First genetic characterization of Toxoplasma gondii infection in donkey meat slaughtered for human consumption in Shandong province, eastern China

First Report on the Molecular Detection and Genetic Characterization of Toxoplasma gondii From Donkeys in Kenya

PURPOSE

The present study was conducted to determine the presence of Toxoplasma gondii in donkeys by molecular tests and genetic diversity analysis of the obtained DNA samples from central Kenya.

METHOD

A total of 363 blood samples were collected from donkeys in Meru and Kirinyaga Counties, and 96 samples that were previously seropositive for T. gondii using indirect ELISA were subjected to nested PCR based on the amplification of the internal transcribed spacer 1 (ITS-1) gene followed by DNA sequencing and phylogenetic analysis. Genotyping was performed on 15 selected positive samples using multilocus nested polymerase chain reaction restriction fragment length polymorphism (Mn-PCR-RFLP) with eight genetic markers ('SAG 2, 5'SAG 2, Alt. SAG 2, SAG 3, GRA 6, C29-2, BTUB and L358).

RESULTS

Toxoplasma gondii DNA was detected in 36.5% (35/96) of the blood samples. The sequences obtained exhibited 98.2-99.5% homology with those deposited in GenBank. Phylogenetic analysis demonstrated that the obtained sequences are conserved and clustered with those of infecting animals from other regions of the world. Eighteen distinct T. gondii haplotypes were identified to be circulating in donkeys from central Kenya. The T. gondii DNA samples exhibited high haplotype diversity (Hd: 0.915) and limited genetic diversity (π = 0.01027). PCR-RFLP of T. gondii DNA-positive samples revealed three different genetic combinations that consisted of alleles I, II and III, indicating the dissemination of atypical genotypes.

CONCLUSION

This study demonstrated that T. gondii is widespread in donkeys from Kenya and could be a possible source of infection in humans. These findings are important for designing control strategies for this parasite to improve the livestock sector, which is one of the main sources of livelihood for farmers in Kenya.

Detection of Toxoplasma gondii infection in buffaloes (Bubalus bubalis) and cattle (Bos taurus) at the Tabriz abattoir, Iran

BACKGROUND

Toxoplasma gondii is a widely prevalent zoonotic protozoan parasite in humans and warm-blooded animals worldwide. Infection of humans by this parasite can result in severe clinical symptoms, particularly in individuals with congenital toxoplasmosis or immunocompromised patients. Contamination mainly occurs through foodborne routes, especially the consumption of raw or undercooked meat from animals.

OBJECTIVES

The aim of this study was to use PCR to detect T. gondii in tissues and organs of buffaloes and cattle slaughtered at Tabriz slaughterhouse, in Iran.

METHODS

Fifty grams of heart, thigh, diaphragm and tongue from 50 buffaloes and 100 cattle slaughtered at the Tabriz industrial slaughterhouse were selected for sampling using a combination of convenience sampling. The samples were tested using a previously published PCR method.

RESULTS

Out of the 150 animal samples, T. gondii was detected in 10 (6.7%, 95%CI: 3.2-11.9), including one buffalo (2%, 95%CI: 0.1-10.6) and nine cattle (9%, 95%CI: 4.2-16.4). There was no statistically significant difference in the rate of T. gondii infection among cattle based on age and sex (p > 0.05).

CONCLUSIONS

The results indicated a potential risk of T. gondii transmission to humans through the consumption of infected meat. Therefore, appropriate and effective preventive measures should be taken to limit the transmission of this parasite to humans, and the consumption of raw and undercooked meat should be discouraged.

Molecular Prevalence of Sarcocystis spp. and Toxoplasma gondii in Slaughtered Equids in Northern Tunisia

Sarcocystis spp. and Toxoplasma gondii are two apicomplexan protozoa that infect a broad range of vertebrates, however, little is known about the infection of equids with these parasites. A total of 184 slaughtered equids from slaughterhouses of Bizerte and Tunis located in Northern Tunisia, were examined for meat infections with Sarcocystis spp. and T. gondii by PCR. The prevalence of infections with Sarcocystis spp. and T. gondii were 38% (95% CI: 31-45) and 39.7% (95% CI: 32.6-46.7), respectively. The highest prevalence of infection with Sarcocystis spp. was observed in donkeys (48.6%; 95% CI: 37.3-60) followed by mules (32.8%; 95%CI: 21.3-44.3), and horses (28.3%; 95% CI: 15.2-41.2) (P = .04). Similarly, the highest prevalence of infection with T. gondii was also observed in donkeys (66.2%; 95% CI: 55.4-77), followed by mules (18.7%; 95%CI: 9.2-28.3), and horses (26.1%; 95%CI: 13.4-38.8) (P < .001). The coinfection prevalence was estimated to be 17.4% (95%CI: 11.9-22.9). Taking into consideration that humans can be infected following consumption of infected equid meat with T. gondii and/or some Sarcocystis species, it is important to assess the risk of human infection. Thus, further studies are needed to better understand the epidemiology of these zoonoses.

A survey report on the donkey original breeding farms in China: Current aspects and future prospective

Introduction

The number of the large-scale donkey breeding farms in China has increased dramatically. However, information regarding the situation of a Chinese donkey population under large-scale donkey breeding farms is limited.

Methods

This survey report was conducted using questionnaires online to investigate the current situation of the donkey original breeding farms in China, in terms of donkey stock, local breeds, reproductive parameters, growth and lactation performance, and future perspectives. China has developed the donkey reserve system based on national, provincial and non-governmental (self-own) donkey original breeding farms.

Results

In the present study, a total of 38 donkey original breeding farms concentrated in Northern of China were studied, and 52% of them keep their donkeys with a stocking density of 100-500 donkeys. China is rich in various local donkey breeds, and 16 local donkey breeds including large-sized, medium-sized and small-sized breeds were collected in our survey. Dezhou donkey are prevalent with a percentage of more than 57% of the total donkeys, while the Cullen donkeys belong to small-sized donkey breeds are scare. The reproductive efficiency and donkey productivity were different across donkey farms, indicating potential differences in management and breeding practices between different donkey original breeding farms. The artificial insemination has been performed in these donkey farms with an average proportion of 73%. Regarding the donkey productivity, the national and provincial donkey original breeding farms showed a higher birthweight and fat content in donkey milk than self-own farms. Furthermore, our results indicate that the donkey breeds with different body size also have important influence on the reproduction parameters and donkey productivity, with the large-sized donkeys had better performance compared to the small-sized donkeys.

Discussion

In summary, our survey provided valuable baseline information on the situation of donkey population dynamics in the donkey original breeding farms. However, further study is required in the future to investigate the factors such as donkey health care, management and nutrition during breeding, fattening and lactation that influence donkey productivity under large-scale farm systems.

Toxoplasma gondii in Foods: Prevalence, Control, and Safety

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, with approximately one third of the population around the world seropositive. The consumption of contaminated food is the main source of infection. These include meat products with T. gondii tissue cysts, and dairy products with tachyzoites. Recently, contamination has been detected in fresh products with oocysts and marine products. Despite the great health problems that are caused by T. gondii, currently there are no standardized methods for its detection in the food industry. In this review, we analyze the current detection methods, the prevalence of T. gondii in different food products, and the control measures. The main detection methods are bioassays, cell culture, molecular and microscopic techniques, and serological methods, but some of these do not have applicability in the food industry. As a result, emerging techniques are being developed that are aimed at the detection of multiple parasites simultaneously that would make their application more efficient in the industry. Since the prevalence of this parasite is high in many products (meat and milk, marine products, and vegetables), it is necessary to standardize detection methods, as well as implement control measures.

Deoxynivalenol and zearalenone: Different mycotoxins with different toxic effects in donkey (Equus asinus) endometrial epithelial cells

Deoxynivalenol (DON) and zearalenone (ZEA), which are commonly found in feed products, exhibit serious negative effects on the reproductive systems of domestic animals. However, the toxicity of mycotoxins on the uterine function of donkey (Equus asinus) remains unclear. This study investigated the biological effects of DON and ZEA exposure on donkey endometrial epithelial cells (EECs). It was administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro. The results showed that 10 μM DON exposure markedly changed the expression levels of pyroptosis-associated genes and that 30 μM ZEA exposure changed the expression levels of inflammation-associated genes in EECs. The mRNA expression of cancer-promoting genes was markedly upregulated in cells exposed to DON and 30 μM ZEA; in particular, 10 μM and 30 μM DON and ZEA markedly disturbed the expression of androgen and estrogen secretion-related genes. Furthermore, Q-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed EECs. Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of EECs from donkey in vitro.

Detection of Specific IgG-Antibodies Against Toxoplasma gondii in the Serum and Milk of Domestic Donkeys During Lactation in China: A Potential Public Health Concern

Toxoplasma gondii is a worldwide zoonotic protozoan. Donkeys are often susceptible to many pathological agents, acting as carriers of pathogens for other animal species and humans. However, data on the prevalence of T. gondii in donkeys during lactation and on the status of antibodies against T. gondii in donkey milk are lacking. A cross-sectional study evaluated the variation of the anti-T. gondii antibodies in the blood and milk of domestic donkeys during lactation. A total of 418 domestic donkeys were randomly selected from the Shandong province, eastern China from January 2019 to March 2020. The anti-T. gondii antibodies were found in 11.72% (49/418) serum and 9.81% (41/418) milk samples using a commercial ELISA kit, respectively. There was a very high consistency between the serum and milk (Spearman’s coefficient = 0.858, p-value < 0.0001 and Kendall’s tau = 0.688, p-value < 0.0001), particularly at the 45th to 60th day of lactation. The present results of the statistical analysis showed that the history of abortion (p = 0.026; adjusted OR = 2.20; 95% CI: 1.15–4.20) and cat in the house (p = 0.008; adjusted OR = 2.36; 95% CI: 1.26–4.44) were significantly associated with T. gondii infection in the domestic donkeys. This is the first report to detect antibodies against T. gondii in donkey milk in China. These results indicate a potential risk of humans contracting the infection through the consumption of raw milk from the naturally infected donkeys.

Deoxynivalenol and Zearalenone: Different Mycotoxins with Different Toxic Effects in the Sertoli Cells of Equus asinus

(1) Background: Deoxynivalenol (DON) and zearalenone (ZEA) are type B trichothecene mycotoxins that exert serious toxic effects on the reproduction of domestic animals. However, there is little information about the toxicity of mycotoxins on testis development in Equus asinus. This study investigated the biological effects of DON and ZEA exposure on Sertoli cells (SCs) of Equus asinus; (2) Methods: We administered 10 μM and 30 μM DON and ZEA to cells cultured in vitro; (3) Results: The results showed that 10 μM DON exposure remarkably changed pyroptosis-associated genes and that 30 μM ZEA exposure changed inflammation-associated genes in SCs. The mRNA expression of cancer-promoting genes was remarkably upregulated in the cells exposed to DON or 30 μM ZEA; in particular, DON and ZEA remarkably disturbed the expression of androgen and oestrogen secretion-related genes. Furthermore, quantitative RT-PCR, Western blot, and immunofluorescence analyses verified the different expression patterns of related genes in DON- and ZEA-exposed SCs; (4) Conclusions: Collectively, these results illustrated the impact of exposure to different toxins and concrete toxicity on the mRNA expression of SCs from Equus asinus in vitro.

Donkey Industry in China: Current Aspects, Suggestions and Future Challenges

Donkey domestication has been essential to human culture and development and has played an important role in economic and social life in human history. China is one of the largest donkey breeders worldwide; donkey farming for meat, milk and hide production is becoming an important industry in rural China as it provides income to the rural livelihoods of many people. Currently, the donkey industry in China is small and relatively young, but it is growing fast. The industry is not adequately exploited economically, which means that it requires the diminution of its role in the traditional activities of rural households and a reorientation towards a more profitable industry. Given the growing importance of the donkey industry in rural China, this paper aims to outline the current situations of the donkey industry in China in terms of animal stock, breeds and distribution, donkey products, suggestions and future challenges to the development of the donkey industry.

L-Proline: An Effective Agent for Frozen and Post-thawed Donkey Semen Storage

The aim of this study was to evaluate the effects of L-proline on the extender quality of frozen and post-thawed jackass semen. Jackass (n = 6) semen samples were collected and cryopreserved in gradient concentrations (0-80 mM) of L-proline in extenders; post-thawed semen samples were cultured in L-proline medium for 10 hours at 37°C. For cryopreservation experiment I, the motile parameters, mitochondrial membrane potential (MMP), and plasma membrane, acrosome, and chromatin structure integrities of post-thawed semen were assessed. For culture experiment II, additional ROS contents were analyzed after incubation. For the fertility trial, jennies (n = 135) were divided into group I (30 mM L-proline in cryopreservation extender), group II (40 mM L-proline in culture medium), and the control. Pregnancy was diagnosed using an ultrasound scanner 30 days after ovulation. The results of experiment I showed that, motile parameters and acrosome and chromatin structure integrities of groups I and 40 mM were significantly higher than the control (P < .05). MMP of group I was significantly higher than the control and 40 mM groups (P < .05). In experiment II, after 4 hours of incubation, motile parameters, MMP, and DNA integrity in group II were significantly higher than the control (P < .05). Additionally, 40 and 80 mM L-proline in culture medium significantly reduced ROS accumulation after 4 and 10 hours of incubation (P < .05). Pregnancy rates of the control and groups I and II were 28.85%, 40%, and 36.84%, respectively. In conclusion, the extenders containing 30 to 40 mM L-proline improved both qualities of frozen and post-thawed semen, and it will be a beneficial agent for donkey frozen spermatozoa or post-thawed semen storage.

Apicomplexan Protozoa Responsible for Reproductive Disorders: Occurrence of DNA in Blood and Milk of Donkeys (Equus asinus) and Minireview of the Related Literature

Donkeys may be susceptible to many pathological agents and may act as carriers of pathogens for other animal species and humans. This study evaluated the occurrence of potentially abortifacient apicomplexan protozoa DNA in blood and milk samples collected at different time periods during lactation (1, 6, and 10 months) from 33 healthy dairy jennies. A total of 73 blood and 73 milk samples were used for DNA extraction and analysis. Blood specimens from 11/33 (33%) jennies scored positive for Theileria equi, while milk samples scored negative. Blood and milk of 3/33 jennies yielded DNA of Toxoplasma gondii at 6 months (n. 1) and 10 months (n. 2) after parturition. Neospora caninum DNA was found in four milk and in five blood samples only at one month after parturition. This study is the first report about the presence of N. caninum DNA in milk of naturally infected jennies. Moreover, the excretion of N. caninum DNA in some of these jennies at 30 days from the parturition may suggest a possible occurrence of an endogenous cycle, while the presence of T. gondii DNA in the milk collected at 6 and 10 months after parturition may be suggestive of a discontinuous excretion.

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.

Toxoplasma gondii infections in horses, donkeys, and other equids: The last decade

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, and genetic diversity of T. gondii in horses, donkeys and other equids in the past decade. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Seroprevalence of Toxoplasma gondii infection in sheep in Inner Mongolia Province, China

Toxoplasma gondii is an important zoonotic parasite that can infect almost all warm-blooded animals, including humans, and infection may result in many adverse effects on animal husbandry production. Animal husbandry in Inner Mongolia is well developed, but data on T. gondii infection in sheep are lacking. In this study, we determined the seroprevalence and risk factors associated with the seroprevalence of T. gondii using an indirect enzyme-linked immunosorbent assay (ELISA) test. A total of 1853 serum samples were collected from 29 counties of Xilin Gol League (n = 624), Hohhot City (n = 225), Ordos City (n = 158), Wulanchabu City (n = 144), Bayan Nur City (n = 114) and Hulunbeir City (n = 588). The overall seroprevalence of T. gondii was 15.43%. Risk factor analysis showed that seroprevalence was higher in sheep ≥12 months of age (21.85%) than that in sheep <12 months of age (10.20%) (p < 0.01). Seroprevalence was higher in male sheep (18.76%) than females (12.80%) (p < 0.01). Barn-feeding sheep (23.13%) had higher prevalence than grazing sheep (10.94%) (p < 0.01). The seroprevalence was significantly different in different districts (p < 0.01). This study shows that sheep are exposed to T. gondii in Inner Mongolia, and provides a data reference for public health and disease control.

Zearalenone: A Mycotoxin With Different Toxic Effect in Domestic and Laboratory Animals' Granulosa Cells

Zearalenone (ZEA), one of the most prevalent estrogenic mycotoxins, is mainly produced by Fusarium fungi and has been proven to affect the reproductive capacity of animals. Exposure of farm animals to ZEA is a global public health concern because of its toxicity and wide distribution in animal feeds. In vitro and in vivo experiments indicate that ZEA possesses estrogenic activity in mice, swine, Equus asinus and cattle. The precise mechanism of the reproductive toxicity of ZEA has not been established yet. This article reviews evidence on the deleterious effects of ZEA on mammalian folliculogenesis from early to final oogenesis stages. Such effects include impaired granulosa cell (GC) development and follicle steroidogenesis, reduced oocyte nest breakdown, damaged meiotic progression, poor fetal oocyte survival, accelerated primordial follicle activation and enhanced follicle atresia. These phenomena may result in reproductive and non-reproductive problems in domestic animals. In addition, emerging data indicates that ZEA may cause mRNA expression changes in the GCs. In general, E. asinus is more sensitive than swine to ZEA exposure. Finally, results of in vivo animal studies and in vitro tests are reported and discussed.

Seroprevalence and Related Factors of Toxoplasma gondii in Pigeons Intended for Human Consumption in Northern China

Toxoplasma gondii, the causative agent of toxoplasmosis, is carried by a range of intermediate hosts, including pigeons. Eating raw or undercooked pigeon meat, as is common in regions of China, can easily pass on a potentially fatal T. gondii infection. However, there are little data about the seroprevalence and genotypes of T. gondii infection in pigeons. In this study, a total of 963 pigeon blood samples were collected from Jilin Province, Liaoning Province, and Inner Mongolia Autonomous Region in China between August 2015 and December 2016. The overall seroprevalence of T. gondii was 10.80% (104/963), with 8.80% (41/466) in males and 12.68% (63/497) in females. The seroprevalence of T. gondii in different regions varied from 9.04% (17/188) in Jilin City to 13.16% (20/152) in Shenyang City, a relatively high prevalence. The seroprevalence of T. gondii in juvenile pigeons (6.38%, 18/282) was significantly lower than in adults (86/681, p < 0.05). These findings could provide useful data for the execution of effective control measures against T. gondii infection in pigeons and/or other hosts. More importantly, the findings also suggest that pigeons should not be eaten raw.