Seroprevalence, isolation, molecular detection and genetic diversity of Toxoplasma gondii from small ruminants in Egypt

Comparison of a commercial ELISA, an in-house indirect ELISA, and a dot-ELISA developed for the serodetection of Toxoplasma gondii antibodies in farm animals

Toxoplasma gondii is a widespread intracellular protozoan that can infect humans and animals. We isolated T. gondii strains from sheep, goats, cattle, buffaloes, and camels to develop and evaluate a modified in-house dot-ELISA for the detection of Toxoplasma antibodies in farm animals, and compared the results with a commercial ELISA (IDvet; gold standard). Animal tissue samples (n = 430) were examined microscopically, and infected tissues were bioassayed in mice as a viability test. Egyptian Toxoplasma strains were isolated from sheep, cattle, and camels and identified via PCR using the B1 gene (GenBank OR837022.1, OR837021.1, OR837020.1 from sheep, cattle, and camels, respectively). A T. gondii tachyzoite antigen from a sheep strain had the highest potential for the detection of specific T. gondii antibodies. We characterized this antigen using SDS-PAGE and separated it into 10 polypeptides of 96-12 kDa. Our modified in-house dot-ELISA detected T. gondii seropositivity in 172 of 430 (40%) farm animals with a sensitivity of 96.6% and specificity of 100%. The results of our dot-ELISA were confirmed in comparison with those of our indirect ELISA and the commercial ELISA. In a western blot, a predominant immunogenic reactive antigen band of 65 kDa was detected in T. gondii-positive sera of sheep, cattle, buffaloes, and camels; no cross-reaction occurred with antibodies to other parasitic infections or samples from healthy controls. Our modified in-house dot-ELISA is a rapid and simple test that showed promise for the detection of Toxoplasma antibodies in farm animals.

First Molecular Detection of Toxoplasma gondii DNA in Blood and Milk of Goats from Algeria

Toxoplasmosis is one of the most important foodborne diseases in humans, potentially acquired by ingesting unpasteurized goat milk. This study examined the role of goat milk as a source of infection of Toxoplasma gondii for humans in Algeria. Sera, blood, and milk samples collected from 106 female goats were tested for the presence of antibodies against T. gondii and its DNA, using indirect ELISA and PCR, respectively. Multiplex PCR was performed using 15 microsatellite markers to determine the clonal type of the T. gondii DNA detected. Seropositive results were found in 51 she-goats (48.11%). T. gondii DNA was detected in 16 (15.09%) and 15 (14.15%) blood and milk samples, respectively. In total, 15 (29.41%) out of 51-seropositive goats were PCR-positive for blood, while only 6 of them (6/15, 40%) showed the presence of T. gondii DNA in their milk. A fair correlation was found between indirect ELISA and PCR assays for T. gondii detection in milk (K = 0.2243) and blood (K = 0.28300), with a substantial difference in the screening ability of the tests (G2 = 38.96, p < 0.0001). The genotyping of samples could not be completed, but showed the absence of type I and type III lineages in goats from the Mila region, northeastern Algeria. The Algerian goat population is highly exposed to T. gondii, with a potentially increased risk of parasite transmission to humans via milk consumption.

Molecular evidence of Toxoplasma gondii from the tissue and blood of naturally infected sheep

Toxoplasmosis is a cosmopolitan zoonotic infection that has significant effects on public health and causes economic losses in the livestock industry. The current study was designed to detect the Toxoplasma parasite in sheep blood samples and tissue samples of slaughtered sheep at the Sulaimani abattoir using molecular technique. A total of 300 peripheral sheep blood samples were randomly collected from 20 small ruminant flocks at 4 locations in the Sulaymaniyah province, northern Iraq. Also, 150 meat samples from thigh muscle, heart, and diaphragm were collected from slaughtered sheep. All collected blood samples were subjected to polymerase chain reaction (PCR) amplification to confirm Toxoplasma infection; in addition, meat samples were also analyzed for Toxoplasma by PCR following the digestion process. Of the 300 amplified blood samples, 94 were considered positive for Toxoplasma gondii, with a prevalence rate of 31.3%. The overall prevalence of Toxoplasma among meat samples was 34%. The diaphragm reported a higher infection rate (46%) than the heart (32%), while the femoral muscle reported an infection rate of 24%. Aged animals (older than 24 months) presented a higher infection rate (32.8%) than younger animals (28.9%). Contact with or consumption of uncooked meat from infected sheep increases the chance of parasite transmission to humans.

Serosurvey of selected reproductive pathogens in domestic ruminants from Upper Egypt

Toxoplasmosis, neosporosis, and Q fever are among the most important abortifacient diseases in ruminants worldwide. These diseases result in huge economic losses in livestock besides the fact that some of are of public health concern. The present study aimed to update the data about the current seroepidemiological situation of these diseases in Upper Egypt. A total of 411 blood samples were collected from small and large ruminants and serologically tested against the presence of T. gondii, N. caninum, and C. burnetii. Generalized estimating equation (GEE) models were performed to assess the potential risk factors associated with the exposure to these pathogens. The overall seroprevalence of T. gondii was 47.9% (197/411) with an individual seropositivity of 59.4% (63/106), 58.6% (17/29), 38.8% (54/139) and 46% (63/137) in cattle, buffalo, sheep and goats, respectively. Meanwhile, 9.7% (38/411) of the examined animals were tested positive for anti-N. caninum antibodies, with an individual seropositivity of 13.2% (12/106), 34.5% (10/29), 8.6% (12/139) and 2.9% (4/137) in cattle, buffalo, sheep and goats, respectively. Furthermore, the overall prevalence of antibodies against C. burnetii was 17.3% (63/411), and exposure to this pathogen was detected in 4.7% (5/106) of cattle, 19.3% (20/129) of sheep, 29.2% (38/130) of goats but none of the examined buffalo were found to be seropositive. A total of 12.1% (50/411) of the examined animals showed co-exposure to at least two of the tested pathogens. Regarding the potential risk factors, there were statistically significant differences among species in the frequency of exposure to the three tested pathogens. Age (> 6 months) was also shown to be a significant risk factor associated with T. gondii exposure. The results obtained provided updated information about the occurrence of three of the main reproductive pathogens in Upper Egypt. The high seropositivity values found for the tested zoonotic pathogens in most of the analyzed ruminant species suggest the necessity of performing additional in-depth studies to evaluate the epidemiology of these pathogens in the study area.

Seroprevalence of Toxoplasma gondii infection in sheep and goats from different geographical regions of the world: Systematic review and meta-analysis

The Toxoplasma gondii is an obligate intracellular protozoan parasite which significantly impact small ruminant productivity, international animal trade and transboundary movement of animal across the globe. The seroprevalence of T. gondii infection (toxoplasmosis) in sheep and goats is widely studied in many parts of the world and there is a lack of comprehensive information on prevalence estimates considering the global and regional perspectives. The aim of the study was to use systematic review and meta-analysis methods to estimate the global and regional pooled seroprevalence of T. gondii infection in sheep and goats, as well as factors that influence prevalence estimations. Relevant articles reporting the seroprevalence of toxoplasmosis in sheep and/goats were searched in five electronic databases, including PubMed, Web of Science, Scopus, Embase and ProQuest. After the publications were checked to verify they fit the inclusion criteria, a total of 225 articles were included in the systematic review and meta-analysis, reflecting data from 70 countries/regions. The pooled prevalence was estimated using a random effect meta-analysis model. Overall, the seroprevalence of T. gondii infection was 33.86% (95% CI: 30.47-37.25%) in sheep and 31.78% (95% CI: 28.99-34.58%) in goats, with significant variation in prevalence estimates across geographical locations (p < .001). Substantial heterogeneity (I²  > 75%) was observed in most pooled seroprevalence estimates. The T. gondii infection in global sheep and goat population showed uptrend over the period. This information would be useful for epidemiologist, health authorities and farmers in order to plan future T. gondii survey and infection management strategies both locally and internationally.

Seroprevalence and risk assessment of Toxoplasma gondii infection in sheep and goats in North and Beqaa governorates of Lebanon

Background and Aim:

Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii that affects both humans and animals, leading to abortions and significant clinical manifestations in pregnant and immunocompromised hosts, in addition to massive economic losses in animal industries. Data from Lebanon are scarce regarding the seroprevalence of T. gondii infection in livestock. This study aimed to estimate the seroprevalence and assess the associated risk factors of T. gondii infection in sheep and goats in Lebanon.

Materials and Methods:

A cross-sectional study was carried out from May 2020 to April 2021. Blood samples from 150 sheep and 145 goats (total 295) destined for human consumption were obtained from 20 Lebanese farms located in the North and Beqaa governorates. The anti-T. gondii immunoglobulin G antibodies were assayed through means of a modified agglutination test with a cutoff titer of 20.

Results:

An overall seroprevalence of 48.5% (143/295) was reported: About 56.6% seroprevalence was found in sheep (85/150) and 40% (58/145) in goats. Adult age, female gender, and the wet season were significantly associated with an increased seropositivity rate of T. gondii infection (p < 0.001, p = 0.001, and p = 0.043, respectively).

Conclusion:

These results confirm the spread of T. gondii in sheep and goats destined for human consumption in various geographical regions in Lebanon. Therefore, continuous monitoring of T. gondii infection in livestock is warranted to control the spread of the infection and limit its potential transmission to humans through the consumption of raw or undercooked meat.

A survey on Apicomplexa protozoa in sheep slaughtered for human consumption

Infections with the Apicomplexa Toxoplasma gondii, Neospora caninum, and Sarcocystis spp. are common causes of reproductive disorders in sheep. However, few epidemiological studies regarding co-infections with these three protozoa are reported in sheep in Italy. For this reason, this study aims to evaluate possible co-infections with T. gondii, N. caninum, and Sarcocystis spp. in sheep slaughtered for human consumption. From April to July 2019, individual blood, brain, heart, and diaphragm samples were collected from 138 sheep after slaughtering. The presence of IgG anti-Toxoplasma in serum samples was evaluated through ELISA. DNA of the three protozoa was investigated using specific PCRs. Co-infection with T. gondii, N. caninum and Sarcocystis spp. was found in 66.7% of the examined sheep. Antibodies against T. gondii were found in the 36.2% of serum samples. The presence of T. gondii DNA was detected in the 67.4%, 77.5%, and 21.7% of the brain, heart, and diaphragm samples, respectively. Neospora caninum DNA was found in 72.5% of the examined brain samples. Sarcocystis spp. DNA was detected in 92% and 52.2% of the heart and diaphragm samples, respectively. Sequence analysis of the Sarcocystis spp. revealed the sole presence of Sarcocystis tenella. The present study demonstrates that sheep have a high risk of infection with the three Apicomplexa investigated, suggesting the need to adopt adequate measures to prevent the spread of these parasitic infections considering their clinical and economic impact on ovine production. Furthermore, the possible role sheep play in the zoonotic transmission of toxoplasmosis to humans was highlighted.

Immunological, Histopathological, Molecular Identification and Genotyping of Toxoplasma gondii in Small Ruminants in Egypt

&lt;b&gt;Background and Objective:&lt;/b&gt; Toxoplasmosis is an infective zoonotic disease caused by protozoan &lt;i&gt;Toxoplasma gondii &lt;/i&gt;(&lt;i&gt;T. gondii&lt;/i&gt;).&lt;i&gt; &lt;/i&gt;Molecular identification of &lt;i&gt;T. gondii&lt;/i&gt; followed by studying the hereditary variety range of &lt;i&gt;T. gondii &lt;/i&gt;isolates in Egypt was investigated. &lt;b&gt;Materials and Methods:&lt;/b&gt; Blood samples were acquired from 138 live ewes and 212 she-goats from 5 governorates of Egypt, also the blood and its related tissue samples (uterus, diaphragm, heart and thigh muscles from each animal) were collected from slaughtered 180 ewes and 206 she-goats from Cairo and Giza abattoirs. &lt;b&gt;Results:&lt;/b&gt; Using ELISA, the total seropositivity of live ewes and she-goats was 26.8 and 21.2%, respectively, while it was 16.6 and 33% in slaughtered ewes and she-goats, respectively. &lt;i&gt;T. gondii&lt;/i&gt; tissue cysts with the associated characteristic histopathological changes were detected in different organs. Twenty-eight &lt;i&gt;T. gondii&lt;/i&gt; isolates were confirmed using PCR, while among 24 milk samples from seropositive live ewes and she-goats, only 12.5 and 6.25%, were positive using PCR, respectively. Genotyping using multiple nested PCR (n-PCR) combined with restriction enzyme analysis (RFLP) of the surface antigen 2 (SAG2) gene confirmed 26 isolates (92.8%) as type II and 2 (7.1%) as type III. &lt;b&gt;Conclusion:&lt;/b&gt; Type II and III are the most common &lt;i&gt;T. gondii&lt;/i&gt; genotypes in Egyptian small ruminants with additional importance for public health in Egypt. Further studies are needed on the role of milk in the transmission of toxoplasmosis.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020

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, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Molecular Detection and Genetic Diversity of Toxoplasma gondii Oocysts in Cat Faeces from Klang Valley, Malaysia, Using B1 and REP Genes in 2018

The major route for Toxoplasma gondii (T. gondii) infection is through the ingestion of foods contaminated with oocyst from cat faeces. The microscopic detection of T. gondii oocysts in cat faeces is challenging, which contributes to the failure of detecting or differentiating it from other related coccidian parasites. This study aims to detect T. gondii oocysts in cat faeces using two multicopy-target PCR assays and to evaluate their genetic diversity. Cat faecal (200) samples were collected from pet cats (PCs; 100) and free-roaming cats (FRCs; 100) within Klang Valley, Malaysia, and screened for coccidian oocysts by microscopy using Sheather's sucrose floatation. PCR assays were performed on each faecal sample, targeting a B1 gene and a repetitive element (REP) gene to confirm T. gondii oocysts. Additionally, the PCR amplicons from the REP gene were sequenced to further confirm T. gondii-positive samples for phylogenetic analysis. Microscopy detected 7/200 (3.5%) T. gondii-like oocysts, while both the B1 gene and the REP gene detected 17/200 (8.5%) samples positive for T. gondii. All samples that were microscopically positive for T. gondii-like oocysts were also shown to be positive by both B1 and REP genes. The BLAST results sequenced for 16/200 (8.0%) PCR-positive T. gondii samples revealed homology and genetic heterogeneity with T. gondii strains in the GenBank, except for only one positive sample that did not show a result. There was almost perfect agreement (k = 0.145) between the two PCR assays targeting the B1 gene and the REP gene. This is the first report on microscopic, molecular detection and genetic diversity of T. gondii from cat faecal samples in Malaysia. In addition, the sensitivities of either the B1 gene or REP gene multicopy-target PCR assays are suitable for the accurate detection of T. gondii from cat faeces.

Majid R. A Review on the Prevalence of Toxoplasma gondii in Humans and Animals Reported in Malaysia from 2008-2018

Toxoplasmosis is a disease caused by the protozoan parasite Toxoplasma gondii (T. gondii). Human toxoplasmosis seroprevalence in Malaysia has increased since it was first reported in 1973 as shown in previous reviews of 1991 and 2007. However, over a decade since the last review, comprehensive data on toxoplasmosis in Malaysia is lacking. This work aimed at reviewing articles on toxoplasmosis research in Malaysia in order to identify the research gaps, create public awareness, and efforts made so far and proffer management options on the disease. The present review examines the available published research articles from 2008 to 2018 related to toxoplasmosis research conducted in Malaysia. The articles reviewed were retrieved from nine credible databases such as Web of Science, Google Scholar, ScienceDirect, PubMed, Scopus, Springer, Wiley online library, Ovid, and Cochrane using the keywords; Malaysia, toxoplasmosis, Toxoplasma gondii, toxoplasma encephalitis, seroprevalence, human immunodeficiency virus (HIV) patients, pregnant women, genotype strain, anti-toxoplasma antibodies, felines, and vaccine. The data highlighted seropositive cases from healthy community members in Pangkor Island (59.7%) and among migrant workers (57.4%) at alarming rates, as well as 42.5% in pregnant women. Data on animal seroprevalence were limited and there was no information on cats as the definitive host. Genetic characterization of Toxoplasma gondii from HIV patients; pregnant women, and domestic cats is lacking. This present review on toxoplasmosis is beneficial to researchers, health workers, animal health professionals, and policymakers. Therefore, attention is required to educate and enlighten health workers and the general public about the risk factors associated with T. gondii infection in Malaysia.

Public health and economic importance of Toxoplasma gondii infections in goats: The last decade

Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasmosis in goats continues to be of public health and economic concern. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, treatment, and genetic diversity of T. gondii in goats in the past decade. There is debate and uncertainty regarding excretion of T. gondii in milk and the ingestion of raw milk as sources of T. gondii infection for humans. Toxoplasmosis can cause abortion and deaths even in adult goats. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates has revealed genetic diversity in goats in North and South America. The significance of T. gondii isolates in domestic goats usually associated with wildlife in USA is discussed. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Characterization of Congenital Toxoplasmosis in Israel: A 17-year Nationwide Study Experience

BACKGROUND

Congenital toxoplasmosis (CT) can cause significant neurologic manifestations and other untoward sequelae. Neither the current epidemiology nor the disease severity of CT in Israel is known.

METHODS

Records of CT were collected from the National Toxoplasmosis Reference Laboratory and from 15 medical centers across Israel between 2001 and 2017. Eligible case-patients were fetuses or infants <12 months of age at the time of diagnosis.

RESULTS

Of the 43 CT cases identified, 24 (55%) were in Jews and the remaining 19 cases were in patients of Arab (non-Bedouin) origin. The overall annual estimated rate of symptomatic CT was calculated as 0.55 per 100,000 live births. One or more severe clinical manifestations were reported in 12 (46%) of the 28 live-born infants and included cerebral calcifications (7 cases), chorioretinitis (4 cases), hydrocephalus (2 cases) and 1 case of death. Sensitivities of blood polymerase chain reaction (PCR), cerebrospinal fluid PCR and IgM antibody tests were 50% each. However, analyzing PCR samples from both sites, together with IgM testing, increased the sensitivity to 93%.

CONCLUSIONS

The relative rate of severe manifestations was higher than in previous European reports. It is possible that the greater disease severity observed in Israel is in part due to the lack of systematic antenatal treatment and screening. Arab (non-Bedouin) infants are at higher risk for contracting CT. Performing serologic and PCR tests simultaneously is essential to improve CT diagnosis. This study demonstrates a need for an educational program to target high-risk populations.

Molecular Detection and Genotyping of Toxoplasma gondii and Neospora caninum in Slaughtered Goats in Central China

Toxoplasma gondii and Neospora caninum infections can cause reproductive failure in animals, including goats, and toxoplasmosis is one of the most important foodborne diseases. However, information on the molecular prevalence and genetic characterization of T. gondii and N. caninum in the tissues of goats in China is limited. In this study, brain samples of 422 slaughtered goats were collected from slaughterhouses in Henan and Anhui provinces, Central China, and examined for the presence of T. gondii and N. caninum by nested polymerase chain reaction (PCR) based on B1 and NC5 genes, respectively. The prevalence of T. gondii and N. caninum DNA was 5.2% and 2.8%, respectively. No significant differences were found between the prevalences of two parasite infections and animal age, sex, and region (p > 0.05). Two of 22 T. gondii-positive samples were completely genotyped at 11 genetic markers (SAG1, [3' + 5'] SAG2, alternative SAG2 [alt. SAG2], SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) using PCR-restriction fragment length polymorphism, and were identified as genotype ToxoDB no. 225, which has not been previously reported in goats in any country worldwide. For N. caninum, two different sequences at the ITS1 region, three genotypes at the MS5 microsatellite locus, and one genotype at the MS8 locus were identified. This study showed that T. gondii and N. caninum are moderately prevalent in goats in Central China; however, it should be emphasized that T. gondii prevalence in goats poses a potential health threat for consumers in the investigated areas. To the best of our knowledge, this is the first report on the genetic characterization of N. caninum isolates from goats in China. Our results have important implications for a better understanding of the genetic diversity of these parasites in China.

A review on toxoplasmosis in humans and animals from Egypt

The present paper summarizes prevalence, epidemiology and clinical disease of natural Toxoplasma gondii infections in humans and animals from Egypt. The current situation of toxoplasmosis in Egypt is confusing. There is no central laboratory or group of researchers actively investigating toxoplasmosis in humans or animals, and no reports on the national level are available. Based on various serological tests and convenience samples, T. gondii infections appear highly prevalent in humans and animals from Egypt. Living circumstances in Egypt favour the transmission of T. gondii. Up to 95% of domestic cats, the key host of T. gondii, are infected with T. gondii; they are abundant in rural and suburban areas, spreading T. gondii oocysts. Many women have been tested in maternity clinics, most with no definitive diagnosis. Toxoplasma gondii DNA and IgM antibodies have been found in blood samples of blood donors. Clinical toxoplasmosis in humans from Egypt needs further investigations using definitive procedures. Reports on congenital toxoplasmosis are conflicting and some reports are alarming. Although there are many serological surveys for T. gondii in animals, data on clinical infections are lacking. Here, we critically review the status of toxoplasmosis in Egypt, which should be useful to biologist, public health workers, veterinarians and physicians.