Bartlett R C, Mazens M F
Appl Microbiol. 1971 Sep;22(3):372-6. doi: 10.1128/am.22.3.372-376.1971.
An established standard antimicrobial disc susceptibility test recommends the use of a 150-mm petri dish. Many workers substitute 100-mm plates and use various types of mechanical dispensers. A comparison of zone diameters was made by testing Staphylococcus aureus and Escherichia coli against penicillin and chloramphenicol with the use of these different sized plates and dispensers. Zone diameters were consistently smaller at the edges of plates than in the center (0.4 to 1.2 mm). Significant small differences of up to 1.2 mm or no differences were observed when the mean diameters from these various plates were compared. All of the zone diameter measurements fell within accepted values for analytical variability in this procedure. There is no evidence that any individual combination of plates, dispensers, or disc locations provides greater precision in zone diameter measurement. More difficulty was encountered in measuring zones at the periphery of small plates. This suggests that busy clinical laboratory workers might not produce work of comparable quality with the smaller plates.
一项既定的标准抗菌药敏纸片扩散法推荐使用150毫米的培养皿。许多工作人员用100毫米的平板代替，并使用各种类型的机械加样器。通过使用这些不同尺寸的平板和加样器，对金黄色葡萄球菌和大肠杆菌进行青霉素和氯霉素药敏试验，比较抑菌圈直径。平板边缘的抑菌圈直径始终比中心小（0.4至1.2毫米）。比较这些不同平板的平均直径时，观察到高达1.2毫米的显著微小差异或无差异。所有抑菌圈直径测量值均在该方法分析变异性的可接受范围内。没有证据表明平板、加样器或药敏纸片位置的任何个别组合在抑菌圈直径测量中能提供更高的精度。在测量小平板边缘的抑菌圈时遇到了更多困难。这表明忙碌的临床实验室工作人员使用较小平板可能无法产生质量相当的结果。
