Nocardia co-Infection in Patients with Pulmonary Tuberculosis

Abstract

Background:Tuberculosis (TB) remains as one of the most serious infectious diseases in the world. Pulmonary tuberculosis can occur with other pulmonary diseases caused by opportunistic organisms such as Nocardia spp. particularly in immunocompromised patients. Therefore, diagnosis of co-infection at the early stage of the disease could be lifesaving.Objectives:The goal of this study was to detect Mycobacterium tuberculosis and Nocardia spp. in sputum specimens in order to assess the concomitant nocardiosis and tuberculosis in patients with suspected pulmonary tuberculosis.Patients and Methods:From March 2011 to April 2012, 189 sputum specimens were obtained from patients who were suspected of having pulmonary tuberculosis. Out of 189 samples, 32 of the samples belonged to hospitalized HIV-infected patients. Samples were examined by Gram and Ziehl-Nelsen staining, culture and PCR methods.Results:From 157 sputum specimens, positive samples by acid fast staining, culture and PCR for M. tuberculosis were reported for 7.6% (12/157), 10.1% (16/157) and 7% (11/157) of samples, respectively. No results were obtained by the described methods for Nocardia spp. Among 32 samples of HIV-infected patients, four (12.5%) had positive results for acid fast staining, culture and PCR detecting M. tuberculosis while only two samples had positive results for Nocardia spp. by PCR and no results were reported by culture, Gram and acid fast staining for this organism.Conclusions:Concurrent pulmonary nocardiosis and tuberculosis is frequent in HIV-infected patients. Rapid and sensitive methods such as PCR are recommended for detection of such co-infections.

Cloning, Expression, Invasion, and Immunological Reactivity of a Mammalian Cell Entry Protein Encoded by the mce1 Operon of Nocardia farcinica

“…Thus far, some 25 Nocordia species have been found to infect human patients, including Nocordia brasiliensis, N. asteroides, N. farcinica, N. abscessus, N. nova , and N. transvalensis complex ; among them, N. farcinica is the most commonly encountered species ( Kandi, 2015 ). Clinically, untreated pulmonary nocardiosis resembles tuberculosis and thus represents a risk for misdiagnosis ( Ekrami et al, 2014 ).…”

Pulmonary nocardiosis and scrub typhus in an immunocompromised host

“…Commonly, coinfections occur among patients with an underlying background of immunocompromised condition such as solid organ transplantation, stem cell transplant, long-term corticosteroid therapy, and acquired immunodeficiency syndrome due to HIV. [ 6 8 ] Pulmonary nocardiosis as such is seen commonly in patients with an underlying chronic lung disease, thereby increasing the list of its differential diagnosis such as Mycobacterial infections, fungal infections (pulmonary aspergillosis and pulmonary zygomycosis), lung malignancy, and actinomycosis. [ 1 ] Coinfections have been commonly reported with tuberculosis and aspergillosis.…”

Pulmonary nocardiosis in Chronic Obstructive Pulmonary Disease: A new clinical challenge

“…Cases of concurrent PN and TB especially in HIV-infected patients are also reported in literature. According to some case series, more than two thirds of PN cases were initially misdiagnosed with TB and about 5% of the patients with proven pulmonary TB were shown to be co-infected by Nocardia spp [11] , [12] , [35] , [45] , [54] , [55] , [56] , [57] , [58] , [59] , [60] . Concurrent infection of PN and Mycobacterium avium-intracellulare complex and PN and aspergillosis have also been reported [29] , [61] , [62] .…”