Bryan L E, Haraphongse R, Van den Elzen H M
J Antibiot (Tokyo). 1976 Jul;29(7):743-53. doi: 10.7164/antibiotics.29.743.
Three strains of Pseudomonas aeruginosa resistant to gentamicin obtained as representative gentamicin-resistant clinical isolates from the University of Alberta Hospital (UAH) in Edmonton, Canada were characterized to determine their mechanism of resistance. All strains showed wide aminoglycoside resistance (tobramycin, sisomicin, amikacin, streptomycin, kanamycin, SCH 20569) but contained no evidence of gentamicin-acetylating, adenylating or phosphorylating activity. Gentamicin inhibited amino-acid incorporation in cell-free systems equally well with either ribosomes or soluble cell fractions obtained from either resistant or sensitive strains. Plasmid DNA was detected in two strains but resistance could not be transferred by conjugation to either P. aeruginosa or Escherichia coli recipients. The resistant strains showed a marked reduction in energy-dependent accumulation of gentamicin compared to a sensitive strain. These strains which are common at UAH are most likely resistant due to a failure of gentamicin to be transported across the cytoplasmic membrane to ribosomal sites until relatively high external gentamicin concentrations.
从加拿大埃德蒙顿的阿尔伯塔大学医院（UAH）获取了三株对庆大霉素耐药的铜绿假单胞菌，作为耐庆大霉素临床分离株的代表进行特性分析，以确定其耐药机制。所有菌株均表现出广泛的氨基糖苷类耐药性（对妥布霉素、西索米星、阿米卡星、链霉素、卡那霉素、SCH 20569耐药），但未发现有庆大霉素乙酰化、腺苷化或磷酸化活性的证据。在无细胞系统中，庆大霉素对从耐药或敏感菌株获得的核糖体或可溶性细胞组分抑制氨基酸掺入的效果相同。在两株菌株中检测到了质粒DNA，但耐药性不能通过接合转移给铜绿假单胞菌或大肠杆菌受体。与敏感菌株相比，耐药菌株中庆大霉素的能量依赖性积累明显减少。这些在UAH常见的菌株很可能是由于在外部庆大霉素浓度相对较高时，庆大霉素无法转运穿过细胞质膜到达核糖体部位而产生耐药性。
