Israel Medical Association Journal

Polymicrobial endocarditis is a rare clinical entity associated with high rate of morbidity and mortality. We present a case of prosthetic valve endocarditis caused by Enterococcus faecalis and Proteus mirabilis, emphasizing the clinical course, microbiological findings, and potential microbial synergy contributing to disease persistence.

E. faecalis is a gram-positive, facultatively anaerobic bacterium that can cause significant morbidity and mortality. It commonly presents as bacteremia and endocarditis and is a major contributor to nosocomial infections. This bacterium produces biofilms on native and artificial tissues, allowing it to establish resistance to antimicrobial agents. Many infections caused by E. faecalis are polymicrobial, as its biofilm creates an environment that supports the colonization of other microorganisms, leading to mixed-species biofilms on endogenous tissues or medical devices.

Background: The recent increase in enterococcal urinary tract infections (EUTI) and the potential morbidity and mortality associated with inappropriate antimicrobial treatment underscores the need for early risk assessment and institution of appropriate empirical antimicrobial therapy.

Objectives: To identify high-risk features associated with hospitalized patients with EUTI.

Methods: Demographic, clinical, laboratory, and bacteriological data of 285 patients hospitalized with UTI during 2016 were retrieved from the computerized database of Shamir Medical Center. Patients were divided into two groups: EUTI and non-EUTI (NEUTI), according to the presence or absence of enterococcus in the urine culture. The features of the two groups were compared.

Results: We obtained 300 urine cultures from 285 patients. Of the total, 80 patients (26.6%) had EUTI and 220 patients (73.3%) had NEUTI. A higher prevalence of urinary multi-bacterial cultures was found in EUTI compared to NEUTI patients (P < 0.01). Higher prevalence of permanent indwelling urinary catheter and dementia were found in hospitalized patients with community-acquired EUTI and nosocomial EUTI respectively (P = 0.02, P = 0.016) compared to patients with NEUTI.

Conclusions: Indwelling urinary catheter and dementia are risk factors for EUTI in patients with community and hospital acquired infection, respectively