[Mutations of gyrA gene and parC gene in Streptococcus pneumoniae].
Fifty-six levofloxacin-susceptible strains of Streptococcus pneumoniae were isolated from various clinical material in July, 2002 from June, 2001, examined antimicrobial susceptibility testing of levofloxacin and sparfloxacin, and performed analysis of gyrA gene and parC gene. 56 strains were not sparfloxacin-resistance. There was not found to mutation of gyrA gene. However, the individual mutations of parC gene were accepted by 13 strains among 56 strains which showed sensitivity by levofloxacin. One strain was Asp-78-->Asn, other one strain was Ser-79-->Phe, and 11 strains were Lys-137-->Asn. These results suggest that fluoroquinolone-resistance could be due to the multiple mutations in gyrA gene and parC gene, although the individual mutation of parC gene existed also in levofloxacin-susceptible strains.
Miyamoto
Hitoshi
H
Department Laboratories, Ehime University Hospital.
Murase
Mitsuharu
M
D027081:DNA Gyrase / Q000235:genetics*; D027101:DNA Topoisomerase IV / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D009154:Mutation; D013296:Streptococcus pneumoniae / Q000235:genetics*
D027101:DNA Topoisomerase IV; D027081:DNA Gyrase