RpoB Gene Mutation Characteristics of Rifampicin-resistant Tuberculosis in Anqing, China

Background: Rifampicin resistant tuberculosis is a serious problem faced by tuberculosis control in China, and rapid detection of rifampicin resistance is urgently needed. Objectives: This study aimed to describe the molecular characteristics and frequency of RNA polymerase β subunit (rpoB) gene mutations in rifampicin-resistant tuberculosis (RR-TB) in the Anqing area. Methods: The rpoB gene fragment was amplified by polymerase chain reaction (PCR), and all isolates were sequenced for mutations in the rpoB gene. The mutations were obtained by comparing the sequencing results with the MUBII database. In addition, logistic regression was used to analyze the relationship between rpoB mutations and rifampicin (RIF) resistance. Results: There were 152 males and 42 females in this study, and the mean age was 56.60 ± 17.91 years. Mutations in the rpoB gene were a risk factor for rifampicin resistance (β = 5.271, P < 0.001 OR = 195.192). Among the 19 RR-TB strains, 16 (84.21%) had mutations in the ropB gene, and three (1.71%) of 175 rifampicin-sensitive strains were mutated. The mutation sites of five strains (31.58%) were at the codon 526 and five strains (31.58%) at the codon 531. However, there were two strains at the codon 513 and two strains at the codon 533 (15.79%), and two strains (10.53%) were double mutations. Conclusions: The mutation characteristics of the rpoB gene in the Anqing area are complex, and rpoB mutation detection can be used as an indicator to screen drug resistance of RIF.