In an effort to unify the nomenclature of Trypanosoma cruzi, the causative agent of Chagas disease, an updated system was agreed upon at the Second Satellite Meeting. A consensus was reached that T. cruzi strains should be referred to by six discrete typing units (T. cruzi I-VI). The goal of a unified nomenclature is to improve communication within the scientific community involved in T. cruzi research. The justification and implications will be presented in a subsequent detailed report.

Xylella fastidiosa is a fastidious, xylem-limited bacterium that causes a range of economically important plant diseases. Here we report the complete genome sequence of X. fastidiosa clone 9a5c, which causes citrus variegated chlorosis--a serious disease of orange trees. The genome comprises a 52.7% GC-rich 2,679,305-base-pair (bp) circular chromosome and two plasmids of 51,158 bp and 1,285 bp. We can assign putative functions to 47% of the 2,904 predicted coding regions. Efficient metabolic functions are predicted, with sugars as the principal energy and carbon source, supporting existence in the nutrient-poor xylem sap. The mechanisms associated with pathogenicity and virulence involve toxins, antibiotics and ion sequestration systems, as well as bacterium-bacterium and bacterium-host interactions mediated by a range of proteins. Orthologues of some of these proteins have only been identified in animal and human pathogens; their presence in X. fastidiosa indicates that the molecular basis for bacterial pathogenicity is both conserved and independent of host. At least 83 genes are bacteriophage-derived and include virulence-associated genes from other bacteria, providing direct evidence of phage-mediated horizontal gene transfer.

Human and animal fungal pathogens are a growing threat worldwide leading to emerging infections and creating new risks for established ones. There is a growing need for a rapid and accurate identification of pathogens to enable early diagnosis and targeted antifungal therapy. Morphological and biochemical identification methods are time-consuming and require trained experts. Alternatively, molecular methods, such as DNA barcoding, a powerful and easy tool for rapid monophasic identification, offer a practical approach for species identification and less demanding in terms of taxonomical expertise. However, its wide-spread use is still limited by a lack of quality-controlled reference databases and the evolving recognition and definition of new fungal species/complexes. An international consortium of medical mycology laboratories was formed aiming to establish a quality controlled ITS database under the umbrella of the ISHAM working group on "DNA barcoding of human and animal pathogenic fungi." A new database, containing 2800 ITS sequences representing 421 fungal species, providing the medical community with a freely accessible tool at http://www.isham.org/ and http://its.mycologylab.org/ to rapidly and reliably identify most agents of mycoses, was established. The generated sequences included in the new database were used to evaluate the variation and overall utility of the ITS region for the identification of pathogenic fungi at intra-and interspecies level. The average intraspecies variation ranged from 0 to 2.25%. This highlighted selected pathogenic fungal species, such as the dermatophytes and emerging yeast, for which additional molecular methods/genetic markers are required for their reliable identification from clinical and veterinary specimens.

Proteasomes degrade most of the proteins inside eukaryotic cells, including transcription factors and regulators of cell cycle progression.Here we show that nanomolar concentrations of lactacystin, a specific irreversible inhibitor of the 20S proteasome, inhibit development of the exoerythrocytic and erythrocytic stages of the malaria parasite. Although lactacystin-treated Plasmodium berghei sporozoites are still invasive, their development into exoerythrocytic forms (EEF) is inhibited in vitro and in vivo. Erythrocytic schizogony of P. falciparum in vitro is also profoundly inhibited when drug treatment of the synchronized parasites is prior, but not subsequent, to the initiation of DNA synthesis, suggesting that the inhibitory effect of lactacystin is cell cycle specific. Lactacystin reduces P. berghei parasitemia in rats, but the therapeutic index is very low. Along with other studies showing that lactacystin inhibits stage-specific transformation in Trypanosoma and Entamoeba spp., these findings highlight the potential of proteasome inhibitors as drugs for the treatment of diseases caused by protozoan parasites. MATERIALS AND METHODS Drugs.Lactacystin and lactacystin analogs were synthesized as previously described (4,13,22). 7-Ethyl lactacystin and des-7-methyl lactacystin were synthesized in the Harvard laboratory. All drugs, except clasto-lactacystin ␤-lactone, were dissolved in H 2 O to 1 mM and stored at 4°C until use. clasto-lactacystin ␤-lactone was solubilized in dimethyl sulfoxide to 10 mM and stored at Ϫ20°C until use. Lactacystin for injection into rats was dissolved in phosphate-buffered saline (PBS), pH 7.4, immediately before use.Assay for EEF development in vitro. This assay was performed as described previously (19) with a few modifications. Briefly, HepG2 cells (ATCC HB8065; American Type Culture Collection, Manassas, Va.) were plated in chamber slides (model 4808; Lab-tek, Naperville, Ill.) 48 h before each experiment. Plasmodium berghei sporozoites were dissected from mosquito salivary glands and resuspended in Dulbecco modified Eagle medium (Gibco BRL, Gaithersburg, Md.) supplemented with 10% fetal calf serum (HyClone Laboratories, Logan, Utah) and 20 mM HEPES (Sigma, St. Louis, Mo.). Approximately 50,000 sporozoites were added per well, and the parasites were allowed to adhere to and invade the HepG2 cells for 2 h. The wells were washed, and the cells were grown for an additional 2 days after which they were fixed with methanol. The EEF were then revealed with monoclonal antibody (MAb) 2E6 (34) followed by goat anti-mouse immunoglobulin (Ig) conjugated to horseradish peroxidase (Accurate Chemical Corp., Westbury, N.Y.) and 3,3Ј-diaminobenzidine (Sigma). The EEF in each well were counted microscopically with a 20ϫ light microscope objective.Microscopic assay for quantification of sporozoite invasion. This assay was conducted according to the method described by Renia et al. (27) with a few modifications. HepG2 cells were plated in chamber slides as described above. P. berghei sporozoites ...

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