Enterococcus species are a gram-positive facultative anaerobic coccus commonly associated with nosocomial infections. Among these, Enterococcus faecium and Enterococcus faecalis are the most common [1] with other rare species known including E. casseliflavus, E. gallinarum, and E. raffinosus [2]. Urinary tract infections, bacteremia, and infective endocarditis are the most commonly associated with the Enterococcus species, with rare reported cases of intra-abdominal infections and meningitis [3]. They are highly resilient species that can survive in a variety of conditions, including treatment with common antiseptic and disinfectant agents [3].

Reports of Enterococcus raffinosus (E. raffinosus), a non-motile, catalase-negative, raffinose-positive, facultative anaerobic bacteria, began over the past two decades [1],[2]. This bacterium species is the leading cause of nosocomial infections due to its widespread antibiotic and multidrug resistance gained over the last several years [1],[2]. Cases of E. raffinosus specifically have been described primarily in bacteremia, endocarditis, as well as reported in sinusitis, decubitus ulcer, vertebral osteomyelitis, vaginal infection, endophthalmitis, and urinary tract infections [1]. E. raffinosus has also been recovered from urine specimens and wound swabs, however, there is no literature published to confirm the ability of E. raffinosus to cause serious invasive disease [4]. A wide range of symptoms have been reported depending on the clinical diagnosis with positive culture for this bacterium; however, there are no clinical features specific to E. raffinosus [3],[4]. Of all enterococcal bacteremia events, only 0.6% are reported positive with E. raffinosus bacteremia with less than a handful reported in the literature related to E. raffinosus deep tissue wound infections [5].

We present a case of a 68-year-old male with pertinent past medical history of recent admission for below-knee amputation (BKA) with wound wash out, who returned to the hospital for evaluation of purulent drainage from the wound site, with subsequent wound cultures positive for E. raffinosus.

The patient was a 68-year-old male with past medical history of BKA five days prior, diabetes mellitus (DM), myelodysplastic syndrome (MDS), stem cell transplant in 2008, and deep vein thrombosis (DVT), brought from a nursing facility, who presented to the ED for profuse purulent foul smelling drainage from his R BKA wound, and was admitted to the intensive care unit due to sepsis secondary to BKA wound infection. Two weeks prior, the patient underwent BKA wound washout and debridement with delayed primary closure. Wound cultures were ordered and the patient was treated with unasyn and discharged back to the nursing facility on augmentin. After discharge, the patient continued to display altered mental status/cognitive decline, decreased appetite, and urinary incontinence. This was a significant departure from his baseline as per nursing staff.

In the ED, the patient was disoriented, with significantly altered mental status, and hypotensive at 60/23 with a mean arterial pressure (MAP) of 35. The patient was afebrile at 97.1 F, normal heart rate of 79 beats per minute, and normal respiratory rate of 18 breaths per minute. The labs were significant for elevated white blood cells (WBCs) of 18.5 (trend seen in Table 1), lactic acid of 11.0, and C-reactive protein of 26.80 (trend seen in Table 2). Blood culture and wound cultures were ordered and obtained. Vascular surgery and infectious disease (ID) were consulted. The patient was started on intravenous (IV) Vancomycin and Zosyn for broad coverage and above-knee amputation (AKA) with wound vaccum-assisted colsure (VAC) placement was scheduled for the next day.

During R AKA procedure, an abscess cavity measuring 10 cm × 5 cm was identified tracking posteriorly to the femur. Acute purulent fluid drainage was noted, additional cultures were obtained, and the decision was made to perform guillotine amputation with wound vacuum-assisted closing (VAC) due musculature pallor. As there was no concern for methicillin-resistant Staphylococcus aureus (MRSA) growth, ID discontinued Vancomycin. Superficial wound cultures of BKA wound demonstrated Diphtheroid, mixed gram-negative rods, and Enterococcus species. Additionally, deep wound culture of the right lower extremity demonstrated mixed gram-negative rods, anaerobic gram-positive cocci, anaerobic gram-positive rods, and E. raffinosus. Infectious disease recommended discontinuing Zosyn and adding Unasyn for additional six weeks to cover gram-negative bacteria. A peripherally inserted central catheter (PICC) line was placed for administration of long-term antibiotics. The white blood cell (WBC) count continued to trend downward, stabilizing between 4.0–5.0 × 10³/µL.

Finally, the patient returned to the OR approximately two weeks after admission to formalize the R AKA with delayed primary closure. Upon inspection of the site, the wound was free of necrotic tissue, non-viable tissue, and purulent drainage. The procedure was completed successfully with placement of 10 French Jackson–Pratt (JP) drain within the surgical stump. Jackson–Pratt drain output was monitored for a few days, then removed, and the patient was discharged back to his nursing facility for further management.

Enterococcus raffinosus is not commonly recognized as part of the natural human bacterial flora and is rarely isolated from clinical specimens [4]. This case highlights a 68-year-old male with a deep wound infection in his right BKA site, in which cultures were positive for E. raffinosus.

Previous reports have linked E. raffinosus infections to the biliary tract, bacteremia, endocarditis, and vaginitis [5]; however, documented cases of deep wound infections caused by this organism are exceedingly rare. A literature review identified one confirmed case—a 2008 report of a patient with a decubitus ulcer wound infection caused by E. raffinosus, which exhibited resistance to all antibiotics except beta-lactams, gentamicin, and ciprofloxacin [6]. Another study analyzing 49 cases of E. raffinosus bacteremia found that 81.6% originated from the biliary tract [5]. The current case contributes to the growing body of evidence by presenting a rare association of E. raffinosus with deep wound infections.

E. raffinosus infections have been associated with a 60-day mortality rate of 4.1% [5], indicating a necessity for early identification and intervention. This case underscores the importance of considering E. raffinosus in the differential diagnosis when deep wound infections are being evaluated. With the significant mortality rate, obtaining cultures upon initial presentation in the emergency department is crucial for prompt and targeted antimicrobial therapy. The exact source of infection in this patient remains unclear; however, several risk factors may have contributed. Examining the patient’s presentation above, the patient had multiple hospital admissions in the past year, resided in a nursing facility, and prior lower extremity procedures were performed—there are all significant predisposing factors that have contributed to the exposure of E. raffinosus. Recognizing these potential risk factors is vital when encountering E. raffinosus in clinical practice, particularly in patients with complex medical histories.

The case presented highlights a rare deep wound infection caused by Enterococcus raffinosus, emphasizing the importance of a thorough clinical evaluation. A good history is essential to identify possible risk factors for infection. The incidence of E. raffinosus continues to grow due to cross contamination, prior hospitalizations, and improper care in healthcare facilities. Early identification through bacterial sampling, adherence to proper wound care protocols, and timely antimicrobial treatment are critical in managing and preventing complications associated with this resistant organism.