Three-dimensional fine structure of feeder organelle in Cryptosporidium parvum

Parasitol Int. 2019 Dec:73:101958. doi: 10.1016/j.parint.2019.101958. Epub 2019 Jul 9.

Abstract

Feeder organelles of Cryptosporidium are the convoluted structures located at the host-parasite interface that uptake of nutrients from host cells. Although the ultrastructure of feeder organelles has been summarized as being highly invaginated structure, the three-dimensional form remains uncertain. Osmium-maceration scanning electron microscopy (OS-SEM) allows visualization of the three-dimensional ultrastructure after removing soluble proteins. Here, we assessed C. parvum attached to mouse ileal epithelial cells using transmission electron microscopy (TEM) and OS-SEM. Feeder organelles visualized by TEM as aggregated structures of concentrically-, vertically- and randomly-lined bars comprised a complex reticulated network of stacked flat bursiform, ring-shaped bursiform and reticulated tubular membranes on OS-SEM. These findings suggested that the feeder organelles are more complex than was previously thought.

Keywords: Cryptosporidium; Feeder organelle; Osmium maceration; SEM; TEM.

MeSH terms

  • Animals
  • Cryptosporidium parvum / ultrastructure*
  • Epithelial Cells / parasitology*
  • Ileum / parasitology*
  • Mice
  • Mice, SCID
  • Microscopy, Electron, Scanning
  • Microscopy, Electron, Transmission
  • Organelles / ultrastructure
  • Osmium

Substances

  • Osmium