Knockdown of argininosuccinate lyase influences the growth of Mycolicibacterium smegmatis in vitro and in vivo.

The rising prevalence of drug-resistant tuberculosis (DR-TB), coupled with stagnation in the development of novel therapeutics, underscores the urgent need for new drug targets and innovative anti-tuberculosis agents. In this study, we demonstrate that CRISPR interference-mediated knockdown of argH, a nitrogen metabolism-associated gene encoding argininosuccinate lyase, significantly impairs the growth of Mycolicibacterium smegmatis (formerly Mycobacterium smegmatis). This growth defect was alleviated in a concentration-dependent manner by arginine supplementation. In a goldfish infection model, argH knockdown led to a marked reduction in bacterial burden within both liver and kidney tissues. Notably, bacitracin and 5-fluorouracil exhibited synergistic effects when combined with argH knockdown. Metabolomic profiling revealed significant perturbations in multiple amino acids, as well as in succinyl-CoA and lactate levels, suggesting that suppression of argH impairs M. smegmatis proliferation by disrupting amino acid homeostasis and interfering with aerobic respiration.