Efficacy of amikacin combinations for nocardiosis.
We isolated five bacterial strains from patients diagnosed as having nocardiosis. Bacterial species were identified based on the similarities in the nucleotide sequences of 16S ribosomal RNAs. Three of the five strains were identified as Nocardia asteroids, but unexpectedly other two were Streptomyces hygroscopicus and Rothia dentocariosa. The latter two species are not members of the family Nocardiaceae. We investigated the susceptibilities of these five strains to the following nine antimicrobial agents: trimethoprim/sulfamethoxazole (TMP/SMX), minocycline (MINO), erythromycin (EM), amikacin (AMK), cefotaxime (CTX), faropenem (FRPM), imipenem (IPM), ciprofloxacin (CPFX), and sparfloxacin (SPFX). The minimum inhibitory concentration (MIC) ranges (mg/ml) were as follows: TMP-SMX, 4- > 32; MINO, 0.125-8; EM, < or = 0.016- > 32; AMK, 1-2; CTX, 0.063- > 32; FRPM, 0.063-16; IPM, 0.125-2; CPFX, 4-32; and SPFX, 0.5-16. Moreover, the synergistic effects of AMK in combination with each of TMP-SMX, MINO, EM, CTX, IPM, and SPFX were investigated by checkerboard synergy testing. No antagonism was recognized for the three N. asteroides strains. Synergistic and additive effects were observed for the combinations of AMK with CTX, IPM, or SPFX.
Kanemitsu
Keiji
K
Department of Molecular Diagnostics, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan. kane2@mail.cc.tohoku.ac.jp
Kunishima
Hiroyuki
H
Saga
Tomoo
T
Harigae
Hideo
H
Ishikawa
Shiho
S
Takemura
Hiromu
H
Kaku
Mitsuo
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000583:Amikacin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D002439:Cefotaxime / Q000008:administration & dosage; D002939:Ciprofloxacin / Q000008:administration & dosage; D004275:DNA, Ribosomal / Q000378:metabolism; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004917:Erythromycin / Q000008:administration & dosage; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology; D006094:Gram-Positive Bacteria / Q000378:metabolism; D006801:Humans; D015378:Imipenem / Q000008:administration & dosage; D007769:Lactams / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D008911:Minocycline / Q000008:administration & dosage; D009615:Nocardia / Q000378:metabolism; D009617:Nocardia Infections / Q000188:drug therapy*; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D013302:Streptomyces / Q000378:metabolism; D013420:Sulfamethoxazole / Q000008:administration & dosage; D014295:Trimethoprim / Q000008:administration & dosage; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D004275:DNA, Ribosomal; D024841:Fluoroquinolones; D007769:Lactams; D012336:RNA, Ribosomal, 16S; D047090:beta-Lactams; D002939:Ciprofloxacin; D004917:Erythromycin; D015378:Imipenem; D000583:Amikacin; D014295:Trimethoprim; C107057:fropenem; D008911:Minocycline; D013420:Sulfamethoxazole; D002439:Cefotaxime; C061363:sparfloxacin