Nolte F S, Williams J M, Maher K L, Metchock B
Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.
Am J Clin Pathol. 1993 Mar;99(3):286-8. doi: 10.1093/ajcp/99.3.286.
Enterococcus faecalis strains that are refractory to aminoglycoside-penicillin synergistic killing can be predicted by their ability to grow in high concentrations of aminoglycoside (2,000 mg/L) or by disk diffusion tests using high content aminoglycoside disks. Forty-eight well-characterized clinical isolates of E. faecalis were used to evaluate recently reformulated gentamicin and streptomycin synergy screening tests on both overnight and rapid MicroScan (MS) Pos MIC panels (Baxter, West Sacramento, CA). The results obtained with the MS screening tests were compared with those from modified agar disk diffusion results. Discrepancies were resolved by an in-house broth microdilution method. The MS overnight tests detected 25 of 25 (100%) gentamicin high-level resistant strains and 23 of 24 (96%) streptomycin high-level resistant strains. No false high level resistance was found with the MS overnight tests. The MS rapid tests detected 100% of the gentamicin and 100% of the streptomycin high-level resistant strains, but one isolate was falsely high-level resistant to gentamicin (96% specific). The reformulated MS synergy screening tests were acceptable alternatives to disk diffusion for detection of high level aminoglycoside resistance in E. faecalis.
对氨基糖苷类 - 青霉素协同杀伤具有耐药性的粪肠球菌菌株，可以通过其在高浓度氨基糖苷类（2000mg/L）中生长的能力或使用高含量氨基糖苷类药敏纸片的纸片扩散试验来预测。48株特征明确的粪肠球菌临床分离株用于评估最近重新配制的庆大霉素和链霉素协同筛选试验，该试验在过夜培养和快速MicroScan（MS）Pos MIC平板（Baxter，加利福尼亚州西萨克拉门托）上进行。将MS筛选试验得到的结果与改良琼脂纸片扩散试验的结果进行比较。差异通过内部肉汤微量稀释法解决。MS过夜试验检测出25株庆大霉素高水平耐药菌株中的25株（100%）和24株链霉素高水平耐药菌株中的23株（96%）。MS过夜试验未发现假高水平耐药情况。MS快速试验检测出100%的庆大霉素和100%的链霉素高水平耐药菌株，但有1株分离株对庆大霉素出现假高水平耐药（特异性为96%）。重新配制的MS协同筛选试验是用于检测粪肠球菌高水平氨基糖苷类耐药性的纸片扩散试验的可接受替代方法。
