Nocardia co-infection in patients with pulmonary tuberculosis.
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.


OBJECTIVE
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.


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.
Department of Medical Laboratory Sciences, School of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Infectious and Tropical Diseases Research center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Alireza
A
Ekrami
Infectious and Tropical Diseases Research center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Azar Dokht
AD
Khosravi
Infectious and Tropical Diseases Research center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Ali Reza
AR
Samarbaf Zadeh
Department of Microbiology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
Mohammad
M
Hashemzadeh
HIV; Mycobacterium tuberculosis; Nocardia; Pulmonary tuberculosis