Correlation of molecular resistance mechanisms and phenotypic resistance levels in streptomycin-resistant Mycobacterium tuberculosis.
Quantitative susceptibility testing of clinical isolates of streptomycin-resistant Mycobacterium tuberculosis demonstrated that there is a close correlation between the molecular resistance mechanism and the in vitro activity of streptomycin: mutations in rpsL were mainly associated with high-level resistance, mutations in rrs were associated with an intermediate level of resistance, and streptomycin-resistant isolates with wild-type rpsL and rrs exhibited a low-level resistance phenotype. Investigations of streptomycin-resistant isolates with wild-type rpsL and rrs revealed that (i) there is no cross-resistance to other drugs and (ii) a permeability barrier may contribute to resistance, because resistance was significantly lowered in the presence of a membrane-active agent.
Meier
A
A
Institut für Medizinische Mikrobiologie, Medizinische Hochschule Hannover, Germany.
Sander
P
P
Schaper
K J
KJ
Scholz
M
M
Böttger
E C
EC
D000904:Antibiotics, Antitubercular / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D005838:Genotype; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics*; D010641:Phenotype; D013307:Streptomycin / Q000494:pharmacology*
D000904:Antibiotics, Antitubercular; D013307:Streptomycin