The first case of cutaneous infection with Mycobacterium parascrofulaceum.

Abstract

The authors present the first, to the best of their knowledge, reported case of cutaneous infection caused by Mycobacterium parascrofulaceum. A 42-year-old woman presented with asymptomatic reddish papules, nodules, plaques, and patches on the right side of her face and on her forehead that had persisted for 5 years, with the lesions gradually increasing in size over that time. No previous intervening medical treatment had been applied. No history or evidence of immunosuppression was found. A skin biopsy was performed for routine histological examination. Samples of lesioned skin were inoculated on Löwenstein–Jensen medium to determine the presence of acid-fast bacilli. Ziehl–Neelsen staining was used to confirm the presence of the organism. In vitro drug susceptibility testing was conducted using the microtiter plate method. Mycobacterium was identified by polymerase chain reaction–restriction fragment length polymorphism analysis and sequencing of the hsp65 and 16S rDNA genes. Cultures for aerobic and anaerobic bacteria, as well as fungus, were also conducted. Routine histopathology revealed granulomatous changes without caseation. Ziehl–Neelsen staining showed that the organisms in both the lesions and the cultures were acid-fast bacilli. The cultured colonies were grown in Löwenstein–Jensen medium and incubated at two different temperatures (32°C and 37°C) for 2–3 weeks, developing pigmentation both in the dark and in the light. In vitro drug susceptibility tests showed that the organism was sensitive to clarithromycin and moxifloxacin. Polymerase chain reaction–restriction fragment length polymorphism analysis and sequencing of the hsp65 and 16S rDNA genes confirmed that the isolated organisms were M. parascrofulaceum. Fungal and other standard bacterial cultures were negative. In conclusion, identification and diagnosis of nontuberculous mycobacteria should be performed promptly to obtain better prognoses. Empirical treatments may be feasible, and drug susceptibility tests are important.