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This case study explores the histopathological features of Thromboembolic Meningoencephalitis (TEME) caused by Haemophilus somnus infection in a steer's brain.
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(back) AAPSP QA program. Case 2, circulated to participating laboratories March 2005 Click on the (back) links to navigate back to the low- power views H&E section of brain of a calf, rostral, at level of thalamus. Death in a feedlot after short illness characterised mainly by depression Click outside the links on any slide to move to the next slide in the sequence (as in any Powerpoint presentation) Click on the rectangular links to view photomicrographs of the designated areas, and follow the links to higher magnifications.
(back) The pigment visible here is probably formalin pigment, formed as a result of acidic formalin acting on autolysing/haemolysing erythrocytes
(back) Australian Animal Pathology Standards Program Histoproficiency, March Round 2005 Case 2: Bovine brain (thalamus) Thromboembolic meningoencephalits (TEME) Haemophilus somnus infection in a steer. • The salient features noted by most respondents were: • Pallor, malacia or necrosis of the neuropil • Haemorrhage • Vasculitis, fibrinoid and/or leucocytoclastic • Thrombosis • Gram negative bacterial emboli • Inflammatory component mainly neutrophilic • Involvement of both neuropil and meninges • Some neuronal necrosis
(back) Australian Animal Pathology Standards Program Histoproficiency, March Round 2005 Case 2: Bovine brain (thalamus) Thromboembolic meningoencephalits (TEME) Haemophilus somnus infection in a steer. The bacteria were difficult/impossible to see in H&E-stained sections. They were also difficult to discern in routine Gram-stained sections; modifications such as Gram-Twort helped demonstrate them. Giemsa-staining also might have been useful.