Mycobacterium cosmeticum catheter-related bloodstream infection in an immunocompetent patient: A case report and review of the literature

Background: Mycobacterium cosmeticum is an emerging rapidly growing mycobacteria (RGM) species that has been rarely reported to cause human disease. RGM catheter-related bloodstream infections (CRBSI) are often challenging to treat given the need for line removal, variable species-dependent antimicrobial susceptibility, combination antimicrobial treatment, and historically longer courses of antibiotics. Case presentation: We present a case of an immunocompetent pediatric patient with severe hemophilia B and M. cosmeticum CRBSI. While the patient’s hemophilia B precluded a standard line holiday, he successfully cleared his infection with two line exchanges followed by two weeks of antibiotics. Conclusions: RGM, including emerging species M. cosmeticum, may be considered in patients with an indolent presentation of CRBSI. Our case suggests source control with shorter courses of antimicrobials can be successful.