First report of Giardia duodenalis assemblage F in humans and dogs in southern Brazil.

The present study aimed to molecularly characterize Giardia duodenalis from stool samples of humans, dogs, and cats. Molecular analyses were performed on 59 samples that tested positive for G. duodenalis on coproparasitological examinations. After extraction, the samples were first tested by nested polymerase chain reaction (n-PCR) analysis of the SSU-rRNA gene, and for the samples that were positive, the ß-giardin, TPI, and GDH genes were analyzed. The amplicons obtained in the n-PCR of the ß-giardin gene were subjected to PCR-restriction length polymorphism (RFLP) analysis and subsequent digestion with the enzyme HaeIII to differentiate the assemblages. Seven (11.8 %), 34 (57.7 %), and 18 (30.5 %) out of 59 samples were from humans, dogs, and cats, respectively. Nested-PCR results showed that 49.2 % (29/59) of samples were positive for the SSU-rRNA gene, with 42.9 % (3/7) of humans, 55.9 % (19/34) of dogs, and 38.9 % (7/18) of catsve. Of the other genes analyzed, ß-giardin was amplified most frequently, in 34.5 % (10/29) of samples, followed by GDH in 27.6 % (8/29) of samples, and TPI in 10.3 % (3/29) of samples. Only one sample from a dog showed the amplification of all genes. PCR-RFLP analysis showed assemblage F in a human, dog, and cat samples; and assemblage C and D in dog samples. This is the first description of assemblage F in humans from Brazil and the first description of assemblage F in dogs. Further studies are needed to verify the frequency with which these infections occur, and provide information that will contribute to the molecular epidemiological understanding of giardiasis.

Neospora caninum infection and reproductive problems in dairy cows from Brazil: A case-control study.

Neosporosis, an infectious disease caused by the protozoan Neospora caninum, has been associated with economic losses in cattle rearing worldwide. However, previous studies have not presented any evidence regarding the association between serological status of neosporosis and alteration of the reproductive parameters. Thus, this study aimed to determine whether N. caninum is associated with reproductive disorders and to evaluate the possible risk factors of the infection. Blood samples from 202 dairy cows, 51 with a history of reproductive disorders (case group) and 151 without (control group), were collected from different farms in Brazil. Epidemiological questionnaires were conducted with all the farmers. Serum samples were subjected to an indirect fluorescent antibody test to detect antibodies against the parasite. In total, 28.22% (57/202) of the cows were seropositive: 47.06% (24/51) from the case group and 21.85% (33/151) from the control group. By logistic regression, cows aged ≥48 months and cows with history of abortion were 4.8 (95% confidence interval [CI] = 1.91-12.05; p = 0.001) and 2.3 (95% CI = 1.06-5.1; p = 0.034) times more likely to be seropositive, respectively. Furthermore, our results show an association between N. caninum seropositivity and abortion in dairy cows from Brazil with poor management conditions and N. caninum seropositivity risk factors for reproductive disorders.

Prevalence and risk factors of Eimeria spp. natural infection in sheep from northern Paraná, Brazil.

The present study aimed to perform an epidemiological and morphological identification of Eimeria infection in sheep in Brazil. Fecal samples from sheep were collected from 20 farms in northern Paraná, Brazil. An epidemiological questionnaire was used to evaluate the risk factors. Fecal samples containing oocysts per gram of feces (OoPG) ≥1000 were subjected to the modified Willis-Mollay method to perform oocyst identification. Sporulated oocysts were observed microscopically for morphological identification. A total of 807 fecal samples were collected. Based on the morphological characteristics of the sporulated oocysts, 10 species of Eimeria were identified, with main species observed: Eimeira ovinoidalis (98.1%), Eimeria crandallis (87.6%), Eimeria parva (79.1%), and Eimeria bakuensis (60.8%). Only 2.6% (7/268) of the sheep were infected with a single species, 4.8% (13/268) contained two different species, and 92.5% (248/268) were infected with three or more species. The analysis of risk factors showed that an intensive rearing, no rotation of pasture, dirt, and slatted floors, and age up to 12 months were associated with infection. This study showed a high prevalence of Eimeria natural infection in sheep from northern Paraná, Brazil. Furthermore, based on the risk factors, good management and hygiene practices must be employed to avoid infection.

Prevalence and risk factors of Eimeria spp. natural infection in sheep from northern Paraná, Brazil / Prevalência e fatores de risco da infecção natural por Eimeira spp. em ovinos na região norte do Paraná, Brasil

Abstract The present study aimed to perform an epidemiological and morphological identification of Eimeria infection in sheep in Brazil. Fecal samples from sheep were collected from 20 farms in northern Paraná, Brazil. An epidemiological questionnaire was used to evaluate the risk factors. Fecal samples containing oocysts per gram of feces (OoPG) ≥1000 were subjected to the modified Willis-Mollay method to perform oocyst identification. Sporulated oocysts were observed microscopically for morphological identification. A total of 807 fecal samples were collected. Based on the morphological characteristics of the sporulated oocysts, 10 species of Eimeria were identified, with main species observed: Eimeira ovinoidalis (98.1%), Eimeria crandallis (87.6%), Eimeria parva (79.1%), and Eimeria bakuensis (60.8%). Only 2.6% (7/268) of the sheep were infected with a single species, 4.8% (13/268) contained two different species, and 92.5% (248/268) were infected with three or more species. The analysis of risk factors showed that an intensive rearing, no rotation of pasture, dirt, and slatted floors, and age up to 12 months were associated with infection. This study showed a high prevalence of Eimeria natural infection in sheep from northern Paraná, Brazil. Furthermore, based on the risk factors, good management and hygiene practices must be employed to avoid infection.

Resumo O presente estudo teve como objetivo realizar uma avaliação epidemiológica e morfométrica da infecção por Eimeria em ovinos no Brasil. Amostras fecais de ovinos foram coletadas em 20 fazendas no sul do Brasil. Um questionário epidemiológico foi utilizado para avaliar os fatores de risco. Amostras fecais, contendo oocistos por grama de fezes (OoPG) ≥1000, foram submetidas ao método de Willis-Mollay modificado para realizar a identificação de oocistos. Oocistos esporulados foram observados microscopicamente para identificação morfológica. Foram coletadas 807 amostras fecais. Com base nas características morfológicas e morfométricas dos oocistos esporulados, foram identificadas 10 espécies de Eimeria, com as principais espécies observadas: Eimeria ovinoidalis (98,1%), Eimeria crandallis (87,6%), Eimeria parva (79,1%) e Eimeria bakuensis (60,8%). Apenas 2,6% (7/268) dos ovinos estavam infectados com uma única espécie, 4,8% (13/268) continham duas espécies diferentes e 92,5% (248/268) estavam infectados com três ou mais espécies. A análise dos fatores de risco mostrou que uma criação intensiva, sem rotação de pasto, terra, piso de ripa e idade até 12 meses foram associadas à infecção. Este estudo mostrou uma alta prevalência de infecção natural por Eimeria em ovinos do norte do Paraná, Brasil. Além disso, com base nos fatores de risco, boas práticas de manejo e higiene devem ser empregadas para evitar infecções.

Evaluation of quantitative polymerase chain reaction for the detection of Toxoplasma gondii oocysts shed by cats.

Felines are definitive hosts of Toxoplasma gondii and can shed oocysts in their feces, contaminating the environment. Sporulated oocysts are highly resistant to the environment and have higher infectivity, which are attributed to many toxoplasmosis outbreaks. The aim of the present study was to evaluate a quantitative polymerase chain reaction (qPCR) technique for the detection of T. gondii oocysts shed by cats. Twelve cats from a previous vaccine experiment were challenged orally with 600 cysts of the TgDoveBr8 strain on day 72. Fecal samples were collected daily using the centrifugal flotation technique, with microscopic examination (Sheather technique) and qPCR for 20 days after the challenge. Cats from all groups shed oocysts in their feces. Five negative cats in the Sheather were positive according to qPCR on the 3rd day post-inoculation (dpi). Oocysts were detected on the 4th dpi using the Sheather; however, there was no statistical difference between the two methods (p=0.1116). In addition, there was no statistically significant difference in oocyst shedding between the groups according to the Sheather technique (p=0.6534) and qPCR (p=0.9670). In conclusion, these results demonstrate that qPCR can be used as an alternative to the Sheather to detect and quantify T. gondii oocysts.

Seroprevalence and risk factors for Neospora caninum and Toxoplasma gondii in goats of Maranhão State, Brazil.

We estimated the seroprevalence and possible risk factors for neosporosis and toxoplasmosis in goats in the state of Maranhão, Brazil. In addition, the variables related to these animals and the management of the farm were investigated in terms of the significance of the associations. In total, 383 serum samples from goats, of both sexes and different ages, were collected from 15 farms in four municipalities. The indirect immunofluorescence test was used for antibody detection against Neospora caninum and Toxoplasma gondii. The overall seroprevalence of N. caninum in goats was 26.4% (101/382; IC 95% 22.3-31.1), and 114 out of 383 serum samples were T. gondii-seropositive (29.8%, IC 95% 25.4-34.5). In addition, the seroprevalence of coinfection of T. gondii and N. caninum in goats was 8.6% (33/382; IC 95% 6.2-11.8). The risk factors significantly associated with the seroprevalence of N. caninum were age, type of sheepfold floor, rearing system, feeding, pasture area cultivated, cats having access to the feed deposits, worming, slaughter place of the animals, history of abortion and the presence of dogs and cats. Regarding the seroprevalence of T. gondii infection, age, category, presence of other species and purpose of breeding were the risk factors. To our knowledge, this is the first report of the seroprevalence and risk factors for N. caninum and T. gondii in goats in the state of Maranhão, Brazil, which provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

Comparison of serological and molecular techniques to detect Toxoplasma gondii in free-range chickens (Gallus gallus domesticus).

The present study aimed to compare different indirect and direct diagnostic techniques to diagnose Toxoplasma gondii in free-range chickens. Samples of 386 chickens obtained from 24 Paraná properties were used for serological analysis by indirect fluorescent antibody test (IFAT), modified agglutination test (MAT), and enzyme-linked immunosorbent assay (ELISA). Animals positive by IFAT and/or MAT had their tissues submitted to the mouse bioassay, and those who were positive in this technique had their blood, tissues, and acidic pepsin tissue digestion submitted to PCR (conventional, nested, and quantitative-PCR (qPCR)). One hundred and nineteen chickens (30.8 %) were positive in at least one of the serological tests, being 102 (26.4 %) in the IFAT, 64 (16.6 %) in the MAT, and 62 (16.0 %) in the ELISA. The IFAT was used as a gold standard, and the MAT showed higher sensitivity (46.0 %) and specificity (94.0) compared to ELISA (43.5 % and 93.6 %, respectively). Ninety samples of eighteen chickens positive in the mouse bioassay were subjected to PCR, and according to molecular tests, the conventional PCR detected the T. gondii DNA in 30 % (27/90) of the samples, in 38.8 % (35/90) with nested-PCR and 40.0 % (36/90) with real-time. According to molecular analyzes, the sensitivity was higher in ITS1 nested-PCR (69.4 %) and specificity in conventional PCR-529bp (90.7 %), using the qPCR as the gold standard. MAT and ELISA had similarities in concordance analyzes. The IFAT was the serological technique with the highest agreement with the mouse bioassay, and serological tests in parallel showed to be a good screening option for the isolation of T. gondii in chick tissues. The PCR markers effectively detected the parasite DNA, and the heart was the tissue with the highest number of positives samples. The conventional PCR had sensitivity similar to nested-PCR and qPCR and could be a cheaper alternative to diagnose T. gondii infection in chicken tissues.

Evaluation of quantitative polymerase chain reaction for the detection of Toxoplasma gondii oocysts shed by cats / Avaliação da reação em cadeia da polimerase quantitativa para a detecção de oocistos de Toxoplasma gondii eliminados por gatos

Abstract Felines are definitive hosts of Toxoplasma gondii and can shed oocysts in their feces, contaminating the environment. Sporulated oocysts are highly resistant to the environment and have higher infectivity, which are attributed to many toxoplasmosis outbreaks. The aim of the present study was to evaluate a quantitative polymerase chain reaction (qPCR) technique for the detection of T. gondii oocysts shed by cats. Twelve cats from a previous vaccine experiment were challenged orally with 600 cysts of the TgDoveBr8 strain on day 72. Fecal samples were collected daily using the centrifugal flotation technique, with microscopic examination (Sheather technique) and qPCR for 20 days after the challenge. Cats from all groups shed oocysts in their feces. Five negative cats in the Sheather were positive according to qPCR on the 3rd day post-inoculation (dpi). Oocysts were detected on the 4th dpi using the Sheather; however, there was no statistical difference between the two methods (p=0.1116). In addition, there was no statistically significant difference in oocyst shedding between the groups according to the Sheather technique (p=0.6534) and qPCR (p=0.9670). In conclusion, these results demonstrate that qPCR can be used as an alternative to the Sheather to detect and quantify T. gondii oocysts.

Resumo Felinos são hospedeiros definitivos do Toxoplasma gondii e podem eliminar oocistos nas fezes, contaminando o meio ambiente. Oocistos esporulados são altamente resistentes ao meio ambiente com elevada infectividade, sendo atribuído a muitos surtos de toxoplasmose. O objetivo do estudo foi avaliar a reação em cadeia da polimerase quantitativa (qPCR) para a detecção de oocistos de T. gondii eliminados por gatos. Doze gatos de um experimento prévio de vacina foram desafiados por via oral com 600 cistos da cepa TgDoveBr8 no dia 72. Amostras fecais foram coletadas diariamente pela técnica de centrifugo-flutuação seguida de exame microscópico (técnica de Sheather) e qPCR por 20 dias após desafio. Gatos de todos os grupos eliminam oocistos nas fezes. Cinco gatos negativos na técnica Sheather foram positivos de acordo com a qPCR no 3º dia pós-inoculação (dpi). Oocistos foram detectados no 4º dpi no Sheather; entretanto, não houve diferença estatística entre os dois métodos (p=0,1116). Não houve diferença estatisticamente significativa na eliminação de oocistos entre os grupos de acordo com a técnica de Sheather (p = 0,6534) e qPCR (p = 0,9670). Em conclusão, esses resultados demonstram que qPCR pode ser usada como uma alternativa ao Sheather para detectar e quantificar oocistos de T. gondii.

First study of Cryptosporidium spp. occurrence in eared doves (Zenaida auriculata).

Cryptosporidium is a protozoan parasite with a wide range of hosts, including humans. However, only a few Cryptosporidium species have been described in birds (C. meleagridis, C. baileyi, C. galli and C. avium). The aim of this study was to investigate the occurrence of Cryptosporidium spp. in feces of eared doves (Zenaida auriculata), followed by molecular characterization of the parasite. A total of 196 animals of both sexes were trap-captured; the animals were culled and the intestinal contents were collected for DNA extraction. After extraction, a nested-PCR (nPCR), which amplifies a fragment of the 18S rRNA gene of Cryptosporidium spp., was performed. The amplicons obtained were purified and sequenced. PCR analysis revealed that 30 animals (15.3%) were positive for Cryptosporidium spp. There was no significant sex-dependent enrichment of Cryptosporidium occurrence (p > 0.05). Only 15 out of the 30 positive samples were successfully sequenced and their species determined, of which, 13 (86.7%) and 2 (13.3%) were C. meleagridis and C. galli, respectively. Herein, we present for the first time a molecular characterization of Cryptosporidium from feces of eared doves (Z. auriculata) and propose that these birds are a potential source of C. meleagridis infection in humans.

First study of Cryptosporidium spp. occurrence in eared doves (Zenaida auriculata) / Primeiro estudo de ocorrência de Cryptosporidium spp. em pomba-de-bando (Zenaida auriculata)

Abstract Cryptosporidium is a protozoan parasite with a wide range of hosts, including humans. However, only a few Cryptosporidium species have been described in birds (C. meleagridis, C. baileyi, C. galli and C. avium). The aim of this study was to investigate the occurrence of Cryptosporidium spp. in feces of eared doves (Zenaida auriculata), followed by molecular characterization of the parasite. A total of 196 animals of both sexes were trap-captured; the animals were culled and the intestinal contents were collected for DNA extraction. After extraction, a nested-PCR (nPCR), which amplifies a fragment of the 18S rRNA gene of Cryptosporidium spp., was performed. The amplicons obtained were purified and sequenced. PCR analysis revealed that 30 animals (15.3%) were positive for Cryptosporidium spp. There was no significant sex-dependent enrichment of Cryptosporidium occurrence (p > 0.05). Only 15 out of the 30 positive samples were successfully sequenced and their species determined, of which, 13 (86.7%) and 2 (13.3%) were C. meleagridis and C. galli, respectively. Herein, we present for the first time a molecular characterization of Cryptosporidium from feces of eared doves (Z. auriculata) and propose that these birds are a potential source of C. meleagridis infection in humans.

Resumo Cryptosporidium é um protozoário com uma grande variedade de hospedeiros, incluindo os seres humanos. No entanto, poucas espécies têm sido descritas em aves (Cryptosporidium meleagridis, C. baileyi, C. galli e C. avium). O objetivo do presente estudo foi investigar a ocorrência de Cryptosporidium spp. em fezes de pombas-de-bando (Zenaida auriculata), e realizar a caracterização molecular dos isolados. Um total de 196 animais de ambos os sexos foram capturados, eutanasiados e o conteúdo intestinal recolhido para extração de DNA. Após a extração, realizou-se uma nested-PCR (nPCR), que amplifica um fragmento do gene 18S rRNA do Cryptosporidium spp.. Os fragmentos obtidos foram purificados e encaminhados para sequenciamento. Os resultados da n-PCR revelaram 30 animais (15.3%) positivos para Cryptosporidium spp.. Quanto ao sexo dos animais não foram observadas diferenças estatísticas significativas (p > 0.05). Somente 15 de 30 amostras positivas foram sequenciadas com sucesso e as espécies determinadas, das quais, 13 (86.7%) e 2 (13.3%) foram C. meleagridis e C. galli, respectivamente. Esse é o primeiro estudo com caracterização molecular de Cryptosporidium de fezes de pombas-de-bando (Z. auriculata), e propõe serem esses animais potenciais fonte de infecção de C. meleagridis para humanos.

Prevalence of Eimeria spp. in calves from dairy farms in northern Paraná state, Brazil.

Bovine coccidiosis is a disease of major importance in cattle herds across the world. The disorder mainly affects young calves, and E. bovis and E. zuernii are considered the most pathogenic species of the genus, however, E. alabamensis have been described in grazing calves. In this study, the prevalence of Eimeria spp. was evaluated in calves on dairy farms in the northern region of the state of Paraná, Brazil. Four hundred calves on 44 dairy farms were tested for the presence of coccidian oocysts. The positives were re-examined and the oocysts were morphometrically analyzed for species identification. All the farms were contaminated and 205 animals (51.25%) presented Eimeria spp. oocysts. Among these, 146 animals (71.22%) were co-infected by two or more species of coccidia. Ten species of Eimeria were identified: E. bovis (in 30.25% of the positive samples), E. alabamensis (26.75%), E. zuernii (22.00%), E. ellipsoidalis (18.50%), E. auburnensis (13.75%), E. canadensis (8.00%), E. cylindrica (7.25%), E. subspherica (5.00%), E. bukidnonensis (3.00%) and E. brasiliensis (0.75%). This study demonstrates the high prevalence of Eimeria spp. in the northern region of Paraná, Brazil, and detection for the first time in our region the pathogenic species E. alabamensis.

First identification of Cryptosporidium parvum subtype IIaA20G1R1 in water buffalos (Bubalus bubalis).

Cryptosporidium can infect a wide variety of vertebrate animals, including mammals, birds, amphibians, reptiles, and fish. There are few molecular characterizations of Cryptosporidium isolated from water buffalo. Thus, the present study investigated the occurrence and molecular characterization of Cryptosporidium spp. in water buffalos by nested-PCR. Non-diarrheic feces were obtained from 122 water buffalo calves. All samples were tested by nested-PCR based on the 18S rRNA gene, after which positive samples were analyzed by RFLP and genetic sequencing. Sixteen fecal (13.1%) samples were positive, and RFLP showed that fifteen presented patterns consistent with C. ryanae and one with C. parvum. Sequencing of the gp60 gene from the C. parvum positive sample indicated the subtype IIaA20G1R1. This is the first identification of the IIaA20G1R1 subtype in water buffalos.

Prevalence of Eimeria spp. in calves from dairy farms in northern Paraná state, Brazil / Prevalência de Eimeria spp. em bezerros de propriedades leiteiras do norte do estado do Paraná, Brasil

Abstract Bovine coccidiosis is a disease of major importance in cattle herds across the world. The disorder mainly affects young calves, and E. bovis and E. zuernii are considered the most pathogenic species of the genus, however, E. alabamensis have been described in grazing calves. In this study, the prevalence of Eimeria spp. was evaluated in calves on dairy farms in the northern region of the state of Paraná, Brazil. Four hundred calves on 44 dairy farms were tested for the presence of coccidian oocysts. The positives were re-examined and the oocysts were morphometrically analyzed for species identification. All the farms were contaminated and 205 animals (51.25%) presented Eimeria spp. oocysts. Among these, 146 animals (71.22%) were co-infected by two or more species of coccidia. Ten species of Eimeria were identified: E. bovis (in 30.25% of the positive samples), E. alabamensis (26.75%), E. zuernii (22.00%), E. ellipsoidalis (18.50%), E. auburnensis (13.75%), E. canadensis (8.00%), E. cylindrica (7.25%), E. subspherica (5.00%), E. bukidnonensis (3.00%) and E. brasiliensis (0.75%). This study demonstrates the high prevalence of Eimeria spp. in the northern region of Paraná, Brazil, and detection for the first time in our region the pathogenic species E. alabamensis.

Resumo A coccidiose bovina é uma doença de grande importância em rebanhos ao redor do mundo. A desordem afeta principalmente bezerros jovens, e E. bovis e E. zuernii consideradas as espécies mais patogênicas deste gênero, causando grave enterite em animais infectados. No entanto, casos de E. alabamensis foram descritos em bezerros mantidos a pasto. No presente estudo, a prevalência de Eimeria spp. foi avaliada em bezerros de gado leiteiro da região norte do estado do Paraná, Brasil. Quatrocentos bezerros foram amostrados e testados para a presença de oocistos de coccídios. Os positivos foram re-examinados e os oocistos analisados morfologicamente para identificação da espécie. Todas as fazendas estavam contaminadas e 205 (51,25%) animais apresentaram oocistos de Eimeria spp. Destes, 146 (71,22%) animais estava co-infectados por duas ou mais espécies de coccídio. Dez espécies de Eimeria foram identificadas: E. bovis (30,25% de amostras positivas), E. alabamensis (26,75%), E. zuernii (22,00%), E. ellipsoidalis (18,50%), E. auburnensis (13,75%), E. canadensis (8,10%), E. cylindrica (8,00%), E. subspherica (5,00%), E. bukidnonensis (3,00%) e E. brasiliensis (0,75%). Este estudo demonstra a alta prevalência de Eimeria spp. na região norte do estado do Paraná, Brasil, e a detecção, pela primeira vez, de E. alabamensis.

Toxoplasma gondii: prevalence and characterization of new genotypes in free-range chickens from south Brazil.

Toxoplasma gondii is an intracellular parasite that can infect all warm-blooded animals including humans. Recent studies showed that T. gondii strains from South America are genetically diverse. The present work aimed to determine T. gondii prevalence in free-ranging chicken in northwest Parana state in Brazil by two serological tests, to isolate the parasites from seropositive chickens and to genotype the isolates. Antibodies to T. gondii in 386 serum samples from 24 farms were investigated by immunofluorescence antibody assay (IFA) and modified agglutination test (MAT). Samples having titers ≥ 16 were considered positive for both tests. Among the 386 serum samples, 102 (26.4%) were positive for IFA, 64 (16.6%) were positive for MAT, 47 (12.2%) were positive in both tests, and 119 (30.8%) were positive in at least one of the two tests. Brain and pool of heart, lung, and liver from the 119 seropositive chickens were used for mouse bioassay to isolate the parasites. Thirty eight (31.9%) of these seropositive chickens were considered positives in mouse bioassay and 18 isolates were obtained. The isolates were characterized by 10 PCR-RFLP genetic markers including SAG1, SAG2 (5'-3'SAG2, alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Results of genotyping were compared with the genotypes in ToxoDB database. It revealed ten genotypes, including ToxoDB PCR-RFLP genotypes #6 (n = 2), #19 (n = 1), #21 (n = 2), #111 (n = 2), #152 (n = 1), and #175 (n = 1) and four new types not described before. Our results confirmed a high genetic diversity of this parasite in southern Brazil and also showed that the use of two serological tests in combination can improve the chance of T. gondii isolation. More studies should be taken to determine the zoonotic potential of chickens in the transmission of T. gondii.

Toxoplasma gondii: A study of oocyst re-shedding in domestic cats.

The aim of the present study was to evaluate the re-shedding of T. gondii oocysts in cats fed tissue cysts of homologous and heterologous strains 12, 24 and 36 months after the first infection. Thirteen cats were used in the present study and were divided into four groups: G1 (n=2), G2 (n=3), G3 (n=5), and G4 (n=3). G1, G3 and G4 cats were infected with brain cysts of ME49 and G2 with TgDoveBr8, both genotype II strains of T. gondii. The G1 and G2 cats were re-infected after twelve months with brain cysts of VEG strain (genotype III), and G3 cats were re-infected with TgDoveBr1 (genotype II). The G3 cats were re-infected a third time after 24 months from the second infection, and the G4 cats were re-infected 36 months after the initial infection with cysts of the VEG strain. The cats' feces were evaluated using fecal flotation and genotyped with PCR-RFLP. The serological responses for IgM, IgA and IgG were determined by ELISA. All cats shed oocysts after the initial infection. Only one G1 cat shed oocysts when re-infected after twelve months with the VEG strain. No G2 cats excreted oocysts after the second infection with VEG. G3 cats, when re-infected after twelve months with the TgDoveBr1 strain, did not shed oocysts. However, when challenged after a third time with the VEG strain, three out of four cats shed oocysts. In the G4 group, when re-infected after thirty-six months with the VEG strain, two out of three cats shed oocysts. All oocyst samples were genotyped and characterized as the same genotype from the inoculum. Protection against oocyst re-excretion occurred in 90%, 25%, and 33.4% of cats after 12, 24, and 36 months from the initial infection, respectively. Therefore, the environmental contamination by oocysts from re-infected adult cats is only 30% lower than from kittens. In conclusion, the excretion of T. gondii oocysts was higher in experimentally re-infected cats throughout the years, especially when a heterologous strain was used.

Survey of Neospora caninum in eared doves (Zenaida auriculata) in Southern Brazil.

Neosporosis is an infectious disease caused by Neospora caninum, a protozoan parasite that has worldwide distribution and is responsible for enormous economic losses in cattle. Birds are considered a good bioindicator of environmental contamination, since they feed on the ground, being exposed to N. caninum oocysts. The aim of this study was to determine the occurrence of antibodies against N. caninum and to verify the presence of parasite DNA in brain from free-ranging eared doves (Zenaida auriculata) from Southern Brazil. For this purpose, blood and brain samples were collected from 249 doves for ELISA and PCR analysis respectively. The prevalence of N. caninum antibodies in doves was 31.72% (79/249) and detection of parasite DNA was not observed in none of birds. This is the first report of antibodies against N. caninum in doves Z. auriculata, what show us that these birds had previously contact with the parasite but since no N. caninum DNA was detected, more studies should be performed to elucidate the real importance of doves in the epidemiologic cycle of the N. caninum.