carbapenems

- Mezlocillin (Schulz- Stübner 2017)

- Vancomycin to 89 % sensitive

- Daptomycin 99.9 % sensitive

- Nitrofurantoin to 99 % (Kasper 2015)

Since 1970, enterococci have become a significant problem in public health because they frequently cause opportunistic infections and are also associated with antibiotic resistance. Today, enterococci are responsible for 7% of all infections in intensive care units (Kao 2019).

E. faecalis is the predominant species in nosocomial infections (Kasper 2015). E. faecalis and E. faecium cause nearly 75% of all enterococcal infections (Chilambi 2021).

A prerequisite for an infection with enterococciis a stronger colonization of the intestine with enterococci.

However, the mechanisms by which enterococci successfully colonize the intestine and gain access to the bloodstream and lymphatic vessels from the colon have not yet been fully elucidated, (Kasper 2015).

E. faecalis occur as single cells, diplococci, or short chains (Kasper 2015).

Enterococci are generally resistant to oxacillin and cephalosporins. They are inactivated but not killed by penicillin, ampicillin and vancomycin . In addition to penicillin, ampicillin, and vancomycin, additional treatment with aminoglycosides such as gentamicin or streptomycin is needed to kill enterococci (Kasper 2015).

For example, infective endocarditis caused by E. faecalis causes a mortality rate of 20-40% , which has remained unchanged over the past 30 years (Beganovic 2018).

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