Khosravi AD, et al. - Researchers studied the prevalence of nontuberculous mycobacteria (NTM) and ascertained the effect of D-cycloserine against Mycobacterium fortuitum and Mycobacterium abscessus isolated from clinical specimens to find out the synergistic effect of D-cycloserine and clarithromycin. From three major Regional Tuberculosis (TB) Centers, they identified 95 isolates as NTM (13.3%) among 714-positive acid-fast bacilli from TB-suspected cases. Identified isolates displayed the prevalence as follows: M. fortuitum 46 (48.4%), Mycobacterium simiae 16 (16.8%), Mycobacterium kansasii 15 (15.7%), M. abscessus 7 (7.3%), Mycobacterium thermoresistibile 4 (4.2%), Mycobacterium elephantis 3 (3.2%), Mycobacterium porcinum 2 (2.1%), and Mycobacterium chimaera 2 (2.1%). D-cycloserine was identified to be very active against M. abscessus and M. fortuitum. Hence, for M. abscessus- and M. fortuitum-associated diseases, D-cycloserine, either alone or in combination with clarithromycin, seems to be a promising treatment option.