Roseomonas

Background

Microbiology

• Genus of slow-growing Gram-negative bacilli or coccobacilli within the family Acetobacteraceae
• Previously referred to as CDC pink coccoid groups I through IV
• Related to Methylobacterium
• Catalase and oxidase positive
• Non-fermentative
• Aerobic
• Pigmented, either pink or purple-pink
• Isolated from environmental samples including soil, water, and plants
• Species of possible clinical importance include:
  • Roseomonas gilardii subspecies gilardii (usually clinically important) and rosea
  • Roseomonas mucosa
  • Roseomonas fauriae
  • Roseomonas genomospecies 4, 5, and 6

Clinical Manifestations

• More common in patients with significant comorbidities or immunocompromise
  • Malignancy on chemotherapy (solid-organ and hematologic), particularly with neutropenia
  • Also advanced HIV, CKD, and diabetes mellitus
• Bacteremia (75%), including central line infection
• Musculoskeletal infections (8%), including osteomyelitis and septic arthritis
• Skin and soft tissue infection (6%)
• Peritoneal dialysis-associated peritonitis (6%)
• Extremely rare cases of endophthalmitis, endocarditis, pneumonia, ventriculitis, and pre-aortic abscess
• Often seen in polymicrobial cultures, particularly coagulase-negative staphylococci, Micrococcus, Pseudomonas, coryneform bacteria, and many others

Management

• Generally susceptible to aminoglycosides, tetracycline, and imipenem
• May be susceptible to fluoroquinolones
• Generally resistant to penicillins (including combinations with β-lactamase inhibitors), cephalosporins, and co-trimoxazole
• Remove the central line if CLABSI is suspected

Further Reading

• Roseomonas species infections in humans: a systematic review. J Chemother. 2020;32(5):226-236. doi: 10.1080/1120009X.2020.1785742