Brevibacterium
Brevibacterium species, which may resemble Corynebacterium, were previously considered contaminants when isolated from clinical specimens.
The genus Brevibacterium includes many species but only nine have been isolated from humans: B. linens, B. iodinum, B. epidermidis, Brevibacterium casei, B. mcbrellneri, B. otitidis, B. paucivorans, B. massiliense and B. sanguinis. Brevibacterium species were thought to be apathogenic until 1991, when the first case of sepsis due to B. epidermidis central line-associated blood stream infection was reported by McCaughey 1).
Though infrequently reported, Brevibacterium species are now well-recognized pathogens causing infections in immunocompetent and immunocompromised patients 2) 3)
These infections include sepsis, peritonitis, skin, and soft tissue infections, and device-related infections, i.e. catheter-related bloodstream infections and prosthetic valve endocarditis. Brevibacterium casei is the most commonly reported species of Brevibacterium isolated from clinical specimens 4)
Talento et al. present a case of Brevibacterium otitidis infection in an immunocompetent patient, and highlight the difficulty with identification and interpretation of antimicrobial susceptibility results for this unusual pathogen 5).
Diagnosis
Brevibacterium species can be differentiated from other coryneform bacteria by testing a wide array of biochemical reactions. The presence of meso-diaminopimelic acid in the peptidoglycan layer of the cell wall of Brevibacterium species and strong, rapid methane-thiol production are helpful in confirming identification of this genus but these tests are rarely available in the clinical diagnostic laboratory setting 6).
Treatment
Brevibacterium spp. was not considered human pathogens until few cases were published in the literature. All reported cases treated with combination of various antibiotics, especially glycopeptides and quinolones.
Case reports
The cases of Brevibacterium brain abscess and osteomyelitis occurred in immunocompetent healthy patients with no apparent predisposition 7) 8)
A case of Brevibacterium tibial osteomyelitis in an immunocompetent individual with implanted hardware and highlight the challenge of identifying the organism and recognizing it as a potential pathogen 9)