Unusual fluorescent granulomas and myonecrosis in danio rerio infected by the microsporidian pathogen pseudoloma neurophilia.

TitleUnusual fluorescent granulomas and myonecrosis in danio rerio infected by the microsporidian pathogen pseudoloma neurophilia.
Publication TypeJournal Article
Year of Publication2014
AuthorsWest K, Miles R, Kent ML, Frazer KJ
JournalZebrafish
Volume11
Issue3
Pagination283-90
Date Published2014 Jun
ISSN1557-8542
Abstract

Abstract Zebrafish are a powerful model organism to study disease. Like other animal models, Danio rerio colonies are at risk of pathogenic infection. Microsporidia, a group of intracellular fungus-like parasites, are one potential threat. Microsporidian spores germinate and spread causing pathological changes in the central nervous system, skeletal muscle, and other anatomic sites. Infection can impair breeding, cause other morbidities, and ultimately be lethal. Previously, detecting microsporidia in zebrafish has required sacrificing animals for histopathologic analysis or microscopic examination of fresh tissues. Here, we show that fish with microsporidial infection often have autofluorescent nodules, and we demonstrate infectious spread from nodule-bearing fish to healthy D. rerio. Histologic analyses revealed that fluorescent nodules are granulomatous lesions composed of spores, degenerating muscle, and inflammatory cells. Additional histologic staining verified that microsporidia were present, specifically, Pseudoloma neurophilia. Polymerase chain reaction (PCR)-based testing confirmed the presence of P. neurophilia. Further PCR testing excluded infection by another common zebrafish microsporidial parasite, Pleistophora hyphessobryconis. Collectively, these studies show that P. neurophilia can induce skeletal muscle granulomas in D. rerio, a previously unknown finding. Moreover, since granulomas autofluoresce, microscopic screening for P. neurophilia infection is feasible in live fish, avoiding the need to sacrifice fish for surveillance for this pathogen.

DOI10.1089/zeb.2013.0933
Alternate JournalZebrafish