Molecular of Non-Tuberculous Mycobacteria among Tuberculosis / HIV co – infected patients

Abstract

This study aimed to identify and characterize Non-Tuberculous Mycobacteria (NTM) among suspected pulmonary tuberculosis / HIV co- infected patients in Khartoum state by using conventional methods and PCR technique. 171 sputum and blood samples were collected from patients attending Abu Anga Hospital, The Reference Tuberculosis Laboratory, ELshaab Teaching Hospital, Ibrahem Malek Hospital, Omdurman Teaching Hospital, and the Academy Charity Hospital during the period from January to March 2010. HIV screening tests has been conducted to all patients, 25 (14.6%) were found positive while 146 (85.4%) were negative. All the 171 samples were tested for the presence of acid fast bacilli by using direct Ziehl-Neelsen stain, 37 (21.6%) were positive while 134 (78.4%) were negative. All sputum samples were cultured in Lowenstein Jensen media. 40 (23.4%) of the isolates gave a characteristic growth of Mycobacterium tuberculosis and six out of 10 (5.8%) rapidly grower isolates were confirmed by the indirect Z.N stain, culture characteristics and biochemical properties as NTM. In this study, 112 (69.6%) males were found to be affected compared to 52 (30.4%) females. Age groups between 21-49 years were more affected with both M. tuberculosis complex and NTM. 21 (84%) out of 25 patients with positive HIV were found infected with MTB while 4 (16%) were infected with NTM. Ten rapidly grower isolates were subjected to PCR. Six isolates showed a band typical in size (136 bp) to target gene (rpoB) as indicated by the standard DNA marker. Four isolates were found negative. From this study, it is obvious that NTM infections are frequent in HIV infected patients. The results obtained from this study revealed clearly the importance of conventional methods in the diagnosis of TB and NTM as well as the effectiveness of PCR as confirmatory diagnostic tool.