Cellulosimicrobium cellulans (formerly known as Oerskovia xanthineolytica) rarely causes human infection. Infections have been reported in immunocompromised hosts or in patients with foreign bodies, such as catheters, where treatment has generally involved removal of the foreign body. We report on a case in which the organism was isolated in multiple blood cultures from a 13-year-old male. After initial therapy failed, treatment with vancomycin and rifampin resulted in infection clearance without removal of the central venous catheter. CASE REPORTA 13-year-old male with a history of midgut volvulus and subsequent short-bowel syndrome, who had received total parenteral nutrition since shortly after birth, presented to the Emergency Department at the University of California-Los Angeles with fever of 39°C, malaise, and bilateral conjunctivitis. The patient had had numerous urinary tract infections and central venous catheter (CVC) line infections in the last few years with organisms such as Micrococcus, coagulase-negative Staphylococcus, Staphylococcus aureus, and Enterococcus species. In the emergency room, blood was drawn from the CVC and from a peripheral vein. Both specimens grew pleomorphic gram-positive rods in aerobic and anaerobic blood culture bottles that were identified as Cellulosimicrobium cellulans. The patient was hospitalized and initially treated with intravenous vancomycin and cefotaxime, which was changed 2 days later to vancomycin and gentamicin. After 3 days in the hospital, the patient became afebrile and was discharged home to continue intravenous vancomycin therapy. Blood cultures (drawn on hospital day 2) became positive for Cellulosimicrobium cellulans after 72 h. Because the patient had been discharged, he was readmitted even though he was afebrile. Due to the difficulty of finding another line of intravenous access for this patient, an attempt to preserve the CVC was made by adding oral rifampin to the treatment regimen. Once rifampin was begun, subsequent blood cultures (drawn 2, 3, and 5 days after readmission, respectively) were negative. The patient was discharged home to complete therapy of 3 weeks on intravenous vancomycin and oral rifampin. A repeat culture obtained 72 h after discontinuation of antibiotics was negative. The patient has not had any recurrent infections with this organism and continues to use the CVC line on a daily basis (1 year posttherapy).

Viridans group streptococci (36 stock strains and 167 single patient blood culture isolates) were assessed using API Rapid Strep, Baxter MicroScan Rapid Pos ID Panel, BBL Minitek Differential Identification System, IDS RapID STR System, and Vitek GPI methods. Identification data obtained with these systems were compared with those indicated by conventional biochemical procedures. API, Baxter MicroScan, BBL, IDS, and Vitek corresponded with conventional biochemical identification in 74%, 66%, 65%, 50%, and 61% of the isolates, respectively; using recommended supplemental tests, agreement was augmented in 9%, 11%, 20%, 11%, and 21% of the isolates, respectively. Disagreement with conventional biochemical methods occurred in 14%, 17%, 14%, 32%, and 10% of the commercial techniques, respectively; no identification was possible in 2%, 5%, fewer than 1%, 6%, and 8% of specimens, respectively. BBL, API, and Baxter MicroScan systems provided the most reliable rapid identification, although supplemental testing often was required. Until a higher percentage of correct identification data can be obtained without supplemental procedures, conventional biochemical techniques will remain the methods of choice for identification of viridans streptococci.

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