Sulphonamides and TB

Hi, i am writing a microbiology report and for my discussion i need to know why sulphonamides are so good at targeting tb. In my report, i have stated they are not effective against gram - due to ABC transporters, and good against gram +. The results against tb are better than the ones for gram + bacteria, and i am struggling to find why they are so good. From reading tb has abc exporters so I'm really confused as to why sulphonamides are so effective. Im assuming its to do with it being a mycolater, and something to do with its wall structure, but I'm stuck. Does anyone know why?