Table 3.
Prior reports of putative Sarcocystis neurona tissue cysts in brain or muscle: microscopic and ultrastructural features.
| Host species | Experimental infection? |
Tissue cyst location |
Cyst size | Surface Villi? | Microtubules extend to granular layer? |
Electron dense surface protrusions |
Wall thickness |
Reference |
|---|---|---|---|---|---|---|---|---|
| Raccoon | Yes | Muscle | ≤ 270×50 μm | Y (≤ 5×0.7 μm) | Y | Y | ≤ 1.5 μm | Stanek et al. 2002 |
| Raccoon | Yes | Muscle | ≤ 125×10μm | Y | NRa | NR | <0.5 μm | Dubey, et al., 2001g |
| Skunk | Yes | Muscle | 27.7 μm | Y (3.0 μm) | Y | Y | ∼1.5 μm | Cheadle et al., 2001b |
| Skunk | No | Muscle | ≤ 500×40 μm | Y | Y | Y | 1-2 μm | Dubey et al., 2002 |
| Fisher | No | Muscle | ≤ 200×30 μm | Y (≤ 2.2×0.4μm) | Y | Y | 1-3 μm | Gerhold et al., 2005 |
| Domestic cat | Yes | Muscle | NR | Y (≤ 2.5μm) | Y | Y | NR | Dubey et al., 2000 |
| Domestic cat | Yes | Muscle | ≤ 700×50 μm | Y (≤ 2.8×0.4μm) | Y (sometimes) | Y | 1-2 μm | Dubey et al., 2001c |
| Domestic cat | Yes | Muscle | NR, > 50 μm in photo |
Y (≤2.4 μm) | NR | NR | ∼2 μm | Butcher et al., 2002 |
| Domestic catb, c | No | Brain | 90×80 μm | Y | NR | NR | ∼2 μm | Dubey et al., 2003a |
| Dog | No | Muscle | ∼100×40 μm | Y (≤ 0.8×0.2μm) | No | Y | NR | Vashist et al., 2005 |
| Armadillo | No | Muscle | NR | Y | NR | Y | NR | Cheadle et al., 2001a |
| Straw-necked ibisb, c, d |
No | Brain | ∼60 × 20 μm | Y | NR | NR | ∼1.5-2 μm | Dubey et al., 2001b |
| Cowbirdb | No | Muscle | ∼600 × 20 μm | Y | NR | NR | NR | Mansfield et al., 2008 |
| Harbor seal | Noc | Muscle | 30×20 μm | NR | NR | NR | 2.5 μm | LaPointe et al., 1998 |
| Sea otter (Enhydra lutris kenyoni) |
No | Muscle | 20×90 μm range |
Y(∼2 μm) | NR | NR | NR | Rosonke et al., 1999 |
| Sea otter (E. l. kenyoni) |
No | Muscle | ∼350×200 μm | Y (1.3×0.25μm) | No | Y (50-75nm) | ∼1.5 μm | Dubey et al., 2001f |
| Sea otterb, c (unspecified) |
No | Brain and muscle |
17 to 40 μm diameter |
NR | NR | NR | NR | Thomas et al., 2007 |
| Sea otter (Enhydra lutris nereis) |
No | Brain and muscle |
15 to 60 μm diameter |
Y (2 × 0.2 μm) | Y | Y | 1-4 μm | This report |
a
NR = not reported.
b
Description based on light microscopy only.
c
Tissue cysts were noted in the cerebrum on histopathology or immunohistochemistry, but parasite identity as S. neurona was not confirmed using PCR or transmission electron microscopy
d
Species not determined-may not be S. neurona.