Sheep abortion associated with Neospora caninum in Mato Grosso do Sul, Brazil

Sheep abortions associated with Neospora caninum and Toxoplasma gondii infections in multiple flocks from Southern Brazil

Neosporosis and toxoplasmosis are important parasitic causes of abortions in small ruminants. This study verified the occurrence of these diseases in sheep fetuses from Santa Catarina State, Southern Brazil from 2015 to 2022. Sheep fetuses were necropsied with organ sampling for histopathology, and polymerase chain reaction (PCR) for Neospora caninum and Toxoplasma gondii using the Nc5 and SAG2 targets, respectively, in frozen brain tissue. Microbiological culture and RT-PCR for Pestivirus were conducted to discard other abortion causes. One positive fetus for toxoplasmosis was genotyped using multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) with ten genetic markers. Fifty-five sheep fetuses were evaluated, with 10 (18.2%) cases of neosporosis and 7 (12.7%) cases of toxoplasmosis, comprising six and four flocks, respectively. Macroscopically, neosporosis abortions exhibited fetal mummification, maceration, and arthrogryposis. Toxoplasmosis abortions showed fetal mummification and maceration. The neosporosis abortions included lymphoplasmacytic myositis (70%; 7/10) and myocarditis (60%; 6/10), in addition to necrotizing encephalitis and gliosis (50%; 5/10). Toxoplasmosis abortions included lymphoplasmacytic necrotizing encephalitis (71.4%; 5/7), lymphoplasmacytic myositis (42.8%, 3/7), and myocarditis (14.3%; 1/7). Through PCR, N. caninum and T. gondii were detected in 6 (60%) and 5 (71.4%) fetuses, respectively. In one fetus, T. gondii genotyping was conducted, which was characterized as atypical genotype ToxoDB #98. All of the cases were negative for Pestivirus and bacterial agents. This study establishes the occurrence of these diseases as causes of abortions, malformations, mummification, and fetal maceration in sheep, with the characterization of an atypical T. gondii genotype in one of the fetuses.

Seroprevalence of Specific Antibodies to Toxoplasma gondii, Neospora caninum, and Brucella spp. in Sheep and Goats in Egypt

Toxoplasmosis, neosporosis, and brucellosis are devastating diseases causing infectious abortion and, therefore, substantial economic losses in farm animals. Toxoplasmosis and neosporosis are caused by the intracellular protozoan parasites Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum), respectively. Brucellosis is a bacterial disease caused by numerous Brucella species in multiple hosts. Toxoplasmosis and brucellosis are also considered foodborne zoonotic diseases. In the current study, specific antibodies to T. gondii and N. caninum, in addition to those to Brucella spp., were detected to gain a better understanding of the epidemiological situation for these three pathogens. Sheep and goat sera from Egypt (n = 360) of animals with and without a history of abortion were tested using commercial ELISAs. Seropositivity rates of 46.1%, 11.9%, and 8.6% for T. gondii, N. caninum, and Brucella spp., respectively, were revealed. Mixed infections with T. gondii and Brucella spp. (4.4%), T. gondii and N. caninum (4.2%), N. caninum and Brucella spp. (1.4%), and even some triple infections (0.6%) have been observed. Animals with a history of abortion had a significantly higher seroprevalence for Brucella spp. infection than those without abortion (12.6%; 28/222 vs. 2.2%; 3/138) (p = 0.0005; Odds ratio = 1.9-21.8), while none of the other pathogens showed a similar effect. This result suggests brucellosis as a possible cause of abortion in the study population. However, the high seroprevalence for T. gondii and N. caninum revealed in our study warrants further investigations.

The Global Prevalence of Neospora caninum Infection in Sheep and Goats That Had an Abortion and Aborted Fetuses: A Systematic Review and Meta-Analysis

Neospora caninum (N. caninum) can be a potential factor causing a significant rate of miscarriages in small ruminants (sheep and goats) worldwide. Therefore, the present study aimed to determine the global status of N. caninum in sheep and goats that had an abortion and aborted fetuses. Five English databases (PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest) were searched for relevant scientific articles published from their inception until November 4, 2021. Finally, 21 studies conducted on sheep (1,671 aborted fetuses and 935 abortive sheep) and 10 studies on goats (130 aborted fetuses and 80 abortive goats) were included for the final meta-analysis. A random-effects meta-analysis model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Moreover, sensitivity analysis, publication bias test, and quality assessment were performed in this study. The pooled prevalence of N. caninum in aborted fetuses of sheep and goats globally was estimated to be 15% (95% CI: 9-21%) and 7% (95% CI: 2-12%) using molecular methods. Besides, the seroprevalence of N. caninum was estimated to be 17% for aborted fetuses of sheep. The overall prevalence rate of N. caninum infection in sheep that had an abortion was 3%. The present results show a relatively high prevalence of N. caninum infection in sheep that had an abortion and aborted fetuses compared to goats. Therefore, further studies using different diagnostic techniques to more accurately estimate the rate of infection in sheep and goats may help provide adequate control measures and strategies to reduce the rate of abortion in sheep and goats and reduce economic damage to the livestock industry. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020216694).

Transplacental transmission of Neospora caninum to lambs in successive pregnancies of naturally infected sheep in Southern Brazil

This study aims to report the detection of N. caninum DNA in a newborn lamb (1) with neurological signs and congenital neosporosis and in a stillborn lamb (2), both born from the same ewe in a herd of Southern Brazil. The lambs were born during different pregnancies of a Suffolk ewe seropositive to N. caninum and seronegative to T. gondii. Histopathological lesions were observed only in the central nervous system of the lambs. The newborn lamb (1) showed mild and focal gliosis in the frontal lobe. In the hippocampal region of the stillborn lamb (2), lymphoplasmacytic perivascular cuffs and N. caninum cysts were observed in the cytoplasm of neurons and confirmed by IHC. PCR was performed using brain samples to detect the protozoa N. caninum and Toxoplasma gondii. The infection with N. caninum was confirmed in the newborn lamb (1) by PCR and in the stillborn lamb (2) by histopathology, immunohistochemistry, and PCR tests.

Seroepidemiology of ovine toxoplasmosis and neosporosis in breeding rams from Rio Grande do Sul, Brazil

This study determined the prevalence of ovine toxoplasmosis and neosporosis and the risk factors associated with the development of these diseases in breeding rams from the State of Rio Grande do Sul (RS), Southern Brazil. Serum samples (n = 1,800) from breeding rams maintained on 705 sheep farms from seven mesoregions were evaluated serologically to detect anti-IgG Toxoplasma gondii by indirect ELISA and anti-IgG Neospora caninum by the indirect immunofluorescence assay (IFA). The prevalence of T. gondii was 33.05% (595/1,800); seropositivity to N. caninum was 18.44% (332/1,800). Additionally, there was simultaneous seropositivity (8.94%;161/1,800) to N. caninum and T. gondii. The variables size of the property (<500 ha) (Prevalence Ratio, PR = 1.36); breeding system (semi-intensive/intensive) (PR = 1.23); and natural mounting without control (PR = 1.50) were considered as risk factors for the occurrence of T. gondii. Size of the property (<500 ha) (PR = 1.58) and natural mounting without control (PR = 2.32) were risk factors associated with the prevalence of N. caninum in rams. Additionally, separation of ewes prior to parturition was considered as a protective factor for the occurrence of T. gondii (PR = 0.82) and N. caninum (PR = 0.74). These results demonstrated that these two parasitic disease agents are endemic in rams throughout all regions of RS.

Ocorrência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em ovinos com distúrbios reprodutivos e fatores de risco

RESUMO: Objetivou-se avaliar a ocorrência, sinais clínicos e fatores de risco associados a soropositividade para Toxoplasma gondii e Neospora caninum em ovinos. Foram utilizados 294 animais com histórico de distúrbios reprodutivos de 28 fazendas do estado de São Paulo, Brasil, diagnosticados através da imunofluorescência indireta (1:64 e 1:50). A ocorrência de T. gondii foi de 29,9% (88/294) e de N. caninum 18% (53/294), sendo 3,7% (11/294) dos ovinos soropositivos para ambos. Observou-se com maiores chances à infecção pelo T. gondii: ovinos mestiços (p=0,04), Santa Inês (p=0,006), fornecimento de pastagem (p<0,001) ou associada a concentrado (p<0,001), uso exclusivamente de monta natural (p=0,002, OR=2,28 e IC95%=1,37-3,79) e a presença de aves nas propriedades (p=0,001). Na infecção por N. caninum essa chance aumentou em: fêmeas (p=0,031), propriedades sem aprisco (p<0,001) e sistema de criação semi-intensivo (p<0,001). Em relação ao histórico de problemas reprodutivos, ovelhas infectadas pelo N. caninum e T. gondii apresentaram redução da chance de apresentarem abortamento (p=0,044) e repetição de estro (p=0,025) respectivamente. O T. gondii esteve mais presente sorologicamente que o N. caninum em ovinos com histórico de distúrbios reprodutivos e apesar de suas semelhanças, diferiram epidemiologicamente em aspectos relacionados as características da criação como raça, sexo, sistema de criação, tipo de alimentação e manejo reprodutivo.

Ocorrência de ovinos portadores da infecção por Campylobacter spp. no estado de Pernambuco

RESUMO: Objetivou-se com este estudo determinar a ocorrência e os fatores de risco associados à infecção por Campylobacter spp. em criações de ovinos no estado de Pernambuco, Brasil. Foram coletadas 421 amostras fecais de ovinos procedentes de 20 rebanhos para o isolamento de Campylobacter spp. As espécies Campylobacter fetus subsp. fetus e Campylobacter jejuni foram identificadas por Reação em Cadeia da Polimerase (PCR). Para análise dos fatores de risco foi realizada uma análise univariada e posteriormente regressão logística a partir de questionário com perguntas objetivas sobre o manejo higiênico-sanitário e reprodutivo. A ocorrência para Campylobacter spp. foi de 4,5% (19/421; I.C. 2,8% - 7,1%). Das 19 amostras positivas no cultivo, oito (1,9%; I.C. 0,9% - 3,9%) foram classificadas como C. fetus subsp. fetus e sete (1,7%; I.C. 0,7% - 3,6%) como C. jejuni, com co-infecção em quatro amostras (0,95%). O número de focos identificados foi de 35,0% (7/20) das criações de ovinos que apresentavam pelo menos um animal positivo. Na análise de regressão logística não foi identificada nenhuma das variáveis como fator de risco. Este é o primeiro registro da infecção por Campylobacter spp. em rebanhos ovinos no Nordeste do Brasil, concluindo-se que a infecção ocorre nesses rebanhos. Dessa forma, se faz necessário à implementação de medidas de controle e prevenção, para impedir a propagação do agente entre as criações, evitando prejuízos para ovinocultura e riscos para saúde pública, uma vez que a campilobacteriose é considerada uma zoonose emergente.

Transplacental transmission of Neospora caninum in naturally infected small ruminants from northeastern Brazil

ABSTRACT: Toxoplasma gondii and Neospora caninum are causative agents of abortion in sheep and goats. Thus, the present study aimed to describe the transplacental transmission of these protozoans in small ruminants of northeastern Brazil. Seventeen fetuses (6 goats and 11 sheep) from farms with history of abortion were necropsied and samples were collected from different tissues (brain, liver, lung, kidney and heart). The samples were analyzed by PCR, histopathology (HP) and immunohistochemistry (IHC) to evaluate whether T. gondii and/or N. caninum infection were the cause of abortion. None of the samples was positive for T. gondii according to PCR and IHC results. Some brain, liver, lung, kidney and heart samples of goat fetuses were positive for N. caninum by PCR. In the histopathology, mild mononuclear infiltration and necrosis with calcification were observed in the liver and brain of one goat fetus, respectively, that also was positive for N. caninum by PCR and IHC. The results confirmed vertical transmission of N. caninum in naturally infected goats of northeastern, Brazil.