ABSTRACT
The sexual life cycle of the hemogregarine Hepatozoon mocassini was studied in Aedes aegypti, an experimental mosquito host, using transmission electron microscopy. Gamonts were observed leaving the host snake erythrocyte as early as 30 min after mosquitoes ingested infected blood, and some gamonts had penetrated the gut epithelial cells by this time. Six hours post-feeding, gamonts were identified within cells of the abdominal fat body. Twenty-four hours post-feeding, gamonts were often entrapped within the peritrophic membrane, but were no longer observed within the gut wall. Parasites pairing up in syzygy and undergoing sexual differentiation were observed within fat cells at this time, and by 48 hours post-feeding, well-developed macro- and microgametocytes as well as microgametes were discernible. Developing zygotes observed 3 days post-feeding were enclosed within a parasitophorous vacuole. By day 6, multinucleate oocysts with crystalloid bodies in the cytoplasm were seen. Sporozoites developing within sporocysts appeared by day 12. Seventeen days post-feeding, mature oocysts with sporocysts containing approximately 16 sporozoites were observed upon dissection of mosquitoes. Large crystalloid bodies no longer bound by rough endoplasmic reticulum were located anterior and posterior to the sporozoite nucleus. Free sporozoites were not observed.
Subject(s)
Eucoccidiida/growth & development , Aedes , Animals , Eucoccidiida/isolation & purification , Gametogenesis , Microscopy, Electron , Snakes/parasitology , SporesABSTRACT
The management of opportunistic infections is a significant problem in acquired immunodeficiency syndrome (AIDS) and the development of more effective chemotherapeutic agents is needed. We present the ocular manifestations of an AIDS-like disease in rhesus monkeys experimentally infected with simian immunodeficiency virus (SIV) at the Delta Regional Primate Research Center. These findings consisted of rubeosis in the anterior segment and retinitis, optic neuritis, choroiditis and panophthalmitis in the posterior segment of the eye. Investigation of the retinas by electron microscopy revealed SIV in both eyes of one animal and a herpes virus in two animals. Serology confirmed cytomegalovirus (CMV) as the likely agent. This primate model will prove useful for both further investigations of the possible interaction between immunosuppressive lentiviruses and CMV in ocular disease and antiviral drug testing.
Subject(s)
Eye Diseases/complications , Simian Acquired Immunodeficiency Syndrome/complications , Simian Immunodeficiency Virus , Animals , Antibodies, Viral/blood , Antigens, Viral/immunology , Cytomegalovirus/immunology , Disease Models, Animal , Eye Diseases/microbiology , Lymphocytes/immunology , Macaca mulatta , Retina/ultrastructure , Simian Immunodeficiency Virus/immunology , Simian Immunodeficiency Virus/ultrastructure , Simplexvirus/immunologyABSTRACT
The lungs of African green monkeys infected with simian varicella virus (Delta herpesvirus) were examined by scanning and transmission electron microscopy. Endothelial cell shrinkage, oedema formation and necrosis characterized the scanning electron microscopy of the affected vasculature. Oedema of the interalveolar septa with swelling of the capillary endothelial cells was observed by transmission electron microscopy. Numerous viral particles were associated with a generalized area of necrosis of the alveolar wall.
