Visualization of Hydatid Elements: Comparison of Several Techniques

Abstract

Some techniques available at our laboratory were tested for their ability to aid in the morphological diagnosis of hydatid elements (Echinococcus granulosus [“Taenia echinococcus”]) isolated from cysts in humans and sheep. Unstained, methanol-fixed hooklets were fluorescent, most starkly so under violet light (excitation filter wavelength, 405 nm; long-pass filter wavelength, 495 nm). Auramine-rhodamine and Gram procedures failed to stain hooklets. Ziehl-Neelsen stain yielded indifferent results when organisms were viewed under transmitted light but resulted in a surprisingly intense red fluorescence when organisms were viewed under green light (excitation, 546 nm; long pass, 590 nm). Wheatley trichrome stain gave better and more uniform results than fuchsin. Ryan trichrome blue stain was the best under transmitted light; hooklets stained uniformly and intensely and were easily distinguishable from the background. Very satisfactory results were also obtained with a much simpler procedure (modified Baxby technique: no fixation, steaming hot 1% safranin for 2 min, and malachite green for 30 s). Therefore, Ryan and modified Baxby stains are recommended for the examination of E. granulosus under transmitted light. For fluorescence microscopy, Ziehl-Neelsen stain under green excitation light, or violet light with no staining, is also very useful. Epifluorescence microscopy is especially convenient for examining samples concentrated by filtration, as it renders the filter pores inconspicuous.

Differentiating Taenia eggs found in human stools: does Ziehl-Neelsen staining help?

“…Samples were stained with carbol-fuchsin 3% for 15', washed with tap water and then decoloured with 70% ethanol 1% HCl for 2'. After a second washing, the slide was contrasted with 3% methylene blue for 5', washed again and left to dry at room temperature (Clavel et al 1999;Chapin & Lauderdale 2007).…”

Mobile Diagnostics Based on Motion? A Close Look at Motility Patterns in the Schistosome Life Cycle

“…Target organisms differ in properties such as size, morphological features, and optical density. They may also have distinguishing properties that can be exploited for diagnostics, such as birefringence [ 57 , 58 ], autofluorescence [ 59 , 60 ], or magnetic [ 61 ], adhesive, antigenic, and lectin-binding properties [ 62 , 63 ].…”

Management of serology negative human hepatic hydatidosis (caused by Echinococcus granulosus) in a young woman from Bangladesh in a resource-rich setting: A case report

“…In this woman's case, microscopic fluid evaluation during the surgical procedure was unrevealing and there was no reported visualization of protoscoleces, hooklets or fragments of laminated membrane. Visualizing diagnostic hydatid elements in wet, unstained mounts of cystic fluid sediment is challenging and time consuming; thus researchers are searching for potentially superior techniques such as rapid antigen detection assays [27] , [28] . Our Institution's access to a parasitology laboratory with technicians experienced in the identification of hydatid fluid sediment was critical for the correct diagnosis and appropriate management of this patient.…”