Another way? An investigation into an institution’s use of the Wayson stain in re-evaluating “no organisms seen” on Gram stain smears from positive blood cultures

Abstract

The Wayson stain, a rapid one-step stain that provides contrast between microorganisms and the background, was historically used for the presumptive diagnosis of Yersinia pestis from bubo specimen. In our laboratory, the Wayson stain has long been used to reevaluate blood culture Gram-stained smears from bottles that were flagged as positive by the automated continuous monitoring instrument but where no organisms are seen. In this study, we show that the Wayson stain provides an easily implemented and interpreted technique, other than a repeat Gram stain or acridine orange, to increase the sensitivity of direct organism visualization from blood culture bottles, particularly for Gram-negative organisms.