Parasitic organisms have emerged from nearly every corner of the eukaryotic kingdom and hence display tremendous diversity of form and function. This diversity extends to their mitochondria and mitochondrion-derived organelles. While the principles of the chemiosmotic theory apply to all these pathogens, the differences from their hosts provide opportunities for therapeutic development. In this...

Toxoplasmosis is an anthropozoonosis caused by the protozoan Toxoplasma gondii, an obligate intracellular parasite belonging to the phylum Apicomplexa. It presents a cosmopolitan geographic distribution, with high rates of infection in humans; capable of infecting nucleated cells from a wide variety of hosts. Toxoplasmosis is one of the most common opportunistic infections affecting HIV positiv...

Virus-like particles (VLP) were observed in different phases of the in vitro zoosporulation of Perkinsus atlanticus (Apicomplexa, Perlunsidae) which parasitized the gill tissues of Rudtapes decussatus (Molluscs, Bivalvia). These VLP were represented by numerous electron-dense bodies (ca 125 nm diameter) not previously described in similar culture processes. The VLP were densely packed in a memb...

We provide the first evidence of Hepatozoon parasites infecting bats. We sequenced a short fragment of the 18S rRNA gene (~600 base pairs) of Hepatozoon parasites from 3 Hipposideros cervinus bats from Borneo. Phylogenies inferred by model-based methods place these Hepatozoon within a clade formed by parasites of reptiles, rodents, and marsupials. We discuss the scenario that bats might be comm...

The lead enzymes of polyamine biosynthesis, i.e. ornithine decarboxylase (ODC) and arginine decarboxylase (ADC), were not detected in Toxoplasma gondii [the limit of detection for ODC and ADC was 5 pmol min(-1) (mg protein)(-1)], indicating that T. gondii lacks a forward-directed polyamine biosynthetic pathway, and is therefore a polyamine auxotroph. The biochemical results were supported by re...

Like many intracellular microbes, the protozoan parasite Toxoplasma gondii injects effector proteins into cells it invades. One group of these effector proteins is injected from specialized organelles called the rhoptries, which have previously been described to discharge their contents only during successful invasion of a host cell. In this report, using several reporter systems, we show that ...

A giant meront containing thousands of merozoites has been found in the intestinal epithelium of an adult specimen of white bream (Blicca bjoerkna). The taxonomic position of this unusual coccidian stage is discussed.