From the Guidelines
Ampicillin or amoxicillin is the most appropriate empiric treatment for Enterococcus faecalis urinary tract infections. The typical dosage for uncomplicated UTIs is amoxicillin 500 mg orally three times daily or ampicillin 500 mg orally four times daily for 7 days, as recommended by recent guidelines 1. For complicated UTIs or pyelonephritis, treatment may be extended to 10-14 days, potentially with initial intravenous therapy using ampicillin 1-2 g every 4-6 hours. If the patient has a penicillin allergy, nitrofurantoin (100 mg orally twice daily for 5-7 days) or fosfomycin (3 g single oral dose) are reasonable alternatives, as suggested by studies 1.
Some key points to consider when treating E. faecalis UTIs include:
- E. faecalis is intrinsically resistant to cephalosporins and trimethoprim-sulfamethoxazole, making these ineffective choices 1.
- The effectiveness of ampicillin and amoxicillin against E. faecalis is due to their ability to inhibit cell wall synthesis in this gram-positive organism.
- For severe infections or those with suspected resistance, combination therapy with an aminoglycoside (like gentamicin) may be necessary, but this is typically reserved for invasive infections rather than uncomplicated UTIs 1.
- High dose ampicillin (18-30 g IV daily) or amoxicillin (500 mg PO/IV every 8 h) is suggested to achieve sufficient urinary concentrations for optimal bactericidal activity in urinary tract infections due to VRE, including E. faecalis 1.
It is essential to differentiate colonization from true infection prior to empiric prescription of anti-VRE antimicrobial agents and to consider the potential for resistance when selecting an empiric treatment regimen 1.
From the FDA Drug Label
Daptomycin has been shown to be active against most isolates of the following microorganisms both in vitro and in clinical infections [see Indications and Usage (1)] Gram-Positive Bacteria Enterococcus faecalis (vancomycin-susceptible isolates only)
The most appropriate empiric treatment for E. faecalis UTI is not directly stated in the provided drug label. However, based on the information provided, daptomycin is active against vancomycin-susceptible isolates of Enterococcus faecalis.
- Key points:
- Daptomycin is effective against Gram-positive bacteria, including E. faecalis (vancomycin-susceptible isolates).
- The label does not provide specific information on the treatment of UTIs caused by E. faecalis.
- Vancomycin susceptibility is a crucial factor in considering daptomycin as a treatment option. Given the available information, daptomycin may be considered for the treatment of E. faecalis UTI, but only if the isolate is vancomycin-susceptible 2.
From the Research
Empiric Treatment for E faecalis UTI
The most appropriate empiric treatment for Enterococcus (E) faecalis urinary tract infection (UTI) is a topic of interest due to the limited treatment options available, especially for vancomycin-resistant Enterococcus (VRE) [ 3 ].
- Oral fosfomycin is a potential option for the treatment of E. faecalis UTI, with studies showing its effectiveness in promoting suppression of regrowth (>3 log10 kill) in the majority of isolates [ 3 ].
- The choice of empiric antibiotic therapy in UTI depends on various risk factors, including residence in nursing homes, male gender, hospitalization within the last 30 days, renal transplantation, antibiotic treatment within the last 30 days, indwelling urinary catheter, and recurrent UTI [ 4 ].
- For patients with no risk factors, cephalosporins seem to be the best choice for empiric therapy, while for patients with risk factors, the beta-lactam penicillin Piperacillin with Tazobactam is an equal or better choice compared to fluoroquinolones, cephalosporins, or gentamicin [ 4 ].
- E. faecalis is frequently isolated in suspected UTI in male patients, and its resistance to ciprofloxacin increases with age [ 5 ].
- The invasive lifestyle of E. faecalis has been reported, with strong evidence of intracellular E. faecalis harbored within urothelial cells shed from the bladder of patients with lower urinary tract symptoms (LUTS) [ 6 ].
- The role of local vaginal estrogen therapy in susceptibility to E. faecalis infection is unclear, with no statistically significant difference in the need for additional antibiotics between postmenopausal and premenopausal patients [ 7 ].
Considerations for Treatment
When considering treatment for E. faecalis UTI, it is essential to take into account the patient's risk factors, the susceptibility of the isolate to various antibiotics, and the potential for biofilm formation and relapse [ 3 , 5 , 4 , 6 , 7 ].