Evaluation of the ELISA test for the antibody detection in cattle naturally and experimentally infected with Cysticerccus bovis

The ELISA test was evaluated for the diagnosis of bovine cysticercosis using heterologous antigens from the larvae of T. solium and T. crassiceps, by using different types of positive and negative control sera, to allow a broader analysis of the results. The ELISA test showed low sensitivity under natural conditions of bovine cysticercosis manifestation, but high rates (up to 90%) under experimental conditions. The high specificity of the test (81-100%) made evident its capacity to differentiate cysticercosis from other bovine diseases. No difference in performance was found among the antigens studied. It was concluded that the ELISA test has deficiencies in detecting anti-cysticercosis antibodies of animals at slaughterhouse. However, it can be useful in detecting experimentally infected animals and differentiating cysticercosis from other bovine diseases.     

Anthelmintic activity of Azadirachta indica A. Juss against sheep gastrointestinal nematodes

Gastrointestinal nematode control has been performed through use of anthelmintics. However, the development of resistant populations has required research into new alternatives. There are popular reports about anti-parasitic activity of Azadirachta indica in animals and plants. The aim of this study was to evaluate the anthelmintic activity of A. indica after feeding sheep with the dried leaves. In this experiment, 40 sheep were allotted into four treatment groups. Group I received a treatment of A. indica dry leaves mixed in a concentrate at a rate of 0.1 g/kg dose for 3 months. Group II was treated with double the dose of Group I. Group III was treated with closantel (Diantel) at the manufacturer-recommended dose once at the beginning of the study and Group IV was not treated. To compare treatment effects, the following parameters were evaluated: egg count per gram of feces (EPG), worm burden, weight gain and haematocrit. EPG and worm burden results were statistically evaluated using the Kruskal-Wallis test. Haematocrit and live weight gain were submitted to analysis of variance (ANOVA) and the means evaluated by Tukey's test with 95% probability. None of the evaluated parameters of the treatment groups were statistically different when compared to the control group, demonstrating that, with the protocol used, A. indica has no anthelmintic effect.     

Acid-base and biochemical stabilization and quality of recovery in male cats with urethral obstruction and anesthetized with propofol or a combination of ketamine and diazepam

This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol (P). Lactated Ringer’s solution was administered by intravenous (IV) beginning 15 min before and continuing for 48 h after relief of urethral obstruction. Quality of recovery and time to standing were evaluated. The urethral catheter was maintained to measure urinary output. Hematocrit (Hct), total plasma protein (TPP), albumin, total protein (TP), blood urea nitrogen (BUN), creatinine, pH, bicarbonate (HCO₃⁻), chloride, base excess, anion gap, sodium, potassium, and partial pressure of carbon dioxide in mixed venous blood (pvCO₂) were measured before urethral obstruction, at start of fluid therapy (0 h), and at subsequent intervals. The quality of recovery and time to standing were respectively 4 and 75 min in the KD group and 5 and 16 min in the P group. The blood urea nitrogen values were increased at 0, 2, and 8 h in both groups. Serum creatinine increased at 0 and 2 h in cats administered KD and at 0, 2, and 8 h in cats receiving P, although the values were above the reference range in both groups until 8 h. Acidosis occurred for up to 2 h in both groups. Acid-base and biochemical stabilization were similar in cats anesthetized with propofol or with ketamine-diazepam. Cats that received propofol recovered much faster, but the ketamine-diazepam combination was shown to be more advantageous when treating uncooperative cats as it can be administered by intramuscular (IM) injection.     

Acaricidal activity of hydroethanolic formulations of thymol against Rhipicephalus sanguineus (Acari: Ixodidae) and Dermacentor nitens (Acari: Ixodidae) larvae

The aim of this study was to assess the acaricidal activity of hydroethanolic formulations of thymol at varying concentrations on Rhipicephalus sanguineus and Dermacentor nitens larvae. The larval packet test was used and the thymol concentrations tested were 2.5, 5.0, 10.0, 15.0 and 20.0 mg/ml. The control group was exposed only to water and ethanol (50/50%) and there were 10 repetitions for each treatment. The mortality was evaluated after 24 h. For the R. sanguineus larvae, the mortality rates were 47.5, 50.2, 96.7, 95.9 and 98.1%, while for D. nitens the rates were 14.1, 75.0, 90.2, 90.3 and 99.5%, at respective thymol concentrations of 2.5, 5.0, 10.0, 15.0 and 20.0 mg/ml. The results indicate that the hydroethanolic formulations of thymol tested have acaricidal activity on R. sanguineus and D. nitens larvae exposed topically, causing mortality greater than 90% 24 h post-treatment starting at the concentration of 10 mg/ml.     

A new type of pterocarpanquinone that affects Toxoplasma gondii tachyzoites in vitro

Toxoplasma gondii, the agent of Toxoplasmosis, is an obligate intracellular protozoan able to infect a wide range of vertebrate cells, including nonprofessional and professional phagocytes. Therefore, drugs must have intracellular activities in order to control this parasite. The most common therapy for Toxoplasmosis is the combination of sulfadiazine and pyrimethamine. This treatment is associated with adverse reactions, thus, the development of new drugs is necessary. In previous studies, naphthoquinone derivatives showed anti-cancer activity functioning as agents capable of acting on groups of DNA, preventing cancer cells duplication. These derivatives also display anti-parasitic activity against Plasmodium falciparum and Leishmania amazonensis. The derivative pterocarpanquinone tested in this work resulted from the molecular hybridization between pterocarpans and naphtoquinone that presents anti-tumoral and anti-parasitic activities of lapachol. The aim of this work was to determine if this derivative is able to change T. gondii growth within LLC-MK2 cells. The drug did not arrest host cell growth, but was able to decrease the infection index of T. gondii with an IC(50) of 2.5 μM. Scanning and transmission electron microscopy analysis showed morphological changes of parasites including membrane damage. The parasite that survived tended to encyst as seen by Dolichos biflorus lectin staining and Bag-1 expression. These results suggest that pterocarpanquinones are drugs potentially important for the killing and encystment of T. gondii.     

Canine visceral leishmaniasis in urban and rural areas of Northeast Brazil

The purpose of this study was to determine the clinical and laboratory profiles of canine leishmaniasis in two distinct areas. Dogs from urban and rural areas were examined. The population studied in the metropolitan area included 54 dogs. Of these, 20 (37%) animals did not present with any signs suggestive of visceral leishmaniasis (VL). Among these, only eight were confirmed negative by ELISA (rK39 and CE) and 12 dogs, clinically negative for leishmaniasis, were seropositive by ELISA (rK39 and CE). Thinness, conjunctivitis and onychogryphosis were the most frequent clinical signs in the urban areas, followed by crusty lesions, alopecia, ulcerated lesions, hyperkeratosis and exfoliation. In the metropolitan area human VL cases occurred mainly in 1991, 1992, 1999 and 2000. In the rural areas the ELISA rK39 test detected a seroprevalence of 11.3% and ELISA CE (Leishmania crude extract) of 20.6%. Thirty-nine dogs were examined 6 months after the first visit. Serological exams using rK39 antigen showed seroconversion of only one dog, whereas Leishmania CE showed seroconversion of 13 (33.4%) dogs. In this rural environment 83.3% of the positive dogs were asymptomatic. Lutzomyia intermedia and Lu. longipalpis were the most predominant sandfly vector species. Amastigotes were identified in spleen and liver fragments of symptomatic necropsied animals. PCR amplification of DNA isolated from promastigote culture indicated that the species was Leishmania chagasi. This finding suggests that delayed diagnosis and euthanasia of potentially infectious animals may occur with an increased transmission risk to sandflies and subsequently to humans.     

The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs

The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp.Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03–16 μg/mL, 0.06 to >16 μg/mL and 0.5–64 μg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.     

Sero-epidemiological survey for toxoplasmosis in wild New World monkeys (Cebus spp.; Alouatta caraya) at the Paraná river basin, Paraná State, Brazil

In this study, we captured 60 wild New World monkeys (Cebus spp.; Alouatta caraya) at the Paraná river basin, Paraná State, Brazil, and modified agglutination test (MAT) was performed to evaluate anti-Toxoplasma gondii antibodies. Prevalence was 30.2% (13/43) in Cebus spp. (capuchin monkeys) and 17.6% (3/17) for A. caraya (black and golden howler monkeys). MAT showed antibody titers of 16 (15/16) and 64 (1/16). Herein, we have observed an odds ratio (OR)=4.67 (1.060.05). The present work is the first report on serum occurrence of anti-T. gondii antibodies in wild capuchin monkeys and in wild black and golden howler monkeys.