A 50-year-old man presented to the emergency room with several months of intermittent fever and progressive lower back pain. He described a mechanical fall one week prior to this admission. He had a medical history of alcohol abuse, intravenous drug use, hepatitis C infection, and native tricuspid valve infective endocarditis secondary to methicillin-resistant Staphylococcus aureus (MRSA) five months prior to his current hospital admission. At that time, his transthoracic echocardiogram showed a tricuspid valve vegetation measuring 11 × 6 mm with severe tricuspid regurgitation. He was partially treated with intravenous vancomycin followed by daptomycin with serial negative blood cultures. Magnetic resonance imaging (MRI) of his spine at that time showed no evidence of vertebral osteomyelitis or epidural abscess.\nTwo months prior to the current hospital admission, he presented to the emergency room with back pain. At this time, his blood cultures were positive for the growth of V. dispar, which was identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. A transthoracic echocardiogram was performed prior to him leaving the hospital against medical advice and showed that the tricuspid valve vegetation was now smaller in size, measuring 7 × 6 mm (Figure ). He received no antimicrobial treatment at this time.\nDuring his current hospital admission, he was visibly agitated on physical examination and described significant lower back pain. His initial vital signs included a temperature of 39.5 degrees Celsius, heart rate of 120 beats per minute, respiratory rate of 20 breaths per minute, oxygen saturation of 97% on ambient room air, and blood pressure of 106/68 mmHg. His neck was supple and his neurological examination demonstrated normal tone throughout his upper and lower extremities. Strength in his right lower extremity was 3/5 for ankle plantar flexion and dorsiflexion, 2/5 for knee extension and flexion, and 3/5 for hip extension and flexion. His strength was 4/5 throughout his left lower extremity. His sensation was normal apart from decreased light touch sensation to his medial right gastrocnemius region. He had spinal and paraspinal tenderness in his mid and lower back. His reflexes were 2+ in his knees and plantars were down-going bilaterally. He had a grade III/VI systolic murmur best heard at the left lower sternal border. Air entry was equal and clear bilaterally with fine crackles to his right lower lung zone. No other peripheral stigmata of infective endocarditis were present on examination. Examination of the oral cavity showed he was missing upper teeth with overall poor dentition. Initial laboratory investigations are summarized in Table .\nHis electrocardiogram was normal. During his hospital admission, two sets of blood cultures obtained 96 hours apart were again positive for the growth of V. dispar. Given his persistent bacteremia, a transthoracic echocardiogram was performed which showed growth in the size of the vegetation previously noted on his tricuspid valve, now measuring 11 × 7 mm. There were also signs of torrential tricuspid regurgitation including a vena contracta width greater than 0.7 cm, a central jet that was filling greater than 50% of the right atrium, and a triangular-shaped continuous-wave Doppler signal which was as dense as the inflow signal along with evidence of systolic hepatic vein flow reversal (Figures , ).\nAn MRI scan of the spine showed early discitis/osteomyelitis of L3-L4 with a right paravertebral and right paracentral anterior epidural phlegmon with no abscess (Figure ). The neurosurgical team assessed the patient and recommended conservative management with ongoing antimicrobial therapy and physiotherapy, and monitoring for any worsening neurological deficits. In addition, given his poor dentition, a computed tomography (CT) scan of the brain, head, and neck was arranged, which showed no obvious evidence of an abscess collection within the neck, oropharynx, or brain. Furthermore, no septic pulmonary emboli were seen on imaging.\nSusceptibility testing was performed on his V. dispar isolate using broth microdilution and showed susceptibility to penicillin (minimum inhibitory concentration [MIC] < 0.5), amoxicillin-clavulanate (MIC < 4/2), and metronidazole (MIC < 8) compared against breakpoints according to the Clinical and Laboratory Standards Institute. He was treated with intravenous ceftriaxone for six weeks with clinical improvement noted within a few days following his admission. The patient reported near-complete resolution of his back pain and his repeat C-reactive protein level toward the end of therapy was 3.8 mg/L (normal 0.0-7.0 mg/L). Subsequently, he developed a central-line-associated bloodstream infection secondary to Candida dubliniensis with no evidence of endophthalmitis, for which he received a two-week course of intravenous caspofungin.\nA repeat MRI was arranged after his therapy which showed resolution of the anterior epidural phlegmon but interval worsening of the L3-L4 discitis/osteomyelitis with a new enhancement of the L3 and L4 facets without effusion (Figure ). A subsequent CT-guided lumbar spine biopsy of the L3/L4 region was performed, and bacterial, fungal, and mycobacterial cultures were negative. A repeat transthoracic echocardiogram was planned to establish a new baseline for his valvular anatomy given his risk of recurrent endocarditis; however, the patient left against medical advice.
A 49-year-old Saudi man, a known case of insulin-dependent diabetes mellitus (IDDM), hypertension and ischemic heart disease, presented to the emergency department with a three-day history of fever, chills and ankle pain after trauma to his left foot. He reported a nonhealing ulcer on his left heel following a hot surface injury 20 days prior to his presentation. On examination, our patient looked ill and septic, with minimal ambulation. His temperature was 38.9°C and his blood pressure and pulse were 140/90mmHg and 108 beats/minutes respectively. A lower limb examination revealed bilateral decrease of sensation and a foot ulcer on his left heel. Careful examination of his left foot showed a 7×5cm deep ulcer on the lateral side that looked badly infected with change of skin color and profuse pus discharge. Our patient was seen by the orthopedic surgeon and an urgent extensive wound debridement involving the bone was undertaken. Blood, pus and bone tissue specimens were collected and sent to the microbiology laboratory for culture and sensitivity testing. A laboratory examination showed a white cell count (WBC) of 29×109g/L with 90% neutrophils, hemoglobin of 6.9g/L, and an erythrocyte sedimentation rate (ESR) of 97mm/h. His serum creatinine was 123umol/L, and urea mmol/L 8.9. His liver function test results were within normal limits except for serum alkaline phosphatase (ALP), which was raised (785IU/L). A left foot X-ray revealed soft tissue swelling, gas formation and fracture of the calcaneus bone. A left foot magnetic resonance imaging (MRI) scan revealed a calcaneus fracture with high suspicion of calcaneus anterior fragment osteomyelitis (Figure \n). An MRI scan of his right foot revealed mild neuropathic arthropathy (Charcot joint) with no evidence of osteomyelitis. Our patient was started empirically on intravenous ciprofloxacin 400mg twice daily, and intravenous clindamycin 600mg eight hourly. During the first three days after starting treatment, our patient showed no clinical improvement and he continued to run a low-grade fever. A pus culture grew Escherichia coli sensitive to ciprofloxacin, imipenem, meropenem, gentamicin and Enterococcus avium sensitive to ampicillin. A bone and tissue biopsy grew Morganella morganii sensitive to gentamicin, imipenem and resistant to ciprofloxacin, ampicillin, amoxicillin-clavulanic acid, piperacillin/tazobactam and cotrimoxazole. No growth occurred on the anaerobic plates despite prolonged incubation. Based on culture results, the initial antibiotics were suspended and our patient was started on imipenem 500mg intravenously (IV) six hourly, vancomycin 1g IV 12 hourly, and colistin 2 million units IV eight hourly. The blood culture obtained before treatment initiation, which was inoculated in an anaerobic bottle (Bactec Lytic/10, Anaerobic/F, Beckton Dickinson, Franklin Lakes, NJ, USA) and processed by an automated blood culture system (Bactec FX, Beckton Dickinson), grew very scanty Gram-negative cocci within 18 hours shown on Gram stain. The blood then was subcultured on Trypticase soy agar with sheep blood (BBL Microbiology Systems, Cockeysville, MD, USA) and incubated at 35°C in 5% CO2, in an anaerobic GasPak™ jar (BBL Microbiology Systems). After 48 hours of anaerobic incubation, the blood agar grew slow-growing tiny colonies (Figure \n) that showed Gram-negative cocci on Gram stain (Figure \n). The organism was identified by the Vitek 2 automated system (bioMérieux, Marcy-l'Étoile, France), as Veillonella species with a 99% probability rate. It was sensitive to imipenem (1.5μg/ml), clindamycin (0.047μg/ml), ceftriaxone (8μg/ml) and colistin, and resistant to penicillin (>32μg/ml), vancomycin, erythromycin and metronidazole. Further identification to species level and genotyping was unable to be performed, as the subcultured isolates failed to grow and the significant time delay before attempting to reisolate the organisms from the blood culture bottle rendered them nonviable. Over the subsequent five days, our patient’s condition worsened with a high temperature (38.9°C), rigors, a high WBC and ESR count. The wound was reevaluated by the surgical team and a decision of above-knee amputation was taken. Colistin and vancomycin were discontinued and imipenem was continued for four weeks. On follow-up, our patient showed gradual improvement of his condition and was discharged.