Clinical emergence of inducible macrolide resistance mediated by acquired <i>erm</i> (41) C28T mutation in <i>Mycobacterium abscessus</i>

Inducible macrolide resistance mediated by the <i>erm</i>(41) T28 allele is a well-established intrinsic mechanism in <i>Mycobacterium abscessus</i>. Here, we report a case of <i>M. abscessus</i> pulmonary disease in which an initial <i>erm</i>(41) C28 isolate developed inducible resistance through a <i>de novo</i> C28T point mutation during prolonged therapy. To our knowledge, this case provides the first clinical evidence that <i>erm</i>(41)-mediated inducible resistance can arise <i>in vivo</i> under antimicrobial selective pressure.