| RRC ID |
46965
|
| 著者 |
Kogure T, Shimada R, Ishikawa J, Yazawa K, Brown JM, Mikami Y, Gonoi T.
|
| タイトル |
Homozygous triplicate mutations in three 16S rRNA genes responsible for high-level aminoglycoside resistance in Nocardia farcinica clinical isolates from a Canada-wide bovine mastitis epizootic.
|
| ジャーナル |
Antimicrob Agents Chemother
|
| Abstract |
Nocardia farcinica strains showing high-level resistance to amikacin were isolated from clinical cases in a Canada-wide bovine mastitis epizootic. Shotgun cloning of the resistance genes in the amikacin-resistant mastitis isolate N. farcinica IFM 10580 (W6220 [Centers for Disease Control and Prevention]) using a multicopy vector system revealed that the 16S rRNA gene with an A-to-G single-point mutation at position 1408 (in Escherichia coli numbering) conferred "moderate" cross-resistance to amikacin and other aminoglycosides to an originally susceptible N. farcinica strain IFM 10152. Subsequent DNA sequence analyses revealed that, in contrast to the susceptible strain, all three chromosomal 16S rRNA genes of IFM 10580, the epizootic clinical strain, contained the same A1408G point mutations. Mutant colonies showing high-level aminoglycoside resistance were obtained when the susceptible strain N. farcinica IFM 10152 was transformed with a multicopy plasmid carrying the A1408G mutant 16S rRNA gene and was cultured in the presence of aminoglycosides for 3 to 5 days. Of these transformants, at least two of the three chromosomal 16S rRNA genes contained A1408G mutations. A triple mutant was easily obtained from a strain carrying the two chromosomal A1408G mutant genes and one wild-type gene, even in the absence of the plasmid. The triple mutant showed the highest level of resistance to aminoglycosides, even in the absence of the plasmid carrying the mutant 16S rRNA gene. These results suggest that the homozygous mutations in the three 16S rRNA genes are responsible for the high-level aminoglycoside resistance found in N. farcinica isolates of the bovine mastitis epizootic.
|
| 巻・号 |
54(6)
|
| ページ |
2385-90
|
| 公開日 |
2010-6-1
|
| DOI |
10.1128/AAC.00021-10
|
| PII |
AAC.00021-10
|
| PMID |
20308368
|
| PMC |
PMC2876378
|
| MeSH |
Amikacin / pharmacology
Aminoglycosides / pharmacology*
Animals
Anti-Bacterial Agents / pharmacology
Base Sequence
Canada / epidemiology
Cattle
DNA Primers / genetics
Drug Resistance, Bacterial / genetics
Female
Genes, Bacterial*
Homozygote
In Vitro Techniques
Mastitis, Bovine / drug therapy*
Mastitis, Bovine / epidemiology
Mastitis, Bovine / microbiology*
Microbial Sensitivity Tests
Nocardia / drug effects*
Nocardia / genetics*
Nocardia / isolation & purification
Nocardia Infections / drug therapy
Nocardia Infections / epidemiology
Nocardia Infections / microbiology
Nocardia Infections / veterinary*
Point Mutation*
RNA, Bacterial / genetics*
RNA, Ribosomal, 16S / genetics*
|
| IF |
4.904
|
| 引用数 |
5
|
|
WOS 分野
|
PHARMACOLOGY & PHARMACY
MICROBIOLOGY
|
| リソース情報 |
| 病原微生物 |
IFM 10152
IFM 10580
IFM 10848
IFM 10849
IFM 10850
IFM 10851 |
