Identification of Non-Tuberculosis Mycobacteria by Line Probe Assay and Determination of Drug Resistance Patterns of Isolates in Iranian Patients

Abstract

The potentially pathogenic Non-Tuberculosis Mycobacteria (NTM) are emerging nowadays which result in pulmonary and non-pulmonary infections in human. This group of bacteria consists of at least 200 different species. While the pulmonary disease is the most common form of NTM infections, NTM can cause diffused infections as well as extrapulmonary infections in every organ, such as bone marrow, skin, eye, and brain. The NTM cause tuberculosis-like infections, therefore, correct identification of these Mycobacteria is necessary to avoid faulty treatment. Different species of NTM isolates were identified from clinical specimens using phenotypic methods and Line Probe Assay. Minimum Inhibitory Concentration for selected antibiotics was obtained by the broth micro-dilution method. Totally, 42 NTM isolates were identified in this study. Moreover, the frequency of NTM between all positive mycobacterium cultures was estimated at 12%. The most common Rapidly Growing Mycobacteria included Mycolicibacterium fortuitum (30.9%), Mycobacterium abscessus (7.1%), and Mycobacterium chelonae (2.3%), whereas Mycobacterium simiae (40.4%), Mycobacterium kansasii (16.6%), and Mycobacterium avium complex (2.3%) were the most recurring among the Slowly Growing Mycobacteria. Amikacin, clarithromycin, and ciprofloxacin were the most effective antibiotics against isolated NTM. The NTM isolates are frequently being separated from Iranian patients, and are mostly resistant to the wide spectrum of antibiotics. Correct identification and determination of antibiotic susceptibility can be helpful in the healing process of the patients who suffer from non-tuberculosis mycobacterial infections.

Keywords

• drug resistance patterns
• line probe assay
• non-tuberculosis mycobacteria