Clinical Significance of Roseomonas Species Isolated from Catheter and Blood Samples: Analysis of 36 Cases in Patients with Cancer

This report analyzes 36 cases of bacteremia or catheter-related infection caused by Roseomonas species, a group of pink, slimy, waterborne, gram-negative coccobacilli. The causative species included the newly described Roseomonas mucosa (22 cases [61%]) and Roseomonas gilardii subspecies rosea (8 cases [22%]) and known species R. gilardii subspecies gilardii (5 cases [14%]) and Roseomonas genomospecies 4 (1 case [3%]). Twenty-nine (81%) of the cases were symptomatic, with fever being the most common symptom (in 27 [75%] of the cases). Twenty (56%) of the infections were monomicrobic. Six cases (17%) involved persistent catheter colonization, and 5 of these cases required removal of the catheter to clear the infection. All infections resolved, most with empirical antibiotic treatment. A summary of the antibiotic susceptibility pattern of these strains and other reported series show that Roseomonas species are consistently susceptible to amikacin and imipenem and frequently susceptible to ciprofloxacin and ticarcillin, but essentially nonsusceptible to ceftazidime and cefepime. This result may guide future therapy for infections due to Roseomonas species.