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 67-year-old man with a history of treated prostate cancer, alcohol abuse and alcoholic cirrhosis presented to an urban, academic hospital with new low back pain. The pain had started 2 weeks prior to his presentation, had gradually worsened, and then became associated with bilateral lower extremity shooting pain and weakness. He denied bowel or bladder incontinence or saddle anaesthesia. He also denied subjective fevers or chills or any other bothersome symptoms. He was found to have normal vital signs, poor dental hygiene, tenderness over the lumbar spinous processes, and normal neurological and prostate exams. Magnetic resonance imaging (MRI) of the spine () showed mild compression fractures, with small lytic lesions throughout the thoracic and lumbar spine, and a large lytic lesion at the L5 vertebral body. The patient had a normal prostate specific antigen (PSA) level and a normal white blood cell count. C-reactive protein was mildly elevated at 30 mg l−1 (normal range 0–10 mg l−1).\nThere was concern for metastatic cancer given the patient's prior history of prostate cancer. His normal PSA level was not reassuring, because his prior prostate cancer had been diagnosed in the setting of a normal PSA level. He was started on intravenous dexamethasone 4 mg every 6 hours given the concern for metastatic spinal lesions and a neurosurgical consult was obtained. The neurosurgery team did not feel that urgent surgical intervention was needed and thus a biopsy of the lesion was obtained by the interventional radiology team for diagnostic purposes. Surprisingly, the vertebral biopsy result showed no evidence of malignancy, but did show findings consistent with osteomyelitis and was sent for culture. Dexamethasone was discontinued and blood cultures were drawn. Antibiotic therapy was withheld while culture data was pending, as the patient was clinically stable.\nThe patient was observed while the cultures were pending, and 2 days later Veillonella species started growing from the broth of the tissue biopsy and from one of two blood cultures. After a great deal of prompting for additional history, the patient reported a mechanical fall 4 weeks prior to the onset of his pain, at which time several teeth had been dislodged. A trans-thoracic echocardiogram obtained to evaluate for possible endocarditis was negative. Additionally, repeat blood cultures obtained to ensure clearance of the bacteraemia after the initiation of antibiotics were also negative. Culture sensitivity results were obtained, but were delayed as the sample had to be sent out to a reference laboratory for further testing. In the meantime, ceftriaxone 1 g intravenous daily was started and the patient was discharged to a nursing home for further rehabilitation, with close clinical follow-up scheduled. The sensitivity testing was performed by broth microdilution and showed that there was no β-lactamase inhibition. The MIC results showed sensitivity to meropenem, ampicillin/sulbactam and piperacillin/tazobactam, and borderline sensitivity to metronidazole and penicillin. The results were delivered with the caveat that there are currently no Clinical and Laboratory Standards Institute guidelines in the USA for the performance and interpretation of susceptibility testing for anaerobes other than Bacteroides fragilis. Thus, the advice of the reference laboratory was to interpret these results with caution. At his follow-up appointment, the patient appeared to be having a good clinical response to ceftriaxone. Given the lack of β-lactamase inhibition in the culture data and the fact that once daily dosing of antibiotics decreases disruption of therapies, ceftriaxone was continued. The patient completed a 6 week course of antibiotics and had complete resolution of his symptoms.