Skin and Soft Tissue Infections Caused by Mycobacterium chelonae: More Common Than Expected?

Abstract

Patients can present with infections of the skin and soft tissues due to the pathogen Mycobacterium chelonae. Clinical presentation of this relatively rare infectious disease may differ from individual to individual. Despite an increasing incidence, affected patients are often misdiagnosed. Thus, in addition to careful history-taking, tissue biopsies for mycobacterial culture and histopathological examination are needed to reach a correct diagnosis. Once diagnosed, culture-directed antibiotic therapy is required. We report here 5 patients with cutaneous and/or soft-tissue infections due to M. chelonae, who were diagnosed and treated appropriately at our centre. Mycobacterium chelonae is a rapidly growing nontuber culous mycobacterium, which causes infections of the human skin and soft tissue. Despite an increasing incidence of such infections, patients are often misdiagnosed. We report here 5 patients with cutaneous and/ or soft tissue infection due to M. chelonae who were diagnosed and treated at our centre. Two of the 5 patients were on immunosuppressive treatment. While clinical presentations differed in each patient, all had a long history of skin lesions. In addition to careful history-taking, tissue biopsies were obtained for mycobacterial culture and histopathological examination. Culturedirected antibiotic therapy was initiated, which resulted in a slow, but continuous, healing of the lesions. In summary, M. chelonae infections are still relatively rare, but should be considered in both immunocompromised and immunocompetent patients with prolonged skin lesions resistant to standard antibiotic treatment. For diagnosis, tissue analysis for mycobacterial culture and histopathological examination, and once diagnosed, adequate antibiotic treatment, is needed.

The clinical value of metagenomic next-generation sequencing in the microbiological diagnosis of skin and soft tissue infections

“…Of note, the strains of some organisms such as B. henselae, V. vulnificus, M. tuberculosis, and NTM were identified by mNGS; these strains are fastidious or time-consuming to culture. SSTI is the most common manifestation of extrapulmonary NTM disease and identifying the causative NTM species is significantly related to improved clinical outcomes of NTM with SSTI (Uslu et al, 2019;Hsueh et al, 2019). Meanwhile, most Vibrio are associated with severe SSTIs and sepsis and therefore require early and exact pathogen diagnosis (Fei et al, 2019).…”

When Should Statins Be Stopped?

“…DISCUSSION M. chelonae is a non-tuberculous mycobacterium which can be found in the soil, water and aquatic animals. The global incidence of infection with this mycobacterium is reportedly increasing [1] . In immunocompetent individuals, M. chelonae can cause localized skin infections, as in our patient.…”

“…For correct diagnosis, a skin biopsy is needed for histopathological examination, including acid-fast staining and mycobacterial culture. Guided by susceptibility testing, combination therapy with at least two antibiotic agents, for a minimum of 4 months for skin disease, is recommended [1] . Rhabdomyolysis is a condition resulting from muscle injury and involves necrosis of muscle tissue that leads to the release of intracellular content into the blood stream.…”

Cutaneous Mycobacterium chelonae infection presenting clinically as a mycetoma

“…1 , 2 Their incidence is increasing worldwide and is thought to result from a combination of more surgical and cosmetic procedures performed, the increased use of immunosuppressive medications, and an improved ability to isolate and identify these organisms. 1 , 3 , 4 Misdiagnoses and delayed diagnoses are still common despite this increased incidence, 2 , 5 thus making the ability to recognize unusual clinical presentations of cutaneous NTM infections increasingly important.…”