Mutations in the gyrA and grlA genes of quinolone-resistant clinical isolates of methicillin-resistant Staphylococcus aureus.
The mutations in the quinolone-resistance determining regions (QRDR) of the gyrA, gyrB and grlA genes and in the norA gene from five clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) were examined by DNA sequencing. The mutation from Ser84 to Leu in GyrA was associated with relatively high-level resistance to quinolones, whereas the mutation from Glu88 to Gly or Lys in GyrA was associated with low-level resistance to quinolones. Mutations of the grlA gene were observed at codon 80 (Ser80) or 84 (Glu84), independent of the mutations of gyrA. No mutations were observed in either the gyrB or norA genes.
Research Laboratories, Toyama Chemical Co., Ltd., Japan.
M
M
Takahata
M
M
Yonezawa
S
S
Kurose
N
N
Futakuchi
N
N
Matsubara
Y
Y
Watanabe
H
H
Narita
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000187:drug effects / Q000235:genetics; D027081:DNA Gyrase; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II / Q000187:drug effects / Q000235:genetics*; D024841:Fluoroquinolones; D016106:Methicillin Resistance / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009154:Mutation; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D027081:DNA Gyrase; D027101:DNA Topoisomerase IV; D004250:DNA Topoisomerases, Type II; D024841:Fluoroquinolones; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C075040:NorA protein, Staphylococcus