Molecular detection of toxoplasma gondii DNA in goats (Capra hircus), sheep (Ovis aries), and donkey (Equus asinus) milk using PCR in East Azerbaijan province, Iran

Molecular detection and genetic diversity of blood borne pathogens infecting domestic donkeys (Equus asinus)

Donkey population in Pakistan was estimated to be 5.9 million during 2023-24 and despite this huge population, donkeys remained unexplored for the presence of blood-borne parasites. This study aimed to report the molecular prevalence and phylogenetic evaluation of Toxoplasma gondii, Anaplasma marginale and Theileria annulata in the donkey blood samples (N = 272) that were collected during May till November 2024 from nine districts (Rajanpur, Khanewal, Dera Ghazi Khan, Lodhran, Bahawalnagar, Pakpattan, Faisalabad, Muzaffargarh and Kasur) in Pakistan. Molecular analyses revealed that the prevalence of T. gondii, A. marginale and T. annulata in screened donkey blood samples was 41%, 4% and 6% respectively. Co-infection with two parasites was also observed but none of the enrolled donkeys from any district were found infected with all three pathogens. DNA sequencing and BLAST analysis confirmed the presence of all three parasites. Phylogenetic analysis of these pathogens showed their genetic similarities with the sequences deposited from worldwide countries. Toxoplasma gondii (P < 0.001) and T. annulata (P = 0.004) prevalence varied between the sampling sites. While donkey breeds, age or sex was not associated with any of the parasitic infection (P > 0.05 for all). In conclusion, we are reporting the presence of T. gondii, A. marginale and T. annulata among Pakistani donkeys and we recommend similar large-scale studies in various geo-climatic regions of Pakistan to further explore the epidemiology, genetic diversity, host-parasite interactions, and effective control of these pathogens among the local donkey breeds.

Seroepidemiology, molecular detection, and isolation attempts of Toxoplasma gondii in dairy goats from Rio de Janeiro, Brazil

Goats are the one of the most susceptible domestic species to toxoplasmosis affecting animal health and production. The present study aimed to determine the seroprevalence of T. gondii infection in dairy goats from Rio de Janeiro, Brazil, as well as to evaluate associated risk factors, parasitic DNA detection in raw goat milk samples, and attempts to isolate the parasite from raw goat milk samples. Between October 2020 and December 2022, blood samples were collected from 460 goats, and 220 milk samples were taken from goats raised in the Rio de Janeiro state, Brazil. The serum samples were tested for anti-T. gondii IgG antibodies using IFAT. The milk samples were tested for parasitic DNA detection using nPCR, and attempts were made to isolate the protozoan in mice. For risk factor analysis, the farmers answered a semi-structured questionnaire covering various epidemiological variables. Overall, 24.1% tested positive for anti-T. gondii IgG in serum samples. Risk factors included farm location, age group, rearing system, presence of cats, grazing, and access of cats to water sources. In nPCR, 38.6% were positive, but none were positive in the bioassay. However, 3.2% of the mice inoculated with goat milk seroconverted. This study found that the exposure of dairy goats in Rio de Janeiro to T. gondii is driven by ineffective management practices in preventing and controlling the parasite in these animals. Moreover, despite the detection of parasitic DNA in raw goat milk, the shedding of viable parasites in milk from naturally exposed goats appears to be low.

Relationship between the serum level, polymorphism and gene expression of IL-33 in samples of recurrent miscarriage Iraqi women infected with toxoplasmosis

One of the many warm-blooded hosts that toxoplasmosis-causing intracellular protozoan parasite Toxoplasma gondii can infect is humans. Cytokines are crucial to stimulate an effective immune response against T. gondii. Interleukin-33 (IL-33) is a unique anti-inflammatory cytokine that suppresses the immune response. The levels of cytokine gene expression are regulated by genetics, and the genetic polymorphisms of these cytokines play a functional role in this process. Single nucleotide polymorphisms (SNPs) are prognostic indicators of illnesses. This study aimed to determine whether toxoplasmosis interacts with serum levels of IL-33 and its SNP in miscarriage women as well as whether serum levels and IL-33 gene expression are related in toxoplasmosis-positive miscarriage women. Two hundred blood samples from patients and controls were collected from AL-Alawiya Maternity Teaching Hospital and AL-Yarmouk Teaching Hospital in Baghdad, Iraq from 2021 to 2022 in order to evaluate the serum level of IL-33 using ELISA test. For the SNP of IL-33, the allelic high-resolution approach was utilized, and real time-PCR was performed to assess gene expression. The results showed that compared to healthy and pregnant women, recurrent miscarriage with toxoplasmosis and recurrent miscarriage women had lower IL-33 concentrations. Additionally, there were significant differences among healthy women, pregnant women, and women with repeated miscarriage who experienced toxoplasmosis. Furthermore, no differences between patients and controls were revealed by gene expression data. The results revealed that recurrent miscarriage, pregnancy, and healthy women all had a slightly higher amount of the IL-33 gene fold. Additionally, the SNP of IL-33 data demonstrated that there was no significant genetic relationship between patients and controls. Recurrent miscarriage women with toxoplasmosis have showed significant differences from pregnant women in the genotypes GG and AA as well as the alleles A and G. There were notable variations between recurrent miscarriage with and without toxoplasmosis in terms of the genotypes AA and AC. The genotypes GG, AA, and allele A in recurrent miscarriage women with toxoplasmosis and recurrent miscarriage women is a protective factor. Taking together, there was a statistically significant negative correlation between toxoplasmosis and IL-33 gene expression, which calls for more quantitative investigation in order to fully comprehend the interaction of mRNA and protein.

Experimental Protocol to Toxoplasma gondii Detection in Fresh Goat Milk

Toxoplasma gondii is a zoonotic parasite with global distribution capable of infecting homeothermic animals. Transmission of protozoan to humans includes ingestion of water and raw food contaminated with sporulated oocysts, ingestion of raw or undercooked meat with tissue cysts, and tachyzoites' transplacental transmission. Fresh goat milk intake has already been linked to human toxoplasmosis outbreaks, but little is known about the infectious potential of this biological sample. Accordingly, the aim of the present study is to assess the survival and infectivity of T. gondii tachyzoites in fresh goat milk samples through an experimental protocol to detect this parasite via bioassay carried out with a murine model, DNA amplification, and serology. Swiss Webster mice were inoculated with fresh goat milk samples contaminated with different T. gondii RH strain tachyzoite concentrations per milliliter and stored for different refrigeration times. Animals showing clinical signs compatible to toxoplasmosis were euthanized. Milk samples contaminated with high parasitic loads and kept for a shorter refrigeration time were the most lethal ones. No significant differences were observed between mean death rates recorded for different goat milk contamination concentrations (p = 0.1888), and for the refrigeration time, contaminated milk samples were kept under (p = 0.9440). T. gondii DNA was amplified in all contaminated milk samples, but only one of the surviving mice was serologically positive. Results of the present study have shown T. gondii survival and infectivity in fresh goat milk samples, and it highlights its significant risk for public health. Therefore, molecular methods must be the tests of choice when milk samples are used to assess infection caused by protozoan in goats' dairy products.

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

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

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.