en Infectious diseases and public health Infectious diseases and public health Letter to the Editor Letter to the Editor [No Abstract]<br> <em>Nocardia</em> is a genus of weakly gram-positive, filamentous, aerobic, relatively slow-growing and partially acid-fast bacteria. These bacteria are ubiquities in environmental resources such as water, soil, dust, decomposing animal feces, and vegetables. This group of bacteria can enter the human body through inhalation and traumatic cutaneous inoculation and cause <em>Nocardia</em> infections. There are various types of nocardiosis including pulmonary, brain, cutaneous, cutaneous-lymphatic, and ocular infections. These infections often occur in immunocompromised patients including organ transplant recipients, corticosteroid drugs consumers, human immunodeficiency virus (HIV) patients, cancerous and even healthy individuals. [No keywords] Nocardia asteroides, Species Level, Nocardia 38 39 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-147-1&slc_lang=en&sid=1 Masoud Keikha masoud.keykha90@gmail.com Yes Department of Microbiology, School of Medicine, Isfahan Medical University, Isfahan, Iran