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 al 1 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-organism 2 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 cotrimoxazole developing a hypersensitivity reaction. 2,6,7 O RCI D Mehdi Fatahi-Bafghi https://orcid.org/0000-0002-4665-9447 R E FE R E N C E S 1. Kavandi H, Hajialiloo M, Varshochi M, Kolahi S, Khabbazi A. A case of granulomatosis with polyangiitis complicated by two opportunistic infections. Int J Rheum Dis. 2017;20(12):2206-2208. 2. Fatahi-Bafghi M. Nocardiosis from 1888 to 2017. Microb Pathog. 2018;114:369-384. 3. Safaei S, Fatahi-Bafghi M, Pouresmaeil O. Role of Tsukamurella species in human infections: first literature review. New Microbes New Infect. 2018;22:6-12. 4. Fatahi-Bafghi M. Nocardia identification at the genus level. Circ J. 2017;81(2):270. 5. Andalibi F, Fatahi-Bafghi M. Gordonia: isolation and identification in clinical samples and role in biotechnology. Folia Microbiol. 2017;62(3):245-252. 6. Fatahi-Bafghi M. Phenotypic and molecular identification of Nocardia in brain abscess. Adv Biomed Res. 2017;6:49. 7. Brown-Elliott BA, Brown JM, Conville PS, Wallace RJ. Clinical and laboratory features of the Nocardia spp. based on current molecular taxonomy. Clin Microbiol Rev. 2006;19(2):259-282.