Visualization of vaginal flora in cervical smears using a modified microwave silver-staining method.

The advantage of studying the vaginal flora to determine the bacteria and fungi present in cervical smears (as opposed to cultivation of these micro-organisms) is that the micro-organisms can be observed in their natural habitat. However, they are only faintly stained by the conventional Papanicolaou method. Accordingly, contrast is weak and visualization poor. For this reason, we developed a modified microwave silver-staining method that can be performed retrospectively on stained smears. Bacteria and fungi stain distinctly black and can be studied in greater detail, and their inter-relationship can be visualized. Haematoxylin or Eosin counterstain allows us to visualize vaginal inhabitants in relation to epithelial cells. In the series presented here, we show that a modified microwave silver-staining method is well suited to studying the ecology of micro-organisms in smears taken from women presenting to their doctor with clinical symptoms. Using this staining method, we have shown that lactobacilli overgrowth is associated with symptoms.