Gondii DNA Research Articles

Prevalence and genotyping of Toxoplasma gondii in questing Ixodes ricinus ticks from forest areas of Northern Poland.

Toxoplasma gondii occurs in a wide range of intermediate hosts, whose blood may be a meal for different tick species. A few studies have examined the role of ticks in the life cycle of T. gondii. This one includes the largest number and all stages of Ixodes ricinus collected from the widest area, covering seven recreational localities within a forest biotope in Northern Poland. This study aimed to determine the prevalence of T. gondii DNA in 2144 collected questing ticks to establish whether they may be involved in T. gondii life cycle. The additional goal was to genotype the detected T. gondii, as knowledge about its genotypes occurring in European ticks is insufficient. A further purpose was to detect coinfection with T. gondii and Borreliaceae in the collected ticks, as all of them have previously been tested for the presence of bacteria DNA. Nested PCR and sequencing of the obtained B1 gene fragment were conducted. T. gondii DNA was detected in 0.9% of all ticks (1.1% of nymphs and 0.7% of larvae). The presence of T. gondii in unfed larvae and nymphs may indicate the possibility of its vertical transmission. The prevalence of T. gondii DNA in ticks collected from individual sites was focal (0-4.3%) and seems to depend on local climatic conditions. Among all examined ticks, 0.3% were coinfected with T. gondii and Borreliella spp., vs. 0.6% of specimens with a single T. gondii infection. The obtained B1 sequences showed the greatest similarity (99.71-100%) to the sequence representing type III.

Metagenomic analysis of atheroma plaques for identification of microorganisms indicates presence of Toxoplasma gondii as a possible etiological agent

BackgroundCardiovascular diseases (CVDs) are the leading cause of death worldwide. Vital organs like the heart are affected by the occlusion of blood vessels due to atherosclerotic plaque formation. However, the role of infectious agents has always been an essential subject of investigation. This study investigated the presence of microorganisms, including nanobacteria, in atherosclerotic plaques removed from human carotid arteries by microbiological and metagenomic examination. MethodsAtheroma plaque samples were obtained from 20 patients with carotid artery stenosis who had atherectomy by surgery or percutaneous intervention. Nanobacteria were grown by culturing homogenates of the atheroma plaques. Whole genome sequencing was done for samples. Because of the high percentage of Toxoplasma gondii (T. gondii) DNA, PCR investigation was applied to detect T. gondii DNA in the samples. ResultsA molecular analysis of nanobacteria revealed them to be made of human proteins, supporting the theory that they are not living organisms. According to sequencing results, samples showed that more than 50 % of the metagenomic sequences belonged to Toxoplasma gondii. PCR investigation indicated that T. gondii DNA was positive in 8 (40 %) of 20 plaques. ConclusionsFurther evidence regarding the role of T. gondii in the etiology of plaque formation may help determine the strategy for prevention and treatment of infections in preventing atheroma plaque formation in the future.

Toxoplasma gondii in rodents and shrews in Armenia, Transcaucasia

Toxoplasma gondii infections in small mammals are important because they serve as source of infection for the felids who excrete environmentally resistant oocysts in their feces. Here, the authors sought evidence for T. gondii infection in shrews and rodents in Armenia for the first time. Toxoplasma gondii DNA was detected in tissues of trapped animals using a specific PCR targeting gene with a non-coding fragment length of 529 bp. Toxoplasma gondii DNA was detected in 15 out of 137 (10.9%) samples from small mammals from 6 different localities of Armenia for the first time.

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

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. 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). 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. 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.

Toxoplasma gondii genotypes and frequency in domestic cats from Romania

BackgroundToxoplasma gondii is a zoonotic protozoan parasite with a heteroxenus life cycle that involves felids as the definitive hosts and any warm-blooded animal, including humans, as intermediate hosts. Cats are key players in parasite transmission as they are capable of shedding high numbers of oocysts in their feces that contaminate the environment.MethodsThe study was performed on 31 domestic cats (31.23 ± 27.18 months old) originating from rural and urban areas (5.17:1) in the center and north-west Romania. Feces (n = 31), blood (n = 28), and heart samples (n = 27) were collected. Fecal samples were analyzed by flotation technique, and PCR (529 bp repetitive element). Fecal samples with T. gondii oocysts were bioassayed in mice. Serum samples were analyzed by modified agglutination test and ImmunoComb for the detection of specific anti-T. gondii IgG antibodies. Heart samples were bioassayed in mice, and analyzed by PCR. Toxoplasma gondii positive samples were genotyped by nPCR-RFLP targeting eleven genetic loci (SAG1, SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico).ResultsToxoplasma gondii oocysts were found in 2 out of 31 fecal samples collected from a 3-months old stray kitten, and a 4-years old female. In total, 17 out of 27 sera were positive for T. gondii IgG antibodies. The antibody titers in MAT ranged from 1:6 to 1:384. Toxoplasma gondii DNA was detected in 7 out of 27 heart samples, and four of them were positive also by bioassay. Six T. gondii DNA samples from bioassayed mice could be assigned to ToxoDB PCR-RFLP genotype #1 or #3 (Type II) and one T. gondii DNA from heart digest to genotype #2 (Type III). Both of these genotypes are common in Europe.ConclusionsOur results revealed that the infection with T. gondii is still high in cats from Romania. The oocysts shedded by these cats represent an important source of infection for intermediate hosts, including humans. Further studies on a wider range of cases are necessary for a more exhaustive definition of the T. gondii genotypes circulating in Romania.

Exposure of Urban European Hedgehogs (Erinaceus europaeus) to Toxoplasma gondii in Highly Populated Areas of Northeast Spain.

Toxoplasma gondii is a generalist zoonotic parasite that involves a wide range of warm-blooded animals as intermediate hosts and felines as definitive hosts. Recent studies have proved significant positive associations between human population density and T. gondii seroprevalence in wildlife. However, there is limited data regarding T. gondii wildlife in urban areas, where the highest human density occurs. The present study aimed to analyse the T. gondii exposure in urban hedgehogs from the Metropolitan Area of Barcelona, NE Spain. One hundred eighteen hedgehogs were analysed for the presence of antibodies (modified agglutination test; n = 55) and parasite DNA (qPCR; heart = 34; brain = 60). Antibodies were detected in 69.09% of hedgehogs. T. gondii DNA was not detected in any of the analysed samples. The present study reports a high T. gondii seroprevalence in urban hedgehogs in areas surrounding Barcelona, the most densely human-populated area of NE Spain, reinforcing the association between human population density and environmental T. gondii oocysts. The lack of detection by molecular techniques warrants more studies. In the last few decades, the distribution and abundance of European hedgehogs have declined, including their urban populations. Further research is needed to investigate the impact of T. gondii on hedgehog populations.

Molecular detection of Toxoplasma gondii in domestic and wild guinea pigs (Cavia spp.) from the Marangani district in Cuzco, Peru

Toxoplasmosis is a foodborne disease caused by the protozoan Toxoplasma gondii, and transmitted to humans by eating raw or undercooked meat, mainly. Poultry, beef, and pork are the main meats consumed in Peru; despite this, guinea pig meat is also widely consumed. For this reason, the objective of this study was to molecularly detect T. gondii in domestic and wild guinea pigs from the Marangani district in Cuzco, Peru, and identify some risk factors associated with this pathogen. DNA was extracted from the brain tissue samples of guinea pigs (30 domestic and 30 wild), and PCR protocols were used to amplify the internal transcribed spacer (ITS-1) region and a 529 bp fragment from the T. gondii genome. T. gondii DNA was detected in 14 (23.3%) guinea pigs. T. gondii frequency was 33.3% in domestic guinea pigs and 13.3% in wild guinea pigs. Our results demonstrated that guinea pigs represent an important source for T. gondii infection in human populations in this locality.

Comparison of Direct and Indirect Detection of Toxoplasma gondii in Ovine Using Real-Time PCR, Serological and Histological Techniques.

Toxoplasma gondii is a zoonotic pathogen and the ingestion of tissue cysts by consumption of lamb or mutton has been identified as a possible cause of infection in humans. Many serological surveys in sheep have been performed, showing relevant serological rates; however, while the detection of antibodies indicates an exposure to T. gondii, this does not necessarily imply the presence of tissue cysts in edible tissue. The current study aims to provide further understanding on the occurrence of T. gondii in sheep muscles and the strength of correlation between serological positivity and presence of the parasite in sheep. From 349 sheep, samples (i.e., blood, heart and diaphragm) were collected and subjected to ELISA tests, real-time PCR and histological tests. Despite the high seroprevalence, T. gondii DNA was detected in the heart and/or the diaphragm from 13 out of the 349 tested sheep (3.7%); all were adults (13/191). Furthermore, the histological tests did not reveal the presence of T. gondii tissue cysts in any of the examined portions of interventricular septum. It should be considered that the likelihood of detecting genetic material of the parasite is probably influenced by the uneven distribution of the tissue cysts in the carcass as well as the methodology applied. The findings of this study support the importance of describing the uncertainty associated with the data used for risk assessment to reduce inaccurate estimation or risk overestimation.

Systemic toxoplasmosis in 2 domestic rabbits in Georgia, United States.

Toxoplasma gondii infections are common in a range of mammalian and avian species, but clinical disease has been reported only rarely in domestic rabbits. Two cases of toxoplasmosis in domestic rabbits from the same premises were submitted to a diagnostic pathology facility in Athens, GA, USA. Both rabbits died after exhibiting clinical signs of gastrointestinal stasis. The gross findings observed in both rabbits comprised miliary, random, white-to-tan, necrotic foci throughout the spleen, liver, and lungs. Histologically, tachyzoites were observed within necrotizing inflammatory foci in the spleens of both rabbits, and in various other organs (tracheobronchial lymph node, lung, heart, and cecal appendix) of one rabbit. In both cases, the tachyzoites were immunoreactive with anti-Toxoplasma gondii antibodies. In addition, T. gondii DNA was detected via PCR and sequencing from a fresh lung sample from one rabbit and formalin-fixed, paraffin-embedded spleen, liver, femoral bone marrow, and haired skin from the second rabbit. Given that T. gondii can cause disease in domestic rabbits and is also a concern for other potential intermediate hosts (e.g., humans, other domestic animals), this parasite warrants consideration in the diagnostic evaluation of lagomorph tissues with compatible lesions.

Oral Sex as a Potential Route for Toxoplasma Gondii Transmission: Experiment with Human Semen and Laboratory Mice Model.

Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally. Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR. We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission. We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

In vitro assay to determine inactivation of Toxoplasma gondii in meat samples

Consumption of raw and undercooked meat is considered as an important source of Toxoplasma gondii infections. However, most non-heated meat products contain salt and additives, which affect T. gondii viability. It was our aim to develop an in vitro method to substitute the mouse bioassay for determining the effect of salting on T. gondii viability. Two sheep were experimentally infected by oral inoculation with 6.5 × 104 oocysts. Grinded meat samples of 50 g were prepared from heart, diaphragm, and four meat cuts. Also, pooled meat samples were either kept untreated (positive control), frozen (negative control) or supplemented with 0.6 %, 0.9 %, 1.2 % or 2.7 % NaCl. All samples were digested in pepsin-HCl solution, and digests were inoculated in duplicate onto monolayers of RK13 (a rabbit kidney cell line). Cells were maintained for up to four weeks and parasite growth was monitored by assessing Cq-values using the T. gondii qPCR on cell culture supernatant in intervals of one week and ΔCq-values determined. Additionally, 500 μL of each digest from the individual meat cuts, heart and diaphragm were inoculated in duplicate in IFNγ KO mice. Both sheep developed an antibody response and tissue samples contained similar concentrations of T. gondii DNA. From all untreated meat samples positive ΔCq-values were obtained in the in vitro assay, indicating presence and multiplication of viable parasites. This was in line with the mouse bioassay, with the exception of a negative mouse bioassay on one heart sample. Samples supplemented with 0.6 %–1.2 % NaCl showed positive ΔCq-values over time. The frozen sample and the sample supplemented with 2.7 % NaCl remained qPCR positive but with high Cq-values, which indicated no growth. In conclusion, the in vitro method has successfully been used to detect viable T. gondii in tissues of experimentally infected sheep, and a clear difference in T. gondii viability was observed between the samples supplemented with 2.7 % NaCl and those with 1.2 % NaCl or less.

Direct evidence of cheetah (Acinonyx jubatus) as intermediate host of Toxoplasma gondii through isolation of viable strains

Toxoplasma gondii causes lifelong infection in most definitive and intermediate hosts. Clinical cases of toxoplasmosis in captive cheetahs have been reported. However, there are few reports of viable T. gondii strains isolated from cheetahs. Here, T. gondii infection was investigated using molecular and serological assays in cheetahs from China. Modified agglutination test (MAT) (cut-off: 1:25) indicated that all six examined cheetahs (n = 6) showed T. gondii antibodies. Toxoplasma gondii DNA was detected in three out of five cheetahs. Two viable T. gondii strains were isolated from the striated muscles of two cheetahs using mice bioassay. They were designated as TgCheetahCHn1 and TgCheetahCHn2. Genetic characterization of DNA derived from tachyzoites was performed using RFLP-PCR of 10 markers. Toxoplasma gondii TgCheetahCHn1 is ToxoDB PCR-RFLP genotype #319, and the alleles of ROP18/ROP5 types were 3/7. TgCheetahCHn2 is ToxoDB genotype #9, and the alleles of ROP18/ROP5 were 3/6. The average survival time of TgCheetahCHn1-infected Swiss mice was 22 ± 1 days (n = 23), and the mice did not have detectable T. gondii-specific antibodies until 117 ± 30 days post-inoculation (n = 8), therefore, TgCheetahCHn1 had intermediate virulence. TgCheetahCHn2 was avirulent for Swiss mice. Few brain tissue cysts (0–50) were observed in the mice inoculated with TgCheetahCHn1 or TgCheetahCHn2. The results provide direct evidence of cheetah as intermediate host of T. gondii.

Toxoplasma gondii molecular detection and phylogenetic analysis in hemodialysis patients from Khuzestan, Southwest Iran

BackgroundThe diagnosis and genetic characterization of Toxoplasma gondii (T. gondii) infection can make a significant influence to the prevention of the dangerous consequences of toxoplasmosis, particularly in immunocompromised people.ObjectiveThe aim of this investigation was to assess the frequency and genotyping of T. gondii in blood samples of patients with hemodialysis.Materials and methodsIn the current investigation, a total of 379 blood samples were taken from subjects with hemodialysis who were referred to teaching hospital of Ahvaz in the southwest of Iran. The samples were evaluated using the Nested PCR by targeting the B1 gene, and then, sequencing and phylogenetic tree were constructed.ResultsT. gondii DNA was found in 112 (29.55%) of the blood samples by Nested PCR. Amplicons from T. gondii revealed high identity with GenBank sequences. The phylogenetic analysis revealed that all sequences were closely related to Type I of T. gondii.ConclusionBecause of the high incidence of toxoplasmosis with type I prevalent in hemodialysis patients, we recommend a systematic screening for toxoplasmosis to carry out for monitoring the possible dissemination of toxoplasmosis during hemodialysis.

Toxoplasma gondii Infection in the Eurasian Beaver (Castor fiber) in Switzerland: Seroprevalence, Genetic Characterization, and Clinicopathologic Relevance.

Toxoplasma gondii is a coccidian parasite able to infect all warm-blooded animals and humans. Rodents are one of the most important intermediate hosts for T. gondii, but little is known about infection in beavers and its clinical relevance. Toxoplasmosis was not considered an important waterborne disease until recently, but with increased outbreaks in humans and animals this perspective has changed. Serum samples from 247 Eurasian beavers (Castor fiber) collected from 2002 to 2022 were tested for antibodies to T. gondii by a commercial ELISA. Antibodies to T. gondii were found in 113 (45.8%) beavers. Higher weight and proximity to urban areas were found to be significant predictors for seropositivity. Additionally, T. gondii DNA was detected in 23/41 brain tissue samples by real-time PCR. Histopathologic examination of brain sections revealed inflammatory changes in 26/40 beavers, mainly characterized by encephalitis, meningitis, choroid plexitis, or a combination of them. In six of these cases the lesions were in direct association with parasitic stages. With an adapted nested PCR multilocus sequence typing and in silico restriction fragment length polymorphism analysis approach, three different T. gondii genotypes were detected in brain samples: the clonal Type II strain (ToxoDB 1), a Type II variant (ToxoDB 3), and a novel genotype exhibiting both Type II and I alleles in a further animal. Toxoplasma gondii infections in beavers have epidemiologic and clinical significance. The high seroprevalence indicates frequent contact with the parasite, and as competent intermediate hosts they may play an important role, contributing to maintaining the life cycle of T. gondii in semiaquatic habitats. In addition, although most beavers appear to develop subclinical to chronic disease courses, acute and fatal outcomes, mainly characterized by encephalitis and generalized infection, do also occur.

Toxoplasma gondii Does Not Inhibit the Assisted Colonization of Eastern Barred Bandicoots (Perameles gunnii) to Phillip Island, Victoria, Australia.

Eastern barred bandicoots (Perameles gunnii) are thought to be highly susceptible to disease caused by infection with the protozoan parasite Toxoplasma gondii. This study followed a population of 67 P. gunnii introduced onto the Summerland Peninsula, Phillip Island, Australia, where the prevalence of T. gondii infection in the feral cat population was known to be very high. Prior to release, bandicoots were tested for serologic exposure to T. gondii using the modified agglutination test. A subset of bandicoots was tested on four occasions after release onto the peninsula. No seroconversion was detected at any time point. A subset of bandicoots was radiotracked after release and at two additional trapping sessions to help monitor survival. Toxoplasma gondii DNA was not detected by PCR in eight carcasses recovered for necropsy. Fourteen founder bandicoots (21% of founders) were known to be alive at 500 d post-release. A total of 29 unmarked bandicoots were trapped over the study period, confirming that the bandicoots were successfully reproducing on the island. Body weight, packed cell volume, and total plasma protein were used as measures of individual animal health; population health was inferred from these data. Body weight was significantly associated with trip number, with a general trend of increasing weight after release onto the island. This study showed that eastern barred bandicoots were able to establish a new population despite a probably high environmental load of T. gondii.

Molecular Detection of Toxoplasma gondii in goats Placenta in Northeastern Algeria

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis of crucial medical and veterinary importance. It is diagnosed mainly by serological methods, which are insufficiently sensitive. It is therefore necessary to rely on the direct detection of the parasite. The present study aimed at the direct detection of T. gondii DNA in placenta fragments by PCR targeting the B1 gene of the parasite. In addition, we identified possible risk factors for infection. The study was carried out on 25 goat farms between 2019 and 2020 in four regions of the Tebessa province in northeastern Algeria and involved 503 goats that had aborted. T. gondii DNA was detected in 30.41% of goat placenta samples (CI: [27.12-41.53]). The on-farm molecular prevalence was 60% (CI: [53.32-72.53]). The molecular prevalence of toxoplasmosis was higher for primiparous females (53.2%) than it was for multiparous ones (15.2%) (p = 0.0001). Likewise, the level of contamination was high in farms with a sedentary management system (36.4%); this system tended to increase the prevalence of toxoplasmosis (P = 0.008). In addition, it appears that the stage of gestation, history of abortion, and season had a significant effect (p < 0.05) on the prevalence of the disease. To conclude, this study revealed that goats included in this experiment were heavily infected with T. gondii, which represents a major risk for consumers in the Tebessa region. Further research is needed to improve our knowledge of the different genotypes of T. gondii infecting populations of small ruminants.

Molecular detection of Toxoplasma gondii and Neospora caninum in seabirds collected along the coast of Santa Catarina, Brazil.

Toxoplasma gondii and Neospora caninum are two closely related protozoans that infect a wide range of animals, including birds. However, the occurrence of N. caninum and T. gondii in seabirds is unknown. Therefore, this study aimed to determine the presence of T. gondii and N. caninum DNA in tissue samples of seabirds. Tissue samples of the pectoral muscles, heart, and brain were collected from 47 birds along the coastline of Santa Catarina State, SC, Brazil. The DNA was extracted from the tissues and screened using nested-PCR (nPCR) targeting internal transcribed spacer 1 (ITS1). T. gondii DNA was detected in tissues from seven seabirds (7/47, 14.8%), kelp gull (Larus dominicanus) (5/21), and Manx shearwater (Puffinus puffinus) (2/8). N. caninum DNA was detected in tissues of nine seabirds (9/47, 19.1%), the kelp gull (L. dominicanus) (4/21), Manx shearwater (P. puffinus) (2/8), neotropic cormorant (Phalacrocorax brasilianus) (1/4), brown booby (Sula leucogaster) (1/5), and white-chinned petrel (Procellaria aequinoctialis) (1/1); however, no co-infection was observed. In conclusion, this study showed the circulation of N. caninum and T. gondii in seabirds along the coastline of Santa Catarina State. Further studies are required to clarify the role of these birds in the epidemiology of neosporosis and toxoplasmosis.

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.

Soil-Transmitted Parasites and Non-Pathogenic Nematodes in Different Regions of Porto Alegre City, Brazil: A Comparison between Winter and Summer

We assessed the prevalence of soil-associated parasites and non-pathogenic nematodes in eight public areas of Porto Alegre (Rio Grande do Sul state, southern Brazil), the most populous city in Rio Grande do Sul. Soil samplings were carried out during the winter of 2022 and summer of 2023: A total of 80 samples were collected in winter and 80 in summer (ten samples from each sampling site per season), totaling 160 soil samples. The frequency of microscopic non-pathogenic nematode larvae was significantly higher (p = 0.048) in winter (93.75%) than in summer (82.50%). Considering the pooled data from winter and summer (n = 160) for human pathogenic parasites, the following frequencies were observed (using microscopy analysis): hookworm (filariform) larvae (1.25%), hookworm (rhabditiform) larvae (11.25%), Strongyloides spp. (filariform) larvae (0.63%), Strongyloides spp. (rhabditiform) larvae (2.5%), hookworm eggs (10.63%), Ascaris spp. eggs (10.00%), and Trichuris spp. eggs (1.25%). Hookworm (rhabditiform) larvae were the most frequent parasitic structures (15.00%) in winter, and A. lumbricoides eggs were the most frequent parasitic structures (8.75%) in summer. No statistically significant difference was observed in the frequency of pathogenic parasites between the seasons (p > 0.05). Toxoplasma gondii DNA was assessed, but all soil samples tested negative in molecular analysis. Our results indicate that soil from many regions of Porto Alegre shows a high prevalence of soil-transmitted helminths, indicating the need for improvements in social conditions and environmental sanitation in the city. Our study also suggests that climate change may affect soil biodiversity, potentially harming non-pathogenic nematodes and favoring human pathogenic parasites.

High prevalence and diversity of Toxoplasma gondii DNA in feral cat feces from coastal California.

Toxoplasma gondii is a zoonotic parasite that can cause severe morbidity and mortality in warm-blooded animals, including marine mammals such as sea otters. Free-ranging cats can shed environmentally resistant T. gondii oocysts in their feces, which are transported through rain-driven runoff from land to sea. Despite their large population sizes and ability to contribute to environmental oocyst contamination, there are limited studies on T. gondii oocyst shedding by free-ranging cats. We aimed to determine the frequency and genotypes of T. gondii oocysts shed by free-ranging domestic cats in central coastal California and evaluate whether genotypes present in feces are similar to those identified in sea otters that died from fatal toxoplasmosis. We utilized a longitudinal field study of four free-ranging cat colonies to assess oocyst shedding prevalence using microscopy and molecular testing with polymerase chain reaction (PCR). T. gondii DNA was confirmed with primers targeting the ITS1 locus and positive samples were genotyped at the B1 locus. While oocysts were not visualized using microscopy (0/404), we detected T. gondii DNA in 25.9% (94/362) of fecal samples. We genotyped 27 samples at the B1 locus and characterized 13 of these samples at one to three additional loci using multi locus sequence typing (MLST). Parasite DNA detection was significantly higher during the wet season (16.3%, 59/362) compared to the dry season (9.7%; 35/362), suggesting seasonal variation in T. gondii DNA presence in feces. High diversity of T. gondii strains was characterized at the B1 locus, including non-archetypal strains previously associated with sea otter mortalities. Free-ranging cats may thus play an important role in the transmission of virulent T. gondii genotypes that cause morbidity and mortality in marine wildlife. Management of free-ranging cat colonies could reduce environmental contamination with oocysts and subsequent T. gondii infection in endangered marine mammals and people.