|
Sir, Recently in your journal, Lee et al.’ demon-strated mutation in the emb2 region in low-level resistant Mycobacterium tuberculosis We support their finding that isolates with a Minimum Inhibitory Concentration (MIQ level lower than 20fighrO may not contain any mutation in the assigned ha spot for ethambutol resismnce. We analyzed a Ihnited number of isolates in our lab with MIC levels lower than 10fig/m1 and could not find any polymorphism in the ethambutol resistance determining region (ERDR), Met306 (manuscript under preparation). Such isolates are categorized as moderately resistant? However, the novel types of mutations mentioned by LED et aL; Deluding A314G, Y322C and D331Y, seem to be ambiguous. lb. Is because the authors have mentioned amble acid Alanine (A), Tyrosine (Y) and Aspartie and (D) at colon positions 314, 322 and 331, respectively, whereas the deciphered genuine sequence of the standard reference strain Mycobaterium tuberculosis H37Ry reveals Glycine (C), Tryptophan (W) and Clyeine (c) amino acid at colon positions 314, 322 and 331, respectively? Whether the authors have used some other reference strain is also not mentioned.
|