Comparison of characteristics of drug-resistant Mycobacterium Tuberculosis from pulmonary between primary treatment and retreatment in local region of Southwest China

A BSTRACT Background: The Mycobacterium tuberculosis (MTB) is a threat to human health. However, the drug-resistant Mycobacterium tuberculosis (DR-MTB) is more threat than MTB. In the patients with pulmonary tuberculosis (PTB), the reasons of recurrence are key points for prevention and treatment. Objective: This study aimed to compare the characteristics of DR-MTB from patients with PTB between primary treatment (PT) and retreatment (RT). Materials and Methods: Patients with DR-PTB, including primary treatment (DR-PTB-PT) and retreatment (DR-PTB-RT), were retrospectively studied from January 2020 to December 2023. Demographic data were collected. All the isolates were cultured using Roche culture method, drug susceptibility test (DST) using the proportion method, and detect the gene mutation using the real-time fluorescent polymerase chain reaction melting curve analysis method (MCA). Results: There were 123 patients with DR-PTB-PT and 133 patients with DR-PTB-RT included in this study. There were no significant differences on mean age, gender, living regions, and residence between two groups. There was a significant difference on phenotypic ( P < 0.05) between two groups. There were positive correlations between the extrapulmonary sites accompanied by MTB, comorbidity, and DR-PTB types. The phenotypic DR types and comorbidity were significant risk factors for DR-PTB-RT. Conclusion: The codons of RpoB529–533, KatG315, Emb306, and GyrA88–94 were main gene mutation sites in the DR-PTB-PT and DR-PTB-RT in the local southwest regions of China. The poly-DR and comorbidity were the risk factors of DR-PTB-RT.