LARVICIDE ACTIVITY OF LACTOBACILLUS SPP. AND SACCHAROMYCES BOULARDII SUPERNATANTS ON TOXOCARA CANIS.

Experimental studies have demonstrated the potential of probiotics to control visceral toxocariasis, which is a tissue parasitosis that is difficult to treat. This study evaluated the in vitro activity of probiotics and their supernatants on Toxocara canis larvae. The probiotics Lactobacillus rhamnosus (ATCC 7469), Lactobacillus paracasei (ATCC 335), Saccharomyces boulardii, Saccharomyces cerevisiae, and Bacillus cereus var. toyoi were tested in the following preparations: probiotic (P) 1 × 102 to 1 × 109 colony-forming units (CFUs), inactivated probiotic (IP) 1 × 102 to 1 × 109 CFUs, supernatant probiotic (SUpP), and inactivated probiotic supernatant (SupIP). The probiotics and their respective supernatants were separately incubated with 100 T. canis larvae per well using microculture plates with RPMI-1640 medium for 48 hr at 37 C and 5% CO2. The evaluation of the in vitro tests was based on the viability of T. canis larvae, through morphologic integrity, positive motility, and the absence of trypan blue stain. Only culture supernatants (SUpP and SUpIP) of Lactobacillus spp. resulted in 100% dead larvae, whereas S. boulardii showed larvicidal activity in T. canis >70%. The rest of the tests did not show larvicide activity. Therefore, it is important to investigate the supernatant effects of Lactobacillus spp. and S. boulardii in vivo on T. canis visceral infections, their mechanisms of action, and major metabolites involved.

Cyclosporine A increases the intensity of Toxocara canis infection in swiss mice.

Toxocariasis is a zoonotic disease of worldwide distribution. The connection between parasitic diseases and conditions that depress the immune system, such as the use of immunosuppressive drugs, has been studied. The purpose of this study was to evaluate the effect of Cyclosporine A (CsA) on the intensity of infection, humoral response and gene transcription of interleukins IL-4, IL-10 and IL-12 in mice experimentally infected with Toxocara canis. To this end, mice were divided into two groups treated with CsA (G1: 10 mg/Kg and G2: 50 mg/kg), the G3 and G4 group received PBS. After the last administration of the drug or PBS (orally every 48 hours for 15 days), groups G1, G2 and G3 were inoculated with 1200 eggs of T. canis. Was collected blood samples on days zero, 15 and 30 days post-inoculation (PI), for ELISA test and the mice were euthanized 30 days PI. The organs and striated muscle tissue were collected for the recovery of larvae. The splenocytes were analyzed by RT-PCR. The intensity of infection in the mice treated with 50 mg/kg of CsA was 65.5% higher than in the control group (p=0.001). An analysis of the kinetics of anti-Toxocara antibody revealed that the groups treated with CsA showed significantly higher mean levels of antibodies on day 15 PI. The transcription of the three tested interleukins showed no statistical difference between G2 and G3 (control). It was concluded that the immunosuppression triggered by CsA (50 mg/Kg) favored the establishment of a larger number of T. canis larvae without, however, altering immunoglobulin production and IL-4, IL-10 and IL-12 transcription on day 30 PI.

Saccharomyces boulardii reduces the vertical transmission of Toxocara canis larvae in mice.

Probiotics have been shown to reduce the intensity of Toxocara canis infection in mice. However, larval transmission of this nematode also occurs via transplacental and transmammary routes. Thus, the aim of this study was to evaluate the effect of the Saccharomyces boulardii probiotic on the vertical transmission of T. canis in Swiss mice. The mice received 107S. boulardii colony-forming units per gram of food. The supplementation began 15 days before mating and was maintained throughout pregnancy and lactation. The animals were inoculated with 300 T. canis embryonated eggs on the 14th day of pregnancy. The presence of larvae was examined in the organs of the females and their offspring. The examined organs included the following: brain, liver, lungs, heart, kidneys, spleen, eye, skeletal muscle (carcass) and mammary glands of lactating females. There was a 42% (P = 0.041) reduction in the number of larvae transmitted to offspring in the group that received probiotic-supplemented food (GI). Additionally, there was a 50% reduction (P = 0.023) in the number of larvae found in the brains of lactating offspring in the GI group. These results reveal the potential of S. boulardii probiotic use as an auxiliary method of controlling visceral toxocariasis.

Antihelminthic action of the Anethum graveolens essential oil on Haemonchus contortus eggs and larvae / Ação anti-helmítica do óleo essencial de Anethum graveolens sobre ovos e larvas de Haemonchus contortus

Abstract Gastrointestinal nematodes are responsible for great economic losses in sheep raising, and their control has long been carried out almost exclusively by the administration of anthelmintics, which have led to serious resistance problems. In the search for alternative control measures, phytotherapic research is highlighted. The aim of this study was to evaluate the action of Anethum graveolens (dill) essential oil on different stages of Haemonchus contortus life cycle, as well its cytotoxicity MDBK (Madin-Darby bovine kidney) cells. H. contortus larvae and eggs were obtained from infected sheep feces, and essential oil extracted from plant seeds through the Clevenger apparatus. 9.4, 4.7, 2.35, 1.17. 0.58 and 0.29 mg/mL concentrations were evaluated. The Egg Hatch Inhibition (HI), Larval Development Inhibition (LDI) and Larval Migration Inhibition (LMI) techniques were used. Thybendazole 0.025 mg/mL in HI and Levamisole 0.02 mg/mL in the LDI and LMI tests were used as positive controls, while distilled water and a Tween 80 solution were used as positive negative controls. The inhibition results obtained for the highest oil concentration were: HI 100%, LDI 98.58% and LMI 63.7%, differing (�� <0.05) from negative controls. Main A. graveolens oil components present in 95.93% of the total oil were Dihydrocarvone (39.1%), Carvone (22.24%), D-Limonene (16.84%), Apiol (10.49%) and Trans-dihydrocarvone (7.26%). Minimum A. graveolens essential oil concentrations required to inhibit 50% (IC50) of egg hatching, larval development and larval migration were 0.006 mg/mL, 2.536 mg/mL and 3.963 mg/mL, respectively. Cell viability in MDBK (Madin-Darby bovine kidney) cells, when incubated with A. graveolens essential oil, was 86% for the highest (9.4 mg/mL) and 99% for the lowest concentration (0.29 mg/mL). A. graveolens essential oil, according to the results obtained in this study, is a promising alternative in sheep gastrointestinal nematode control.

Resumo Os nematoides gastrintestinais são responsáveis ​​por grandes perdas econômicas na ovinocultura, e seu controle tem sido realizado quase exclusivamente pela administração de anti-helmínticos, que levaram a sérios problemas de resistência. Na busca de medidas alternativas de controle, destaca-se a pesquisa fitoterápica. O objetivo deste trabalho foi avaliar a ação do óleo essencial de Anethum graveolens (endro) em diferentes estágios de Haemonchus contortus, bem como testar a viabilidade celular para o óleo. Larvas e ovos de H. contortus foram obtidos de fezes de ovinos infectados e óleo essencial extraído de sementes de plantas através do aparelho de Clevenger. As concentrações avaliadas foram 9,4, 4,7, 2,35, 1,17, 0,58 e 0,29 mg/mL. Verificou-se a Inibição de eclosão dos ovos (IE), Inibição de Desenvolvimento Larval (IDL) e Inibição de Migração Larval (IML). Tiabendazol 0,025 mg/mL em IE e Levamisole 0.02 mg/mL nos testes IDL e IML foram usados ​​como controles positivos, enquanto água destilada e uma solução Tween 80 foram usados como controles negativos. Os resultados de inibição obtidos para a maior concentração de óleo foram: IE 100%, IDL 98,58% e IML 63,7%, diferindo (�� <0,05) dos controles negativos. Os principais componentes presentes em 95,93% do óleo total de A. graveolens foram Di-hidrocarvona (39,1%), Carvona (22,24%), D-Limoneno (16,84%), Apiol (10,49%) e Trans-di-hidrocarvona (7,26%). As concentrações mínimas de óleo essencial de A. graveolens necessárias para inibir 50% (IC50) de eclosão dos ovos, desenvolvimento larval e migração larval foram de 0,006 mg/mL, 2,536 mg/mL e 3,963 mg/mL, respectivamente. A viabilidade celular nas células MDBK (rim bovino Madin-Darby), quando incubadas com o óleo essencial de A. graveolens, foi de 86% para a maior (9,4 mg/mL) e 99% para a menor concentração (0,29 mg/mL). O óleo essencial de A. graveolens mostrou ser uma alternativa promissora no controle de nematoides gastrintestinais de ovinos.

Antihelminthic action of the Anethum graveolens essential oil on Haemonchus contortus eggs and larvae.

Gastrointestinal nematodes are responsible for great economic losses in sheep raising, and their control has long been carried out almost exclusively by the administration of anthelmintics, which have led to serious resistance problems. In the search for alternative control measures, phytotherapic research is highlighted. The aim of this study was to evaluate the action of Anethum graveolens (dill) essential oil on different stages of Haemonchus contortus life cycle, as well its cytotoxicity MDBK (Madin-Darby bovine kidney) cells. H. contortus larvae and eggs were obtained from infected sheep feces, and essential oil extracted from plant seeds through the Clevenger apparatus. 9.4, 4.7, 2.35, 1.17. 0.58 and 0.29 mg/mL concentrations were evaluated. The Egg Hatch Inhibition (HI), Larval Development Inhibition (LDI) and Larval Migration Inhibition (LMI) techniques were used. Thybendazole 0.025 mg/mL in HI and Levamisole 0.02 mg/mL in the LDI and LMI tests were used as positive controls, while distilled water and a Tween 80 solution were used as positive negative controls. The inhibition results obtained for the highest oil concentration were: HI 100%, LDI 98.58% and LMI 63.7%, differing (𝑝 <0.05) from negative controls. Main A. graveolens oil components present in 95.93% of the total oil were Dihydrocarvone (39.1%), Carvone (22.24%), D-Limonene (16.84%), Apiol (10.49%) and Trans-dihydrocarvone (7.26%). Minimum A. graveolens essential oil concentrations required to inhibit 50% (IC50) of egg hatching, larval development and larval migration were 0.006 mg/mL, 2.536 mg/mL and 3.963 mg/mL, respectively. Cell viability in MDBK (Madin-Darby bovine kidney) cells, when incubated with A. graveolens essential oil, was 86% for the highest (9.4 mg/mL) and 99% for the lowest concentration (0.29 mg/mL). A. graveolens essential oil, according to the results obtained in this study, is a promising alternative in sheep gastrointestinal nematode control.

Intestinal parasites in cancer patients in the South of Brazil / Parasitos intestinais em pacientes com câncer do Sul do Brasil

Abstract Intestinal parasitic infections in immunocompromised patients can lead to serious complications when not diagnosed and treated early. This study aimed to investigate the frequency of intestinal parasites in cancer patients undergoing chemotherapy in the South of Brazil. Three fecal samples collected from each patient (73 individuals) were processed by Ritchie and Faust techniques and submitted to specific staining methods for intestinal protozoa. A 61.6% parasite and/or commensal positivity was found. Helminths identified were Ascaris lumbricoides (33.3%), Taenia spp. (6.6%), Strongyloides stercoralis (4.4%) and Trichuris trichiura (2.2%). Among protozoans, Giardia lamblia (26.6%), Cryptosporidium spp. (13.3%) and Cystoisospora belli (4.4%) were identified. The presence of Entamoeba coli, Endolimax nana and Entamoeba hartmanni was also recorded. The results obtained warn of the importance of fecal parasitological diagnosis and the use of specific staining methods for the detection of intestinal parasites in cancer patients. These exams should be regularly requested at the patient's first clinic visit, given the high prevalence found in this study and the possible severity of such conditions for these individuals.

Resumo As parasitoses intestinais em pacientes imunocomprometidos podem levar a graves complicações se não diagnosticadas e tratadas precocemente. Este estudo teve como objetivo investigar a frequência de parasitos intestinais em pacientes oncológicos submetidos ao tratamento quimioterápico. Foram coletadas três amostras de fezes de cada paciente, sendo processadas pelas técnicas de Ritchie e Faust e submetidas à métodos de coloração específicos para protozoários intestinais. Foi encontrada positividade de 61,6% para parasitos e/ou comensais. Os helmintos identificados foram Ascaris lumbricoides (33,3%), Taenia spp. (6,6%), Strongyloides stercoralis (4,4%) e Trichuris trichiura (2,2%). Dentre os protozoários, foram identificados Giardia lamblia (26,6%), Cryptosporidium spp. (13,3%) e Cystoisospora belli (4,4%). Também foi registrada presença de Entamoeba coli, Endolimax nana e Entamoeba hartmanni. Os resultados encontrados alertam para a importância do diagnóstico parasitológico de fezes junto à utilização de colorações específicas para parasitos intestinais em pacientes oncológicos, sendo que os mesmos deveriam ser requeridos como conduta já na primeira consulta clínica destes pacientes, dada à elevada prevalência aqui constatada e a possível severidade que tais moléstias podem acarretar nestes indivíduos.

Intestinal parasites in cancer patients in the South of Brazil.

Intestinal parasitic infections in immunocompromised patients can lead to serious complications when not diagnosed and treated early. This study aimed to investigate the frequency of intestinal parasites in cancer patients undergoing chemotherapy in the South of Brazil. Three fecal samples collected from each patient (73 individuals) were processed by Ritchie and Faust techniques and submitted to specific staining methods for intestinal protozoa. A 61.6% parasite and/or commensal positivity was found. Helminths identified were Ascaris lumbricoides (33.3%), Taenia spp. (6.6%), Strongyloides stercoralis (4.4%) and Trichuris trichiura (2.2%). Among protozoans, Giardia lamblia (26.6%), Cryptosporidium spp. (13.3%) and Cystoisospora belli (4.4%) were identified. The presence of Entamoeba coli, Endolimax nana and Entamoeba hartmanni was also recorded. The results obtained warn of the importance of fecal parasitological diagnosis and the use of specific staining methods for the detection of intestinal parasites in cancer patients. These exams should be regularly requested at the patient's first clinic visit, given the high prevalence found in this study and the possible severity of such conditions for these individuals.

Risk and other factors associated with toxoplasmosis and toxocariasis in pregnant women from southern Brazil.

Toxoplasmosis causes complications during pregnancy that have serious effects on fetal development. Thus far, toxocariasis has been reported to spread only via vertical transmission. Nonetheless, the population of pregnant women is also exposed to this infection. Co-infection with both Toxoplasma gondii and Toxocara spp. has been reported in children, but there are no reports of co-infection in the population of pregnant women. The aim of this study was to determine the prevalence of co-infection with T. gondii and Toxocara spp. in pregnant women at a university hospital in southern Brazil, and to identify the risk factors associated with infection by both parasites. Two hundred pregnant women were tested for the presence of anti-T. gondii and anti-Toxocara spp. antibodies and were asked to complete an epidemiological questionnaire. In this study, the co-infection rate observed in the total population of pregnant women was 8%. In addition, women with a positive result for a serology test for Toxocara spp. were at increased risk of infection by T. gondii (P = 0.019). Co-infection with both parasites in pregnant women was associated with low birth weights in neonates. The similar modes of transmission of both parasites could explain the co-infection. Only a few previous studies have investigated this phenomenon. The findings of the present study emphasize the importance of serological diagnosis during prenatal care and further research in this area to identify risk factors associated with this co-infection, and the possible implications of this co-infection during pregnancy and on the health of newborns.

Antihelminthic action of the Anethum graveolens essential oil on Haemonchus contortus eggs and larvae

Abstract Gastrointestinal nematodes are responsible for great economic losses in sheep raising, and their control has long been carried out almost exclusively by the administration of anthelmintics, which have led to serious resistance problems. In the search for alternative control measures, phytotherapic research is highlighted. The aim of this study was to evaluate the action of Anethum graveolens (dill) essential oil on different stages of Haemonchus contortus life cycle, as well its cytotoxicity MDBK (Madin-Darby bovine kidney) cells. H. contortus larvae and eggs were obtained from infected sheep feces, and essential oil extracted from plant seeds through the Clevenger apparatus. 9.4, 4.7, 2.35, 1.17. 0.58 and 0.29 mg/mL concentrations were evaluated. The Egg Hatch Inhibition (HI), Larval Development Inhibition (LDI) and Larval Migration Inhibition (LMI) techniques were used. Thybendazole 0.025 mg/mL in HI and Levamisole 0.02 mg/mL in the LDI and LMI tests were used as positive controls, while distilled water and a Tween 80 solution were used as positive negative controls. The inhibition results obtained for the highest oil concentration were: HI 100%, LDI 98.58% and LMI 63.7%, differing ( 0.05) from negative controls. Main A. graveolens oil components present in 95.93% of the total oil were Dihydrocarvone (39.1%), Carvone (22.24%), D-Limonene (16.84%), Apiol (10.49%) and Trans-dihydrocarvone (7.26%). Minimum A. graveolens essential oil concentrations required to inhibit 50% (IC50) of egg hatching, larval development and larval migration were 0.006 mg/mL, 2.536 mg/mL and 3.963 mg/mL, respectively. Cell viability in MDBK (Madin-Darby bovine kidney) cells, when incubated with A. graveolens essential oil, was 86% for the highest (9.4 mg/mL) and 99% for the lowest concentration (0.29 mg/mL). A. graveolens essential oil, according to the results obtained in this study, is a promising alternative in sheep gastrointestinal nematode control.

Resumo Os nematoides gastrintestinais são responsáveis por grandes perdas econômicas na ovinocultura, e seu controle tem sido realizado quase exclusivamente pela administração de anti-helmínticos, que levaram a sérios problemas de resistência. Na busca de medidas alternativas de controle, destaca-se a pesquisa fitoterápica. O objetivo deste trabalho foi avaliar a ação do óleo essencial de Anethum graveolens (endro) em diferentes estágios de Haemonchus contortus, bem como testar a viabilidade celular para o óleo. Larvas e ovos de H. contortus foram obtidos de fezes de ovinos infectados e óleo essencial extraído de sementes de plantas através do aparelho de Clevenger. As concentrações avaliadas foram 9,4, 4,7, 2,35, 1,17, 0,58 e 0,29 mg/mL. Verificou-se a Inibição de eclosão dos ovos (IE), Inibição de Desenvolvimento Larval (IDL) e Inibição de Migração Larval (IML). Tiabendazol 0,025 mg/mL em IE e Levamisole 0.02 mg/mL nos testes IDL e IML foram usados como controles positivos, enquanto água destilada e uma solução Tween 80 foram usados como controles negativos. Os resultados de inibição obtidos para a maior concentração de óleo foram: IE 100%, IDL 98,58% e IML 63,7%, diferindo ( 0,05) dos controles negativos. Os principais componentes presentes em 95,93% do óleo total de A. graveolens foram Di-hidrocarvona (39,1%), Carvona (22,24%), D-Limoneno (16,84%), Apiol (10,49%) e Trans-di-hidrocarvona (7,26%). As concentrações mínimas de óleo essencial de A. graveolens necessárias para inibir 50% (IC50) de eclosão dos ovos, desenvolvimento larval e migração larval foram de 0,006 mg/mL, 2,536 mg/mL e 3,963 mg/mL, respectivamente. A viabilidade celular nas células MDBK (rim bovino Madin-Darby), quando incubadas com o óleo essencial de A. graveolens, foi de 86% para a maior (9,4 mg/mL) e 99% para a menor concentração (0,29 mg/mL). O óleo essencial de A. graveolens mostrou ser uma alternativa promissora no controle de nematoides gastrintestinais de ovinos.

Modulation of IL-12 and IFNγ by probiotic supplementation promotes protection against Toxocara canis infection in mice.

In this study, supplementation with the probiotic Saccharomyces boulardii promoted a reduction in intensity of infection by Toxocara canis and modulates cytokines mRNA expression in experimentally infected mice. IL-12 gene transcription had 40-fold increase in S. boulardii supplemented uninfected mice and sevenfold increase in supplemented infected mice comparing with not supplemented group. Regarding IFNγ, similar results were observed, since probiotic supplementation induced approximately 43-fold increase, but only in uninfected mice (P < 0·05). T. canis infection upregulated IL-10 expression while S. boulardii downregulated it and no change was observed for IL-4. Thus, based in these findings; we suggest that one possible mechanism responsible for S. boulardii protection effect against T. canis infection is by the modulation of cytokines expression, especially IL-12.

Toxocara canis: anthelmintic activity of quinone derivatives in murine toxocarosis.

Human toxocarosis is a chronic tissue parasitosis most often caused by Toxocara canis. The seroprevalence can reach up to 50%, especially among children and adolescents. The anthelmintics used in the treatment have moderate efficacy. The aim of this study was to evaluate the in vitro and in vivo anthelmintic activity of quinones and their derivatives against T. canis larvae and the cytotoxicity of the larvicidal compounds. The compounds were evaluated at 1 mg mL(-1) concentration in microculture plates containing third stage larvae in an Roswell Park Memorial Institute (RPMI) 1640 environment, incubated at 37 °C in 5% CO2 tension for 48 h. Five naphthoxiranes were selected for the cytotoxicity analysis. The cell viability evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays using murine peritoneal macrophages isolated from C57BL/6 mice revealed that the naphthoxiranes (1 and 3) were less cytotoxic at a concentration of 0.05 mg mL(-1). The efficacy of naphthoxiranes (1 and 3) was examined in murine toxocarosis also. The anthelmintic activity was examined by evaluating the number of larvae in the brain, carcass, liver, lungs, heart, kidneys and eyes. Compound (3) demonstrated anthelmintic activity similar to that of albendazole by decreasing the number of larvae in the organs of mice and thus could form the basis of the development of a new anthelmintic drug.

Anti-Trypanosoma cruzi antibody detection in blood donors in the Southern Brazil

Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values ± 20 percent cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in situations where blood samples showed conflicting results. From 4,482 samples collected in 2004 and 2005, the reactivity for anti-T. cruzi was 0.96 percent (43). Among those, 21 cases (0.47 percent) were confirmed as positive - most of them were female, with low school level and averaging 47.2 percent years old. Interestingly, the blood donors are not aware of being contaminated and this fact makes it difficult for controlling the disease. Chagas' Disease was one of the main reasons for discarding blood bags through serological control in Southern Brazil. Sampling reactivity showed variation among the different techniques used for anti-T. cruzi research. In order to obtaining more secure and conclusive results, more than one diagnostic technique must be used.

Anti-Trypanosoma cruzi antibody detection in blood donors in the Southern Brazil.

Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values +/- 20% cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in situations where blood samples showed conflicting results. From 4,482 samples collected in 2004 and 2005, the reactivity for anti-T. cruzi was 0.96% (43). Among those, 21 cases (0.47%) were confirmed as positive - most of them were female, with low school level and averaging 47.2% years old. Interestingly, the blood donors are not aware of being contaminated and this fact makes it difficult for controlling the disease. Chagas' Disease was one of the main reasons for discarding blood bags through serological control in Southern Brazil. Sampling reactivity showed variation among the different techniques used for anti-T. cruzi research. In order to obtaining more secure and conclusive results, more than one diagnostic technique must be used.

New molecular data on mammalian Hepatozoon species (Apicomplexa: Adeleorina) from Brazil and Spain.

Molecular techniques were used to examine the phylogenetic relationships among Hepatozoon species isolated from 13 foxes and 15 opossums from Brazil, and from 15 dogs, 20 foxes, 45 rodents, and 330 domestic cats from Spain. Hemogregarine infection was confirmed by amplification of the 18S rRNA gene and later sequencing. No hemogregarine infections were found in opossums. The prevalence of Hepatozoon in canids ranged from 26.6% (symptomatic domestic dogs) to 90% (Spanish foxes). Four different H. canis genotypes were detected, as well as an H. americanum-related protozoan (97% identical to the USA strain). Two Spanish cats were parasitized by a Hepatozoon species (0.6% prevalence) that showed 96% sequence identity to H. canis. DNA amplification assays performed on Spanish rodents showed 2 bank voles (Clethrionomys glareolus) to be infected by a Hepatozoon species (4.44% prevalence) with 95% sequence identity to Hepatozoon sp. from cats. Phylogenetic analysis showed Hepatozoon to be a monophyletic genus, in which species from carnivorous mammals (Hepatozoon sp. from cats, H. americanum and H. canis) appear as a sister lineage of that of lower vertebrates and rodents. This association suggests that H. americanum evolved in ticks and carnivores (either canids, or felids, or both) rather than in other ectoparasites and other types of mammal.

Antileishmanial antibody profile in dogs naturally infected with Leishmania chagasi.

Visceral leishmaniasis (VL) presents vigorous Th2 immune response, which is mainly characterized in human by augmented expression of Il-4, polyclonal B cell activation, intense hypergammaglobulinemia and production of antileishmanial IgE antibodies. However, few aspects of this type of immune response have been demonstrated in studies of canine visceral leishmaniasis (CVL). This work investigated by ELISA and western immunoblotting the production of antileishmanial IgE antibodies (IgE Ab) in symptomatic and asymptomatic dogs naturally infected by Leishmania chagasi, and also compared this IgE immune response with those of IgG, IgG1 and IgG2 antibodies. Three groups of dogs were evaluated: 12 VL dogs with positive Leishmania biopsies (GI), 44 dogs with a positive leishmanial indirect fluorescent antibody test (IFAT), 30 of them presenting clinical signs of VL and 14 asymptomatic (GII) and 21 healthy dogs living in kennels located in leishmaniasis endemic areas (GIII), which were seronegative in the IFAT. Eighteen dogs from an area free of CVL were used as controls (GIV). Antileishmanial IgE antibodies were detected in 4 of 12 VL dogs from group I (33%) and 14 of 30 symptomatic dogs from group II (47%). While all asymptomatic dogs from group II (100%) were seronegative for antileishmanial IgE Ab, 7 of 21 healthy animals from group III (33%) had these immunoglobulins. A strong correlation was verified between antileishmanial IgG and IgG2 antibody titers in all symptomatic dogs, but only 15 of these 42 animals (36%) produced simultaneously IgE, IgG, IgG1 and IgG2 antibodies to Leishmania. IgE antibodies recognized leishmanial antigens of 12, 36, 61, 81 and 118 KDD, while a more complex pattern of immunoblotting was verified mainly for IgG and IgG2 antibodies from symptomatic animals. IgG1 and IgG2 antibodies shared the recognition of L. chagasi polypeptides of 118, 81, 61, 36, 18, 14 and 12 KDD, being more intense the immune reactions between IgG1 Ab and the leishmanial polypeptides of 61 and 36 KDD, and also between IgG2 antibodies and the antigens of 26, 21, 18, 14 and 12 KDD. Our results suggest that the polyclonal production of antileishmanial antibodies that includes IgE Ab could characterize a Th2 immune response in CVL and can help the laboratory diagnosis of this disease.

Clinical and serological aspects of visceral leishmaniasis in northeast Brazilian dogs naturally infected with Leishmania chagasi.

Human visceral leishmaniasis is endemic in the northeast of Brazil, where the domestic dog is an important parasite reservoir in the infectious cycle of Leishmania chagasi. In this study, we evaluated the clinical signs of canine visceral leishmaniasis (CVL), serum protein profile and the antileishmanial IgG antibody production in 86 dogs living in northeast endemic areas of leishmaniasis. Thirty dogs from a leishmaniasis-free area were used as a control group. The major clinical signs of CVL seen were emaciation and skin ulcers (80%), followed by onychogryphosis and conjunctivitis (73%). Depilation was observed in 60% of animals while lymphadenomegaly, splenomegaly, liver enlargement or kidney involvement was less frequent (< or =20%). VL seropositive dogs presented with serum hyperproteinemia, hypoalbuminemia, hypergammaglobulinemia and decreased albumin/globulin ratio. A lower sensitivity and higher specificity was observed for promastigote indirect fluorescent antibody test (IFAT) (83 and 100%, respectively) compared with enzyme-linked immunosorbent assay (ELISA) (94 and 90%), which uses a crude extract of Leishmania. There was a positive correlation between IFAT and ELISA titers of antileishmanial IgG antibodies (Spearman test, P < 0.05), which was augmented in CVL dogs. This study found that the determination of serum protein, A/G ratio and the use of two different leishmanial serological tests like IFAT and ELISA are essential in CVL screening.

Variability of resistance in goats infected with Haemonchus contortus in Brazil.

The variability between and within breeds with respect to nematode egg counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) was studied in 36 yearling female goats of the Caninde (15), Bhuj (6) and Anglo-Nubian (15) breeds, exposed to Haemonchus contortus. Nematode-free goats were turned to a contaminated paddock in late February. From then on, fecal egg per gram counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) were determined at 2-week intervals up to Week 18. The EPG, transformed as [log(EPG + 75)], varied (P < 0.01) between goats within breeds and between weeks of exposure, but not between goat breeds (P > 0.05). PCV and Hb were affected by goat breeds (P < 0.05), by goats within breeds (P < 0.01) and by weeks of exposure (P < 0.01). Anglo-Nubians had higher (P < 0.01) PCV and Hb than Caninde; Bhuj had intermediate values. There were two EPG rises; one between Weeks 6 and 10 and the other between Weeks 14 and 16. The within breed variability was marked during the EPG rise on Week 6, when individual egg counts ranged from 130 to 2500. The EPG rises coincided with drops in Hb. PCV presented a similar trend, though not as marked. Haemonchus was responsible for more than 95% of nematode eggs counted. Considering the goat as experimental unit, the correlation coefficients (r) were: -0.45, P = 0.0064, between log(EPG + 75) and PCV; and -0.53, P = 0.0009, between log(EPG + 75) and Hb. The negative correlation between egg counts and blood values suggested breed differences in PCV and Hb were related to resistance to H. contortus infection and/or to its effects.

Haemonchus contortus resistance to ivermectin and netobimin in Brazilian sheep.

Suffolk, Texel, Hampshire Down and Ile de France sheep from the municipalities of Porto Amazonas, Piraquara and Araucaria in the State of Paraná, and Bagé in the State of Rio Grande do Sul were brought to Sobral, State of Ceará, to be used in a cross-breeding project. On arrival they had clinical signs of nematode parasitosis, and one Suffolk female died. The animals were treated orally with ivermectin (0.2 mg kg-1) and fifteen days later with netobimin (20.0 mg kg-1). Neither drug reduced the egg counts (measured in eggs per gram, EPG) significantly, and this suggested that the nematodes in the sheep were resistant to the anthelmintics used. Haemonchus contortus was the species involved. The egg counts were reduced after oral treatment with trichlorfon (100.0 mg kg-1). Haemonchus contortus larvae obtained from these animals before trichlorfon treatment and passaged through two nematode-free sheep were used in a further experiment. Twenty 6- to 9-month-old nematode-free lambs were infected with the H. contortus larvae (10,000 per animal) and after the infection was confirmed, were randomly divided into four groups of five animals. Group I was orally treated with ivermectin at 0.2 mg kg-1, Group II with oral netobimin at 20.0 mg kg-1, Group III with oral trichlorfon at 100.0 mg kg-1 and Group IV was a non-treated control. Egg counts and faecal cultures were taken before dosing on the day of treatment and seven days later when all animals were necropsied and the nematodes were collected from the abomasa and counted.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of parasitism and nutrition in goats: effects on haematological parameters, correlations, and other statistical associations.

Weaned wether goats (n = 144) approximately 6 months of age were placed in a 2 x 3 factorial experiment to test the effects and interaction of two levels of nutrition (growth+maintenance, NUT1; and twice growth+maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500, and 2000 larvae administered every 2 weeks; W0, W500, and W2000, respectively) on packed cell volume, red blood cell count, total serum protein and leukocytes. The statistical analysis revealed clear and proportionate differences among levels of infection for all variables. A significant (P < 0.05) nutritional effect was also found associated with all the variables except leukocytes. Nutrition by worm load interactions were found for packed cell volume and leukocytes. The neutrophil/lymphocyte ratio was higher in the NUT1-infected animals, leading to the nutrition by worm load interaction for leukocytes. An analysis for the different leukocyte types revealed significant (P < 0.05) differences among infection levels for lymphocytes, while nutrition level was found to be a significant effect for basophil count and immature white cells. Several significant correlations were observed between pairs of variables. Faecal egg output could be predicted from actual worm count in three of the four necropsy periods. The clear differences observed for blood parameters were not present in production traits, suggesting that physiological thresholds may play an important role in framing the metabolic activity of biological organisms. Total serum protein was the best indicator of these effects on production parameters.

Interaction of parasitism and nutrition and their effects on production and clinical parameters in goats.

Weaned wether goats (n = 144) approximately 6 months of age were placed in a 2 x 3 factorial design experiment for 5 months to test the main effects and interaction of two levels of nutrition (growth + maintenance, NUT1; twice growth + maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500 and 2000 larvae administered every 2 weeks: W0, W500 W2000, respectively) on weight, feed intake, level of infection and packed cell volume (PCV). The rationale for the experimental design was based on the lack of information concerning the interaction between nutritional status and worm burden. Results indicated significant effects of worm burden levels on PCV, faecal egg contents (eggs per gram of feces (EPG)), actual worm numbers, feed intake and efficiency of feed utilization. Nutrition x worm burden interactions were also significant for PCV and EPG. However, the differences detected for PCV and actual worm numbers did not translate into large or consistent differences in body weight. Goats on NUT2, after an initial period, showed little difference in body weight, irrespective of worm burden. Within the NUT1 level, W0 kids weighed more than W500 or W2000 kids throughout the study. Although not statistically significant, this constitutes a trend towards an interaction between nutrition and worm burden. In both nutrition levels, there were no body weight differences between W500 and W2000 until the last 14 days. Feed intake was depressed in the first 3 months of the experiment for infected animals, but was subsequently followed by a compensatory reaction. Lower establishment rates, based on actual worm counts, were observed for the higher infection level, but in both infection levels establishment rates tended to decrease with time. Nutrition was found to be more important to counteract the consequences of a parasitic infection than to counteract the establishment of that same infection.