Toxoplasma gondii in sympatric wild herbivores and carnivores: epidemiology of infection in the Western Alps

Toxoplasma gondii in Wild Boars (Sus scrofa) in Germany: Serological Screening from Thuringia

Game meat is an important source of meat borne parasitic infections. Due to its omnivorous diet, the wild boar is an important host of zoonotic parasites such as Toxoplasma gondii. T. gondii can cause severe to fatal disease in immunosuppressed patients, as well as congenital disorders in foetus and neonates. Consumption of undercooked infected meat is a main source of T. gondii infection. Information about the risk of toxoplasmosis through game meat is scarce. We collected serum samples from 42 wild boars from the federal state of Thuringia (Germany) between December 2017 and February 2018. Identification of anti-T. gondii IgG antibodies was conducted using a commercial indirect ELISA kit. Seropositivity was confirmed in 18 of the 42 samples (37.50%). From these, the highest seroprevalence was found in adult animals. This study joins another single database from wild boars in Brandenburg. The necessity of a country-wide database regarding T. gondii prevalence in wild boar and other game meat is pivotal for a profound risk analysis with its consequential impact in future mean hygiene policies.

An investigation into Toxoplasma gondii at the human-livestock-wildlife interface, South Africa

Interface areas shared by humans, domestic and wild animals may serve as high transmission contexts for Toxoplasma gondii. However, knowledge about the epidemiology of T. gondii in such areas is currently limited. The present study assessed the seroprevalence of T. gondii in different hosts from Mpumalanga, South Africa. Furthermore, we investigated the local knowledge and related practices about T. gondii by conducting a questionnaire study in the community. Blood samples were obtained and analysed for T. gondii antibodies using a commercial multispecies latex agglutination kit. The seroprevalence detected in humans (n = 160; patients showing signs of acute febrile illness), cats (n = 9), chickens (n = 336) and goats (n = 358) was 8.8%, 0.0%, 4.2% and 11.2%, respectively. Seroprevalence in impalas (n = 97), kudus (n = 55), wild dogs (n = 54), wildebeests (n = 43), warthogs (n = 97) and zebras (n = 68) was calculated at 5.2%, 7.3%, 100.0%, 20.9%, 13.4% and 9.1%, respectively. The questionnaire revealed that 63.0% of household owners were subsistence farmers, and 35.9% were pet owners. A high level of female participation was found (75.3%) when compared to male participation (24.7%). The results show a low circulation of T. gondii in the domestic cycle and suggest the presence of possible bridges between the wildlife cycle and the surrounding domestic cycle.Contribution: The study contributes to identifying transmission patterns and risk factors of T. gondii within human and animal populations. This topic fits within the scope of the journal presenting original research in veterinary science, with the focus on wild and domestic populations on the African continent on a topic of universal importance.

Revealing the Prevalence of Toxoplasma in Sierra Morena's Wild Boar: An ELISA-Based Study Using Meat Juice

This research work focused on the prevalence of Toxoplasma gondii in wild boar from the Sierra Morena region. We conducted an ELISA analysis using meat juice samples. A total of 892 samples from six hunting seasons (2013-2019) were collected from the provinces that constitute the Sierra Morena Mountain range. These samples were analyzed using the Pigtype® ELISA kit, specifically developed for detecting T. gondii in meat juice. The overall prevalence of T. gondii in Sierra Morena was 23.2%. The highest prevalences were observed in Córdoba (31.6%) and Jaén (25.9%). These provinces exhibit the highest density of wild boar as well as the greatest presence of the Iberian lynx (Lynx pardinus). Further in-depth studies are necessary, but it appears that the presence of wild felids and scavenger behavior may be associated with this observation.

Seroepidemiological and biomolecular survey on Toxoplasma gondii in Sardinian wild boar (Sus scrofa)

Toxoplasma gondii is a zoonotic parasite able of infecting all warm-blooded animals. Toxoplasmosis is one of the major foodborne diseases globally. The consumption of wild boar (Sus scrofa) meat from recreational hunting has been linked to outbreaks of human toxoplasmosis. The island of Sardinia (Italy) contains a large wild boar population, thus providing an opportunity to assess the distribution of Toxoplasma in this species and the associated risks of transmission to humans. A total of 562 wild boars were screened: heart and meat juice samples were tested for T. gondii DNA via nested-PCR and IgG anti-Toxoplasma by commercial ELISA. Anti-Toxoplasma IgG were detected in 24.6% (138/562) of animals, while 37.2% (209/562) of the heart samples were PCR positive. The prevalence of T. gondii antibodies and DNA highlights the potential role of wild boar as an important reservoir for this parasite. The study suggests that wild boar could play a significant role in spreading the parasite to humans. As wild boar numbers are increasing throughout their range, their potential role in transmitting toxoplasmosis should be communicated to stakeholders, and the impact of different population control methods on disease transmission should be thoroughly assessed to mitigate potential threats effectively.

Toxoplasma gondii infection in ticks infesting migratory birds: the blackbird (Turdus merula) and the song thrush (Turdus philomelos)

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is the zoonosis widespread all over the world. Birds constitute an important group of T. gondii intermediate hosts often attacked by definitive hosts, e.g. domestic cats. Due to confirmation of an additional way of T. gondii transmission via tick bite, the aim of our study was to state and evaluate the infection prevalence of ticks feeding on blackbirds (Turdus merula) and song thrushes (Turdus philomelos). The real-time PCR amplification of the B1 gene fragment was used for detection of T. gondii infection in 157 Ixodes ricinus ticks removed from captured birds. The results showed the thrushes as hosts intensively attacked by ticks (prevalence 88.5% and 70% for blackbirds and song thrushes, respectively), and T. gondii infected individuals were detected. Among all ticks infected, 7 (5.8%; n = 120) were collected from blackbirds, and 2 (5.4%; n = 37) from song thrushes. The thrushes small body sizes and their tendency to urban ecosystems colonization, suggest that they relatively often become a pray of domestic cats, and combined with our findings, are potentially involved in maintenance the T. gondii population, especially in anthropogenic habitats, where the presence of toxoplasmosis is likely to constitute a serious danger to public health.

A Health Status Update of Myocastor coypus in Northern Italy

Myocastor coypus is a pest animal present in Africa, Europe, North America and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. Forty-four coypus from the "Parco Naturale La Mandria" (Piedmont region, Northwest Italy) have been analysed. A complete necropsy and a whole histological evaluation of the liver, kidney and lung have been carried out on all the animals. Moreover, the positivity to Hepatitis E Virus (HEV), Encephalomyocarditis virus (EMCV), Francisella spp., Toxoplasma gondii and Neospora caninum have been investigated. None of the animal were positive for HEV, EMCV, Francisella spp. or Neospora caninum. Two animals tested positive for Toxoplasma gondii. A high presence of histological lesions has been identified in different organs, suggesting that lesions could be induced by different pathogens. As previously reported, coypu can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary to fully understand the biological role and the importance of coypu as a disease reservoir in our country.

The role of species ecology in predicting Toxoplasma gondii prevalence in wild and domesticated mammals globally

Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a protozoan that infects any warm-blooded animal, including humans, in almost every habitat worldwide. Toxoplasma gondii infects its hosts through oocysts in the environment, carnivory of tissue cysts within intermediate host prey and vertical transmission. These routes of infection enable specific predictions regarding the ecological and life history traits that should predispose specific taxa to higher exposure and, thus infection rates of T. gondii. Using T. gondii prevalence data compiled from 485 studies representing 533 free-ranging wild mammalian species, we examined how ecological (habitat type, trophic level) and life history (longevity, vagility, gestation duration and torpor) traits influence T. gondii infection globally. We also compared T. gondii prevalence between wild and domesticated species from the same taxonomic families using data compiled from 540 studies of domestic cattle, sheep, and pigs. Across free-ranging wildlife, we found the average T. gondii prevalence was 22%, which is comparable to the global human estimate. Among ecological guilds, terrestrial species had lower T. gondii prevalence than aquatic species, with freshwater aquatic taxa having an increased prevalence compared to marine aquatic species. Dietary niches were also influential, with carnivores having an increased risk compared to other trophic feeding groups that have reduced tissue cyst exposure in their diet. With respect to influential life history traits, we found that more vagile wildlife species had higher T. gondii infection rates, perhaps because of the higher cumulative risk of infection during movement through areas with varying T. gondii environmental loads. Domestic farmed species had a higher T. gondii prevalence compared to free-ranging confamilial wildlife species. Through a macroecological approach, we determined the relative significance of transmission routes of a generalist pathogen, demonstrating an increased infection risk for aquatic and carnivorous species and highlighting the importance of preventing pathogen pollution into aquatic environments. Toxoplasma gondii is increasingly understood to be primarily an anthropogenically-associated pathogen whose dissemination is enhanced by ecosystem degradation and human subsidisation of free-roaming domestic cats. Adopting an ecosystem restoration approach to reduce one of the world's most common parasites would synergistically contribute to other initiatives in conservation, feline and wildlife welfare, climate change, food security and public health.

Spread of Toxoplasma gondii among animals and humans in Northern Italy: A retrospective analysis in a One-Health framework

Toxoplasmosis occurs worldwide and is considered one of the most important food-borne parasitic zoonoses. The consumption of undercooked meat containing viable tissue cysts and ingestion of environmental oocyst are the most important sources of infection. The aim of this retrospective study was to evaluate the spread of Toxoplasma gondii in the province of Bologna (Emilia-Romagna region) in northern Italy, with a One Health approach, comparing seropositivity rates in different animal species and in humans over the last 19 and 4 years respectively. Analyses were performed on serological data collected over different periods at three separate locations: Istituto Zooprofilattico Sperimentale della Lombardia e della Emilia-Romagna (IZSLER); Veterinary University Hospital Clinical Pathology Service, Department of Veterinary Medical Sciences, University of Bologna; and Unit of Microbiology, St. Orsola Hospital, Bologna. Most relevant seropositivity rates observed in animals were 15.5% (wild boar), 25% (roe deer), 18.7% (goat), 29.9% (sheep), 9.7% (pigs), 42.9% and 21.8% in cat and dog, respectively. A comprehensive screening was conducted on a population of 36,814 individuals, revealing a prevalence of 20.4%. Among pregnant women, a frequence of 0.39% for active toxoplasmosis was observed. Despite certain limitations, this study provided valuable insights into the extensive distribution of this parasitic infection among diverse animal species and human populations in the province of Bologna. These findings underscore the importance of implementing consistent and proactive toxoplasmosis screening protocols during pregnancy, while emphasizing the critical need for adopting a One Health approach for effective control of this parasitic disease.

Prevalence of Toxoplasma gondii in Galapagos birds: Inference of risk factors associated with diet

Toxoplasma gondii is a zoonotic intracellular parasite of particular concern in the conservation of wildlife due to its ability to infect all homeotherms and potentially cause acute fatal disease in naive species. In the Galapagos (Ecuador), an archipelago composed of more than a hundred islets and islands, the presence of T. gondii can be attributed to human-introduced domestic cats, but little is known about its transmission in wildlife populations. We compared the prevalence of antibodies against T. gondii in sympatric Galapagos wild bird species that differ in diet and contact with oocyst-contaminated soil to determine the relative importance of trophic habits as an exposure factor. Plasma samples were obtained from 163 land birds inhabiting Santa Cruz, one of the cat-inhabited islands, and from 187 seabirds breeding in cat-free surrounding islands (Daphne Major, North Seymour, and South Plaza). These samples were tested for the presence of T. gondii antibodies using the modified agglutination test (MAT ≥ 1:10). All seven species of land birds and 4/6 species of seabirds presented seropositive results. All great frigatebirds (Fregata minor) (N = 25) and swallow-tailed gulls (Creagrus furcatus) (N = 23) were seronegative. Prevalence ranged from 13% in Nazca boobies (Sula granti) to 100% in Galapagos mockingbirds (Mimus parvulus). It decreased from occasional carnivores (63.43%) to granivores-insectivores (26.22%), and strict piscivores (14.62%). These results indicate that the consumption of tissue cysts poses the highest risk of exposure to T. gondii for Galapagos birds, followed by the ingestion of plants and insects contaminated by oocysts as important transmission pathways.

Serological Prevalence of Toxoplasma gondii, Neospora caninum, and Sarcoptes scabiei var. suis in Wild Boars (Sus scrofa) Hunted in a Highly Anthropized Area in Italy

Due to the increasing expansion into urban and rural areas, wild boars represent a potential source of infection with zoonotic and animal-specific parasites for both humans and animals. Therefore, the aim of this study was to investigate the serological prevalence to Toxoplasma gondii, Neospora caninum, and Sarcoptes scabiei var. suis in blood samples from wild boars (Sus scrofa) hunted in an anthropized area in Italy. Enzyme-linked immunosorbent assay (ELISA) tests were used to detect antibodies anti-T. gondii and anti-S. scabiei and an immunofluorescence antibody test (IFAT) for antibodies anti-N. caninum. 81 out of 128 wild boars (P = 63.3%) resulted positive for at least one of the three parasites. 68 of them were seropositive to T. gondii (P = 53.1%) and 14 to N. caninum (P = 10.9%). 9 wild boars resulted seropositive to S. scabiei var. suis (P = 7.0%). Sampling season was the only significant risk factor related to S. scabiei var. suis seroprevalence (OR = 7.8). The high occurrence of T. gondii supports the role of this species as a source of infection for other animals and humans. Furthermore, the serological prevalence of N. caninum and S. scabiei var. suis in wild boars from the study area characterized by the presence of numerous dairy cattle and pig farms is relevant to demonstrate its suitability for the circulation of these parasites both in domestic and wild species.

Molecular Survey of Toxoplasma gondii in Wild Mammals of Southern Italy

Systematic wildlife surveillance is important to aid the prevention of zoonotic infections that jeopardize human health and undermine biodiversity. Toxoplasma gondii is an opportunistic zoonotic protozoan that can infect all endothermic vertebrates, causing severe disease in immunocompromised humans and cases of congenital transmission. Humans can be infected by ingestion of raw meat containing bradyzoites or water contaminated by oocysts. In our study, we assessed the potential circulation of Toxoplasma gondii in wild mammals by performing surveillance in the Campania region (southern Italy) and surveyed its presence from 2020 to 2022 within the framework of the Regional Plans for Wildlife Surveillance. In detail, 211 individuals belonging to five wild mammals (wolf, fox, wild boar, badger, and roe deer) underwent necropsy and the organs were analyzed by real-time PCR for the detection of the parasite. Toxoplasma gondii was found in 21.8% (46/211) of the subjects examined. No statistically significant differences were noticed between the prevalence and the host’s trophic level or age, rejecting the hypotheses that Toxoplasma gondii will have a higher prevalence in top predators and adult individuals, respectively. Our work emphasized the high circulation of Toxoplasma gondii in wildlife and remarked on the critical role of anthropized areas where domestic cats and wildlife may come into contact, urging a systematic surveillance.

Toxoplasma gondii Serotypes in Italian and Foreign Populations: A Cross-Sectional Study Using a Homemade ELISA Test

Toxoplasma gondii is a protozoan parasite responsible for human toxoplasmosis. The three major clonal lineages and different recombinant strains of T. gondii have a varied global distribution. This study aimed at evaluating the epidemiological distribution of types II and I–III and recombinant or mixed T. gondii in Italians and foreigners residing in Italy, establishing an association between serotypes and demographic characteristics. We collected the sera of 188 subjects who had tested positive for specific T. gondii antibodies. The population was differentiated into groups based on sex, nationality, and place of birth (Italy, Africa, South America, Asia, or Europe (except Italy)). We then performed a homemade ELISA test that detected both the antibodies against the amino acid sequences of the three main genotype antigens (I–III) in human sera and discerned the T. gondii strains. Serotype II of T. gondii was the most prevalent in the Italian population, whereas type I–III was the most prevalent in the foreign group. Surprisingly, we observed a notable amount of recombinant or mixed serotypes in European and Italian subjects. Moreover, we showed a significant difference in the prevalence of T. gondii serotypes between men and women, Italians, and foreigners. This descriptive study is the first to investigate the epidemiological distribution of T. gondii serotypes in humans in Italy using a homemade ELISA. We considered this technique suitable for discriminating between serotypes II and I–III and, consequently, for an epidemiological study focusing on the observation of circulating T. gondii strains and clinical correlations.

Toxoplasma gondii in African Wildlife: A Systematic Review

Toxoplasma gondii (T. gondii) is a protozoan parasite, which infects a wide variety of mammals and bird species globally. In large parts of the world, this parasite is relatively well documented in wildlife species, however, this topic is poorly documented in Africa. The current review systematically explores the presence and distribution of T. gondii in African wildlife species through a key word search in PubMed, Web of Science and CAB Direct. A total of 66 records were identified and included in the qualitative analysis, of which 19 records were retained for the quantitative synthesis. The presence of T. gondii was reported in a wide range of wildlife species, found in twelve countries, spread over the African continent. The retained records report a prevalence range of 6-100% in herbivores, 8-100% in omnivores and 14-100% in carnivores. In wild felines (cheetahs, leopards, and lions) a prevalence range of 33-100% was found. Reports from South Africa, and on the presence of T. gondii in lion were most common. Overall, the results indicate the scarcity of information on T. gondii in Africa and its circulation in wildlife. The lack of knowledge on the parasite in Africa, especially in areas at the human-livestock-wildlife interface, prevents us from understanding how prevalent it is on the continent, what strains are circulating in wildlife and what the most common routes of transmission are in the different habitats in Africa.

Sero-prevalence and risk factors of Toxoplasma gondii infection in wild cervids in Denmark

Toxoplasma gondii is a zoonotic protozoan parasite capable of infecting possibly all warm-blooded animals including humans, and is one of the most widespread zoonotic pathogens known. Free-ranging wildlife can be valuable sentinels for oocyst contaminated environments, as well as a potential source for human foodborne infection with T. gondii. Here we aimed to determine the sero-prevalence of T. gondii in Danish wild deer populations and examine risk factors associated with increased exposure to the parasite. Blood samples were collected from 428 cervids (87 fallow deer (Dama dama), 272 red deer (Cervus elaphus), 55 roe deer (Capreolus capreolus) and 14 sika deer (Cervus Nippon) from 23 hunting sites in Denmark. The animals were shot during the hunting season 2017/2018, and screened for antibodies against T. gondii using a commercial ELISA kit. One hundred and five (24.5%) cervids were sero-positive. Sero-prevalence was significantly different between species (p < 0.05), with odds of sero-positivity being 4.5 times higher in roe deer than fallow deer, and 3.0 times higher in red deer than in fallow deer. A significant increase in sero-prevalence with age was observed, driven by a significant increase in risk in adult red deer compared to calves (OR: 13.22; 95% CI: 5.96-33.7). The only other significant risk factor associated with wild cervid T. gondii sero-positivity was fencing, with the highest exposure associated with deer from non-fenced hunting areas (OR: 2.21; 95% CI: 1.05-4.99). This study documented a widespread exposure to T. gondii in Danish cervids. Therefore the meat of the wild deer, in particular from roe deer and red deer, should be considered a significant risk of T. gondii infections to humans, if not properly cooked. Further, molecular studies to confirm the presence of infective parasitic stages in the muscles of deer used for consumption is recommended.

A Review on Alaria alata, Toxoplasma gondii and Sarcocystis spp. in Mammalian Game Meat Consumed in Europe: Epidemiology, Risk Management and Future Directions

Simple Summary

In many European countries, game meat consumption is related to the traditional hunting culture. Its demand and consumption are increasing, also due to the growing populations of wild ungulates. However, specific public health issues exist and should be taken into account. This review focuses on the causal agents, epidemiology, potential risk for human health and its management along the supply chain, including parasite detection at slaughtering and inactivation in meat, of three parasites (Alaria alata, Toxoplasma gondii and Sarcocystis spp.), which can be transmitted by the main mammalian game meat species in the EU: wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama), Alpine chamois (Rupicapra rupicapra), moose (Alces alces), hare (Lepus europaeus) and wild rabbit (Oryctolagus cuniculus). By presenting the main issues and knowledge gaps, this study aims to contribute to an improved control supporting the risk analysis process.

Abstract

Game meat is increasingly appreciated and consumed in Europe, also due to the growing population of wild ungulates. In addition to interesting nutritional properties and market opportunities, game meat is characterized by some specific public health issues. This review focuses on the etiology, epidemiology, public health aspects and risk management along the supply chain, including parasite detection at slaughtering and inactivation in meat, of three selected foodborne parasitic hazards (Alaria alata, Toxoplasma gondii and Sarcocystis spp.) in the main mammalian game meat species in the EU: wild boar (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), fallow deer (Dama dama), Alpine chamois (Rupicapra rupicapra), moose (Alces alces), hare (Lepus europaeus) and wild rabbit (Oryctolagus cuniculus). The presented data point out the main issues, and knowledge gaps as well as the potential for improved control in order to contribute to the risk analysis process. To pursue an effective management of these parasitic zoonoses, awareness raising should involve all figures in the supply chain, including hunters, restaurateurs and consumers. Human behaviour and the lack of knowledge regarding meat borne parasitic zoonoses and the health risks they pose seem to be the most important factors responsible for human infections. However, detection methods, starting from the sampling procedure, should be further developed and standardized in order to improve the collection of accurate and up-to-date epidemiological data.

Human density is associated with the increased prevalence of a generalist zoonotic parasite in mammalian wildlife

Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a zoonotic protozoan that infects any warm-blooded animal, including humans, in almost every ecosystem worldwide. There is substantial geographical variation in T. gondii prevalence in wildlife populations and the mechanisms driving this variation are poorly understood. We implemented Bayesian phylogenetic mixed models to determine the association between species' ecology, phylogeny and climatic and anthropogenic factors on T. gondii prevalence. Toxoplasma gondii prevalence data were compiled for free-ranging wild mammal species from 202 published studies, encompassing 45 079 individuals from 54 taxonomic families and 238 species. We found that T. gondii prevalence was positively associated with human population density and warmer temperatures at the sampling location. Terrestrial species had a lower overall prevalence, but there were no consistent patterns between trophic level and prevalence. The relationship between human density and T. gondii prevalence is probably mediated by higher domestic cat abundance and landscape degradation leading to increased environmental oocyst contamination. Landscape restoration and limiting free-roaming in domestic cats could synergistically increase the resiliency of wildlife populations and reduce wildlife and human infection risks from one of the world's most common parasitic infections.

Analysis of seroprevalence data on Hepatitis E virus and Toxoplasma gondii in wild ungulates for the assessment of human exposure to zoonotic meat-borne pathogens

Seroprevalence data for Toxoplasma gondii and Hepatitis E virus (HEV) in wild boar (Sus scrofa), roe deer (Capreolus capreolus), red deer (Cervus elaphus), mouflon (Ovis aries/musimon) and chamois (Rupicapra rupicapra) hunted/culled in northern Italy were used to fit seroprevalence distributions describing the exposure and co-exposure of the species to the two pathogens. The higher proportion of T. gondii and HEV seropositive animals was observed in wild boars with point estimate seroprevalence of 49% (N = 331) and 15% (N = 326) respectively. Data allowed comparisons by area (pre-Alpine Vs Alpine environment) for roe deer, red deer and mouflons. Contrasts between the distributions describing the uncertainty in seroprevalence suggest roe deer, red deer and mouflons have higher probability of being seropositive to T. gondii in pre-Alps. When considering HEV, few seropositive animals were detected and contrasts were symmetrically centred to zero for roe deer and red deer; mouflons shown higher probability of being seropositive in Alpine environment. HEV seropositive animals also included chamois (P = 5.1%, N = 97) in the Alpine districts, confirming circulation of HEV in remote areas. Evidence of HEV and T. gondii co-exposure was limited except for wild boars where it was observed in 30 samples representing 60% of the overall HEV-positive samples. Seroprevalence data of single infection and co-infection are extremely useful to investigate circulation of zoonotic pathogens in wild animals and estimate the foodborne risk of human exposure, however, these type of data do not directly translate into the presence/absence of the pathogen in seropositive and seronegative animals. At benefit of future development of quantitative risk assessments aiming at estimating the risk of human infection/co-infection via consumption of game meat, we developed and made available an online application that allows estimating the probability of the pathogen(s) being present as a function of seroprevalence data.

Comparison of Direct and Indirect Toxoplasma gondii Detection and Genotyping in Game: Relationship and Challenges

The importance of game as a source of Toxoplasma gondii (T. gondii) infection in humans is largely unknown. New data on the presence of T. gondii in game hunted in the Federal State of Brandenburg, Germany, were obtained by direct and indirect detection (ELISA). DNA extracted either directly (5 g heart or foreleg muscle, DE) or after acid pepsin digestion (50 g heart, PD) or enriched by magnetic capture (50 g heart, MC) was examined by real-time PCR (qPCR). ELISA revealed seroprevalences of 20% in wild boar (Sus scrofa), 11% in roe deer (Capreolus capreolus) and 6% in red deer (Cervus elaphus). T. gondii DNA was detected by at least one direct detection method in 12% of wild boar, 6% of roe deer, 2% of fallow deer (Dama dama) and 2% of red deer. In both, positive wild boar and roe deer, T. gondii type II specific alleles were the most prevalent, as assessed by PCR-restriction fragment length polymorphism. The highest proportion of positive animals was detected by MC qPCR, followed by PD qPCR with a similar proportion of positive findings. Investigation of 50 g of heart muscle revealed a significantly higher proportion of positive qPCR results than analysis of 5 g (p = 0.048). An association between seropositivity and direct detection was evident in wild boar and roe deer (p < 0.001). Infectivity of T. gondii DNA–positive samples was confirmed by bioassay (4/4), providing evidence that game could represent a relevant source of viable T. gondii posing a risk for human infection.

Beware of dogs! Domestic animals as a threat for wildlife conservation in Alpine protected areas

Diseases are natural regulating factors of wildlife populations, but some pathogens may become an important threat in wildlife conservation, especially for endangered species. The presence of domestic animals may foster the spread of diseases in natural population, although their role in the dynamic of infections in wildlife is not clear. In this study, we investigated the presence and prevalence of a range of multi-host pathogens in wild species (red fox, Eurasian badger, beech marten, pine marten, stoat for a total of 89 carcasses analysed) and domestic animals (n = 52 shepherd and n = 25 companion dogs) living in a protected area of the Alps (the Gran Paradiso National Park) and discussed the role of domestic dogs as possible source of infection for wild species. Our results showed that domestic dogs are potential shedder of three important pathogens: Canine distemper virus, Toxoplasma sp. and Neospora caninum. In particular, shepherd dogs seem to represent a threat for wildlife as they are exposed to multiple pathogens because of free-roaming, scavenging lifestyles and close proximity to livestock. However, also companion dogs more subject to veterinary care may foster the spread of pathogens. Our results highlight the importance of regulating the access of domestic dogs to protected areas that aim at preserving biodiversity and enhancing the conservation of endangered species.

Epidemiologic and Public Health Significance of Toxoplasma gondii Infections in Venison: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. The ingestion of food or water contaminated with oocysts excreted by infected cats or ingestion of uncooked or undercooked meat containing tissue cysts of T. gondii are the 2 major modes of transmission of T. gondii. Deer are a popular game. Recently, outbreaks of clinical toxoplasmosis were reported in humans in North America linked to ingestion of undercooked venison. Here, we review prevalence, persistence of infection, clinical disease, epidemiology, and public health risks of T. gondii infections in deer and other cervids for the past decade. Estimates of worldwide serological prevalence are summarized individually for each species of deer, elk, moose, and caribou. Genetic diversity of 112 viable isolates of T. gondii from cervids is discussed, including its public health significance. Prevalence of T. gondii in deer is very high. Any part of a deer, including liver, spleen, and muscles, should be cooked thoroughly before human consumption.

Recent epidemiologic and clinical Toxoplasma gondii infections in wild canids and other carnivores: 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, and genetic diversity of T. gondii in wild canids and other carnivores for the past decade. Seroprevalence estimates of T. gondii worldwide were tabulated for each host. Seroprevalence in wild foxes was very high compared with farmed Arctic foxes. Economic and public health aspects of some of the carnivore species raised for fur and meat (raccoon dogs, mink) are discussed. Diagnostic efficacies of different serological methods and PCR methods are discussed. Clinical toxoplasmosis was observed mainly in carnivores concurrently infected with immunosuppressive Canine Distemper Virus infection. Abortion and blindness were noted in mink. Genetic diversity of isolates using DNA derived from 162 (89 viable T. gondii isolates and 73 DNA extracted from tissues) of wild carnivores from several countries is discussed. However, 69 of the 162 T. gondii isolates were strains from USA and these were genetically diverse with predominance of ToxoDB genotypes #4 and #5 (haplogroup 12). Only limited information is available concerning genotyping of T. gondii isolates from other countries; none of the 93 T. gondii isolates from other countries (Brazil, China, France, Grenada) were haplogroup 12.

A systematic review and meta-analysis of Toxoplasma gondii in roe deer (Capreolus capreolus) and red deer (Cervus elaphus) in Europe

The objective of this systematic review and meta-analysis was to summarize the available knowledge on the seroprevalence of T. gondii in roe deer (Capreolus capreolus) and red deer (Cervus elaphus) in Europe. A computerized literature search of electronic databases (PubMed and CAB abstracts) was performed along with hand searches of library resources for relevant papers, books, abstracts and conference proceedings. A random-effect model was employed to calculate pooled seroprevalence estimates with 95% confidence intervals, and I² statistic was used to assess heterogeneity. Further, moderator analysis was performed to evaluate the effect of geographical area on the seroprevalence in roe deer. From a total of 190 studies initially identified, 16 and 8 articles were included for roe deer and red deer, respectively. These comprise 3,913 roe deer and 2,913 red deer from different European countries. The pooled seroprevalence was estimated to be 29% (95% CI: 23%-35%) in roe deer and 15% (95% CI: 10%-20%) in red deer. High heterogeneity was detected in the seroprevalence data within each species. In roe deer, the pooled seroprevalence estimate was significantly different according to geographical area with 40% (95% CI: 31%-49%) in Western Europe, 31% (95% CI: 21%-43%) in Northern Europe, 27% (95% CI: 15%-41%) in Eastern Europe and 21% (95% CI: 14%-28%) in Southern Europe. The present study indicates a moderate exposure to T. gondii in roe deer and red deer in Europe, with very high prevalence in Western Europe. Our results highlight the significant risk associated to the consumption of venison, encouraging proper handling and cooking of game meat to prevent toxoplasmosis in humans.

Fractional seroprevalence rates in common prey species can cause more than half of feral cats to be exposed to Toxoplasma gondii annually

Rodents comprise a major component of cat (Felis catus) diets in many ecosystems, and life cycle diagrams of Toxoplasma gondii typically depict small rodents as quintessential intermediate hosts. Counter-intuitively, small rodents often experience a lower T. gondii seroprevalence than do larger sympatric mammals. This observation has repeatedly caused confusion about the relative importance of small rodents to the ecology of T. gondii. To address this confusion, we modified the Reed-Frost epidemic model to develop a simple binomial equation to model T. gondii transmission from prey to feline predators. This equation takes into account variations in prey seroprevalence and the frequency with which they are consumed by felids. Even when T. gondii seroprevalence in prey is < 1%, computation reveals that the risk of feline exposure to T. gondii can easily exceed 50 % annually. For example, if cats eat an average of 1 mouse per day, a seroprevalence of 0.2 % (1/500) in mice will cause 51.9 % of cats to be exposed to T. gondii annually. Our simple equation demonstrates that both prey seroprevalence and the rate at which prey are consumed are of approximately equal importance to the ecology of T. gondii. When inferring the importance of various prey species to the ecology of T. gondii, researchers must consider the predation and dietary habits of felids from within their study system. Our simple binomial equation could also be used to predict T. gondii exposure rates of humans or other carnivorous animals from various dietary sources or be applied to other predator-prey parasite life cycles.

Genotyping of Toxoplasma gondii in wild boar (Sus scrofa) in southern Italy: Epidemiological survey and associated risk for consumers

Toxoplasma gondii is a widespread protozoan parasite (phylum Apicomplexa), which causes a zoonotic parasitic disease, known as toxoplasmosis. The aim of this study was to evaluate the occurrence and genotypes of T. gondii in wild boars of southern Italy and thus to assess the risk of infection for consumers. The boars were inspected during the hunting season within the regional project 'Wild Boar Emergency Plan in Campania', and molecular analyses were performed on 338 boars analysing a total number of 884 matrices (263 brains, 310 hearts and 311 masseter muscles). Toxoplasma gondii was detected in 134 out of 338 boars (39.6%). No significant statistical difference between genders was found (χ²  = 0.15 p = .70). The prevalence was 47.1%, 39.3% and 39.2% in piglets, yearlings and adults, respectively (χ²  = 0.41; p = .81). The highest prevalence of T. gondii was found in masseter muscles (74/311, 23.8%), followed by the heart (70/310, 22.6%) and brain (58/263, 22.0%), respectively. Microsatellite (MS) analysis of 11 samples revealed eleven T. gondii genotypes (nine atypical, one belonging to type II one to type III). Most of the genotypes found were thus atypical and may be virulent in humans. Hierarchical clustering analysis showed the presence of three distinct clusters, with the majority of atypical genotypes in the GII-GIII cluster. The high prevalence of infection in masseters highlights the potential risk for public health, considering that this muscle is commonly used to prepare raw meat products ('guanciale' and sausages), which may be a source of T. gondii infection in humans. Wild boars may act as an interface role between wildlife, livestock and humans. Our data highlight the urgent need to minimize the risk of infection for animals and humans by setting up a surveillance programme and preventive strategies in a One Health approach to wildlife species.

All about Toxoplasma gondii infections in pigs: 2009-2020

Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasma gondii infection in pigs continues to be of public health concern. Pigs are important for the economy of many countries, particularly, USA, China, and European countries. Among the many food animals, pigs are considered the most important for T. gondii transmission in USA and China because viable parasites have rarely been isolated from beef or indoor raised chickens. Besides public health issues, T. gondii causes outbreaks of clinical toxoplasmosis in pigs in China, associated with a unique genotype of T. gondii (ToxoDB genotype #9 or Chinese 1), rarely found in other countries. The safety of ready to eat pork products with respect to T. gondii infection is a matter of recent debate. Here, we review in detail seroprevalence, prevalence of viable and nonviable T. gondii, epidemiology, risk assessment, diagnosis, and curing of pork products containing T. gondii for the past decade. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Seroprevalence of anti-Toxoplasma gondii antibodies in wild boars (Sus scrofa), hunting dogs, and hunters of Brazil

Seroprevalence of Toxoplasma gondii has been extensively studied in wild boars worldwide due to the emerging risk for human infection through meat consumption. However, this is the first study that reports toxoplasmosis seroprevalence in wild boars, wild boar hunters and their hunting dogs. The aim of the present study was to evaluate the seroprevalence of anti-T. gondii antibodies in the complex wild boars, hunting dogs and hunters, and to determine the risk factors associated with seropositivity in southern and central-western Brazil. Overall, anti-T. gondii seropositivity was observed in 15/71 (21.1%) wild boars by modified agglutination test (MAT); and 49/157 (31.2%) hunting dogs and 15/49 (32.7%) hunters by indirect immunofluorescent antibody test (IFAT). Seroprevalence of toxoplasmosis in Brazilian wild boars was within the national and international range, posting wild boars as potential environmental sentinels for T. gondii presence. In addition, the findings have comparatively shown that wild boars have been less exposed to infection than hunting dogs or hunters in both Brazilian regions. Seropositivity for T. gondii was statistically higher in 12/14 (85.7%) captured wild boars when compared to 5/57 (7.0%) free-range wild boars (p = 0.000001). Similarly, captured wild boars from anthropized areas were more likely to be seropositive than of natural regions (p = 0.000255). When in multiple regression model, dogs with the habit of wild boar hunting had significant more chance to be positive (adjusted-OR 4.62 CI 95% 1.16–18.42). Despite potential as sentinels of environmental toxoplasmosis, seroprevalence in wild boars alone may provide a biased basis for public health concerns; thus, hunters and hunting dogs should be always be included in such studies. Although hunters should be aware of potential T. gondii infection, wild boars from natural and agricultural areas may present lower protozoa load when compared to wild boars from anthropized areas, likely by the higher presence of domestic cats as definitive hosts.

Real-time PCR detection of Toxoplasma gondii in tissue samples of wild boars (Sus scrofa) from southern Italy reveals high prevalence and parasite load

Background

Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii, a widespread protozoan in the phylum Apicomplexa. In Europe, several studies have demonstrated the presence of the parasite in tissues of wild boars (Sus scrofa), but no data exists on the T. gondii load in tissues which in turn may be an useful way to assess the infection risk for the consumer of wild boar meat.

Methods

We sampled and tested a total of 472 tissue samples of brain, heart and masseter muscle from 177 wild boars from the Campania region of southern Italy by real-time PCR analyses for detection and quantification of T. gondii. The sensitivity and specificity of the method were calculated by ROC analysis curves.

Results

PCR analysis revealed the presence of T. gondii in tissue samples of 78 out of 177 (44%) wild boars. In general, the brain presented the highest PCR prevalence (31%), followed by the heart (28.3%) and the masseter muscle (24.2%), with the highest estimated parasite numbers observed in the brain followed by the heart and masseter muscle. The PCR method showed an excellent discriminating ability for each of the examined tissues. According to the ROC analysis curves, the respective sensitivity and specificity were 99 and 100% for masseter muscle, 98 and 98% for brain and 96 and 98% for heart samples.

Conclusions

The high prevalence of infection here detected suggests a widespread distribution of the parasite in the wildlife of the Campania region of southern Italy. The T. gondii burdens detected may potentially represent a source of infection for humans.

Prevalence and genotype identification of Toxoplasma gondii in suburban rodents collected at waste disposal sites

To assess the prevalence of Toxoplasma gondii infection in native and commensal rodents as indicators of environmental pollution, we analyzed brain tissue from small mammals collected on legal and illegal waste sites in the Slovenian and Croatian parts of Istria. A total of 136 animals and five species of the family Muridae were analyzed: black rat (Rattus rattus), domestic mouse (Mus musculus), wood mouse (Apodemus sylvaticus), striped field mouse (Apodemus agrarius), and yellow-necked mouse (Apodemus flavicollis). Using quantitative Polymerase Chain Reaction (qPCR), T. gondii DNA was detected in four homogenized brain tissue samples (2.94%), from all of the analyzed species, except black rat. Out of these, two samples, domestic mouse (Mus musculus) and wood mouse (Apodemus sylvaticus) had sufficient DNA for genotyping of T. gondii isolates in which we demonstrated the presence of clonal type II using RFLP PCR with four markers (SAG1, SAG2, GRA6 and GRA7). Three of four infected animals (75%) were collected on dumpsites.

Wild Boar: A Reservoir of Foodborne Zoonoses

Wild boar populations around the world have increased dramatically over past decades. Climate change, generating milder winters with less snow, may affect their spread into northern regions. Wild boars can serve as reservoirs for a number of bacteria, viruses, and parasites, which are transmissible to humans and domestic animals through direct interaction with wild boars, through contaminated food or indirectly through contaminated environment. Disease transmission between wild boars, domestic animals, and humans is an increasing threat to human and animal health, especially in areas with high wild boar densities. This article reviews important foodborne zoonoses, including bacterial diseases (brucellosis, salmonellosis, tuberculosis, and yersiniosis), parasitic diseases (toxoplasmosis and trichinellosis), and the viral hepatitis E. The focus is on the prevalence of these diseases and the causative microbes in wild boars. The role of wild boars in transmitting these pathogens to humans and livestock is also briefly discussed.

Occurrence of selected zoonotic food-borne parasites and first molecular identification of Alaria alata in wild boars (Sus scrofa) in Italy

Wild boar is a source of human infections with zoonotic pathogens, including food-borne parasites. With the aim of a characterization of the human exposure risk, a survey on wild boars intended for human consumption was planned, selecting three pathogens, Toxoplasma gondii, Alaria alata, and Trichinella spp., as markers of meat infection. Diaphragm muscle samples from 100 wild boars hunted in Piedmont region (Northern Italy) in two hunting seasons (2015-2016) were collected. Concerning T. gondii, a combined approach of antibody detection and molecular techniques with genotyping was performed. For the detection of A. alata and Trichinella spp., the larva migration technique and the magnetic stirrer method were employed, respectively; in addition, molecular confirmation of the morphological identification of the recovered specimen was performed. Anti-T. gondii antibodies were found in meat juice samples (43.3%) and T. gondii DNA (type II) was detected in three animals (7.1%) out of 42 seropositive examined. In none of the sampled wild boars (0%), Trichinella spp. larvae were found, whereas one animal (1%) scored positive to A. alata mesocercariae. The molecular diagnosis proved the morphological identification of the trematode. This is the first finding of A. alata in Italian wild boar population. The present study confirmed the role of wild boars as a source of parasitic zoonotic diseases and thus the risk derived for humans posed by the consumption of game meat. Considering the zoonotic implications, the results underline the importance of monitoring and surveillance of zoonotic parasites in Italian wild boar populations.

Molecular and serological investigation of infectious diseases in captive and free-range crab-eating fox (Cerdocyon thous - Linnaeus, 1776) from northeastern Brazil

The aim of this study was to detect DNA and antibodies anti-Leishmania spp., Neospora caninum and Toxoplasma gondii in captive and free-range crab-eating fox (Cerdocyon thous) from northeastern Brazil. Twenty-five crab-eating foxes from different states of northeastern Brazil were sampled by this study. Blood samples were collected by cephalic or jugular vein punctures. The whole blood was submitted to PCR, and the sera samples to the serological analysis as follows: MAT for T. gondii, NAT for N. caninum, and ELISA for L. chagasi. The frequence of antibodies anti-T. gondii was 50% and 29.41% for free-range and captive wild canids, respectively. The frequence of antibodies anti-N. caninum observed by this study was 62.50% and 23.52% for free-range and captive wild canids, respectively. The frequence of antibodies anti-L. chagasi was 4.0% for captive wild canids. Co-infections cases were identified as follows: one captive wild canid seropositive for T. gondii and L. chagasi and two free-range animals seropositive for T. gondii and N. caninum. All PCR assays performed were negative for the pathogens analyzed. This study describes the presence of antibodies anti-T. gondii, N. caninum e L. chagasi in wild canids from northeastern Brazil and highlights the necessity of further studies on infectious diseases in free-range and captive wild canids.

Prevalence of Toxoplasma gondii and Potentially Zoonotic Helminths in Wild Boars (Sus scrofa) Hunted in Central Italy

Our aim was to evaluate the risk of human toxoplasmosis via meat consumption from wild boars by estimating the seroprevalence of Toxoplasma gondii in animals hunted in central Italy. Using a modified agglutination test, 213 sera from wild boars were examined for anti-Toxoplasma IgG antibodies. Diaphragm samples (n=65) from seropositive and seronegative animals were tested by nested-PCR to detect T. gondii DNA. Toxoplasma DNA from diaphragms was genotyped by PCR-RFLP using 12 genetic markers. Moreover, the aim of the study was also to identify helminth infections of wild boars in the selected area and to evaluate their hazard for humans. Examination of sera revealed a seroprevalence of 12.2%. Only one T. gondii strain could be genotyped from a seropositive animal and PCR-RFLP revealed that it belonged to type II. Analysis of 50 samples of faeces and 32 small intestines revealed that 78% and 15.6% of the samples harboured parasites, respectively, with the occurrence of parasites potentially dangerous for humans. These latter included Ascaris suum, Macracanthorhynchus hirudinaceus, Trichuris suis, and Metastrongylus spp. A significant association was found between coprological positivity and male sex. These results indicate that T. gondii infection may be present in wild boar tissues and consumption of undercooked or raw wild boar meat may expose humans to risk of toxoplasmosis in the study area. Furthermore, the study highlights that wild boars are hosts of helminths of veterinary and medical importance transmissible to pigs and humans.

Spread and genotype of Toxoplasma gondii in naturally infected alpine chamois (Rupicapra r. rupicapra)

The complex life cycle of Toxoplasma gondii involves many animal species, raising zoonotic, economic, and conservation issues. This complexity is reflected in the molecular structure of T. gondii, whose different genotypes differ in pathogenicity. Among the intermediate hosts of T. gondii, wild ungulates may be a source of human infection. Despite intense hunting activity and the consumption of raw or undercooked meat, little information is available on the spread of T. gondii and the distribution of its genotypes in these species, including the alpine chamois (Rupicapra r. rupicapra). Ninety-three sera and 50 brain tissues from chamois were sampled (1) to investigate the spread of T. gondii with serological and molecular analyses, and (2) to genotype the strains with a restriction fragment length polymorphism analysis of the SAG2 locus. The prevalence of T. gondii was low on both serological (3.2 %) and molecular (2 %) analyses, and infections were concentrated in individuals >1 year old. These findings demonstrate the sporadic presence of the protozoan in this species on consistent diagnostic tests. Horizontal transmission seems to be the main route of infection, and cats are the only definitive host in the study area. This prevalence suggests that the environment of the chamois is less contaminated with oocysts than environments close to human settlements. The SAG2 type II genotype was detected in this species for the first time. Although this genotype is predominant in human toxoplasmosis, these results suggest that the chamois is a minor source of human infection.

Wild boar (Sus scrofa) - reservoir host of Toxoplasma gondii, Neospora caninum and Anaplasma phagocytophilum in Slovakia

In Central Europe the wild boar population is permanently growing and consequently Cf foodborne infections. In this study serological and molecular detection of Toxoplasma gondii and Neospora caninum in wild boars was evaluated. Moreover, same samples were screened for the presence and genetic variability of tick-borne bacterium Anaplasma phagocytophilum. Blood samples collected from 113 wild boars from Southern Slovakia were examined for antibodies to T. gondii by indirect and to N. caninum by competitive ELISA. The presence of parasitic DNA in blood samples was determined by standard or real time PCR techniques. Antibodies against T. gondii and N. caninum were detected in 45 (39.8%) and 38 (33.6%) animals, respectively. Females were more frequently infected for both pathogens than males. The high seropositivity against both coccidia indicates a permanent occurrence of these pathogens in the studied locality. T. gondii DNA was confirmed in five seropositive boars (4.4%) and N. caninum in 23 blood samples (20.4%). Three out of 23 N. caninum PCR positive animals did not show seropositivity. Three out of 113 blood samples of wild boars were positive for A. phagocytophilum (2.7%). The obtained A. phagocytophilum sequences were 100% identical with GenBankTM isolates from Slovak dog (KC985242); German horse (JF893938) or wild boar (EF143810) and red deer (EF143808) from Poland. Coinfections of T. gondii with N. caninum and N. caninum with A. phagocytophilum were detected in single cases. Results suggest a potential zoonotic risk of toxoplasmosis transmission to humans and the spread of neosporosis to farm animals.

Cross-Sectional Serosurvey and Risk Factors Associated with the Presence of Toxoplasma gondii Antibodies in Pigs in Greece

INTRODUCTION

Toxoplasmosis is a worldwide reported zoonotic infection caused by the protozoon Toxoplasma gondii. Pigs may become infected by ingesting feed or water contaminated with cat faeces, by cannibalism, and/or by eating infected rodents. T. gondii infected edible tissues of pigs are a source of infection for humans. This study was undertaken to detect seropositivity of pigs against T. gondii and identify possible risk factors as well as to compare two serological methods.

METHODS

A total of 609 blood samples were collected from 10% of the sows from 65 pig farms located in mainland Greece. Information about the geographical location, size, and biosecurity level of the herd was recorded. Samples were tested for the presence of antibodies against T. gondii employing the indirect fluorescent antibody test and the enzyme-linked immunosorbent assay.

RESULTS

Twenty-six positive samples were detected (4.3%) in 17 out of the 65 farms tested (26.2%). The average seroprevalence in affected herds was 26.8% (95% confidence interval 21.0-32.6%). Among the categorical data evaluated, the biosecurity level (odds ratio 0.17, p < 0.01) and the geographical characteristics (odds ratio 13.55, p < 0.05) significantly affected the presence of toxoplasmosis in the herd. Toxoplasmosis was recorded in significantly higher percentages in mountainous farms as compared to lowlands (p < 0.05) and in those with poor biosecurity levels than in those with very good (p < 0.05). A very good agreement (κ = 0.958) was observed between the two serological methods.

CONCLUSION

The presence of antibodies in pigs is indirect information on the risk of the infection and an indication of the necessity of biosecurity measures to be taken in order to control infection at least in the areas at highest risk.

The use of loop-mediated isothermal amplification improves Toxoplasma gondii detection in wildlife

Toxoplasma gondii is among the most widespread parasites worldwide. Wildlife is recognized as an important reservoir and source of infection of T. gondii. The goal of the present work was to assess the performance of loop-mediated isothermal amplification (LAMP) as a diagnostic tool for T. gondii infection in the skeletal muscle and central nervous system (CNS) of free-ranging ungulates and carnivores. Fifty-seven wild animals were tested for the presence of T. gondii DNA by polymerase chain reaction (PCR) and LAMP. The use of LAMP amplification improved sensitivity in T. gondii molecular detection compared with conventional PCR on skeletal muscle (χ2 = 5.8, P < 0.05), having a lower minimum detection limit (0.1 tachyzoite) than PCR (1 tachyzoite). No significant differences existed between the detection capacities of both assays when performed on CNS. LAMP is a valid tool to improve the diagnosis of T. gondii infection in wild game meat. The technique provides a sensitive yet specific method that can be applicable to both field surveys and large-scale testing of wildlife samples.

Seroprevalence of Toxoplasma gondii in wild boars, red deer and roe deer in Poland

Little is known about the prevalence of Toxoplasma gondii in wild life, particularly game animals in Poland. Meat juice collected during the 2009/2010 and 2010/2011 hunting seasons from 552 red deer (Cervus elaphus), 367 wild boars (Sus scrofa) and 92 roe deer (Capreolus capreolus) was tested for T. gondii antibodies using the multi-species ID Screen Toxoplasmosis Indirect kit (IDvet, Montpellier, France). Antibodies to T. gondii were detected in 24.1% of red deer (95% CI: 20.7%, 27.8%), 37.6% of wild boar (95% CI: 32.8%, 42.7%) and 30.4% of roe deer (95% CI: 22.0%, 40.5%). To the authors' best knowledge, this is the first epidemiological report of T. gondii prevalence in red deer, roe deer and wild boars in Poland. T. gondii is present in wildlife animal tissues and consumption of the game may be a potential source of infection for humans.

Identification of host proteins interacting with the integrin-like A domain of Toxoplasma gondii micronemal protein MIC2 by yeast-two-hybrid screening

Background

Toxoplasma gondii is an obligate intracellular protozoan, causing the important zoonosis toxoplasmosis. This parasite utilizes a unique form of locomotion called gliding motility to find and invade host cells. The micronemal adhesin MIC2 plays critical roles in these processes by binding to substrates and host cell receptors using its extracellular adhesive domains. Although MIC2 is known to mediate important interactions between parasites and host cells during invasion, the specific host proteins interacting with MIC2 have not been clearly identified. In this study, we used a yeast-two-hybrid system to search for host proteins that interact with MIC2.

Methods

Different adhesive domains of MIC2 were cloned into the pGBKT7 vector and expressed in fusion with the GAL4 DNA-binding domain as baits. Expression of bait proteins in yeast cells was analyzed by immuno-blotting and their autoactivation was tested via comparison with the pGBKT7 empty vector, which expressed the GAL4 DNA binding-domain only. To identify host proteins interacting with MIC2, a mouse cDNA library cloned into a GAL4 activation-domain expressing vector was screened by yeast-two-hybrid using the integrin-like A domain of MIC2 (residues 74–270) as bait. After initial screening and exclusion of false positive hits, positive preys were sequenced and analyzed using BLAST analysis and Gene Ontology Classifications.

Results

Two host proteins that had not previously been reported to interact with T. gondii MIC2 were identified: they are LAMTOR1 (late endosomal/lysosomal adaptor, MAPK and mTOR activator 1) and RNaseH2B (ribonuclease H2 subunit B). Gene Ontology analysis indicated that these two proteins are associated with many cellular processes, such as lysosome maturation, signaling transduction, and RNA catabolism.

Conclusion

This study is the first one to report interactions between Toxoplasma gondii MIC2 and two host proteins, LAMTOR1 and RNaseH2B. The data will help us to gain a better understanding of the function of MIC2 and suggest that MIC2 may play roles in modulating host signal transduction and other biological processes in addition to binding host cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-014-0543-1) contains supplementary material, which is available to authorized users.