title: [Relationship between streptomycin susceptibility and rpsL mutations of Mycobacterium tuberculosis strains].
abstract: The relationship between streptomycin (SM) susceptibility and rpsL mutations of Mycobacterium tuberculosis strains was studied. Of 18 clinically isolated SM-resistant M.tuberculosis strains, mutation was suspected in 9 strains (50%) with SM MICs of > or = 256 micrograms/ml by PCR-single strand conformation polymorphism targeting rpsL gene. On the other hand, using PCR-direct sequence method, amino acid substitution caused by single nucleotide point mutation in rpsL gene was demonstrated in 11 out of 18 strains (61%). The same amino acid substitution at codon 43 (Lys-->Arg) was observed in all 11 strains with SM MICs of > or = 256 micrograms/ml. In addition, PCR products obtained from these 11 strains could not be cut by a restriction enzyme, Mbo II, while H37Rv strain and the other 32 strains with SM MICs of < 256 micrograms/ml were cut into 2 fragments. In conclusion, our results suggest that highly SM-resistant M.tuberculosis strains with MICs of > or = 256 micrograms/ml could be rapidly and easily detected by the restriction enzymatic method.
authors.affiliation: Second Department of Internal Medicine, Nagasaki University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Fukuda
authors.forename: H
authors.initials: H
authors.lastname: Koga
authors.forename: H
authors.initials: H
authors.lastname: Ohno
authors.forename: K
authors.initials: K
authors.lastname: Ogawa
authors.forename: B
authors.initials: B
authors.lastname: Yang
authors.forename: J
authors.initials: J
authors.lastname: Miyamoto
authors.forename: K
authors.initials: K
authors.lastname: Tomono
authors.forename: S
authors.initials: S
authors.lastname: Kohno
mesh_terms: D000904:Antibiotics, Antitubercular / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D005798:Genes, Bacterial; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D017354:Point Mutation; D013307:Streptomycin / Q000494:pharmacology*
chemical_list: D000904:Antibiotics, Antitubercular; D013307:Streptomycin