Neosporosis, Toxoplasmosis, and Sarcocystosis in Ruminants

Molecular identification of Sarcocystis species in wild boar (Sus scrofa) and pigs (Sus scrofa domesticus) in Brazil

Sarcocystis spp. are protozoan parasites that form cysts in the organs and musculature of various animal species. The species Sarcocystis miescheriana and Sarcocystis suihominis are pathogenic to pigs and wild boars (Sus scrofa), acting as intermediate hosts, while humans are the definitive host for S. suihominis. To date, there have been no reports of the identification of these coccidian species in Sus scrofa in Brazil. Therefore, in this study, we conducted the first molecular identification of Sarcocystis species using PCR-RFLP and sequencing. A total of 210 samples were analyzed, of this total, 67 tested positive for Sarcocystis spp., representing 31.9% of the total samples assessed. Out of the total positive samples, 55 (82.1%) were identified as S. miescheriana and 8 (11.9%) as S. suihominis, a zoonotic species. Additionally, other species related to bovines, such as S. cruzi and zoonotic S. hominis, were detected in 3.0% of the samples, serving as contaminants in the pork products. The presence of S. suihominis in swine and wild boar samples is concerning due to the zoonotic risk and potential environmental contamination, as humans act as definitive hosts, also for the presence of S. hominis as a bovine contaminant in pork sausages. Furthermore, we confirmed the efficacy of the PCR-RFLP technique as a reliable tool for the identification of Sarcocystis species, demonstrating its potential use in laboratories for molecular diagnosis and rapid identification of these parasites, aiming to protect public health and ensure food safety.

Evaluation of species-specific polyclonal antibodies to detect and differentiate between Neospora caninum and Toxoplasma gondii

Neosporosis and toxoplasmosis are major causes of abortion in livestock worldwide, leading to substantial economic losses. Detection tools are fundamental to the diagnosis and management of those diseases. Current immunohistochemistry (IHC) tests, using sera raised against whole parasite lysates, have not been able to distinguish between Toxoplasma gondii and Neospora caninum. We used T. gondii and N. caninum recombinant proteins, expressed in Escherichia coli and purified using insoluble conditions, to produce specific polyclonal rabbit antisera. We aimed to develop species-specific sera that could be used in IHC on formalin-fixed, paraffin-embedded (FFPE) tissue sections to improve the diagnosis of ruminant abortions caused by protozoa. Two polyclonal rabbit sera, raised against recombinant proteins, anti-Neospora-rNcSRS2 and anti-Toxoplasma-rTgSRS2, had specificity for the parasite they were raised against. We tested the specificity for each polyclonal serum using FFPE tissue sections known to be infected with T. gondii and N. caninum. The anti-Neospora-rNcSRS2 serum labeled specifically only N. caninum-infected tissue blocks, and the anti-Toxoplasma-rTgSRS2 serum was specific to only T. gondii-infected tissues. Moreover, tissues from 52 cattle and 19 sheep previously diagnosed by lesion profiles were tested using IHC with our polyclonal sera and PCR. The overall agreement between IHC and PCR was 90.1% for both polyclonal anti-rNcSRS2 and anti-rTgSRS2 sera. The polyclonal antisera were specific and allowed visual confirmation of protozoan parasites by IHC, but they were not as sensitive as PCR testing.

Molecular prevalence of Toxoplasma gondii and Trypanosoma evansi in recently calved female cattle from Phayao, Thailand

Background and Aim

Toxoplasma gondii and Trypanosoma evansi, the zoonotic protozoa responsible for toxoplasmosis and trypanosomiasis, are significant threats to the productivity and financial stability of livestock farming. T. gondii can be transmitted horizontally through ingestion of fecal oocysts and T. evansi through arthropod vectors. In addition, both species can be transmitted from mother to fetus through the placenta. This study aimed to assess the molecular prevalence of T. gondii and T. evansi transplacental-transmitted protozoans and to identify the epidemiological risk factors in recently calved female cattle across Phayao, Thailand.

Materials and Methods

We collected 106 bovine placentas from beef and dairy cow full-term pregnancies in Phayao, Thailand. T. gondii and T. evansi DNA were detected using targeted B1 gene and expression site-associated gene (ESAG) species-specific polymerase chain reaction (PCR), respectively.

Results

Forty-three placentas were positive for T. gondii B1 PCR, whereas only one was positive for T. evansi ESAG PCR, resulting in an overall prevalence of transplacental-transmitted protozoan infection of 41.5% (44/106). The prevalence of T. gondii and T. evansi was 40.6% (43/106) and 0.9% (1/106), respectively. No significant correlation was found between T. gondii infection and various risk factors, including locality, age, and cattle type.

Conclusion

The prevalence of transplacental-transmitted protozoan T. gondii infection was high among female cattle in Phayao, Thailand, whereas the prevalence of T. evansi infection was notably lower. Although the conventional modes of transmission differ between these two parasites, the transplacental transmission of T. evansi and especially T. gondii may play a crucial role in the persistence of these protozoan species in this area.

New insights into phenotype and genotype relationships in Neospora caninum

The successful isolation of four new Neospora caninum strains from different regions and with different backgrounds (obtained from an abortion storm or congenitally infected and asymptomatic calves) allowed us previously to characterize natural isolates, finding differences in phenotype and microsatellites. Given the variability observed, we wondered in this work whether these differences had consequences in virulence, invasion and vertical transmission using cell cultures and murine neosporosis models. In addition, we performed the genomic analysis and SNP comparative studies of the NcURU isolates. The results obtained in this work allowed us to establish that NcURU isolates are of low virulence and have unique phenotypic characteristics. Likewise, sequencing their genomes has allowed us to delve into the genetic singularities underlying these phenotypes, as well as the common mutated genes. This work opens a new perspective for diagnostic purposes and formulating possible vaccines based on attenuated strains.

Toxoplasma gondii infection in sheep from Romania

BACKGROUND

Toxoplasmosis is a widespread zoonosis caused by the intracellular protozoan parasite Toxoplasma gondii. Limited epidemiological information is available about the prevalence of T. gondii in sheep in Romania, and a high incidence would have implications for both the economy and public health. To our knowledge, no studies are available about the T. gondii strains circulating in lambs. The objective of this study was to assess the prevalence of T. gondii in sheep (serology), lambs (serology, bioassay, PCR) and sheep abortions (PCR) in Romania. Moreover, the study aimed to perform the genetic characterization of T. gondii isolates from lambs.

METHODS

Serum samples collected from 2650 sheep (2067 adults and 583 lambs) were tested for anti-T. gondii antibodies (IgG) using a commercial ELISA kit. Likewise, 328 pairs of diaphragmatic muscle-serum samples were collected from lambs aged between 2 and 4 months. Lamb serum samples were analyzed using MAT for anti-T. gondii antibody detection. The diaphragm tissue samples from MAT-positive lambs (at a dilution ≥ 1:25) were bioassayed in mice. The T. gondii strains were genotyped using 15 microsatellites markers. Additionally, brain and heart samples from 76 sheep abortions were analyzed for T. gondii DNA by polymerase chain reaction (PCR) targeting the 529-bp repeat region (REP529).

RESULTS

The results showed that more than half of the tested sheep were T. gondii seropositive (53.5%). The seroprevalence was significantly higher in adults (61.1%) than in lambs (26.4%). The seroprevalence of T. gondii infection in slaughtered lambs, by MAT, was 37.5% (123/328). There were bioassayed in mice 56 diaphragmatic tissues from 123 seropositive lambs. Toxoplasma gondii strains were isolated from 18 (32.1%) lambs intended for human consumption. All T. gondii strains were confirmed by PCR. Six strains were genotyped using 15 microsatellite markers and belonged to genotype II. Toxoplasma gondii DNA was detected in 11.8% (9/76) of sheep abortions.

CONCLUSIONS

The present study showed the presence of T. gondii in sheep in all the regions considered in the study. The high prevalence of T. gondii infection in sheep and lambs, demonstrated by serology, molecular analysis and bioassay, highlighted that there is an important risk of human infection in consuming raw or undercooked sheep/lamb meat.

Molecular Identification, Pathogenesis, and Life Cycle of Sarcocystis cruzi from Cattle (Bos taurus) in New Valley Governorate, Egypt

Sarcocystis cruzi was identified by molecular methods from an intermediate host, cattle (Bos taurus), in El-Kharga, New Valley Governorate, Egypt, and its life cycle and pathogenicity were studied in the final host, dogs (Canis familiaris). 600 slaughtered cattle aged 6-8 years (480/120 males/females) were included. In addition, three laboratory-bred, coccidian-free puppies aged 2-3 months were fed infected bovine muscles to locate the definitive host and analyze sporogony. 18S rRNA-specific gene primers were used for DNA amplification from esophageal muscles. These polymerase chain reaction (PCR) amplicons were subjected to restriction fragment length polymorphism (RFLP) and molecular sequence analysis. Infection was detected in 78.8% (473/600; 95% CI, 75.56-82.11%). Histopathological examination of esophageal muscles showed oval- to spherical-shaped cysts, 96.7 μm wide by 326.9 μm long; cysts in cardiac muscles were ovoid and smaller. Infected puppies began shedding sporocysts in feces 7 days post-inoculation and showed distorted organ architecture, severe cellular damage, and inflammatory lesions in liver, kidney, esophagus, and stomach. Three oocysts with different shapes and sizes were identified. Partial 18S rRNA gene sequences of isolated New Valley sarcocysts were identical to S. cruzi isolated from different areas, verifying their genetic relatedness. Our analysis suggests that S. cruzi is the most prevalent in slaughtered cattle in New Valley Governorate, Egypt.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS)

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

Seroprevalence of Toxoplasma gondii and Neospora caninum in camels recently imported to Egypt from Sudan and a global systematic review

INTRODUCTION

Toxoplasma gondii and Neospora caninum are closely related intracellular protozoan parasites of medical and veterinary concern by causing abortions and systemic illness. Limited or ambiguous data on the prevalence of T. gondii and N. caninum in camels triggered us to conduct this study.

METHODS

Camels (n = 460) recently imported from Sudan and destined mainly for human consumption, were tested for specific antibodies against these protozoans using commercially available ELISAs. From the two only quarantine stations for camels from Sudan, 368 camels were sampled between November 2015 and March 2016 in Shalateen, Red Sea governorate, and 92 samples were collected between September 2018 and March 2021 from Abu Simbel, Aswan governorate.

RESULTS & DISCUSSION

Overall, seropositive rates in camels were 25.7%, 3.9% and 0.8% for T. gondii, N. caninum and mixed infection, respectively. However, marked differences were found between the two study sites and/or the two sampling periods: For T. gondii, a higher rate of infection was recorded in the Red Sea samples (31.5%, 116/368; odds ratio 20.7, 5.0-85.6; P<0.0001) than in those collected in Aswan (2.2%, 2/92). The opposite was found for N. caninum with a lower rate of infection in the Red Sea samples (0.82%, 3/368; odds ratio 23.7, 6.7-83.9; P<0.0001) than in the samples from Aswan (16.3%, 15/92). Additionally, our systematic review revealed that the overall published seroprevalence of T. gondii and N. caninum was 28.6% and 14.3% in camels worldwide, respectively. To the best of our knowledge, this study provides the first record of seroprevalence of both T. gondii and N. caninum in recently imported camels kept under quarantine conditions before delivery to other Egyptian cities and regions. In addition, our review provides inclusive data on the prevalence of T. gondii and N. caninum in camel globally. This knowledge provides basic data for the implementation of strategies and control measures against neosporosis and toxoplasmosis.

Seroepidemiology of Neospora caninum in Cattle of Pastoral Production System in Teltelle District of Borana Zone, Southern Ethiopia

Background

Neosporosis is a major cause of abortion in smallholder dairy farms in Ethiopia. However, its status and impact in pastoral cattle production settings were uncovered. This study was performed with the aims of estimating the seroprevalence and associated potential risk factors for Neospora caninum in Boran cattle in Teltelle district of Borana zone, Ethiopia.

Methods

180 blood samples were collected from 48 randomly selected pastoral herds using a multistage sampling technique and subjected to an indirect enzyme-linked immunosorbent assay (ELISA) test to detect antibodies specific to N. caninum. A questionnaire survey was also used to identify the potential risk factors of N. caninum in the study area. Evaluation of the associated risk factors was conducted using a multivariable logistic regression model.

Results

Antibodies against N. caninum exposure were detected in 5% of cattle (95% CI: 1.816–8.184) from 180 animals tested. Similarly, the seroprevalence of N. caninum in herds with at least one positive animal was 14.6% (95% CI: 4.598–24.567) from 48 herds examined. A multivariable logistic regression model identified the following as significant risk factors: a history of abortion (AOR = 23; 95% CI: 2.354–188.702; P = 0.006), dystocia (AOR = 11; 95% CI = 22.275–55.860; P = 0.003), wells water sources (AOR = 9; 95% CI: 1.599–47.568; P = 0.012), and dogs fed with raw animal products (AOR = 6; 95% CI: 11.213–27.222; P = 0.028).

Conclusion

This study revealed the first serological evidence of N. caninum exposure in cattle reared under pastoral production system. Our findings suggest N. caninum is likely to be an important cause of abortion and dystocia in cattle in Ethiopia. Management practices, such as provision of hygienic water and restriction of dogs fed with raw animal products, are likely to reduce the risk of infection. Thus, maximizing community awareness about these disease management practices is suggested.

Epidemic abortions due to Neospora caninum infection in farmed red deer (Cervus elaphus)

This study describes for the first time an abortion outbreak caused by Neospora caninum in farmed red deer. During a 5-year period, farmed hinds, naturally mated, were regularly ultrasound monitored to detect reproductive losses over their gestation. During the 4 years previous to the outbreak, abortion rates ranged from 4.7 to 8.6% (average 6.5%), and serology for indirect diagnosis of neosporosis and toxoplasmosis was performed. At the fifth year, the abortion rate increased to 25.3%. During this outbreak, three aborted foetuses and their placentas were recovered and submitted to laboratory for etiological diagnosis. Blood samples were collected from the 81 hinds at the end of the gestational period and the seropositivity rate for N. caninum, Toxoplasma gondii, Brucella abortus, bovine viral diarrhoea virus and bovine alphaherpesvirus type 1 was 66.7%, 67.9%, 0.0%, 8.6% and 0.0%, respectively. Neospora caninum-seropositive hinds (OR = 5.7, P = 0.0271) and hinds with high antibody titres to N. caninum (OR = 7.4, P = 0.0130) were more likely to abort than seronegative hinds. In addition, N. caninum seropositivity rate in the aborted hinds was higher (OR = 5.4, P = 0.033) than the non-aborted hinds. No association was found between T. gondii nor BVDV-seropositivity and abortions. Typical protozoal histopathologic findings (necrotizing non suppurative encephalitis, meningitis, myocarditis, hepatitis, among others) were observed in all foetuses. Neospora caninum was immunolabelled by immunohistochemistry in several tissues from two foetuses, and infection was also confirmed in the three foetuses by serology and/or DNA detection. No other abortifacient agent was detected in the foetuses. Their dams showed high N. caninum antibody titres (≥ 6400). Serologic evidence and epidemiological data recorded suggested a point-source of N. caninum infection before the occurrence of the outbreak, probably related with contaminated feedstuff with oocysts. Moreover, the intensive production system with a high stocking rate could be also considered a factor which might have increased the risk of horizontal N. caninum infection in this herd.

Role of dense granule antigen 7 in vertical transmission of Neospora caninum in C57BL/6 mice infected during early pregnancy

Neosporosis is a parasitic disease affecting the health of dogs and cattle worldwide. It is caused by Neospora caninum, an obligate intracellular apicomplexan parasite. Dogs are its definitive host, it mostly infects livestock animals, especially cattle that acts as intermediate host. It is necessary to have well-established models of abortion and vertical transmission in experimental animals, in order to determine basic control measures for the N. caninum infection. We evaluated the role of N. caninum dense granule antigen 7 (NcGRA7) in the vertical transmission of N. caninum using the C57BL/6 pregnant mouse model. We inoculated mice on day 3.5 of pregnancy with parental Nc-1 or NcGRA7-deficient parasites (NcGRA7KO). Post-mortem analyses were performed on day 30 after birth and the surviving pups were kept until day 30 postpartum. The number of parasites in the brain tissues of offspring from NcGRA7KO-infected dams was significantly lower than that of the Nc-1-infected dams under two infection doses (1 × 10⁶ and 1 × 10⁵ tachyzoites/mouse). The vertical transmission rates in the NcGRA7KO-infected group were significantly lower than those of the Nc1-infected group. To understand the mechanism by which the lack of NcGRA7 decreases the vertical transmission, pregnant mice were sacrificed on day 13.5 of pregnancy (10 days after infection), although parasite DNA was detected in the placentas, no significant difference was found between the two parasite lines. Histopathological analysis revealed a greater inflammatory response in the placentas from NcGRA7KO-infected dams than in those from the parental strain. This finding correlates with upregulated chemokine mRNA expression for CCL2, CCL8, and CXCL9 in the placentas from the NcGRA7KO-infected mice. In conclusion, these results suggest that loss of NcGRA7 triggers an inflammatory response in the placenta, resulting in decreased vertical transmission of N. caninum.

Serological and molecular detection of Toxoplasma gondii in farm-reared ostriches (Struthio camelus) in the Czech Republic

Toxoplasmosis is a globally spread disease, affecting humans and many animal species, including birds. Antibodies to Toxoplasma gondii were detected in ostriches from South and North America, Africa and Asia. Except for one study from Spain, there is a lack of information about T. gondii seroprevalence in ostriches from Europe. For this reason, the aim of the study was to detect antibodies to T. gondii in farm-reared ostriches from the Czech Republic. Serum samples of 409 ostriches (Struthio camelus), collected at 9 farms were tested by Latex agglutination test. Antibodies to T. gondii were detected in 149 (36%) birds with a statistical difference for individual farms (8%-71%, p = 0.0121), and regions (8%-65%, p = 0.002). Seropositivity did not statistically differ (p > 0.05) in size of farms (50% and 35% on small and large farms, respectively), sex of birds (38% and 35% in males and females, respectively), season and year of collection. Tissue samples (brain, heart, and pectoral muscle) of 105 birds were also tested by PCR to detect T. gondii DNA. The parasite T. gondii was detected in the brain and heart of one seronegative ostrich (1%) from a small farm. Based on our results, we can assume that ostriches may present high risk of toxoplasmosis for humans through consumption of raw or undercooked ostrich meat and even seronegative individuals could harbor T. gondii in their tissues. To our knowledge, this is the first serological detection of T. gondii in ostriches in the Czech Republic, and the first PCR detection in Europe.

Molecular and Microscopic Investigation of Sarcocystis Species Isolated from Sheep Muscles in Iran

Sarcocystis species is a genus of cyst-forming parasites infecting both humans and animals globally. Some of these species cause clinical and subclinical diseases in the host and may lead to economic losses. This study was carried out to identify the distribution patterns of Sarcocystis spp. in slaughtered sheep based on the digestion method and PCR-RFLP in Isfahan, the center of Iran. In total, 150 fresh muscle samples (30 hearts, 60 esophagi, and 60 diaphragms) were investigated by naked eye observation and then scrutinized based on the digestion method. To this end, pepsin and HCl were used to observe the Sarcocystis parasite via a light microscope. The PCR was carried out to intensify a fragment of the 18S rRNA gene. Afterward, the PCR products were exposed to digestion by endonuclease TaqI, HindII, EcoRI, and AvaI. Consequently, the results of RFLP were confirmed by sequencing, and the phylogenetic placement of all species was analyzed. Through the examination by the naked eye, 5/150 (3.33%) macroscopic cysts were found in the samples. With the tissue digestion and microscopic examination, 116 (77.33%) samples were positive for Sarcocystis spp.; however, 125 (83.33%) samples were positive with PCR. Moreover, the results of sequence analysis on macrocysts and microcysts showed that 4% and 96% of the species belonged to S. gigantea and S. tenella, respectively. According to the results of the current study, sarcocystosis caused by S. tenella are highly prevalent among sheep in the Isfahan region. Due to the high prevalence of Sarcocystis infection in the world and Iran, the development of disease control and prevention policies in sheep would be essential, and changing attitudes in the way of keeping livestock from the traditional type to the industrial method is recommended in this regard.

Molecular Detection and Characterization of Sarcocystis Infection in Naturally Infected Buffaloes, Brazil

ABSTRACT

Sarcocystosis is a disease caused by various Sarcocystis species, a coccidian protozoan parasite that infects humans and animals and is commonly found in ruminants. Although Sarcocystis occurs all over the world, the species responsible for infecting buffaloes in Brazil have not been identified. In this study, we used molecular methods to estimate the prevalence of natural Sarcocystis infection in buffaloes. Phylogenetic analyses were conducted for the first time to identify the species of this protozoan that are responsible for infecting buffalos in southern Brazil, Rio Grande do Sul state. Heart samples from 80 buffaloes were subjected to microscopic examination followed by molecular analysis. Microcysts were present in 19 (23.75%) of 80 samples. The genomic DNA from the 19 cyst samples was extracted and amplified, and six sequences were obtained. The analysis was performed with the StandenPackage software, and the nucleotide sequences generated were analyzed by comparison with sequences in GenBank. All the sequenced samples were identified as Sarcocystis levinei.

HIGHLIGHTS

Modeling the Ruminant Placenta-Pathogen Interactions in Apicomplexan Parasites: Current and Future Perspectives

Neospora caninum and Toxoplasma gondii are one of the main concerns of the livestock sector as they cause important economic losses in ruminants due to the reproductive failure. It is well-known that the interaction of these parasites with the placenta determines the course of infection, leading to fetal death or parasite transmission to the offspring. However, to advance the development of effective vaccines and treatments, there are still important gaps on knowledge on the placental host-parasite interactions that need to be addressed. Ruminant animal models are still an indispensable tool for providing a global view of the pathogenesis, lesions, and immune responses, but their utilization embraces important economic and ethics restrictions. Alternative in vitro systems based on caruncular and trophoblast cells, the key cellular components of placentomes, have emerged in the last years, but their use can only offer a partial view of the processes triggered after infection as they cannot mimic the complex placental architecture and neglect the activity of resident immune cells. These drawbacks could be solved using placental explants, broadly employed in human medicine, and able to preserve its cellular architecture and function. Despite the availability of such materials is constrained by their short shelf-life, the development of adequate cryopreservation protocols could expand their use for research purposes. Herein, we review and discuss existing (and potential) in vivo, in vitro, and ex vivo ruminant placental models that have proven useful to unravel the pathogenic mechanisms and the host immune responses responsible for fetal death (or protection) caused by neosporosis and toxoplasmosis.

High Exposure to Toxoplasma gondii and Neospora Spp. in Donkeys in Israel: Serological Survey and Case Reports

Simple Summary

Toxoplasma gondii and Neospora spp. are major pathogenic parasites of animals worldwide, with the first also affecting humans. These parasites have two-host life cycles, with the cat and the dog being the definitive hosts of T. gondii and N. caninum, respectively. Both parasites can infect various animal species, as intermediate hosts, in which they form tissue cysts and may cause abortions and neurological disease. Both parasites have been reported in wild and domestic animals in Israel. This study aimed to evaluate the serologic exposure of donkeys to these parasites. A total of 98 donkeys were examined. Half of them (n = 49) were from animal shelters in Israel, and the rest (n = 49) were working donkeys from the Palestinian Authority. Anti-T. gondii antibodies and anti-Neospora spp. antibodies were found in 94% and in 70% of the donkeys, respectively. In addition, two cases of donkeys presenting N. caninum tissue cysts, which were detected during post-mortem examination, were described. This is the first report of the exposure of donkeys to Toxoplasma gondii and Neospora spp. in the area. The exposure of donkeys to both parasites was considerably higher than the exposure of other species in the area and may be the result of poor husbandry conditions and higher exposure to infection. These results indicate that donkeys may have an important role in the maintenance and transmission of these parasites.

Abstract

Toxoplasma gondii and Neospora spp. are closely related cyst-forming coccidian parasites, which infect various animal species and have considerable zoonotic and economic implications, respectively. Both parasites are endemic in Israel and have been reported to infect wild and domestic animals. This study was conceived to evaluate the serologic exposure of donkeys to these parasites. Serum samples were collected from 98 donkeys. Half of them (n = 49) were from animal shelters in Israel, and the rest (n = 49) were working donkeys from the Palestinian Authority. The donkeys were screened for the presence of anti-Toxoplasma and anti-Neospora antibodies by immunofluorescence antibody tests (IFATs). The seroprevalence of T. gondii and Neospora spp. was 94% and 70%, respectively, and 69% of the donkeys were exposed to both parasites. In addition, N. caninum tissue cysts were documented in two donkeys during post-mortem examination. This is the first report of the exposure of donkeys to T. gondii and Neospora spp. in the area. The high prevalence found in this study suggests that donkeys may have a role in the maintenance of these parasites in the area, thus serving as a source of infection for the definitive hosts.

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.

An indirect ELISA for Neosporosis: Associating recombinant Neospora caninum proteins NcSRS2 and NcSAG1

Neosporosis is caused by infection with the protozoa Neospora caninum. It manifests as various neurological symptoms and is considered as one of the main causes of abortion in cattle, and induces uncommon congenital infection in sheep. The standard diagnosis is based on indirect immunofluorescence (IFI); however, cross-reactivity with other protozoa proteins is common. Aiming a more specific diagnosis, recombinant antigens have been tested in several immunoassays; of these, NcSAG1 (surface antigen-1) and NcSRS2 (SAG1-related sequence 2) were the most promising. In this context, we developed an indirect ELISA with recombinant NcSRS2 (ELISA-rNcSRS2) and NcSAG1 (ELISA-rNcSAG1) proteins alone and in association (ELISA-rNcSRS2/rNcSAG1) for the diagnosis of cattle and ovine neosporosis. A total of 216 samples from cattle and 154 samples from sheep were used to evaluate the ELISAs. The sensitivity and specificity results of the ELISA-rNcSRS2 were 91.5 % and 96.4 % for cattle, and 89.6 % and 96.3 % for sheep, respectively. For the ELISA-rNcSAG1, the sensitivity and specificity were 84.9 % and 97.3 % for cattle, and 89.6 % and 92.6 % for sheep, respectively. The sensitivity and specificity of the ELISA-rNcSRS2/rNcSAG1 was 98.1 % and 99.1 % for cattle, 100 % and 97.2 % for sheep, respectively. These results indicated that indirect ELISA using the rNcSRS2 and rNcSAG1 proteins are a highly sensitive and specific method, especially when used in association, for detecting antibodies in cattle and ovine populations infected with N. caninum.

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.

Frequency and factors associated with Toxoplasma gondii infection in pregnant women and their pets in Ilhéus, Bahia, Brazil

INTRODUCTION

Toxoplasmosis is an asymptomatic disease that can lead to systemic disease in the fetus of pregnant women with primary infection. This study aimed to determine the prevalence of toxoplasmosis, associated factors, and correlation between the serology of pregnant women and their pets, in the municipality of Ilhéus, Bahia, Brazil.

METHODS

This cross-sectional study was conducted in 196 pregnant women and their cats or dogs (n=89). Semi-structured interviews were conducted and serum samples from the pregnant women were tested to detect IgM and IgG antibodies against Toxoplasma gondii, and avidity tests were performed for IgM-positive samples. The serum collected from pets were tested for IgG antibodies, and IgM antibodies in cats. A non-conditional logistic regression analysis was performed to identify infection-associated factors.

RESULTS

IgG and IgM antibodies were detected in 67.9% (133/196) and 1.5% (3/196) samples, respectively, for women with an avidity of over 60%. Age ≥ 25 and the presence of cats in the vicinity were found to be associated with infection, while the level of education and previous orientation toward prevention of toxoplasmosis were protective factors in pregnant women. IgG antibodies were detected in 46.1% (41/89) of the animals, and cats were found to be negative for IgM. For the animals, age ≥ 1 year was a factor associated with infection. There was no correlation between serology of the pregnant women and the animals (p=0.15).

CONCLUSIONS

An elevated prevalence of toxoplasmosis was detected in the region. Therefore, the adoption of preventive measures by public healthcare bodies is recommended.

Effects of challenge dose and inoculation route of the virulent Neospora caninum Nc-Spain7 isolate in pregnant cattle at mid-gestation

Parameters such as pathogen dose and inoculation route are paramount in animal models when studying disease pathogenesis. Here, clinical findings, including foetal mortality, parasite transmission rates and lesion severity, and immune responses were evaluated in Asturiana pregnant heifers at day 110 of gestation challenged with a virulent (Nc-Spain7) Neospora caninum isolate. Four different doses of parasite tachyzoites were inoculated intravenously (IV1, 10⁷ parasites, n = 6; IV2, 10⁵, n = 6; IV3, 10³, n = 6; and IV4, 10², n = 5), and the subcutaneous (SC) inoculation route was also assessed for the dose of 10⁵ tachyzoites (SC, n = 6). In addition, a control group (n = 4 pregnant heifers) was evaluated. Foetal death was observed in all infected groups from 25 to 62 days post-infection, varying with the dose (IV1:4/6, IV2:3/6; IV4:2/5, IV3:1/6), and was three times less frequently associated with the SC route than IV inoculation (1/6 vs. 3/6). A dose-dependent effect for parasite loads in placental and foetal brain tissues was also detected. After SC challenge, a reduced number of tachyzoites were able to reach foetal brain tissues, and no lesions were observed. In calves, specific IgG responses in precolostral sera were mainly associated with high-dose groups (IV1 [100.0%] and IV2 [66.7%]), and cerebral parasite DNA detection was scarce (3/18). In dams, IFN-γ production and the dynamics of anti-N. caninum IgG antibodies varied with the dose, and the cell-mediated immune response was also found to be route-dependent. Our results confirm the influence of parasite dose and inoculation route on the outcome and dynamics of bovine neosporosis at mid-gestation.

Muscular Sarcocystis infection in ruminants slaughtered at Municipality abattoir and selected Hotels in Hawassa city, southern Ethiopia: Prevalence and associated risk factors

Sarcocystosis is a parasitic zoonosis caused by Sarcocystis spp. which are Apicomplexan parasites requiring intermediate and definitive hosts to complete their life cycle. Although the parasite has worldwide distribution in man and many species of animals, the prevalence in most parts of Ethiopia is not clearly known. This cross sectional study was conducted between Nov. 2016 and May 2017 to estimate the prevalence of Sarcocystis infection in ruminants slaughtered in the municipality abattoir and at selected hotels of Hawassa city and to assess the potential risk factors. Data were collected through gross and histopathological examination of myocardial and esophageal muscles sampled from a total of 561 ruminants (176 sheep, 181 goats and 204 cattle). The overall prevalence of Sarcocystis infection in ruminants was 68.98%. All of the cysts were microscopic, and found more frequently (p < .05) in heart (62.08%) than esophageal muscle (45.45%) although concurrent infection of both organs was observed in 33.87% of the ruminants examined. No significant association was noted between Sarcocystis infection and the origin, sex and species of ruminants examined (p > .05). The higher prevalence recorded in the study area can be explained by the abundance of stray dogs, cats and wild carnivores that are roaming in the villages, lack of proper latrine, uncontrolled disposal of condemned offals and carcass, and provision of uncooked meat for dogs and cats. Thus, farmers' awareness creation and strategies targeted at breaking the life cycle of the parasite are required to reduce the prevalence of the parasite and thereby the foreseen zoonotic and economic impact.

Imunodetecção de Toxoplasma gondii em tecido placentário de cabras naturalmente infectadas

RESUMO A imuno-histoquímica (IHQ) é considerada uma ferramenta rápida e precisa para a identificação de protozoários, como Toxoplasma gondii, em tecidos fetais e placentários. Neste estudo foi avaliada a imunodetecção de Toxoplasma gondii em tecido placentário de cabras naturalmente infectadas. Foram coletadas e analisadas 80 amostras de placentas de cabras procedentes de único rebanho com sorologia positiva para T. gondii na técnica de ELISA. Na histopatologia, 27/80 amostras apresentaram lesões sugestivas de infecção por protozoários. Após a avaliação histopatológica, procedeu-se à realização da técnica de imuno-histoquímica, obtendo-se 85,2% (23/27) de amostras com marcação positiva. A imunodetecção ocorreu no epitélio de revestimento das vilosidades coriônicas e foi classificada de acordo com o grau de intensidade da imunomarcação. Também foi evidenciada imunomarcação no interior dos vasos sanguíneos fetais em 8,69% (2/23) das amostras. Este estudo demonstrou que a técnica de IHQ se comportou como uma ferramenta valiosa no diagnóstico da infeção por T. gondii em tecido placentário de cabras naturalmente infectadas e complementou, de forma decisiva, o diagnóstico, além de agregar maior valor aos resultados obtidos nas análises histopatológica e sorológica.

Occurrence of Sarcocystis gigantea macrocysts and high frequency of S. tenella microcysts in sheep from southern Brazil

The aim of this study was to investigate the occurrence of sarcocysts in sheep slaughtered in the Rio Grande do Sul state, Brazil. Heart and esophagus samples from 130 sheep were subjected to macroscopic and microscopic examination, followed by molecular analysis. Ten sheep (7.7%) had Sarcocystis gigantea macrocysts in esophagus, as identified by gene sequencing. Microcysts were present in 96.1% of the sheep, with a higher frequency (p < .05) in the heart (91.5%) compared to the esophagus (81.5%) samples. The microcysts were identified as Sarcocystis tenella by gene sequencing. Our results revealed a high frequency of Sarcocystis spp. infection in sheep from southern Brazil. To the authors knowledge, this is the first molecular confirmation of S. gigantea presence in Brazil.

Sarcocystis species identification in cattle hearts destined to human consumption in southern Brazil

Sarcocystis spp. are ubiquitous protozoan parasites that can form cysts in striated muscle and CNS of cattle. Cattle hearts are commonly infected by microscopic sarcocysts. Humans can get infected by consuming cattle meat containing the zoonotic parasites Sarcocystis hominis and Sarcocystis heydorni. However, bovine myocardium is generally infected by Sarcocystis cruzi. The aims of this study were to investigate the occurrence of sarcocysts and the identity of Sarcocystis species present in cattle hearts destined to human consumption in the Central region of the Rio Grande do Sul state, southern Brazil. A total of 314 cattle myocardium samples collected from a local abattoir were microscopically examined for the presence of sarcocysts. The sarcocysts isolated from 134 of these samples (ten sarcocysts per sample) were subjected to DNA extraction and PCR amplification. The PCR-amplified DNA fragments were digested with the restriction enzymes BclI and RsaI (PCR-RFLP) for differentiation among S. cruzi, S. hirsuta, and S. hominis. Sarcocystis species identification was confirmed using DNA sequencing of the cox1 mitochondrial DNA. Sarcocysts were detected in all the bovine myocardium samples. PCR-RFLP analysis resulted in successful amplification of 78 of the 134 samples tested. Only the S. cruzi DNA restriction pattern was identified from all of the 78 amplified samples. DNA sequencing also confirmed the presence of S. cruzi DNA. In conclusion, all myocardium samples evaluated were infected with microscopic sarcocysts. S. cruzi was the only species detected infecting the cattle hearts.

Toxoplasma gondii Lineages Circulating in Slaughtered Industrial Pigs and Potential Risk for Consumers

Toxoplasma gondii is a cosmopolitan zoonotic protozoan parasite, and the consumption of raw or undercooked pig meat is one of the most important sources of T. gondii infection. Three predominant lineages, types I, II, and III, are widespread in Europe. Although still poorly understood, a relationship between each type and the severity of illness represents a public health issue. To gain further knowledge of the genotypes in circulation and of the potential risk for consumers, one heart sample and one diaphragm sample (206 total) were taken from each of 103 pig carcasses at an abattoir in Italy. Then, we used 529-bp repetitive element PCR and a B1 real-time PCR high-resolution melting assay coupled with sequencing to detect and genotype T. gondii isolates. T. gondii DNA was detected in 14 pigs (13.6%, 95% confidence interval = 7 to 20.2%), and types I (3.9%), II (5.8%), and III (3.9%) were identified. We found that heart tissue had a significantly higher PCR positivity rate for T. gondii than did diaphragm tissue. This is Europe's largest study on genotyping of T. gondii from pigs, and it demonstrates that all three main lineages are present in carcasses of industrially reared pigs in Italy. There is a potential risk to consumers of infection with any or all of the three lineages, and the related clinical consequences should be taken into account. This study suggests that monitoring of T. gondii types in meat is essential, especially in meat that is traditionally eaten raw or that is minimally processed.

Detection and Identification of Sarcocystis cruzi (Protozoa: Apicomplexa) by Molecular and Ultrastructural Studies in Naturally Infected Korean Cattle (Bos taurus coreanae) from Daejeon, Korea

To survey the prevalence of Sarcocystis infections, 210 heart samples were collected from Korean native cattle (Bos taurus coreanae) at an abattoir in Daejeon Metropolitan City, Republic of Korea. Sarcocysts were detected form 31 specimens (14.8%) and identified as Sarcocystis cruzi via transmission electron microscopy. The wall of S. cruzi has flattened protrusions that did not contain fibrils or microfilaments. The protrusions arose irregularly from the base, contained a fine granular substance, lacked internal microfilaments, and measured approximately 0.21–1.25 μm in length and 0.05–0.07 μm in width. Sequence analysis revealed 99.5% homology to S. cruzi. This is the first report on the prevalence of S. cruzi in native cattle from the Republic of Korea.

Recolonizing gray wolves increase parasite infection risk in their prey

The recent recolonization of Central Europe by the European gray wolf (Canis lupus) provides an opportunity to study the dynamics of parasite transmission for cases when a definitive host returns after a phase of local extinction. We investigated whether a newly established wolf population increased the prevalence of those parasites in ungulate intermediate hosts representing wolf prey, whether some parasite species are particularly well adapted to wolves, and the potential basis for such adaptations. We recorded Sarcocystis species richness in wolves and Sarcocystis prevalence in ungulates harvested in study sites with and without permanent wolf presence in Germany using microscopy and DNA metabarcoding. Sarcocystis prevalence in red deer (Cervus elaphus) was significantly higher in wolf areas (79.7%) than in control areas (26.3%) but not in roe deer (Capreolus capreolus) (97.2% vs. 90.4%) or wild boar (Sus scrofa) (82.8% vs. 64.9%). Of 11 Sarcocystis species, Sarcocystis taeniata and Sarcocystis grueneri occurred more often in wolves than expected from the Sarcocystis infection patterns of ungulate prey. Both Sarcocystis species showed a higher increase in prevalence in ungulates in wolf areas than other Sarcocystis species, suggesting that they are particularly well adapted to wolves, and are examples of "wolf specialists". Sarcocystis species richness in wolves was significantly higher in pups than in adults. "Wolf specialists" persisted during wolf maturation. The results of this study demonstrate that (1) predator-prey interactions influence parasite prevalence, if both predator and prey are part of the parasite life cycle, (2) mesopredators do not necessarily replace the apex predator in parasite transmission dynamics for particular parasites of which the apex predator is the definitive host, even if meso- and apex predators were from the same taxonomic family (here: Canidae, e.g., red foxes Vulpes vulpes), and (3) age-dependent immune maturation contributes to the control of protozoan infection in wolves.

First molecular characterization of Sarcocystis spp. in cattle in Qena Governorate, Upper Egypt

Cattle are intermediate hosts for several Sarcocystis species with different definitive hosts. The present study, to our knowledge, is the first to determine the prevalence of Sarcocystis infection and morphologically and molecularly identify Sarcocystis species in cattle in Qena Governorate, Upper Egypt. The samples were collected from the heart and oesophagus muscles of 84 slaughtered cattle (76 males and 8 females) aged between 11 months and 3 years from slaughterhouses in different localities in Qena Governorate, Upper Egypt. The samples were macroscopically and histologically examined, and the molecular identification of the species was performed using 18S ribosomal subunit DNA through PCR and DNA sequencing. Infection was detected in 72 out of 84 animals (85.7%) and was more prevalent in males (76.2%) than in females (9.5). Using light microscopy, the microscopic sarcocysts were observed to be thin-walled. Sequencing and genotyping revealed one isolate that had 99 and 100% identity, respectively, to Sarcocystis cruzi, while another isolate had 95 and 99% identity to Sarcocystis hjorti. The present study is the first to identify Sarcocystis infection in cattle in Qena Governorate, Upper Egypt both morphologically and molecularly. Sarcocystis cruzi and S. hjorti species were isolated from cattle, which is of veterinary importance and indicates that morphologically similar Sarcocystis species are genetically distinct. Additionally, the results show that Sarcocystis species are not host-specific.

Surveillance and diagnosis of zoonotic foodborne parasites

Foodborne parasites are a source of human parasitic infection. Zoonotic infections of humans arise from a variety of domestic and wild animals, including sheep, goats, cattle, camels, horses, pigs, boars, bears, felines, canids, amphibians, reptiles, poultry, and aquatic animals such as fishes and shrimp. Therefore, the implementation of efficient, accessible, and controllable inspection policies for livestock, fisheries, slaughterhouses, and meat processing and packaging companies is highly recommended. In addition, more attention should be paid to the education of auditors from the quality control (QC) and assurance sectors, livestock breeders, the fishery sector, and meat inspection veterinarians in developing countries with high incidence of zoonotic parasitic infections. Furthermore, both the diagnosis of zoonotic parasitic infections by inexpensive, accessible, and reliable identification methods and the organization of effective control systems with sufficient supervision of product quality are other areas to which more attention should be paid. In this review, we present some examples of successful inspection policies and recent updates on present conventional, serologic, and molecular diagnostic methods for zoonotic foodborne parasites from both human infection and animal‐derived foods.

Feline Toxoplasmosis: Tumor Necrosis Factor, Nitric Oxide, and Free Radicals in Seropositive Cats

Toxoplasma gondii is a cosmopolitan protozoan that causes disease in several species, including humans. In cats, these infections are usually asymptomatic, but in other species they can lead to high levels of inflammatory and cell damage markers, causing cellular damage. Therefore, the aim of this study was to measure levels of tumor necrosis factor (TNF-α), reactive oxygen species (ROS), and nitric oxide (nitrite/nitrate-NO_x) in the serum of cats seropositive for T. gondii. Initially, we investigated the presence of antibodies against T. gondii in cats in the city of Concordia, Santa Catarina, Brazil, with the use of indirect immunofluorescence (IFA), and found 30 cats seropositive for T. gondii and 30 seronegative cats. In this study, seropositive cats showed higher levels of TNF-α, ROS, and NO_x compared to seronegative cats. Although cats do not show clinical signs of disease, constant inflammatory response can cause cell damage, which over time may adversely affect the animal.

Antibodies to Neospora caninum in sheep from slaughterhouses in the state of São Paulo, Brazil

Neosporosis is an emergent disease responsible for considerable economic impact due to reproductive losses. Its zoonotic potential remains unknown. This study involved a survey of antibodies to Neospora caninum in slaughtered sheep and their association with epidemiological variables. Serum samples from 596 sheep from the states of São Paulo and Rio Grande do Sul, Brazil, were collected in two slaughterhouses located in São Paulo and evaluated by indirect fluorescence antibody test (IFAT), using cut-off titers of 25. Among these samples, 353/596 (59.23%; 95%CI 55.23-63.10) were positive and 263/353 (74.50%; 95%CI 69.71-78.77%) were from Rio Grande do Sul. Statistical associations were determined in the univariate analysis between the serological results and sex, breed and municipality of origin. Sheep that came from extensive breeding system showed higher chance (OR=2.09) of presenting antibodies to N. caninum in relation to those from semi-intensive system. Higher chance was also observed for the different studied breeds, except Bergamácia, in relation to Hampshire Down. The results revealed the presence of infection by N. caninum in sheep from slaughterhouses.

Importance of serological cross-reactivity among Toxoplasma gondii, Hammondia spp., Neospora spp., Sarcocystis spp. and Besnoitia besnoiti

Toxoplasma gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and Besnoitia besnoiti are genetically related cyst-forming coccidia. Serology is frequently used for the identification of T. gondii, Neospora spp. and B. besnoiti-exposed individuals. Serologic cross-reactions occur in different tests among animals infected with T. gondii and H. hammondi, as well as among animals infected by T. gondii and N. caninum. Infections caused by N. caninum and N. hughesi are almost indistinguishable by serology. Neospora caninum, B. besnoiti and Sarcocystis spp. infections in cattle show some degree of serologic cross-reactivity. Antibody cross-reactivity between Neospora spp. and H. heydorni-infected animals is suspected, but not proven to occur. We review serologic cross-reactivity among animals and/or humans infected with T. gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and B. besnoiti. Emphasis is laid upon antigens and serological methods for N. caninum diagnosis which were tested for cross-reactivity with related protozoa. Species-specific antigens, as well as stage-specific proteins have been identified in some of these parasites and have promising use for diagnosis and epidemiological surveys.

Population expansion and individual age affect endoparasite richness and diversity in a recolonising large carnivore population

The recent recolonisation of the Central European lowland (CEL) by the grey wolf (Canis lupus) provides an excellent opportunity to study the effect of founder events on endoparasite diversity. Which role do prey and predator populations play in the re-establishment of endoparasite life cycles? Which intrinsic and extrinsic factors control individual endoparasite diversity in an expanding host population? In 53 individually known CEL wolves sampled in Germany, we revealed a community of four cestode, eight nematode, one trematode and 12 potential Sarcocystis species through molecular genetic techniques. Infections with zoonotic Echinococcus multilocularis, Trichinella britovi and T. spiralis occurred as single cases. Per capita endoparasite species richness and diversity significantly increased with population size and changed with age, whereas sex, microsatellite heterozygosity, and geographic origin had no effect. Tapeworm abundance (Taenia spp.) was significantly higher in immigrants than natives. Metacestode prevalence was slightly higher in ungulates from wolf territories than from control areas elsewhere. Even though alternative canid definitive hosts might also play a role within the investigated parasite life cycles, our findings indicate that (1) immigrated wolves increase parasite diversity in German packs, and (2) prevalence of wolf-associated parasites had declined during wolf absence and has now risen during recolonisation.

Human intestinal sarcocystosis in Iran: there but not seen

Human sarcocystosis is a rare infection caused by the genus Sarcocystis who human serve as definitive (intestinal form of infection) host or intermediate (extraintestinal form) host for some various Sarcocystis species. The detection of Sarcocystis oocysts/sporocysts in the feces usually incidentally and is achieved by microscopic examination of the fresh or preserved specimens. To rule out any parasitological etiology among 23,875 (aged 2 months to 95 years) apparently immunocompetent Iranian individuals (from October of 2010 to June of 2016) with abdominal discomforts referred to several teaching hospitals and local clinical laboratories in Fars Province, Iran, their fecal samples were examined using light microscopy. Most pathogenic parasite-positive and doubtful samples were sent to the Intestinal Protozoology Laboratories of Fasa and Shiraz Universities of Medical Sciences to further examination to detect probable co-infection with other underdiagnose parasitoses. In addition to the common protozoal and helminthic infections, during the course of examining stool specimens using direct smear mixed with saline or iodine mounts and by formalin-ethyl acetate techniques, four cases of intestinal Sarcocystis infection as only or concurrently infected with other parasites were found. The present paper presents cases of human intestinal Sarcocystis infection in Iran. Since Sarcocystis are small in size and usually rare in stool, they often go unnoticed. It should be noted that stool smears must be examined with great care to avoid misinterpretation of Sarcocystis infections in microscopic examinations. To the best of our knowledge, co-infection of intestinal sarcocystosis and other principal parasitoses in stool investigations has not been reported earlier.

Embryonated pigeon eggs as a model to investigate Neospora caninum infection

It has been shown that embryonated chicken eggs can be used as animal models for experimental infections. The aim of the present study was to investigate pigeon embryonated eggs as animal models for experimental neosporosis. An infection with Neospora caninum Nc1 isolate was conducted in chicken and pigeon embryonated eggs to evaluate LD50. After calculation of LD50, 2LD50 of tachyzoites were injected into the eggs. Macroscopic changes of each embryo were observed, and immunohistochemistry (IHC) and molecular methods were used to investigate the parasitic distribution in the tissues. In the present study, histopathological changes were considered, and sections of those used for histopathological examination including the heart, liver, brain and chorioallantoic (CA) membrane were also subjected to IHC. Pigeon embryos showed more macroscopic changes than chicken embryos. A hemorrhage of the CA membrane was the main gross lesion. Microscopic examination of tissues revealed acute neosporosis due to hemorrhage, necrosis and infiltration of mononuclear inflammatory cells. Based on IHC and molecular results, the parasite DNA was detected in the liver, heart and CA membrane. As with chicken embryonated eggs, these results reinforce the susceptibility of pigeon embryonated eggs to N. caninum, and provide new insights into using an inexpensive and available animal model for N. caninum research. The results of the present study suggest that pigeon embryos may be a good choice for studying the biology of N. caninum in living organisms.

Morphological and molecular characterization of Sarcocystis taeniata and Sarcocystis pilosa n. sp. from the sika deer (Cervus nippon) in Lithuania

The diaphragm muscles of eight sika deer (Cervus nippon) bred in Lithuania were examined for Sarcocystis cysts. Two Sarcocystis species, Sarcocystis taeniata, which were previously reported in Canadian moose (Alces alces) and Argentinean red deer (Cervus elaphus), and Sarcocystis pilosa n. sp. were described using light microscopy (LM), transmission electron microscopy (TEM), 18S ribosomal DNA (rDNA), and subunit I of cytochrome c oxidase (cox1) sequences analysis. By LM, cysts of S. taeniata were 424.8 × 57.9 (200-837 × 30-100) μm in size and had a thin (up to 1 μm) and smooth cyst wall, while short ribbon-like protrusions arising from broadened cone-shaped bases were seen under TEM. Cysts of S. pilosa (by LM) were ribbon-shaped, measured 848.5 × 63.8 (350-1700 × 30-125) μm and had thin 7-8-μm long hair-like protrusions. By TEM, cyst wall was type 7a-like; protrusions arose from 0.3 μm wide dome-shaped base with minute indentations of the parasitophorous vacuolar membrane near it, the surface of protrusions seemed to be smooth, and the ground substance layer was thin (0.18-0.22 μm). The 18S rDNA, in contrast to the cox1, lacked variability to discriminate S. pilosa from closely related Sarcocystis hjorti from the red deer and moose. S. taeniata, but not S. pilosa, showed a considerable intraspecific variation in both genes analyzed. The phylogenetic analyses based on 18S rDNA and cox1 sequences suggest that canids are definitive hosts of both S. taeniata and S. pilosa. This paper represents the first identification of Sarcocystis species in the sika deer by morphological and molecular methods.

Molecular differentiation of bovine sarcocysts

Cattle are common intermediate hosts of Sarcocystis, and the prevalence in adult bovine muscle is close to 100 % in most regions of the world. Three Sarcocystis spp. are known to infect cattle as intermediate hosts, namely, S. cruzi, S. hirsuta, and S. hominis. The aim of the present study was the molecular identification and differentiation of these three species, Neospora caninum and Besnoitia by PCR and RFLP methods. Tissue samples were obtained from diaphragmatic muscle of 101 cattle slaughtered in Shiraz, Fars Province, Iran, for both smear preparation and DNA extraction. The samples were digested by Pepsin, washed three times with PBS solution before taking smears, fixed in absolute methanol and stained with 10 % Giemsa. The slides were examined microscopically for Sarcocystis bradyzoites and DNA was extracted from 100 mg of Sarcocystis-infected meat samples. Since the primers also bind to 18S rRNA gene of some tissue cyst-forming coccidian protozoa, DNA was also extracted from 100 μl of tachyzoite-containing suspension of N. caninum and Besnoitia isolated from goat to compare RFLP pattern. Polymerase chain reaction (PCR) was performed on DNA of samples which were microscopically positive for Sarcocystis. Five restriction enzymes Dra1, EcoRV, RsaI, AvaI, and SspI were used for RFLP and DNA of one sample from protozoa was sequenced. Based on the RFLP results, 87 (98.9 %) DNA samples were cut with DraI, indicating infection by S. cruzi. One sample (1.1 %) of PCR products of infected samples was cut only with EcoRV which showed S. hominis infection. Forty-eight samples (53.3 %) of PCR products were cut with both DraI, EcoRV, or with DraI, EcoRV, and RsaI while none of them was cut with SspI, which shows the mixed infection of both S. cruzi and S. hominis and no infection with S. hirsuta. It seems by utilizing these restriction enzymes, RLFP could be a suitable method not only for identification of Sarcocystis species but also for differentiating them from N. caninum and Besnoitia.

Anti-Neospora caninum and anti-Sarcocystis spp. specific antibodies cross-react with Besnoitia besnoiti and influence the serological diagnosis of bovine besnoitiosis

Bovine besnoitiosis control remains a challenge because the disease continues to spread and control relies solely on accurate diagnosis coupled to management measures. However, recent studies have reported that routinely used ELISAs may raise a high number of false-positive results. Herein, cross-reactions between Besnoitia besnoiti antigens and anti-Neospora caninum and/or anti-Sarcocystis spp.-specific antibodies were studied in an in house ELISA since N. caninum and Sarcocystis spp. are closely related parasites, and both infections are highly prevalent in cattle worldwide. The serum panel was composed of the following categories: sera from B. besnoiti-seronegative (n=75) and -seropositive cattle (n=66), B. besnoiti-based-ELISA false-positive reactors (n=96) together with N. caninum (n=36) and Sarcocystis spp. (n=42) -seropositive reference cattle sera. B. besnoiti tachyzoite based western blot (WB) results classified animals as seropositive or seronegative. Sera were analyzed for the detection of anti-N. caninum by WB and ELISA and anti-Sarcocystis spp.-specific antibodies by WB and IFAT. Those samples recognizing a Sarcocystis spp. 18-20 kDa antigenic region and N. caninum 17-18 kDa immunodominant antigen were considered to be Sarcocystis spp. and N. caninum seropositive, respectively. The category of B. besnoiti based-ELISA false-positive reactors showed the highest number of sera with specific anti-Sarcocystis spp. and anti-N. caninum antibodies (74%; 71/96), followed by the N. caninum-seropositive cattle category (52.8%; 19/36). In contrast, few B. besnoiti-seronegative and -seropositive cattle showed antibodies against Sarcocystis spp. and N. caninum (10.7%; 8/75 and 1.5%; 1/66), respectively). This study revealed that B. besnoiti false-positive ELISA results were associated not only with the presence of anti-N. caninum and anti-Sarcocystis spp. antibodies (χ(2): 78.36; p<0.0001; OR: 34.6; CI: 14-88) but also with high antibody levels against them using ELISA and IFAT tests, respectively (p<0.05; t-test). These results may explain why only some animals seropositive to Sarcocystis spp. and/or N. caninum are Besnoitia false-positive reactors. Therefore, sera meeting these requirements should be included in future validations of serological tests for bovine besnoitiosis.

Sarcocystis Spp. Prevalence in Bovine Minced Meat: A Histological and Molecular Study

Sarcosporidiosis is caused by ingestion of contaminated raw or undercooked bovine meat and, although considered a minor zoonosis, it can represent a threath for immunocompromised people. Aim of this study was to determine the prevalence of Sarcocystis spp. in bovine minced meat intended for raw consumption collected from butcher shops and retail stores in Turin’s province (Piedmont region, Northwest Italy). Twenty-five samples were examined in parallel by histology and polymerase chain reaction (PCR). The prevalence of infestation of Sarcocystis spp. resulted to be 64% [confidence interval (CI) 95% 42-82] and 88% (CI 95% 69-97) respectively by histology and PCR. In detail, the prevalence resulted 80% for S. cruzi (CI 95% 59-93), 68% for S. hominis (CI 95% 46-85) and 4% for S. hirsuta (CI 95% 0.10-20). The high prevalence of S. hominis highlights that sarcosporidiosis may constitute a public health problem in Italy, particularly in regions like Piedmont, that has traditional dishes prepared from raw or undercooked bovine meat.

Sarcocystis-infection of cattle in Hungary

BACKGROUND

Reports on Sarcocystis-infection of cattle are outdated or lacking in many European countries, including those in the Central-Eastern part of the continent. Therefore, to assess the prevalence of Sarcocystis spp. among bovids in Hungary, a countrywide survey was initiated. In addition, fulminant deaths of four cattle, that showed clinical signs and post mortem lesions resembling acute sarcocystiosis ("Dalmeny disease"), were investigated.

METHODS

During the countrywide survey individual heart and oesophagus samples were collected at slaughterhouses from 151 beef cattle and from 15 buffalo, kept in 31 places of Hungary. Analysis for Sarcocystis spp. was carried out with conventional PCRs for the 18S rDNA gene and gel electrophoresis, followed by sequencing of 36 strongly positive samples. Mortality cases were evaluated by histological, molecular, bacteriological and virological analyses of samples from various organs.

RESULTS

Among slaughtered cattle the rate of Sarcocystis-infection was 66%. S. cruzi was identified as the most prevalent species in aurochs-like breed, and the zoonotic S. hominis in Hungarian grey cattle. Concerning the sudden deaths of cattle, Sarcocystis-infection could not be demonstrated in organs showing haemorrhages, but S. cruzi cysts were present in the muscles. In one case "S. sinensis" was molecularly identified in the blood (indicating sarcocystaemia). Results of analyses for bacterial/viral pathogens were negative.

CONCLUSIONS

S. cruzi appears to be the most prevalent Sarcocystis sp. in cattle in Hungary, followed by the zoonotic S. hominis. However, the rate of infection with both species was shown to differ between cattle breeds. The suspected role of Sarcocystis spp. as causative agents of the fatal cases could not be confirmed.

Detection of Sarcocystis spp. in cattle (Bos taurus) and water buffaloes (Bubalus bubalis) in Iran by PCR-RFLP

Sarcocystis species are cyst-forming intracellular protozoan parasites. Cattle are mainly infected with Sarcocystis cruzi, Sarcocystis hominis and Sarcocystis hirsuta. Water buffaloes are intermediate hosts for Sarcocystis fusiformis, Sarcocystis levinei (S. cruzi-like species), Sarcocystis dubeyi, Sarcocystis sinensis (S. hominis-like species) and Sarcocystis buffalonis (S. hirsuta- like species). The aim of this study was Identification of Sarcocystis spp. in slaughtered cattle and water buffaloes in Ahvaz, Khuzestan province by PCR-restriction fragment length polymorphism. Meat inspection was done on 124 cattle and 147 water buffaloes. From each animal tissue samples (each 50 g) from heart, esophagus, diaphragm and intercostal muscle were collected during meat inspection. Samples examined with digestion method. Genomic DNA of 80 positive samples was extracted and their 18S rRNA gene was amplified. PCR products were digested by restricted enzymes (FokI, SspI and DraI). S. cruzi in cattle and S. fusiformis in water buffaloes were identified. Our study clarified that sarcocystosis in cattle in Ahvaz district may be results acute infection according to determined species, but in buffaloes as S. fusiformis was detected we may expect only economic loss follow up slaughterhouse inspection.

Seroprevalence and risk factors of toxoplasmosis in cattle from extensive and semi-intensive rearing systems at Zona da Mata, Minas Gerais state, Southern Brazil

BACKGROUND

Concerning the infection of humans by T. gondii, limited efforts have been directed to the elucidation of the role of horizontal transmission between hosts. One of the main routes of transmission from animals to humans occurs through the ingestion of raw or insufficiently cooked meat. However, even though the detection of T. gondii in meat constitutes an important short-term measure, control strategies can only be accomplished by a deeper understanding of the epidemiology of toxoplasmosis. The present study aimed to investigate the seroprevalence of toxoplasmosis in cattle from Zona da Mata, Minas Gerais, Brazil, and to identify associated risk factors, through an epidemiological investigation.

METHODS

The animals studied (Bos indicus, breed Nelore or Gir) were reared in the Zona da Mata micro-region and killed at a commercial slaughterhouse at Juiz de Fora, Minas Gerais state. The animals came from 53 cattle farms with extensive (predominantly pasture feeding management) or semi-intensive (food management based on grazing, salt mineral and feed supplementation) rearing systems. Blood samples were collected from 1200 animals, and assigned to Indirect Fluorescent Antibody Test.

RESULTS

When analyzing IgG anti-T.gondii we found an overall seroprevalence of 2.68%. In Brazil prevalences vary from 1.03% to 60%. Although in the present study, the seroprevalence per animal is considered low compared to those observed in other studies, we found out that of the 53 farms analyzed, 17 (34.69%) had one or more positive cattle. It is a considerable percentage, suggesting that the infection is well distributed through the Zona da Mata region. The results of the epidemiological investigation showed that the main risk factors of Toxoplasma gondii infection are related to animal management and to the definive host. There was a relationship between the number of seropositive cattle and the presence and number of resident cats, presence and number of stray cats, presence of cats walking freely, rat control by using cats and feed storage.

CONCLUSION

These results may contribute to the development of preventive strategies in Brazil and other developing countries were extensive and semi-intensive cattle rearing systems are very widespread and the efforts to control this important zoonotic disease have attained little success.