Luna stain, an improved selective stain for detection of microsporidian spores in histologic sections.

TitleLuna stain, an improved selective stain for detection of microsporidian spores in histologic sections.
Publication TypeJournal Article
Year of Publication2011
AuthorsPeterson TS, Spitsbergen JM, Feist SW, Kent ML
JournalDiseases of aquatic organisms
Volume95
Issue2
Pagination175-80
Date Published2011 Jun 16
ISSN0177-5103
KeywordsAnimals, Brachyura, Coloring Agents, Fishes, Microsporidia, Mycoses, Mytilus, Spores, Fungal, Staining and Labeling
Abstract

Microsporidia in histologic sections are most often diagnosed by observing spores in host tissues. Spores are easy to identify if they occur in large aggregates or xenomas when sections are stained with hematoxylin and eosin (H&E). However, individual spores are not frequently detected in host tissues with conventional H&E staining, particularly if spores are scattered within the tissues, areas of inflammation, or small spores in nuclei (i.e. Nucleospora salmonis). Hence, a variety of selective stains that enhance visualization of spores is recommended. We discovered that the Luna stain, used to highlight eosinophils, red blood cells, and chitin in arthropods and other invertebrates, also stains spores of Pseudoloma neurophilia. We compared this stain to the Gram, Fite's acid fast, Giemsa, and H&E stains on 8 aquatic microsporidian organisms that were readily available in our 2 laboratories: Loma salmonae, Glugea anomala, Pseudoloma neurophilia, Pleistophora hyphessobryconis, Pleistophora vermiformis, Glugea sp., Steinhausia mytilovum, and an unidentified microsporidian from UK mitten crabs Eriocheir sinensis. Based on tinctorial properties and background staining, the Luna stain performed better for detection of 6 of the 8 microsporidia. Gram stain was superior for the 2 microsporidia from invertebrates: S. mytilovum and the unidentified microsporidian from E. sinensis.

Alternate JournalDis. Aquat. Org.