Comment on: A case of granulomatosis with polyangiitis complicated by two opportunistic infections.

Abstract

Dear Editor, I read with interest the article entitled “A case of granulomatosis with polyangiitis complicated by two opportunistic infections” by Kavandi et al1 The genus Nocardia is normal soil micro-flora and causes various infections (nocardiosis) in humans.2 I have 3 comments about this article: 1. The gold standard for nocardiosis identification is isolation and culture of the micro-organism2 and radiologic findings or direct microscopy examination of specimens is not appropriate for accurate identification. 2. In Actinobacteria phylum, other genera such as non-Mycobacterium tuberculosis (NTM), Gordonia, Tsukamurella, Rhodococcus, and etc. have mycolic acids in their cell walls that are positive in modified acid-fast staining similar to Nocardia species.2-5 3. Although co-trimoxazole has been used for nocardiosis treatment, some Nocardia species are resistant to these agents. Therefore, accurate identification at the species level and antibacterial susceptibility testing (AST) is necessary. Further, several articles have reported patients with nocardiosis treated with co-trimoxazole developing a hypersensitivity reaction.2, 6, 7