A systematic analysis of ultrastructural lesions in the Plasmodium coatneyi splenectomized rhesus macaque model of severe malaria.

Plasmodium falciparum remains one of the world's deadliest diseases and with ongoing concerns of evolving drug resistance, there is a need for continued refinement of the Plasmodium coatneyi infection model in macaques to study severe malaria. As such, the systemic ultrastructural lesions associated with P. coatneyi infection in splenectomized rhesus macaques was evaluated in 6 animals. Autopsy samples from multiple areas of the central nervous system (CNS), kidneys, heart, liver, and lungs of all 6 animals were processed for electron microscopy. A systematic analysis of the ultrastructural changes associated with the plasmodium was undertaken by multiple pathologists to ensure consensus. All tissues exhibited marked sequestration of infected red blood cells comprised either of cytoadherence to endothelium or rosette formation, associated with variable degrees of host cell damage in a range of tissues that in severe cases resulted in necrosis. This is the first complete systemic evaluation of ultrastructural tissue lesions in P. coatneyi-infected rhesus macaques, and the findings have important implications evaluating of the use of this model for the study of severe malaria caused by P. falciparum in humans.

Combined Fatal Systemic Chlamydia sp. and Aeromonas sobria Infection in Juvenile Siamese Crocodiles ( Crocodylus siamensis).

Chlamydial infections in crocodiles have been described in several countries and in several different species. These are typically associated with severe pharyngitis and conjunctivitis, with death occurring secondary to compromise of the upper respiratory tract due to obstruction of the trachea. A population of ranched Siamese crocodiles in central Thailand experienced an epizootic of sudden death in juvenile animals. The affected animals had fulminant systemic disease primarily involving the liver and spleen but also affecting the kidneys, heart, and the whole of the respiratory tract. Chlamydia sp. were noted in liver and spleen during histopathological examination and confirmed with transmission electron microscopy and polymerase chain reaction (PCR). The sequence of the PCR product suggested a novel Chlamydia sp. of Siamese crocodiles. Crocodile farming represents an important economy in several parts of the world. Epizootics, such as the one described in this manuscript in association with Chlamydia sp., can have devastating impact on the industry and represent a potential zoonosis of significant public health concern. This is the first report of Chlamydia sp. and Aeromonas sobria causing systemic disease in crocodiles as well as the first histopathological and ultrastructural description of Chlamydia infection in Siamese crocodiles.

Mammary carcinoma in a male rhesus macaque (Macaca mulatta): histopathology and immunohistochemistry of ductal carcinoma in situ.

BACKGROUND: A mammary nodule was noted in a male rhesus macaque during physical examination. METHODS AND RESULTS: Histopathological and immunohistochemical analysis was performed. Ductal carcinoma in situ was confirmed. CONCLUSIONS: To date, there are two reports of mammary carcinoma in male non-human primates, and none in the rhesus macaque.