IDENTIFICATION OF NON-TUBERCULOUS MYCOBACTERIA FROM CLINICAL SPECIMENS REFERRED TO ADAMA TB REFERENCE LABORATORY, ETHIOPIA

Abstract

Non-tuberculous mycobacteria (NTM) are opportunistic
pathogens that can be acquired from the environment like water and soil.
They can cause pulmonary and extrapulmonary diseases in both HIV-positive
and HIV-negative individuals. There is no information in Ethiopia on the
identity and diversity of NTM in clinical specimens. The aim of this study
was to identify and characterize NTM from clinical samples stored between
November 2016 to May 2017 at Adama TB reference laboratory. A total of
47 NTM isolates were grouped using Runyon system and speciation was
determined using molecular method of GenoType Mycobacterium CM/AS
assays. Of the 47 isolates, 24 (51%) were found to be slow growers while 23
(49%) were rapid growers (Group IV). Of the slow growers, 4(16.7%) were
photochromogen (Group I), 7(29.2%) scotochromogen (Group II) and 13
(54.2%) non-photochromogen (Group III). NTM species distribution among
identified isolates revealed the following groups: M. intracellulare (n=6), M.
abcessus/M. immunogenum (n=4), M. gordonae (n=4), M. simiae (n=3), M.
fortuitum (type 1) (n=3), M. chelonae/M. immunogenum (n=1), M.
scrofulaceum/M. paraaffinicum (n=1), M. avium (n=1) and M. mucogenicum
(n=1). The study showed that there are different species of NTM that were
known to cause NTM infection as well as disease. Mycobacterium avium
complex (Mycobacterium avium and intracellulare 29.2%) was found to be
the most common species out of the identified stains. Based on our findings,
we suggest that due emphasis should be given to NTM while diagnosing TB
and laboratories should be capacitated to properly identify NTM.