VCOM Research Day Program Book 2023

Medical Resident Research Case Reports

04 Lactococcus Raffinolactis Bacteremia: a Case Study of a Rare Variant

Deborah L. Enns, DO, PhD 1 and William S. Cox, DO 2 Corresponding author: Deborah.enns@hcahealthcare.com

1 Department of Family Medicine and 2 Department of Internal Medicine LewisGale Hospital Montgomery

We present the case of a 71-year-old male who was admitted to hospital with initial complaints of fatigue, weakness, and lack of appetite. Patient had experienced a fall the week prior to admission, but denied hitting his head or any loss of consciousness. Past medical history was significant for prostate cancer, coronary artery disease (status post coronary artery bypass graft), prosthetic heart valve, and pacemaker. In the emergency room, a small pulmonary embolism was found and patient was started on anticoagulation. Patient was also found to have a significant white cell count of 21.9 x 10^9 per liter. Blood cultures revealed bacteremia which was later identified as Lactococcus raffinolactis, a coccoid gram-positive anaerobe. Patient was initially started on vancomycin, which was later switched to ampicillin/sulbactam. Patient underwent extensive workup to determine the source of his bacteremia, including urinalysis, which was

negative, echocardiogram which showed no signs of endocarditis, and CT scans of the chest and abdomen/pelvis, which showed no abnormalities. Throughout admission, patient had complaint of moderate to severe left ankle and lower leg pain that he attributed to his earlier fall. Plain radiographs of the leg and ankle were negative for any acute bony abnormalities. A three-phase bone scan was negative for osteomyelitis. Venous duplex ultrasound showed no signs of DVT. Finally, an infection PET/CT scan was ordered which showed an area of hypermetabolism on the left posterior tibial region. Follow-up CT of the leg revealed a 2.5-cm intramuscular fluid collection along the posterior aspect of the mid-left tibial region most consistent with an intramuscular abscess. Patient had been receiving IV antibiotics throughout admission and had been discharged home with a PICC line to complete a 4-week course of IV ertapenem. Patient returned

to hospital and underwent surgical I&D of the left calf. Unfortunately, no abscess or other source of infection was found during exploration. The patient was continued on IV antibiotics and advised to follow up with an Infectious Disease specialist at completion of treatment. While a definitive source of this patient’s bacteremia was never found, this case nonetheless illustrates a rare and interesting study as very little is currently available in the literature regarding infection by this variant.

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