: Here we describe Haemoproteus (Haemoproteus) multivolutinus n. sp. from a tambourine dove ( Turtur timpanistria ) of Uganda and Haemoproteus (Haemoproteus) paramultipigmentatus n. sp. (Haemosporida, Haemoproteidae) from the Socorro common ground dove ( Columbina passerina socorroensis ) of Socorro Island, Mexico. These parasites are described based on the morphology of their blood stages and segments of the mitochondrial cytochrome b gene that can be used for molecular identification and diagnosis of these species. Gametocytes of H. multivolutinus possess rod-like pigment granules and are evenly packed with volutin, which masks pigment granules and darkly stains both macro- and microgametocytes in the early stages of their development. Based on these 2 characters, H. multivolutinus can be readily distinguished from other species of hemoproteids parasitizing columbiform (Columbiformes) birds. Haemoproteus paramultipigmentatus resembles Haemoproteus multipigmentatus ; it can be distinguished from the latter parasite primarily due to the broadly ovoid shape of its young gametocytes and significantly fewer pigment granules in its fully developed gametocytes. We provide illustrations of blood stages of the new species, and phylogenetic analyses identify DNA lineages closely related to these parasites. Cytochrome b lineages of Haemoproteus multivolutinus and H. paramultipigmentatus cluster with hippoboscid-transmitted lineages of hemoproteids; thus these parasites likely belong to the subgenus Haemoproteus . We emphasize the importance of using cytochrome b sequences in conjunction with thorough microscopic descriptions to facilitate future identification of these and other avian hemosporidian species.

: The Socorro dove Zenaida graysoni , endemic to Socorro Island, was last reported in the wild in 1972. Fortunately, the species has been propagated in zoos in Europe and the United States, and plans are under way to re-introduce it to its native habitat. This will be the first known attempt to return a bird species extinct in the wild to its ancestral island. In order to assess the disease threats the Socorro dove may face, the avifauna of Socorro Island, with a specific focus on Socorro ground doves Columbina passerina socorroensis and mourning doves Zenaida macroura , as well as Socorro doves in captivity, were screened for blood parasites of the genera Plasmodium , Haemoproteus, Leucocytozoon, and Trypanosoma spp. We found Haemoproteus spp. in 17 (74%) of 23 Socorro ground doves, 23 (92%) of 25 mourning doves, and 3 (14%) of 21 northern mockingbirds; none of the other bird species showed infections. Here, we report the phylogenetic analysis of 19 distinct lineages of Haemoproteus spp. detected in birds of Socorro Island and compare their evolutionary relationships to parasites detected in the avifauna of the Galápagos Islands, continental Latin America, and Europe. Microscopic examination revealed 1 mourning dove infected with Plasmodium ( Haemamoeba ), thus underscoring the importance of using both PCR and microscopy when analyzing avian blood samples for hemosporidian parasites. The study confirms that the Socorro dove will most likely be exposed to Haemoproteus spp. that currently infect mourning doves and Socorro ground doves of Socorro Island. A monitoring program for both birds and vectors should be implemented to establish the prevalence of Plasmodium sp. and as a necessary conservation measure for critically endangered birds on the island.

Chagas disease, caused by Trypanosoma cruzi , is a widespread infection in Latin America. Currently, only 2 partially effective and highly toxic drugs, i.e., benznidazole and nifurtimox, are available for the treatment of this disease, and several efforts are underway in the search for better chemotherapeutic agents. Here, we have determined the trypanocidal activity of 2,3-diphenyl-1,4-naphthoquinone (DPNQ), a novel quinone derivative. In vitro, DPNQ was highly cytotoxic at a low, micromolar concentration (LD 50 = 2.5 μM) against epimastigote, cell-derived trypomastigote, and intracellular amastigote forms of T. cruzi , but not against mammalian cells (LD 50 = 130 μM). In vivo studies on the murine model of Chagas disease revealed that DPNQ-treated animals (3 doses of 10 mg/kg/day) showed a significant delay in parasitemia peak and higher (up to 60%) survival rate 70 days post-infection, when compared with the control group (infected, untreated). We also observed a 2-fold decrease in parasitemia between the control group (infected, untreated) and the treated group (infected, treated). No apparent drug toxicity effects were noticed in the control group (uninfected, treated). In addition, we determined that DPNQ is the first competitive inhibitor of T. cruzi lipoamide dehydrogenase (TcLipDH) thus far described. Our results indicate that DPNQ is a promising chemotherapeutic agent against T. cruzi .

Random amplified polymorphic DNA (RAPD) is a useful tool for species identification. The obtained band patterns can be used for specific primer pair design that is useful for species identification. In this study, a distinctive 485-bp band in Acanthamoeba astronyxis band patterns was found, using the OPC20 primer (ACTTCGCCAC). The band specificity was confirmed by hybridization, using it as a probe, against all OPC20 amplifications from different Acanthamoeba species. Once the fragment was sequenced, we used it to design a specific primer pair that was useful for the identification of different isolates as A. astronyxis species.

By screening a Leishmania braziliensis complementary DNA library with a pool of sera from leishmaniasis patients, the gene coding for L6 ribosomal protein was isolated. The sequence, genomic organization, and transcription of this gene are described in this article. The sequence analysis of the L. braziliensis L6 gene shows a single open reading frame, which codes for a protein of 192 amino acids (aa) with a hypothetical molecular mass of 20.9 kDa. The protein exhibits significant sequence similarity to L6 ribosomal proteins from higher eukaryotes and yeast. Thus, the L. braziliensis L6 protein contains 4 functional motifs, which are located at equivalent positions in other L6 ribosomal proteins described previously. Interestingly, the L6 ribosomal protein from L. braziliensis contains a specific region of 14 aa and a tyrosine kinase motif, which is absent in human and C. elegans L6 protein. The locus coding the L. braziliensis L6 ribosomal protein is formed by 2 gene copies arranged in tandem and located in a chromosome of approximately 0.9 Mb. The genes are actively transcribed as 2 polyadenylated transcripts of approximately 1.15 and 0.85 kb, which differ in their steady-state level and stability.

The isolation and molecular characterization of the histone H1-encoding gene from Leishmania braziliensis was carried out. The gene is present in the genome as a single copy and transcribed as a polyadenylated transcript of 830 nucleotides. The deduced amino acid sequence has in its central region the DNA binding K-[K/R]-A-A-[A/P] motif, which is repeated in tandem 9 times.

Metastatic disease is a major concern of dermal leishmaniasis caused by Leishmania of the Viannia subgenus. The golden hamster provides an experimental model of systemic dissemination and cutaneous metastasis of Leishmania Viannia. We have exploited this model to examine the expression of parasite virulence in cloned populations derived from a strain of L. guyanensis previously shown to be highly metastatic in the hamster. Metastatic capacity manifested as dissemination throughout the lymphoid organs; cachexia and secondary cutaneous lesions were found to differ among clones, yielding a spectrum of virulence. The metastatic phenotype of clonal populations was stable over 5 sequential passages in hamsters. In addition, the low or high propensity to disseminate and produce cutaneous metastatic lesions was reproduced. Capacity to disseminate from the inoculation site was conserved following subcloning of metastatic clones that had been passaged in culture for several generations; clinical manifestations, cachexia, and cutaneous metastatic lesions were variably expressed. Dissemination of parasites and cachexia were significantly related ( P = 0.004). Overall, cachexia was an earlier manifestation of dissemination than cutaneous metastases ( P < 0.001). The reproducible expression of virulence phenotypes by discrete populations of Leishmania in the golden hamster provides an experimental model for clinically relevant expression of virulence in human leishmaniasis.