Toxoplasma gondii in milk of naturally infected dairy ewes on west mesoregion of Santa Catarina state, 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.

Detection of Toxoplasma gondii Infection in Small Ruminants: Old Problems, and Current Solutions

Toxoplasmosis is a parasitic zoonosis of veterinary importance, with implications for public health. Toxoplasma gondii infection causes abortion or congenital disease in small ruminants. Moreover, the consumption of infected meat, cured meat products, or unpasteurized milk and dairy products can facilitate zoonotic transmission. Serological studies conducted in various European countries have shown the high seroprevalence of specific anti-T. gondii antibodies in sheep and goats related to the presence of oocysts in the environment, as well as climatic conditions. This article presents the current status of the detection possibilities for T. gondii infection in small ruminants and their milk. Serological testing is considered the most practical method for diagnosing toxoplasmosis; therefore, many studies have shown that recombinant antigens as single proteins, mixtures of various antigens, or chimeric proteins can be successfully used as an alternative to Toxoplasma lysate antigens (TLA). Several assays based on DNA amplification have been developed as alternative diagnostic methods, which are especially useful when serodiagnosis is not possible, e.g., the detection of intrauterine T. gondii infection when the fetus is not immunocompetent. These techniques employ multicopy sequences highly conserved among different strains of T. gondii in conventional, nested, competitive, and quantitative reverse transcriptase-PCR.

Prevalence of Neospora caninum and Toxoplasma gondii Antibodies and DNA in Raw Milk of Various Ruminants in Egypt

The prevalence of Neospora caninum and Toxoplasma gondii antibodies in raw milk samples was estimated in different ruminants and Egyptian governorates. Of 13 bulk milk samples tested by ELISA, five (38.5%) were positive for antibodies to N. caninum, and two samples were additionally positive for antibodies to T. gondii, resulting in a seroprevalence of 15.4% for both T. gondii and co-infection. In individual milk samples (n = 171) from the same bulks, antibodies to N. caninum were detected in 25.7%, to T. gondii in 14%, and 3.5% had antibodies to both parasites. A strong correlation between the OD values of the bulk samples and of the relevant individual milk samples was found for T. gondii (Pearson r = 0.9759) and moderately strong for N. caninum (Pearson r = 0.5801). Risk factor assessment for individual milk samples revealed that antibodies to T. gondii were significantly influenced by animal species, while no risk factors were detected for N. caninum antibodies. Additionally, DNA of N. caninum was detected in a bulk milk sample of cattle for the first time in Egypt, and DNA of T. gondii was found in bulk milk samples of cattle, sheep and goats. This is the first study in Egypt in which bulk milk samples of different ruminants were tested for the presence of N. caninum and T. gondii antibodies and DNA. Both individual and bulk milk samples are useful tools for monitoring antibody response to N. caninum and T. gondii infections in different ruminants in Egypt.

Microcephaly and hydrocephalus in a sheep fetus infected with Neospora caninum in Southern Brazil - Short communication

A case of non-communicating hydrocephalus and microcephaly in a sheep fetus infected with Neospora caninum from Lages, Santa Catarina, Brazil, is reported. Macroscopically, there was moderate flattening and narrowing of the skull, and the portion of the cerebral hemispheres was markedly reduced in size, measuring 3.5 × 3.5 × 0.5 cm, with marked diffuse flattening of the brain gyri and dilation of the lateral ventricles. Cerebrospinal fluid samples were positive to N. caninum detection by PCR. Histologically, there was discrete focal lymphoplasmacytic necrotising encephalitis on the floor of the lateral ventricle, discrete multifocal gliosis and discrete multifocal lymphoplasmacytic myositis. Through the molecular detection of N. caninum in the cerebrospinal fluid, it was possible to report what appears to be the first case of non-communicating hydrocephalus and microcephaly in an ovine fetus infected with N. caninum.

A systematic literature review and meta-analysis of Toxoplasma gondii seroprevalence in goats

The aim of this study was evaluate to seroprevalence of Toxoplasma gondii in goats worldwide and the main risk factors associated from 2000 to 2020, through meta-analysis with 55,317 goats from 75 reports published in seven electronic databases of major global importance. A global seroprevalence detected was 27.49% (95% CI 24.15-30.95; I2 = 99%), with the lowest percentage in Asia (20.74%; 95% CI 16.45-25.39) and highest in Central America (62.15%; 95% CI 57.28-66.90) and Europe (31.53%; 95% CI 21.71-42.26). The seropositivity in Africa and South America were (29.41%; 95% CI 19.11-40.89) and (29.76%; 95% CI 25.84-33.83), respectively. The seroprevalence was associated with presence of cats (OR 2.22; 95% CI 1.30-3.82), goats older than one year (OR 1.77; 95% CI 1, 37-2.29), females (OR 1.43; 95% CI 1.23-1.65), rearing system (extensive vs. intensive) (OR 4.82; 95% CI 1.96-11, 84) and rearing system (semi-intensive vs. intensive) (OR 1.48; 95% CI 1.48-6.13). The heterogeneity was evidenced in most world regions and the risk factors may play roles in varying the seroprevalence.

Congenital Transmission of Apicomplexan Parasites: A Review

Apicomplexans are a group of pathogenic protists that cause various diseases in humans and animals that cause economic losses worldwide. These unicellular eukaryotes are characterized by having a complex life cycle and the ability to evade the immune system of their host organism. Infections caused by some of these parasites affect millions of pregnant women worldwide, leading to various adverse maternal and fetal/placental effects. Unfortunately, the exact pathogenesis of congenital apicomplexan diseases is far from being understood, including the mechanisms of how they cross the placental barrier. In this review, we highlight important aspects of the diseases caused by species of Plasmodium, Babesia, Toxoplasma, and Neospora, their infection during pregnancy, emphasizing the possible role played by the placenta in the host-pathogen interaction.

Occurrence of Toxoplasma gondii in raw goat, sheep, and camel milk in Upper Egypt

BACKGROUND AND AIM

Toxoplasmosis is a worldwide zoonotic disease with harmful effects on animal and human health. Ingestion of contaminated raw milk has been suggested as a vehicle for transmission of Toxoplasma gondii to human. The present study was performed for the detection of T. gondii in raw milk samples of goat, sheep, and camel in Upper Egypt using two different techniques (enzyme-linked immunosorbent assay [ELISA] and quantitative polymerase chain reaction [qPCR]).

MATERIALS AND METHODS

This study was conducted to determine the T. gondii prevalence using ELISA and qPCR in raw goat, sheep, and camels milk (30 samples for each) collected from different locations in Upper Egypt.

RESULTS

T. gondii IgG antibodies were detected in 90.0, 60.0, and 3.33% of goat, sheep, and camel milk samples, respectively. From the positive samples of T. gondii IgG, the parasitic DNA was detected only in two examined milk samples, one of them was present in goat milk sample and another one was found in sheep milk sample. On the other hand, the parasite was not detected in camels' milk samples.

CONCLUSION

These results concluded that the raw milk was contaminated by T. gondii tachyzoites which could be a source of human infection. Restricted hygienic programs should be implemented in the animal farms to decrease the risk of milk contamination by this parasite.