Complex sentence: Since then, drugs such as isoniazid and rifampinhave been used, but resistance of "Mycobacterium tuberculosis" to isoniazid, rifampin, and other common treatments has become an increasingly relevant clinical challenge.
Split into simpler sentences: Since then, drugs such as isoniazid and rifampinhave been used. Resistance of "Mycobacterium tuberculosis" to isoniazid, rifampin, and other common treatments has become an increasingly relevant clinical challenge.