Elimination of GPI2 suppresses glycosylphosphatidylinositol GlcNAc transferase activity and alters GPI glycan modification in Trypanosoma brucei.

Many eukaryotic cell-surface proteins are post-translationally modified by a glycosylphosphatidylinositol (GPI) moiety that anchors them to the cell membrane. The biosynthesis of GPI anchors is initiated in the endoplasmic reticulum by transfer of GlcNAc from UDP-GlcNAc to phosphatidylinositol. This reaction is catalyzed by GPI GlcNAc transferase, a multisubunit complex comprising the catalytic subunit Gpi3/PIG-A as well as at least five other subunits, including the hydrophobic protein Gpi2, which is essential for the activity of the complex in yeast and mammals, but the function of which is not known. To investigate the role of Gpi2, we exploited Trypanosoma brucei (Tb), an early diverging eukaryote and important model organism that initially provided the first insights into GPI structure and biosynthesis. We generated insect-stage (procyclic) trypanosomes that lack TbGPI2 and found that in TbGPI2-null parasites, (i) GPI GlcNAc transferase activity is reduced, but not lost, in contrast with yeast and human cells, (ii) the GPI GlcNAc transferase complex persists, but its architecture is affected, with loss of at least the TbGPI1 subunit, and (iii) the GPI anchors of procyclins, the major surface proteins, are underglycosylated when compared with their WT counterparts, indicating the importance of TbGPI2 for reactions that occur in the Golgi apparatus. Immunofluorescence microscopy localized TbGPI2 not only to the endoplasmic reticulum but also to the Golgi apparatus, suggesting that in addition to its expected function as a subunit of the GPI GlcNAc transferase complex, TbGPI2 may have an enigmatic noncanonical role in Golgi-localized GPI anchor modification in trypanosomes.

First report of trypanosomiasis in farmed largemouth bass (Micropterus salmoides) from China: pathological evaluation and taxonomic status.

The aim of this study was to evaluate the effect of trypanosomes on cultured largemouth bass (Micropterus salmoides) and describe the taxonomic identification of the parasite. The effects of the parasite on M. salmoides were examined based on clinical symptoms, hemograms, histopathology, and serum biochemistry. Diseased fish showed typical clinical symptoms of trypanosomiasis, which included lethargy, anorexia, and histopathological lesions in the liver, head kidney, and spleen. The serum of diseased fish had significantly lower concentrations of glucose, triglyceride, and low-density lipoprotein, and significantly higher alanine transaminase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) activities. The morphology of the trypanosomes was also analyzed using light microscopy, and their 18S rDNA sequence was analyzed to establish genetic relationships with other known strains. We found that the trypomastigote form of the trypanosomes from M. salmoides was similar to those isolated from Pelteobagrus fulvidraco. The trypanosomes had a slender and narrow body with a relatively long free flagellum, not well-developed undulating membrane, and an oval kinetoplast located near the subterminal posterior end of the body. The 18S rDNA sequences of the trypanosome from M. salmoides had the highest similarity (99.8%) with that of P. fulvidraco, suggesting they are identical species. Based on the differences in morphological characteristics and 18S rDNA sequence compared to trypanosomes isolated from other freshwater fish, it is considered as a new species and we propose the name Trypanosoma micropteri n. sp.

Trypanosoma carassii infection in goldfish (Carassius auratus L.): changes in the expression of erythropoiesis and anemia regulatory genes.

Trypanosoma carassii is a flagellated bloodstream parasite of cyprinid fish with pathogenesis manifesting primarily as anemia in experimentally infected fish. This anemia is characterized by decreases in the number of circulating red blood cells (RBCs) during peak parasitemia. We examined changes in the key blood metrics and expression of genes known to be important in the regulation of erythropoiesis. Increasing parasitemia was strongly correlated with an overall decrease in the total number of circulating RBCs. Gene expression of key erythropoiesis regulators (EPO, EPOR, GATA1, Lmo2, and HIFα) and proinflammatory cytokines (IFNγ and TNFα) were measured and their expressions differed from those in fish made anemic by injections of phenylhydrazine (PHZ). Significant upregulation of pro-erythropoietic genes was observed in PHZ-induced anemia, but not during peak parasitic infection. Previously, we reported on functional characterization of goldfish erythropoietin (rgEPO) and its ability to induce survival and differentiation of erythroid progenitor cells in vitro. Treatment of goldfish during the infection with rgEPO reduced the severity of anemia but failed to fully prevent the onset of the anemic state in infected fish. Proinflammatory cytokines have been implicated in the suppression of erythropoiesis during trypanosomiasis, specifically the cytokines TNFα, IFNγ, and IL-1ß. Analysis of key proinflammatory cytokines revealed that mRNA levels of IFNγ and TNFα were upregulated in response to infection, but only TNFα increased in response to PHZ treatment. Synergistic activity of the proinflammatory cytokines may be required to sustain prolonged anemia. These findings provide insight into the relationship between T. carassii and host anemia and suggest that T. carassii may directly or indirectly suppress host erythropoiesis.

Clinico-hematological and oxidative stress status in Nili Ravi buffaloes infected with Trypanosoma evansi.

Hemoparasitic diseases like trypanosomiasis have an adverse influence on the health and working capability of infected animals. Monitoring and identification of blood born parasitic infections in dairy animals are of vital importance to get the optimum production. In this study blood samples were collected from Nili Ravi buffaloes (n = 390) kept at different villages of district Lodhran, Punjab province of Pakistan. Blood samples were evaluated for red blood cell counts, total and differential leukocyte counts, hematocrit, hemoglobin, total proteins and different serum parameters such as alanine aminotransferase, aspartate aminotransferase, malondialdehyde, alkaline phosphatase, lactate dehydrogenase, phosphorous, copper, calcium and magnesium. Overall prevalence of Trypanosoma evansi was 4.61% based on microscopic smear examination, 11.02% with Formol Gel Test and 16.15% with PCR. Infected buffaloes showed different clinical signs, including high fever (105 ±â€¯1.0 °F), edema of face and legs, hyperemic mucosa of eyes, lachrymation, bulging eyes, pale mucus membranes and frequent urination. Microscopic examination of blood films showed morphologically different parasites. Statistical analysis did not indicate an association of infection based on age and sex of buffaloes. Results revealed significantly (p < 0.05) lower values of red blood cell counts, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration and total proteins, while increased values of mean corpuscular volume, total white blood cells, monocyte, neutrophils, basophils and eosinophils in infected animals. Infected buffaloes were suffering from macrocytic hypochromic anemia. A significant (p < 0.05) increase in serum lipid per oxidation product (malondialdehyde) level and serum enzymes while a decrease in macrominerals and trace mineral (copper) in trypanosomiasis positive buffaloes were recorded. It was concluded that Trypanosoma evansi is prevalent in Pakistan under tropical and subtropical climatic conditions. It causes clinical disease with macrocytic hypochromic anemia and oxidative stress in infected buffaloes.

Achyrocline satureioides essential oil-loaded in nanocapsules reduces cytotoxic damage in liver of rats infected by Trypanosoma evansi.

The aim of this study was to evaluate whether the treatment with Achyrocline satureioides essential oil-loaded in nanocapsules (AS-NC) is able to protect the hepatic tissue against cytotoxic damage caused by Trypanosoma evansi. Thus, the rats were divided into four groups (n = 6 per group): uninfected/saline, uninfected/AS-NC, infected/saline, and infected/AS-NC. At day 4 post-infection (PI), the animals were euthanized and liver and sera samples were collected to perform the hepatic cell viability assay, and to determine seric levels of reactive oxygen species (ROS) and nitric oxide metabolites (NOx). Cell viability decreased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this alteration in infected rats. Seric ROS and NOx levels increased (p < 0.05) in the infected/saline group compared to uninfected/saline group, while the treatment with AS-NC avoided this effect on ROS levels of infected rats. In summary, the treatment with AS-NC was able to protect the liver tissue against the cytotoxic effect caused by the parasite by avoiding exacerbated production of ROS.

Prevalence of Trypanosoma cruzi and organ alterations in Virginia opossums (Didelphis virginiana) from western Mexico - short communication.

Small populations of Virginia opossum (Didelphis virginiana) in western Mexico are endangered by hunting and natural predators as well as by different kinds of diseases. After two serological analyses using Serodia® latex particle agglutination and indirect haemagglutination (IHA) tests, 35 (53.03%) of 66 collected opossums in two small towns in western Mexico were positive for the presence of Trypanosoma cruzi. Twenty-eight of the 35 seropositive opossums had pathological lesions: 11 had changes in only one organ, 13 in two organs, and four had pathological changes in three organs. Splenomegaly was the most common finding in the examined opossums, followed by hepatomegaly. These potentially fatal pathological changes could contribute to the scarcity of the opossum population, even leading to the extinction of this species in western Mexico.

FIRST REPORT OF TRYPANOSOMA EVANSI INFECTION (SURRA) IN A PUMA (FELIS CONCOLOR) OF LAHORE ZOO, PAKISTAN.

The blood protozoan Trypanosoma evansi, which is transmitted by biting flies, is frequently neglected due to subclinical infections. This report describes a case of trypanosomiasis due to T. evansi in a 9-yr-old male puma (Felis concolor) housed at the Lahore Zoo in Pakistan. Early in January 2015, this male puma presented with chronic lethargy, weight loss, incoordination, hyperthermia, anorexia, sunken eyes, and unthriftiness. Microscopic examination of Giemsa-stained blood smears showed numerous Trypanosoma parasites. The puma was treated with diminazene aceturate subcutaneously twice. A few days later, a blood smear examination showed absence of trypanosomes. Five months later the cat presented with acute epistaxis and died. Postmortem examination showed emaciation, pale liver and kidneys, and hemorrhages on the spleen. Examination of a blood smear taken at the time of death showed numerous Trypanosoma parasites. PCR testing confirmed the presence of Trypanosoma DNA. DNA sequencing of two amplicons confirmed the presence of Trypanosoma in the blood smears with a 98-99% identity with the previously identified GenBank sequences. A phylogenetic tree was then constructed. Further studies are needed to improve our knowledge about the epidemiology and pathogenesis of T. evansi infection in wild animal species.

Involvement of oxidative stress, cholinergic and adenosinergic systems on renal damage caused by Trypanosoma evansi infection: Relationship with lipid peroxidation.

The aim of this study was to evaluate the oxidative stress variables, and enzymes of cholinergic (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)) and adenosinergic (adenosine deaminase (ADA)) systems in renal tissue, as well as the relationship between these systems and lipid peroxidation. The animals were divided into two groups with six animals each: uninfected (negative control) and infected (positive control). On day 4 post-infection (PI), animals were euthanized and the kidney was collected. Thiobarbituric acid reactive species (TBARS) and lipid peroxidation (FOX) levels increased, while the catalase (CAT), AChE, BChE and ADA activities decreased in kidney tissue on day 4 PI. A negative correlation between AChE and TBARS (r = -0.750), AChE and FOX (r = -0.650), as well as ADA and TBARS (r = -0.345) and ADA and FOX (r = -0.540) were observed (p < 0.05). In summary, the T. evansi infection cause lipid peroxidation in the renal tissue, altering the antioxidant-oxidant status, alterations compatible to oxidative stress and oxidative damage. Also, the T. evansi decrease the activities of AChE, BChE and ADA in order to reduce the oxidative damage increasing the levels of ACh, BCh and adenosine. These alterations in the kidney may be contribute on pathophysiology of T. evansi infection.

Relationship between DNA damage in liver, heart, spleen and total blood cells and disease pathogenesis of infected rats by Trypanosoma evansi.

Trypanosoma evansi is an important pathogen that causes changes in nitric oxide (NO) levels and antioxidant enzymes, as well as oxidative stress. The present study evaluated the in vivo effect of T. evansi infection on frequency and index of DNA damage in liver, heart, spleen and total blood of rats. Twenty rats were assigned into two groups with ten rats each, being subdivided into four subgroups (A1 and A2, 5 animals/group; and B1 and B2, 5 animals/group). Rats in the subgroups A1 and A2 were used as control (uninfected) and animals in the subgroups B1 and B2 were inoculated with T. evansi (infected). NO in serum and the comet assay were used to measure DNA damage index (DI) and damage frequency (DF) in liver, heart, spleen and total blood of infected rats. Increased NO levels on days 3 and 9 post-infection (PI) was observed (P < 0.001). Also, it was verified an increase on DI and DF in the evaluated organs on days 3 and 9 PI (P < 0.001). Our data show that T. evansi infection causes genotoxicity due to the production of NO, causing not only the death of the protozoan, but also inducing DNA damage in the host.

Cytokine gene expression and pathology in mice experimentally infected with different isolates of Trypanosoma evansi.

Aim of the present study was to assess the cytokine gene expression in liver, kidney and spleen and histopathological changes in mice infected with buffalo and dog isolates of Trypanosoma evansi. Forty-four Swiss albino mice was divided into eleven groups of four mice each and injected subcutaneously with 1 × 105 trypanosomes of buffalo and dog isolate to twenty mice each, four mice served as control. Mice were examined for clinical signs, blood smear for trypanosome counts. Blood for PCR, liver, kidney, spleen, heart, lung, testis and abdominal muscle for histopathology and liver, kidney, spleen for cytokine gene expression studies, were collected. Mice showed dullness, lethargy, hunched back, sluggish movements on D4 and D5 in buffalo and dog isolate, respectively. Parasite count in blood varied between the two isolates of T. evansi. By PCR, trypanosome DNA was detected on D1 and D2 for buffalo and dog isolate, respectively. Splenomegaly was observed in mice infected with buffalo isolate but not with dog isolate. Histopathological changes were observed in liver, kidney, spleen and heart of mice but no changes in testis and abdominal muscles. Blood vessels of liver, heart, lung showed presence of trypanosomes in mice infected with buffalo isolate but not for dog isolate. Cytokine gene expression of IL-2, IL-4, IL-6, IL-12, TNF-α and IFN-γ increased in liver, kidney and spleen in both these isolates. However, the buffalo isolate exhibited pronounced increase in cytokine gene expression when compare to dog isolate of T. evansi. Anti-inflammatory cytokine gene IL-10 showed 50-60 and 10-20 folds increment in buffalo and dog isolates, respectively. This is the first report of IL-4, IL-6, IL-10 and IL-12 cytokine changes in mice infected with T. evansi. A variation in pathogenicity between buffalo and dog isolates was recorded indicating buffalo isolate of T. evansi remained more pathogenic in mice.

Prevalence of camel trypanosomosis (surra) and associated risk factors in Borena zone, southern Ethiopia.

A study was made to determine the prevalence of camel trypanosomosis (surra) and its associated risk factors in Borena zone, southern Ethiopia during 2013-2014. A total of 2400 blood samples were collected and examined by the buffy coat and thin blood film laboratory methods, and data were analyzed using the SPSS statistical software. The overall prevalence of camel trypanosomosis in the area was found to be 2.33 %. Prevalence was significantly different among the surveyed districts (P = 0.000), the pastoral associations (F = 6.408, P = 0.000), altitudinal divisions (P = 0.000), age groups (P = 0.034), and between animals possessing packed cell volume (PCV) values greater than 25 % and less than 25 % (P = 0.000); whereas, prevalence of the disease was not statistically significantly different between the sexes (P = 0.311) and among the body condition score groups (P = 0.739). The PCV of trypanosome positive and trypanosome negative camels differ significantly (P = 0.001), and prevalence of trypanosomosis was seen to be negatively correlated with packed cell volume (r = -0.069, P = 0.000) revealing the effect of camel trypanosomosis on anemia state of parasitized animals. In conclusion, camel trypanosomosis is a serious and economically important disease hampering camel production and productivity in southern Ethiopia. Further studies involving more sensitive molecular techniques to reveal the precise magnitude of the disease and to identify the vector species of the parasite are recommended.

Oxidative Stress in the Heart of Rats Infected with Trypanosoma evansi.

This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi.

Trypanocidal activity of free and nanoencapsulated curcumin on Trypanosoma evansi.

This study aimed to evaluate in vitro and in vivo trypanocidal activity of free and nanoencapsulated curcumin against Trypanosoma evansi. In vitro efficacy of free curcumin (CURC) and curcumin-loaded in lipid-core nanocapsules (C-LNCs) was evaluated to verify their lethal effect on T. evansi. To perform the in vivo tests, T. evansi-infected animals were treated with CURC (10 and 100 mg kg(-1), intraperitoneally [i.p.]) and C-LNCs (10 mg kg(-1), i.p.) during 6 days, with the results showing that these treatments significantly attenuated the parasitaemia. Infected untreated rats showed protein peroxidation and an increase of nitrites/nitrates, whereas animals treated with curcumin showed a reduction on these variables. As a result, the activity of antioxidant enzymes (superoxide dismutase and catalase) differs between groups (P<0.05). Infected animals and treated with CURC exhibited a reduction in the levels of alanine aminotransferase and creatinine, when compared with the positive control group. The use of curcumin in vitro resulted in a better parasitaemia control, an antioxidant activity and a protective effect on liver and kidney functions of T. evansi-infected adult male Wistar rats.

Effect of zinc supplementation on E-ADA activity, seric zinc, and cytokines levels of Trypanosoma evansi infected Wistar rats.

The aim of this study was to evaluate the effect of zinc supplementation on the ecto-adenosine deaminase activity (E-ADA), zinc seric levels and cytokines (TNF-α, IL-1, IL-6, and IL -10) on rats experimentally infected by Trypanosoma evansi. Four groups with 10 rats each were used as negative controls (groups A and B), while the animals from the groups C and D were infected intraperitoneally with 0.1 mL of cryopreserved blood containing 1.4 × 10(4) of trypanosomes. Animals of groups B and D received two doses of Zinc (Zn) at 5 mg kg(-1), subcutaneously, on the 2nd and 7th day post-infection (PI). Blood samples were collected on days 5 (n = 5) and 15 PI (n = 5). Zn supplementation was able to increase the rat's longevity and to reduce their parasitemia. It was observed that seric Zn levels were increased on infected animals under Zn supplementation. Animals that were infected and supplemented with Zn showed changes in E-ADA activity and in cytokine levels (P < 0.05). Zn supplementation of healthy animals (Group B), increased the E-ADA activity, as well as reduced the concentration of cytokines. Infected animals from groups C and D showed increased levels of cytokines. Finally, we observed that Zn supplementation led to a modulation on cytokine's level in rats infected by T. evansi, as well as in E-ADA activity.

Neurological trypanosomiasis in quinapyramine sulfate-treated horses--a breach of the blood-brain barrier?

Trypanosoma evansi infection typically produces wasting disease, but it can also develop into a neurological or meningoencephalitis form in equids. Trypanosomiasis in horses was treated with quinapyramine sulfate, and all the 14 infected animals were recovered clinically. After clinical recovery, four animals developed a neurological form of the disease at various intervals. Two of these animals treated with diminazene aceturate recovered temporarily. Repeated attempts failed to find the parasite in the blood or the cerebrospinal fluid (CSF), but all of the animals were positive in enzyme-linked immunosorbent assay. The calculation of the antibody index (AI) in the serum and the CSF and polymerase chain reaction (PCR) analysis of the CSF and brain tissue were carried out to confirm the neuro-infection. We found PCR and AI analyses of the CSF to be useful tools in the diagnosis of the neurological form of trypanosomiasis when the organism cannot be found in the blood or CSF. The increased albumin quotient is indicative of barrier leakage due to neuroinflammation. The biochemical changes in the CSF due to nervous system trypanosomiasis include increases in the albumin quotient, total protein, and urea nitrogen. It seems to be the first report on relapse of the nervous form of trypanosomiasis in equids even after quinapyramine treatment in endemic areas.

Glutathione and iron at the crossroad of redox metabolism in rats infected by Trypanosoma evansi.

The aim of this study was to evaluate the changes in hematological and biochemical parameters of blood during acute Trypanosoma evansi infection in Wistar rats. The end points studied were hematologic parameters, red blood cell fragility, iron content, and glutathione and lipid peroxidation levels. Forty-eight animals were infected with trypomastigotes and distributed into five groups according to the level of parasitemia. Twelve non-inoculated animals were used as control. Parasitemia increased progressively, reaching highest scores at 15 days post-inoculation. At this point, several deleterious effects were observed such as an increase in iron content, in osmotic fragility, and in lipid peroxidation index, while glutathione decreased drastically. These changes were highly correlated to parasitemia (p < 0.0001) and among each other (p ≤ 0.001). Hematological indices (Hb, packed cell volume (PCV), red blood cells (RBC), and mean corpuscular hemoglobin concentration) were also correlated to parasitemia (p ≤ 0.0003) but failed to correlate to the other variables. Along with increase in iron, RBC fragility produced a decrease in RBC, PCV, and Hb, but not in mean corpuscular volume. Decrease in glutathione was negatively correlated to the end products of lipid peroxidation, clearly indicating the establishment of a pro-oxidant condition. The results show that the infection causes hematological impairments, increases iron and osmotic fragility, along with marked oxidative stress in red blood cells of rats inoculated with T. evansi.

Isolation, cloning, and pathologic analysis of Trypanosoma evansi field isolates.

In recent years, the emergence of highly pathogenic Trypanosoma evansi strains in the Philippines has resulted in substantial losses in livestock production. In this study, we isolated T. evansi from infected-water buffaloes in the Philippines and analyzed their virulence using mice and cattle. A total of 10 strains of T. evansi were isolated. Evaluation of the virulence of each strain using mice depicted significant differences among the strains in the prepatent period, the level of parasitemia, and the survival time of the infected animals. In mice infected with the highly pathogenic T. evansi, signs of excessive inflammation such as marked splenomegaly and increase more than 6-fold in the number of leukocytes were observed at 8 days post-infection. To study the virulence of the parasite strains in cattle (which are the common T. evansi hosts in Philippines), cattle were infected with the T. evansi isolates that showed high and low virulence in mice. The rate of parasite growth and the length of the prepatent periods were found to be similar to those observed in mice for the respective strains. The cattle infected with the highly pathogenic strain developed anemia and a marked decrease in leukocyte counts. To determine the cause of the pathological changes, we analyzed the expression levels of inflammatory cytokines and observed up-regulation of tumor necrosis factor-α in anemic infected cattle. Our findings suggest that the epidemic of T. evansi in the Philippines is characterized by T. evansi strains with varying virulences from low to very high pathogenicity in cattle.

Comparative virulence of three Trypanosoma evansi isolates from water buffaloes in the Philippines.

The virulence of three Trypanosoma evansi isolates in Luzon, Visayas and Mindanao water buffaloes was compared determining the mortality rate, parasitemia level, clinical signs, and lesions on mice. A total of 51 inbred Balb/c mice (5-6 weeks old) were used and divided into two sets. Set A had three groups corresponding to three trypanosomes isolates (Luzon, Visayas, and Mindanao) with seven mice each whose parasitemia level, clinical signs, and lesions were noted at necropsy. Set B had three groups corresponding to the three isolates with ten mice each whose mortality was monitored. Each infected mouse was inoculated with 0.2 ml of T. evansi intraperitoneally and blood was examined under high power magnification. Their parasitemia level was determined using "Rapid Matching Method". Dead mice were subjected to necropsy and the lungs, liver, spleen, brain and heart were subjected to histopathological processing. Results showed that the mortality rate was highest at Day 3 for the Visayas isolates (70%), while at Day 5 for Luzon (90%) and Mindanao (70%) isolates. The parasitemia level of Visayas isolates (1×10(8.7)) reached the earliest peak at Day 4 while Luzon isolates (1×10(9)) at Day 6 and Mindanao isolates (1×10(8.7)) at Day 8. Statistical analysis using Least significant difference (LSD) revealed significant difference among treatment means at Days 2 and 4. All of the affected mice showed rough hair coat, decreased body weight, and decreased packed cell volume. The most obvious gross lesions observed were pale liver with petechiations and pale muscles. Histopathological examination revealed depletion of the red pulp and extramedullary hematopoiesis in the spleen. Congestion, intralesional trypanosomes in blood vessel and extramedullary hematopoiesis were observed in the liver. In the lungs non-specific lesions observed were pulmonary edema, congestion and hemosiderosis.

The potential impact of native Australian trypanosome infections on the health of koalas (Phascolarctos cinereus).

Whole blood collected from koalas admitted to the Australian Zoo Wildlife Hospital (AZWH), Beerwah, QLd, Australia, during late 2006-2009 was tested using trypanosome species-specific 18S rDNA PCRs designed to amplify DNA from Trypanosoma irwini, T. gilletti and T. copemani. Clinical records for each koala sampled were reviewed and age, sex, blood packed cell volume (PCV), body condition, signs of illness, blood loss, trauma, chlamydiosis, bone marrow disease, koala AIDS and hospital admission outcome ('survival'/ 'non-survival') were correlated with PCR results. Overall 73.8% (439/595) of the koalas were infected with at least 1 species of trypanosome. Trypanosoma irwini was detected in 423/595 (71.1%), T. gilletti in 128/595 (21.5%) and T. copemani in 26/595 (4.4%) of koalas. Mixed infections were detected in 125/595 (21%) with co-infections of T. irwini and T. gilletti (101/595, 17%) being most common. There was a statistical association between infection with T. gilletti with lower PCV values and body condition scores in koalas with signs of chlamydiosis, bone marrow disease or koala AIDS. No association between T. gilletti infection and any indicator of health was observed in koalas without signs of concurrent disease. This raises the possibility that T. gilletti may be potentiating other disease syndromes affecting koalas.

Trypanosoma evansi: Activities of adenine nucleotide degradation enzymes in cerebral cortex of infected rats.

This study aimed to evaluate the activities of the ectoenzymes NTPDase and 5'-nucleotidase in synaptosomes from cerebral cortex of rats experimentally infected with Trypanosoma evansi. The animals were divided in four groups (n=10) according to the time and degree of parasitemia (groups A, B, C and D). The animals from group A were euthanized on day 3 (low parasitemia), group B on day 5 (high parasitemia) and group C on day 15 (low parasitemia). Group D consisted of healthy rats (not-infected, n=15) and were divided in three periods (n=5) in order to compare with the infected groups. After euthanasia, cerebral cortex was removed for the preparation of synaptosomes and enzymatic assays. Group A showed no changes in enzymatic activities compared with control. The hydrolysis of ATP, ADP and AMP by the enzymes NTPDase and 5'-nucleotidase were increased (P<0.05) in group B (38%, 140% and 61%, respectively) when compared with control. In the group C it was observed a decreased (22%) hydrolysis of ATP when compared with control group. The activities of NTPDase and 5'-nucleotidase in synaptosomes alters the acute phase of the disease when the number of circulating parasites is high, thus the change observed is probably due to the parasitemia.