Mycobacterium maeseillense bloodstream infection combined with skin fungal infection: a case report and literature review

Abstract

Background Non-tuberculous mycobacteria (NTM) are widely present in the natural environment and can invade the human body through the respiratory tract, gastrointestinal tract, and skin. They are particularly prone to infecting immunocompromised patients, primarily affecting multiple organs including the lungs, lymph nodes, and skin. However, reported cases of NTM bloodstream infections are rare. We aim to report a rare case of Mycobacterium massiliense bloodstream infection with concurrent skin fungal infection in a patient after kidney transplantation. We also provide a literature review to enhance understanding of this uncommon condition. Case presentation A 58-year-old male with a history of long-term steroid and immunosuppressant use after kidney transplantation presented with limb swelling for three years, which worsened over the past two months. Physical examination revealed redness and swelling of the skin on all four limbs, with a non-healing wound on the lower left limb. Skin tissue analysis using metagenomic next-generation sequencing (mNGS) and fungal culture indicated infection with red-colored trichophyton rubrum. Blood culture suggested infection with Mycobacterium massiliense. After receiving anti-NTM treatment, the patient’s symptoms have significantly improved and they are currently still undergoing treatment. Conclusion Mycobacterium maeseillense belongs to NTM. Gram staining is prone to miss detection and acid-fast staining was positive. This bacterium could be identified by mass spectrometry and mNGS. The drug sensitivity test of NTM was performed by broth microdilution method. The results of the susceptibility test showed that Mycobacterium maeseillense was sensitive to clarithromycin, intermediary to moxifloxacin and linezolid. The bacteria needs a combination of drugs and an adequate course of medication. NTM bloodstream infections are relatively rare, and early identification and proactive intervention are key to successful management.