Honkonen E, Lassila O, Erkkola R
Am J Perinatol. 1985 Jan;2(1):17-20. doi: 10.1055/s-2007-999904.
A new method for assessing antibacterial activity in amniotic fluid (AF) is presented. Sample sizes of 100 microliter were incubated at 37 degrees C in an equal amount of growth medium with inoculated bacteria. The quantification of bacterial growth was established by measuring the change in optical density with an automated spectrophotometer. In this study, Escherichia coli, type K 12, was used for inoculation and the bacterial growth was assessed after 6, 18, 30, 42, and 54 hours' incubation. The variation coefficients in intra-assay and interassay measurements were 3.8 and 5.2%, respectively. Shaking of the incubated sample significantly changed the results by increasing the number of viable cells in the most probable number method and decreasing the optical density difference in the spectrophotometric method. Nevertheless, the correlation between the results in both methods was good (r = 0.94, p less than 0.05, and r = 0.98, p less than 0.01, respectively). By filtering the AF sample before incubation, a great deal of antibacterial activity was removed. The reproducibility, simplicity, and rapidity of this spectrophotometric method of assessing antibacterial activity in AF may make it a useful clinical tool.
本文介绍了一种评估羊水（AF）抗菌活性的新方法。将100微升样本与接种细菌的等量生长培养基在37℃下孵育。通过使用自动分光光度计测量光密度变化来确定细菌生长的定量。在本研究中，使用K12型大肠杆菌进行接种，并在孵育6、18、30、42和54小时后评估细菌生长情况。批内和批间测量的变异系数分别为3.8%和5.2%。孵育样本的振荡显著改变了结果，在最大可能数法中增加了活细胞数量，在分光光度法中降低了光密度差异。然而，两种方法的结果之间相关性良好（分别为r = 0.94，p < 0.05，以及r = 0.98，p < 0.01）。通过在孵育前过滤AF样本，大量抗菌活性被去除。这种评估AF抗菌活性的分光光度法的重现性、简便性和快速性可能使其成为一种有用的临床工具。
