Mutations of rpoB gene in multidrug resistant Mycobacterium tuberculosis clinical isolates from Henan province

Aim:To analyze the characteristics of the mutations of rpoB genes in multidrug resistant Mycobacterium tuberculosis(MDR-TB) clinical isolates from Henan province.Methods:A total of 150 MDR-TB clinical strains were collected and the mutation patterns of rpoB full ORF was detected by PCR and sequencing with H37Rv as control.Results:97.2%(140/144) isolates carried mutations in the full ORF of rpoB gene,and 96.5%(139/144) isolates carried mutations in RRDR.99%(139/140) isolates showed mutations both in the RRDR and outside the RRDR.The top 3 loci with high mutation frequency were rpoB531,rpoB526 and rpoB516.Discovered 15 mutation loci and 4 mutation types that had not been recorded previously.Among them,rpoB1284 probably was polymorphism locus and had nothing to do with rifampcin resistance.Conclusion:It is of high sensitivity to discover MDR-TB by detecting mutation loci within RRDR.