Besnoitiosis in a southern plains woodrat (Neotoma micropus) from Uvalde, Texas.

Recently, Besnoitia neotomofelis was described from a southern plains woodrat (Neotoma micropus) from southern Texas. During May 2010, 1 of 55 southern plains woodrats trapped in Uvalde County, Texas, was diagnosed with besnoitiosis. Grossly, the woodrat had bilateral swellings of the cheeks, and numerous Besnoitia sp.-like cysts were observed in the tongue, facial region, musculature of the limbs, and subcutis of the dorsum and flanks. Little to no inflammation was noted around cysts. The cysts were morphologically similar to B. neotomofelis based on light and transmission electron microcopy. The sequence of the internal transcribed spacer region-1 was identical to the type isolate of B. neotomofelis. Attempts to isolate Besnoitia sp. in laboratory mice failed; however, Toxoplasma gondii was isolated in a Swiss Webster mouse. This represents the first report of besnoitiosis caused by B. neotomofelis in a southern plains woodrat and the first concurrent Besnoitia sp. and T. gondii infection in any host species.