the effect of ubiquitin like protein-proteasome system on the drug resistance of isoniazid mono-resistant mycobacterium tuberculosis

Background: tuberculosis (tb) is one of the most widespread and lethal infectious diseases worldwide. the emergence of drugresistant tb has hampered effective tb treatment and control. prokaryotic ubiquitin-like protein-proteasome system (pps) contributes to the survival of mycobacterium tuberculosis in the host. however, whether pps effects drug resistance of isoniazid monoresistant mycobacterium tuberculosis (inh-mtb) is still unknown. objectives: this study aimed at exploring the effect of pps on drug resistance of inh-mtb strain. methods: in this study, over-expression of strains and deletion of mutant strains were constructed using electroporation. the researchers identified these constructed strains by quantitative reverse transcription polymerase chain reaction (rt-qpcr) or pcr. the minimum inhibitory concentration (mic) of isoniazid in inh-mtb strain and its derivative pps mutant strains were determined using the resazurin micro-titre assay. results: the mic of isoniazid was 8 g/ml higher in inh-mtb with pup over-expression strain than that in inh-mtb. the mic of isoniazid was 4.82 g/ml, 4.98 g/ml, 4.99 g/ml, and 4.9 g/ml lower in inh-mtb with deletion of pup, dop, pafa or mpa strains than that in inh-mtb, respectively. the differences had statistical significance (p < 0.05). the mic of isoniazid was 1.03g/ml higher in inh-mtb with pafa over-expression strain than that in inh-mtb. the mic of isoniazid was 1.03 g/ml and 0.68 g/ml lower in inh-mtb with dop, mpa over-expression strains than that in inh-mtb, respectively. the differences had no statistical significance (p > 0.05). conclusions: these results show that pps effects the drug resistance of the inh-mtb strain.