OBJECTIVE: To observe the resistance of Mycobacterium abscessus to rifampin and to investigate if there is any mutation of rpoB gene in strains with high minimal inhibitory concentration (MIC). METHODS: Mycobacterium abscessus was identified with both biochemical methods and PCR-RFLP. The MICs of rifampin to all the clinical strains and the type strain ATCC19977 were determined. DNA sequences were obtained from a 1272 bp fragment of the rpoB gene from either low or high rifampin MIC strains using PCR amplification. RESULTS: Only one strain had low MICs of 4 microg/ml. MICs of all the other 14 strains, as well as the type stain were above 128-256 microg/ml. Although there were some differences in nucleotide sequence of rpoB gene, all strains had the same amino acid sequence without any mutations. CONCLUSIONS: Mycobacterium abscessus showed a high resistance to rifampin. Mutations of rpoB gene do not seem to be the responsible mechanism.
OBJECTIVE: To observe the resistance of Mycobacterium abscessus to rifampin and to investigate if there is any mutation of rpoB gene in strains with high minimal inhibitory concentration (MIC). METHODS:Mycobacterium abscessus was identified with both biochemical methods and PCR-RFLP. The MICs of rifampin to all the clinical strains and the type strain ATCC19977 were determined. DNA sequences were obtained from a 1272 bp fragment of the rpoB gene from either low or high rifampin MIC strains using PCR amplification. RESULTS: Only one strain had low MICs of 4 microg/ml. MICs of all the other 14 strains, as well as the type stain were above 128-256 microg/ml. Although there were some differences in nucleotide sequence of rpoB gene, all strains had the same amino acid sequence without any mutations. CONCLUSIONS:Mycobacterium abscessus showed a high resistance to rifampin. Mutations of rpoB gene do not seem to be the responsible mechanism.
Authors: Uday S Ganapathy; Tian Lan; Philipp Krastel; Marissa Lindman; Matthew D Zimmerman; HsinPin Ho; Jansy P Sarathy; Joanna C Evans; Véronique Dartois; Courtney C Aldrich; Thomas Dick Journal: Antimicrob Agents Chemother Date: 2021-08-17 Impact factor: 5.191