Alexandre A. Tonin

Trypanocidal activity of the essential oils in their conventional and nanoemulsion forms: in vitro tests.

The aim of this study was to investigate the susceptibility in vitro of Trypanosoma evansi to the essential oils of andiroba (Carapa guaianensis) and aroeira (Schinus molle), in their conventional and nanostructured forms. For that, pure oils at concentrations of 0.5%, 1.0% and 2.0% were used. A negative control (untreated) and a positive control (diminazene aceturate 0.5%) were used as comparative parameters. Later, the same tests were performed, using nanoemulsions oils at concentrations of 0.5% and 1.0%. The tests were carried out in triplicates and the numbers of parasites were quantified on 1, 3 and 6 h from onset of the study. A dose-dependent reduction in the number of parasites to the forms of two oils tested was observed after 1 h. The concentration of parasites was significantly reduced at low concentrations after 3 h, as well as at 6 h no alive parasites were observed for the essential oils tested. Ours findings indicate, for the first time, that oils of andiroba and aroeira (in their conventional and nanoemulsion forms) have high activity against T. evansi in vitro, leading to the suggestion that these oils may be applied as an alternative treatment for this disease.

Trypanosoma evansi: levels of copper, iron and zinc in the bloodstream of infected cats.

The aim of this study was to evaluate the concentrations of copper, iron and zinc in blood serum of cats experimentally infected with Trypanosoma evansi. Animals were divided into two groups: control and infected with T. evansi. The animals were infected with 10(8) trypomastigotes each and parasitemia was estimated daily for 56 days by microscopic examination of smears. Hematological and biochemical parameters were evaluated for monitoring of the disease. Serum metal levels were determined in blood samples collected at days 7, 28 and 56 of the experiment. Inductively coupled plasma optical emission spectrometry was used to measure the levels of copper, iron and zinc. Significant differences were observed among groups (P<0.05). Increased levels of copper and decreased iron and zinc levels were observed. A decrease in the number of red blood cells was also observed 7 days after inoculation. Biochemical parameters were not altered. Therefore, the infection by T. evansi might alter the serum metal levels, causing metabolic disturbances in cats.

Novel markers of inflammatory response and hepatic dysfunction in canine leishmaniasis.

Dogs are the main host of Leishmania infantum, and the clinical presentation may range from asymptomatic to systemic manifestations. The immune mechanisms in infected, but clinically healthy dogs, prevails Th1 response mediated by cytokines. In this sense, adenosine deaminase (ADA) and butyrylcholinesterase (BChE) are considered as key enzymes in several physiological processes, including the modulation of inflammatory process. Considering the variable immune response against Leishmania and the known participation of ADA and BChE, the aim of this study was to assess the relation between these two enzymes with the inflammatory response as well as hepatic function in dogs naturally infected with L. infantum. For this purpose, the activity of ADA and BChE was assessed in sera of 24 dogs naturally infected with L. infantum, plus 17 healthy dogs. The naturally infected dogs had clinical signs compatible with leishmaniasis and sera activities of ADA (P<0.01) and BChE (P<0.05) decreased, when compared to the healthy group. The reduction of ADA activity probably represented an effect on inflammatory response, especially due to the decreased hydrolysis of extracellular adenosine, might in order to protect against tissue damage and, also, setting a down-regulation on pro-inflammatory cytokines. BChE enzyme had no effect on modulating the immune response in leishmaniasis, but it decreased, a fact may related to deficiency of synthesis in the liver. Therefore, ADA and BChE activities reduced probably in order to protect against extra tissue damage and due failure in synthesis, respectively.

Echinococcus canadensis (G7) and Echinococcus granulosus sensu stricto (G1) in swine of southern Brazil

The cystic echinococcosis (CE) is an important zoonotic disease caused by the parasite Echinococcus spp. In Brazil, this parasite is present in Rio Grande do Sul (RS) state, border with Argentina and Uruguay, causing several damages to human and animal health. This study aimed to identify Echinococcus spp. in hydatid cysts of swine and evaluate the similarity of the genotypes through the phylogenetic analysis. A total of 3,101,992 swine were slaughtered in the central/northern region of RS/Brazil, during 2008-2012. Five isolates were characterized as hydatid cyst by molecular analysis, based on the mitochondrial gene cytochrome c oxidase subunit I (cox-I). The genotypes E. granulosus sensu stricto (G1) (n=2) and E. canadensis (G7) (n=3) were identified in the hydatid cysts. The swine represents a potential intermediate host for different genotypes of Echinococcus spp., besides it can contribute to the perpetuation of the parasites life cycle in rural areas.

Adenosine deaminase activity in serum, erythrocytes and lymphocytes of rats infected with Leptospira icterohaemorrhagiae.

Leptospirosis is a systemic disease of humans and domestic animals, mainly dogs, cattle and swine. The course of human leptospirosis varies from mild to severe fatal forms and the most severe form of human leptospirosis is principally caused by Leptospira interrogans serovar icterohaemorrhagiae (L. icterohaemorrhagiae). The enzyme adenosine deaminase (ADA) plays an important role in the production and differentiation of blood cells. The aim of this study was to evaluate the activity of ADA in serum, erythrocytes and lymphocytes of rats infected with L. icterohaemorrhagiae, as compared with non-infected rats. Twenty-four adult rats, divided into two uniform groups (A and B) were used for the enzymatic assays. The animals in Group B were inoculated intraperitoneally with 2×10(8) leptospires/rat, and the rodents in Group A (control) were not-inoculated. Blood collection was performed on days 5 and 15 post-infection (PI) and the blood used to assess the ADA activity. The infection by L.icterohaemorrhagiae altered erythrocyte count, hemoglobin concentration and hematocrit, causing a decrease in all these parameters on day 15 PI. Lymphocytes decreased significantly on day 15 PI, and ADA activity in serum was inhibited in infected rats on days 5 and 15 PI and its activity in erythrocytes were increased on day 5 PI. On day 5 PI, we found an increase in ADA activity in erythrocytes of infected rats. No correlation was observed between hematocrit and erythrocyte ADA activity on days 5 and 15 PI. The ADA activity was inhibited in rats infected on day 15 PI. A positive correlation (r(2)=60) was also observed between the number of lymphocytes and ADA activity in lymphocytes on day 15 PI (P<0.05). In conclusion, our results showed that the ADA activity is altered in serum, lymphocytes and erythrocytes in experimental infection by L.icterohaemorrhagiae in rats, concomitantly with hematological parameters.

Serum levels of LH, FSH, estradiol and progesterone in female rats experimentally infected by Trypanosoma evansi.

The goal of this study was to evaluate reproductive hormones in sera samples of female rats experimentally infected by Trypanosoma evansi during different phases of the estrous cycle. For that, 64 animals were divided into two groups: 24 rats for the control group (uninfected), and 40 animals were infected by T. evansi. These groups were divided into subgroups according to the time of infection (days 5 and 15 post-infection; PI) and the phase of the estrous cycle (proestrus, estrus, metestrus and diestrus). Serum was collected at days 5 and 15 PI and the levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), progesterone and estradiol were assessed by enzyme immunoassay technique. The concentration of nitrite/nitrate (NOx), advanced oxidation protein products (AOPP), and thiobarbituric acid reactive substances (TBARS) were measured in ovaries and uteruses in these same periods. Infected females showed significant decrease (P<0.05) of LH, FSH, estradiol and progesterone in different periods and phases of the estrous cycle when compared to uninfected rats. In addition, it was observed an increase in the concentration of NOx, AOPP, and TBARS in the ovaries, which is indicative of cell damage. Therefore, our experimental study showed that T. evansi infection in female rats may cause changes in LH, FSH, estradiol, and progesterone levels regardless of the time of infection or phase of the estrous cycle.

Biochemical changes in cats infected with Trypanosoma evansi

This study aimed at evaluating biochemical changes of cats (Felis catus) experimentally infected with Trypanosoma evansi. Seven animals were infected with 10(8) blood trypomastigotes per animal and six were used as controls. Blood smears were performed daily for 56 days and the hepatic, renal and muscular parameters in blood serum were evaluated at days 0, 7, 21, 35 and 49. The protozoan was found in the bloodstream 24-48 h post-inoculation (PI) and irregular peaks of parasitemia were observed throughout the experiment. Muscular enzymatic activities (aspartate aminotransferase and creatine kinase) were increased in infected cats compared to controls. Increased concentrations of total proteins and globulins and decreased levels of albumin and albumin/globulin ratio were observed in infected group versus the controls values (P<0.05). No alteration in serum activity of alanine aminotransferase, gamma-glutamyltransferase, creatinine and urea was observed in both groups.

Lice Outbreak in Buffaloes: Evidence of Anaplasma marginale Transmission by Sucking Lice Haematopinus tuberculatus

Abstract: Lice infestations are commonly seen in buffaloes, causing damage directly to the animal, i.e., itching, skin lesions, and anemia. In addition, these insects can also be vectors for infectious diseases. The present study describes an outbreak of lice in buffaloes as well as evidence for Haematopinus tuberculatus acting as a vector of anaplasmosis. Lice and blood were collected from 4 young buffaloes (2- to 4-mo-old) and a molecular analysis for the presence of Anaplasma marginale was conducted. DNA of A. marginale was detected in the blood of all 4 animals. Twelve lice were collected and separated in 4 groups, with 3 insects each, to comprise a pool of samples. After DNA extraction and molecular analysis, a positive PCR for A. marginale was found in all pooled samples. These results identify sucking lice as potential vectors of anaplasmosis. However, additional studies are necessary to fully evaluate the vector potential of H. tuberculatus for A. maginale transmission.

Diminazene aceturate associated with sodium selenite and vitamin E in the treatment of Trypanosoma evansi infection in rats

The aim of this study was to evaluate the utilization of a standard treatment with diminazene aceturate against the infection caused by Trypanosoma evansi, associated to sodium selenite and vitamin E. In vitro tests showed trypanocidal effect related to the treatment with diminazene aceturate and sodium selenite, but vitamin E had no harmful effect on the trypanosomes. In vivo experiments utilized a total of 72 adult outbreed females rats, separated into 9 groups (A, B, C, D, E, F, G, H and I), 8 animals each. Group A was the uninfected group; groups B to I were infected with 0.2mL of blood containing 10(6) trypanosomes. Parasitemia was estimated daily by microscopic examination of blood smears. Group B served as positive control; group C was treated with diminazene aceturate; group D with sodium selenite; group E with vitamin E; group F received an association of diminazene aceturate and sodium selenite; group G received an association of diminazene aceturate and vitamin E; group H received an association of diminazene aceturate, sodium selenite and vitamin E, and group I received an association of sodium selenite and vitamin E. Diminazene aceturate was administrated in a single dose on the 3rd day post infection (PI). Sodium selenite and vitamin E were administered at the 3rd and 23rd day PI. In vivo tests showed increase of longevity in groups treated with diminazene aceturate associated with sodium selenite (groups F and H). No difference was found between groups C and E, thus the vitamin E did not increase the efficacy of treatment against T. evansi when associated to diminazene aceturate. The curative efficacy of treatments was 37.5, 87.7, 37.7 and 75% to the groups C, F, G and H, respectively. Other treatments showed no efficacy. The sodium selenite when combined with chemotherapy may represent an alternative in the treatment of trypanosomosis.

Seroprevalence and risk factors for Neospora caninum in goats in Santa Catarina state, Brazil

Neosporosis is an infectious disease caused by the parasite Neospora caninum. Knowledge regarding neosporosis in goats is still quite limited, especially in the state of Santa Catarina (SC), southern Brazil. Therefore, this study aimed to assess the seroprevalence and risk factors for N. caninum in goats in the western and mountain regions of SC. Blood samples were collected from 654 goats in 57 municipalities. The indirect immunofluorescence test was used for antibody detection against N. caninum. Thirty samples (4.58%) were seropositive, with titers ranging from 1:50 to 1:6400. An epidemiological survey was also conducted in order to identify risk factors for neosporosis in goats. It was found that reproductive problems on the farms, as well as the diet and direct contact with dogs were casual risks for neosporosis. These results indicate that N. caninum infects goats in these regions, which may lead to reproductive problems.