High occurrence of viable forms of Cryptosporidium and Giardia in domestic sewage from an agricultural region of Brazil.

Cryptosporidium and Giardia are the main etiologies of waterborne outbreaks caused by protozoa. These parasites are commonly detected in wastewater; however, there is little knowledge about the concentration of viable forms in treated sewage, mainly in small communities. To understand more about the presence of viable oocysts and cysts in domestic sewage, we monitored the affluent and effluent of a wastewater treatment plant (WWTP) in inner-city Brazil. Ten samplings and seven follow-ups were performed in 2020. Samples were concentrated by centrifugation, filtration and purified by fluctuation. Viability was accessed by propidium-monoazide (PMA) associated with nPCR and qPCR. Both viable protozoa were detected in all raw sewage samples (average: 438.5 viable oocysts/L). Regarding treated sewage, Cryptosporidium was detected in all of the samples (average: 92.8 viable oocysts/L) and Giardia was detected in 70% with viable cysts in 30%. Considering the follow-ups, 31.17% of Cryptosporidium viable oocysts remained in the effluent after the treatment. High amounts of Cryptosporidium and a high frequency of Giardia were detected, therefore both arrived at WWTP and were discharged into the river. These alert the presence of agro-industrial effluents into domestic sewage and demonstrated the effectiveness of the concentration technique for monitoring protozoa in wastewater.

Seroprevalence of Neospora caninum and risk factors associated with infection in water buffaloes (Bubalus bubalis) from Maranhão State, Brazil.

The aim of this work was to determine the seroprevalence of Neospora caninum in buffaloes (Bubalus bubalis) from Maranhão State, Brazil, and identify risk factors associated with infection. In total, 338 buffaloes of different ages and both sexes from four farms were randomly selected. Information about the study region, animals and management was collected using an epidemiological questionnaire. Sera were subjected to an indirect fluorescent antibody test (IFAT) to detect anti-N caninum antibodies, while N. caninum DNA was detected using the polymerase chain reaction (PCR) assays. The overall seroprevalence of N. caninum in buffaloes was 27.5% (93/338), while DNA was detected in 3.0% (3/101) samples. The proportion of positive animals detected by IFAT and PCR simultaneously was 2.6% (2/77). The risk factors for N. caninum infection were contact with fomites (p = 0.022), management conditions (p = 0.005), calving interval of 20 months (p = 0.010) and deworming management (application 3 times a year in adults and calves, p = 0.020; change of anthelmintic group, p = 0.040). By multivariate analysis, management conditions was a risk factor for N. caninum infection with odds ratio of 2.2 (95% CI 1.0-4.6). This is the first report of the prevalence and risk factors for neosporosis in B. bubalis of Maranhão State, Brazil. Thus, N. caninum is widely distributed in buffalo herds in Maranhão, with management conditions being a risk factor for infection. Further studies should be conducted to elucidate the importance of buffaloes in the epidemiology of neosporosis in Maranhão State.

Epidemiological study of toxoplasmosis outbreaks in Brazil.

In Brazil, notification of toxoplasmosis outbreaks and epidemiological investigation is a mandatory activity of health surveillance. We investigated the risk factors for toxoplasmosis during outbreaks, notifications of outbreaks by the health secretary and reports in the literature. Other factors related to the municipalities were determined through the Institute of Geography and Statistics portal. We found that fruits and vegetables were the most described transmission routes in outbreaks, and oocysts were the most common parasitic form; in recent years; there has been an increase in outbreak notifications. We also found that municipalities with high municipal human development index have a higher number of toxoplasmosis infections during outbreaks. There is a need to raise awareness among the population and producers regarding good water management and quality practices and to facilitate the acquisition of complex data to improve preventive strategies.

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.

Toxoplasma gondii infection impairs the colonic motility of rats due to loss of myenteric neurons.

BACKGROUND: Toxoplasma gondii infection causes intestinal inflammation and diarrhea indicating possible intestinal motor dysfunction. Anatomical studies have shown alterations in the colonic myenteric plexus, but it is unknown whether this impacts motility and therefore whether motility is a target for treatment. We determined whether colonic coordinated movements are compromised by toxoplasmic infection and how it is associated with anatomical changes. METHODS: Male Wistar rats were evaluated at 6, 12, 24, 48, and 72 hours and 30 days postinfection (dpi) and controls. Infected rats received orally 5 × 103 sporulated oocysts of strain ME-49 (genotype II) of T gondii. The colon was collected for anatomical analysis (including the myenteric plexus immunolabeled with HuC/D, nNOS, and ChAT) and motility analysis in vitro (conventional manometry). Fecal output was measured daily. KEY RESULTS: At 12 hours postinfection, T gondii caused hypertrophy of the muscularis externa layer of the distal colon. There was loss of total, nitrergic, and cholinergic myenteric neurons in the proximal colon at 30 day postinfection (dpi); however, only loss of cholinergic neurons was found in the distal colon. Contractile complexes in the middle and distal colon were longer in duration in infected animals, which was associated with slower migration of the colonic motor complex. However, gastrointestinal transit time and fecal pellet output remained unchanged during the T gondii infection. CONCLUSIONS AND INFERENCES: Toxoplasma gondii caused myenteric neuronal loss in the proximal and distal colon and altered the motility pattern in the middle and distal colon to a more propulsive phenotype.

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.

Neospora caninum in free-range chickens (Gallus gallus domesticus) from southern Brazil.

Neospora caninum is an obligate intracellular parasite that can infect many domestic and wild animals, including birds. These animals are important sources for monitoring of environmental contamination, as they could become infected through sporulated oocysts; however, the real role of birds in the biological cycle of N. caninum remains uncertain. This study aimed to determine the prevalence of anti-N. caninum antibodies, evaluate associated factors, detect the parasite by molecular testing of free-range chickens from Brazil, and evaluate different techniques for its serological diagnosis. Blood samples of 366 chickens from 25 farms were collected for serological assays. The indirect fluorescent antibody test (IFAT) and the indirect enzyme-linked immunosorbent assay (ELISA) were used to detect anti-N. caninum antibodies. Chickens that tested seropositive by IFAT had their brain tissues and a pool of organs (heart, lung, and liver) submitted to PCR for molecular detection of the parasite. Out of 366 chickens, 65 (17.8%) and 163 (44.6%) were seropositive by IFAT and ELISA, respectively. Brain tissues (n=60) and the pools of organs (n=65) were negative in the PCR. Our results showed a high prevalence of antibodies in free-range chickens and that IFAT is the more sensitive technique for the detection of anti-N. caninum antibodies.

Isolation, genetic and immunohistochemical identification of Toxoplasma gondii from human placenta in a large toxoplasmosis outbreak in southern Brazil, 2018.

The present study aimed to describe a molecular analysis of environmental and pork samples, the isolation, genetic identification and immunohistochemistry (IHC) of Toxoplama gondii from placenta and amniotic fluid from five pregnant women that miscarried during a toxoplasmosis outbreak in 2018, Santa Maria, Rio Grande do Sul. Environmental and pork samples were submitted to polymerase chain reaction (PCR); placenta and amniotic fluid samples to histopathology, IHC, mouse bioassay and PCR. All samples were genotyped by PCR-RFLP with 11 loci. Histopathologic and IHC were compatibles with toxoplasmosis. All pregnants were positive in PCR and bioassay, the genotypes were compared, and all were equal suggesting a same source of infection. Among the environmental and food samples, a sludge sample from a water tank and two porks samples were positive in PCR, and the genotypes were different from the pregnant women isolates. It is concluded that obtain and compare isolates is essential to elucidate outbreak source.

Epidemiology of a toxoplasmosis outbreak in a research institution in northern Paraná, Brazil.

Toxoplasmosis is a reportable disease in Brazil. The objective of this study was to investigate a toxoplasmosis outbreak at a research institution in Londrina-PR, Brazil. The outbreak was reported in October 2015; however, the first cases occurred in August 2015. Blood samples were collected from 674 persons at the institution. Samples were collected from soil, water (water tank) and food (vegetables) served in the restaurant. Each participant responded to an epidemiological questionnaire. For the blood samples, a chemiluminescent microparticle immunoassay was performed to detect IgM, IgG and specific IgG avidity antibodies; 10.8% (73/674) had evidence of acute toxoplasmosis. Statistical analysis showed a significant association (p < .001) between acute infection and eating lunch in the restaurant of the institution. Regarding the types of food offered in the restaurant during the period, there was a significant association between consuming raw salad (p < .001) and becoming ill. We conclude that the vegetables or raw vegetables served in the restaurant were probably the source of infection; however, the long period between exposure and case reporting made it difficult to identify the source of transmission.

Isolation and molecular characterization of Toxoplasma gondii from placental tissues of pregnant women who received toxoplasmosis treatment during an outbreak in southern Brazil.

Toxoplasma gondii is a protozoan that has great genetic diversity and is prevalent worldwide. In 2018, an outbreak of toxoplasmosis occurred in Santa Maria, Brazil, which was considered the largest outbreak ever described in the world. This paper describes the isolation and molecular characterization of Toxoplasma gondii from the placenta of two pregnant women with acute toxoplasmosis who had live births and were receiving treatment for toxoplasmosis during the outbreak. For this, placental tissue samples from two patients underwent isolation by mice bioassay, conventional PCR and genotyping using PCR-RFLP with twelve markers. Both samples were positive in isolation in mice. The isolate was lethal to mice, suggesting high virulence. In addition, the samples were positive in conventional PCR and isolates submitted to PCR-RFLP genotyping presented an atypical genotype, which had never been described before. This research contributes to the elucidation of this great outbreak in Brazil.

Investigation and environmental analysis of samples from outbreak of toxoplasmosis at research institution in Londrina, Paraná, Brazil, 2016.

The objective of this study was to report an outbreak of human toxoplasmosis at a research institution in Londrina, Paraná, from December 2015 to February 2016. Blood samples from 26 symptomatic individuals were collected and the microparticle chemiluminescence immunoassay was performed to detect IgM, IgG and specific IgG avidity test in the official laboratory. A total of 20 people with symptoms and serology compatible with acute toxoplasmosis (IgM positive and IgG with low avidity) were selected as cases, while 45 asymptomatic employees working in the same teams and during the same shifts were selected as controls. All the participants of the investigation answered an epidemiological questionnaire. Three samples of water and one sludge from the institution's supply cisterns, 10 soil samples, 11 plant samples, three cat fecal samples and one domestic feline cadaver were collected for analysis of the polymerase chain reaction (PCR) for T. gondii. After analyzing the epidemiological data, the consumption of vegetables in the restaurant of the institution was the only variable associated with the occurrence of the disease. In laboratory results, all the samples showed negative results to PCR. The rapid recognition of the outbreak, early notification and investigation could have broken the chain of transmission early, thus preventing the emergence of new cases. In addition, the adoption of good food handling practices could have prevented the occurrence of the outbreak.

Investigation and environmental analysis of samples from outbreak of toxoplasmosis at research institution in Londrina, Paraná, Brazil, 2016 / Investigação e análise ambiental de amostras oriundas de surto de toxoplasmose em uma instituição de pesquisa em Londrina, Paraná, Brasil, 2016

Abstract The objective of this study was to report an outbreak of human toxoplasmosis at a research institution in Londrina, Paraná, from December 2015 to February 2016. Blood samples from 26 symptomatic individuals were collected and the microparticle chemiluminescence immunoassay was performed to detect IgM, IgG and specific IgG avidity test in the official laboratory. A total of 20 people with symptoms and serology compatible with acute toxoplasmosis (IgM positive and IgG with low avidity) were selected as cases, while 45 asymptomatic employees working in the same teams and during the same shifts were selected as controls. All the participants of the investigation answered an epidemiological questionnaire. Three samples of water and one sludge from the institution's supply cisterns, 10 soil samples, 11 plant samples, three cat fecal samples and one domestic feline cadaver were collected for analysis of the polymerase chain reaction (PCR) for T. gondii. After analyzing the epidemiological data, the consumption of vegetables in the restaurant of the institution was the only variable associated with the occurrence of the disease. In laboratory results, all the samples showed negative results to PCR. The rapid recognition of the outbreak, early notification and investigation could have broken the chain of transmission early, thus preventing the emergence of new cases. In addition, the adoption of good food handling practices could have prevented the occurrence of the outbreak.

Resumo O objetivo deste estudo foi relatar um surto de toxoplasmose humana em uma instituição de pesquisa em Londrina, Paraná, no período de dezembro de 2015 a fevereiro de 2016. Amostras de sangue de 26 indivíduos sintomáticos foram coletadas e o imunoensaio de quimioluminescência de micropartículas foi realizado para detectar IgM, IgG e teste de avidez de IgG específica em laboratório oficial. Um total de 20 pessoas com sintomas e sorologia compatíveis com toxoplasmose aguda (IgM positiva e IgG com baixa avidez) foi selecionado como casos, enquanto 45 funcionários assintomáticos que trabalhavam nas mesmas equipes e durante os mesmos turnos foram utilizados como controles. Todos os participantes da investigação responderam a um questionário epidemiológico. Foram coletadas três amostras de água e uma de lodo das cisternas de abastecimento da instituição, 10 de solo, 11 de vegetais, três amostras de fezes de gato e um cadáver de filhote felino doméstico para detecção de T. gondii pela reação em cadeia da polimerase (PCR). Após análise dos dados epidemiológicos, o consumo de hortaliças no restaurante da instituição foi a única variável associada à ocorrência da doença. Em resultados laboratoriais, todas as amostras apresentaram resultados negativos a PCR. O rápido reconhecimento do surto, notificação e investigação prematura poderia ter quebrado a cadeia de transmissão, evitando assim o surgimento de novos casos. Além disso, a adoção de boas práticas de manipulação de alimentos poderia ter impedido a ocorrência do surto.

Experimental inoculation of Neospora caninum tachyzoites in eared doves (Zenaida auriculata).

Neospora caninum is an apicomplexan parasite distributed worldwide. Although a positive association between the presence of birds and abortions in cattle associated to N. caninum has been reported, the role of the birds in the epidemiologic cycle of the parasite is unknown. To the best knowledge, no experimental studies have evaluated N. caninum in the eared dove, Zenaida auriculata. Therefore, we aimed to determine whether Z. auriculat can act as intermediate host for N. caninum. Eighteen birds were divided into four groups, G1, G2, G3, and G4 (control); G1, G2 and G3 received 2 × 106 tachyzoites of NC-1 strain via different routes: subcutaneous, intramuscular, and intraperitoneal, respectively. G4 composed of three birds. Serum samples were collected weekly, and one bird each from G1, G2 and G3 was euthanized on the 7th and 14th day post-inoculation (dpi). The remaining birds were euthanized after the 28th dpi. Tissues from the doves were evaluated using histopathological analysis, PCR and dog bioassay to detect the parasite. Dogs were fed with tissues from the birds and monitored for 30 days. Serum samples were collected weekly from the dogs for serological analysis, and feces samples were collected daily until the end of the experiment for coproparasitological examinations. No dove showed clinical signs of the infection; however, all of them seroconverted after the inoculation, with stronger immunological response in the G3 birds. The lung tissue of one G3 bird showed positive PCR results; it was euthanized on the 7th dpi, and an inflammatory infiltrate was observed in the lung and kidney from this dove. The dogs did not shed oocysts or seroconverted. Our results indicate that the intraperitoneal route induced infection in the doves; however, the parasite may have been eliminated by the host, and the doves may be resistant to chronic infection.

Anti-Neospora caninum antibodies in beef cattle from the northern region of Paraná state, Brazil / Anticorpos anti-Neospora caninum em bovinos de corte da região norte do estado do Paraná, Brasil

ABSTRACT: The presence of anti-Neospora caninum antibodies in beef cattle slaughtered in the northern region of the state of Paraná, Brazil, was evaluated. A total of 401 blood samples were collected; 281 samples from the municipality of Rolândia and 120 from the municipality of Borrazópolis, between April 2015 and November 2016. Of the total samples, 289 were from females and 112 from males, aged one and a half to eight years. Indirect fluorescent antibody test (IFAT) was performed, using a cut-off of 1:100. Variables were tabulated for statistical analyses (Fisher's exact test and chi-square tests, p≤0.05). The analysis showed that of the 401 samples, 37 were positive for N. caninum, indicating a prevalence of 9.2 %, and observed titers were 1:100 (16), 1:200 (14), and 1:400 (7). The variables sex, age, and location did not differ statistically (p>0.05). Our results showed a sero-occurrence of N. caninum in cattle slaughtered in the northern region of the state of Paraná.

RESUMO: A presença de anticorpos anti-Neospora caninum em bovinos de corte, abatidos na região norte do estado do Paraná, Brasil, foi avaliada. Foram coletadas 401 amostras de sangue, sendo 281 amostras no município de Rolândia e 120 no municipio de Borrazopolis, entre os meses de abril de 2015 e novembro de 2016. Do total de amostras, 289 eram de fêmeas e 112 amostras de machos, na faixa etária de um ano e meio até oito anos de idade. Foi realizada a reação da imunofluorescência indireta (RIFI) utilizando ponte de corte de 1:100. Em seguida, foram tabulados as variáveis para análise estatística (testes exato de Fisher e do qui-quadrado, p≤0,05). A análise mostrou que das 401 amostras, 37 foram positivas para N. caninum, indicando uma prevalência de 9,2 % e os títulos observados foram 1:100 (16), 1:200 (14) e 1:400 (7). As variáveis sexo, idade e local não diferiram estatisticamente (p>0,05). Nossos resultados demonstram uma soro-ocorrência de N. caninum em bovinos abatidos na região norte do Paraná.

Spatial and simultaneous seroepidemiology of anti-Leishmania spp. antibodies in dog owners and their dogs from randomly selected households in a major city of southern Brazil.

Although leishmaniasis has been described as a classic example of a zoonosis requiring a comprehensive approach for control, to date, no study has been conducted on the spatial distribution of simultaneous Leishmania spp. seroprevalence in dog owners and dogs from randomly selected households in urban settings. Accordingly, the present study aimed to simultaneously identify the seroprevalence, spatial distribution and associated factors of infection with Leishmania spp. in dog owners and their dogs in the city of Londrina, a county seat in southern Brazil with a population of half a million people and ranked 18th in population and 145th in the human development index (HDI) out of 5570 Brazilian cities. Overall, 564 households were surveyed and included 597 homeowners and their 729 dogs. Anti-Leishmania spp. antibodies were detected by ELISA in 9/597 (1.50%) dog owners and in 32/729 (4.38%) dogs, with significantly higher prevalence (p = 0.0042) in dogs. Spatial analysis revealed associations between seropositive dogs and households located up to 500 m from the local railway. No clusters were found for either owner or dog case distributions. In summary, the seroepidemiological and spatial results collectively show a lack of association of the factors for infection, and the results demonstrated higher exposure for dogs than their owners. However, railway areas may provide favorable conditions for the maintenance of infected phlebotomines, thereby causing infection in nearby domiciled dogs. In such an urban scenario, local sanitary barriers should be focused on the terrestrial routes of people and surrounding areas, particularly railways, via continuous vector surveillance and identification of phlebotomines infected by Leishmania spp.

Anti-Neospora caninum antibody detection and vertical transmission rate in pregnant zebu beef cows (Bos indicus): Neospora caninum in pregnant beef cows (Bos indicus).

The aim of the present study was to evaluate anti-Neospora caninum antibodies and the vertical transmission rate in naturally infected pregnant zebu beef cows (Bos indicus) reared on pasture. The present study began with 200 cows from four farms (50 cows from each farm), and these animals were submitted to timed artificial insemination (TAI). After ultrasonography, 76 pregnant cows were selected, 22, 15, 22, and 17, respectively, from farms 1, 2, 3, and 4. Blood samples were taken from cows thrice during the first, second, and third trimester of gestation, and a blood sample was collected from 31 calves before colostrum milking. From 76 cows 23 (30.3%) had anti-N. caninum antibodies detected by indirect ELISA (Idexx), and 53 (69.7%) did not. Sixty-four cows that initiated the experiment were negative to N. caninum and 11 became positive either during the second or third trimester of gestation, this mean an infection incidence of 17.2% (11/64). OD for ELISA was higher (OD=2.08) during the second and third (OD=2.10) trimesters of pregnancy when compared with the first (OD=1.81), however, there were no statistical differences (P=0.45). The vertical transmission was calculated to be 29.0% (9/31), and the risk of vertical transmission of N. caninum in seropositive dams was 26.25 times higher than seronegative animals (OR=26.25, 2.38

Diagnosis and isolation of Toxoplasma gondii in horses from Brazilian slaughterhouses.

This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed to T. gondii.

Diagnosis and isolation of Toxoplasma gondii in horses from brazilian slaughterhouses / Diagnóstico e isolamento de Toxoplasma gondii em equídeos de frigoríficos brasileiros

This study aimed to investigate anti-Toxoplasma gondii antibodies and to isolate the parasite from the brains of horses processed at slaughterhouses in Brazil. We collected brain and blood samples from 398 horses of various ages, from six Brazilian states. Serum samples were evaluated by indirect fluorescent antibody test (IFAT cut-off titre ≥ 1:64), and brains were submitted to mouse bioassay. Among the 398 horses, positivity for T. gondii was identified in 46 (11.6%) by IFAT and in 14 (3.5%) by mouse bioassay. In 12 of those 14 bioassays, mice were positive only by IFAT (cut-off titre ≥ 1:16), T. gondii being isolated in the remaining two. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of 18S rDNA to differentiate among T. gondii, Neospora caninum, and Sarcocystis neurona, we found that two of the 14 brains were positive for T. gondii only. For genotyping of the two isolates and the PCR-positive brain, we performed PCR-RFLP based on 13 markers, and SAG2 all samples were Toxoplasma gondii type I. Collectively, IFAT of horse sera and mouse bioassay identified positivity in 60 (15%) of the samples. Our results show that some horses sent to slaughter in Brazil have been exposed toT. gondii.

O objetivo do estudo foi investigar anticorpos anti-Toxoplasma gondii e isolar o parasita do cérebro de equídeos abatidos em matadouros-frigoríficos no Brasil. Colheram-se amostras de 398 cérebros e sangue de equídeos machos e fêmeas de idades variadas, provenientes de seis estados brasileiros. As amostras de soro foram avaliadas pelo teste de imunofluorescência indireta (IFI) para T. gondii (ponto de corte ≥ 64), e os fragmentos de cérebros foram submetidos ao bioensaio em camundongos. Por meio da IFI, 46 (11,6%) equídeos foram soropositivos. Pelo bioensaio em camundongos, 14 (3,5%) cérebros de equídeos testados foram positivos. Em doze dos bioensaios, os camundongos foram positivos somente pela IFI (ponto de corte ≥ 16) e T. gondii foi isolado nos outros dois bioensaios. A PCR-RFLP com base em 18S rDNA para diferenciar entre T. gondii, Neospora caninum, e Sarcocystis neurona foram feitas em todos os 14 cérebros e dois foram positivos apenas para T. gondii. De dois isolados positivos para T. gondii e do cérebro positivo à PCR em que realizou-se a PCR-RFLP, com base em 13 marcadores e SAG2, a genotipagem mostrou ser o T. gondii tipo I para todas as amostras. A IFI de soros de equídeos e do bioensaio em camundongos identificaram positividade em 60 (15%) amostras testadas. Os resultados mostram que alguns cavalos enviados para abate foram expostos ao T. gondii.