Genetic characterization of viable Toxoplasma gondii isolates from stray dogs from Giza, Egypt

Seroprevalence of IgG and IgM Antibodies against Toxoplasma gondii in Dogs in Greece

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a zoonotic disease that affects various animal species, including dogs, that can serve as sentinels for indirectly estimating the environmental contamination. The current study aimed to determine the seroprevalence of T. gondii IgG and IgM antibodies in dogs across different regions of Greece and assess their living area as a potential risk factor. In total, 1282 blood samples were collected from dogs in urban and rural areas of Greece, including Attica and Thessaloniki. Serum samples were tested for T. gondii-specific IgG and IgM antibodies using an indirect immunofluorescent antibody test. A chi-square test was performed to assess the association between seropositivity for T. gondii and geographical location (urban/rural). The overall T. gondii seroprevalence was 47.6%, while the seroprevalence of IgG and IgM antibodies was 34.3% and 22.2%, respectively. Dogs from rural areas exhibited a significantly higher seroprevalence (53.8%) than those from urban areas (43.9%) (p < 0.001), with the estimated odds ratio being equal to 1.49 (95% CI, 1.18 to 1.65) and the relative risk increased by 22.4%. Dogs in Greece are highly exposed to T. gondii, particularly in rural areas. Measures to prevent canine infections are necessary, and basic hygiene practices, such as hand washing after petting dogs, are required to reduce human infection risk and safeguard public health.

Far-East Asian Toxoplasma isolates share ancestry with North and South/Central American recombinant lineages

Toxoplasma gondii is a global protozoan pathogen. Clonal lineages predominate in Europe, North America, Africa, and China, whereas highly recombinant parasites are endemic in South/Central America. Far East Asian T. gondii isolates are not included in current global population genetic structure analyses at WGS resolution. Here we report a genome-wide population study that compared eight Japanese and two Chinese isolates against representative worldwide T. gondii genomes using POPSICLE, a novel population structure analyzing software. Also included were 7 genomes resurrected from non-viable isolates by target enrichment sequencing. Visualization of the genome structure by POPSICLE shows a mixture of Chinese haplogroup (HG) 13 haploblocks introgressed within the genomes of Japanese HG2 and North American HG12. Furthermore, two ancestral lineages were identified in the Japanese strains; one lineage shares a common ancestor with HG11 found in both Japanese strains and North American HG12. The other ancestral lineage, found in T. gondii isolates from a small island in Japan, is admixed with genetically diversified South/Central American strains. Taken together, this study suggests multiple ancestral links between Far East Asian and American T. gondii strains and provides insight into the transmission history of this cosmopolitan organism.

Toxoplasma gondii and Neospora caninum Antibodies in Dogs and Cats from Egypt and Risk Factor Analysis

BACKGROUND

Toxoplasma gondii and Neospora caninum are major protozoan parasites of worldwide distribution and significance in veterinary medicine and, for T. gondii, in public health. Cats and dogs, as final hosts for T. gondii and N. caninum, respectively, have a key function in environmental contamination with oocysts and, thus, in parasite transmission. Very little is known about the prevalence of T. gondii infections in dogs and cats in Egypt, and even less about the prevalence of N. caninum in the same hosts.

METHODS

In the current study, 223 serum samples of both dogs (n = 172) and cats (n = 51) were investigated for specific antibodies to T. gondii and N. caninum using commercially available ELISAs. A risk factor analysis was conducted to identify factors associated with seropositivity.

RESULTS & DISCUSSION

Exposure to T. gondii was reported in 23.3% of the dogs and in 9.8% of the cats, respectively. In addition, N. caninum-specific antibodies were recorded in 5.8% of dogs and in 3.4% of cats. A mixed infection was found in two dogs (1.2%) and in one cat (2%). Antibodies to T. gondii in dogs were significantly more frequent in dogs aged 3 years or more and in male German Shepherds. As this breed is often used as watchdogs and was the most sampled breed in Alexandria governorate, the purpose "watchdog" (compared to "stray" or "companion"), the male sex, and the governorate "Alexandria" also had a significantly higher seroprevalence for T. gondii. No factors associated with antibodies to N. caninum could be identified in dogs, and no significant factors were determined in cats for either T. gondii or N. caninum infection. Our study substantially adds to the knowledge of T. gondii infection in dogs and cats and presents data on N. caninum infection in cats for the first and in dogs in Egypt for the second time.

Prevalence and risk factors of Toxoplasma gondii and Leishmania spp. infections in apparently healthy dogs in west Shewa zone, Oromia, Ethiopia

BACKGROUND

In urban settings, the presence of a high density of the human population and contact with domestic and/or stray animals such as dogs and cats can be risk factors for the transmission of zoonotic protozoa parasites. Toxoplasma gondii (T. gondii) and Leishmania spp. are zoonotic protozoon parasites with significant health burdens worldwide.

METHODS

A cross-sectional study was used to investigate the antibody prevalence and risk factors of T. gondii and Leishmania spp. infections in 385 randomly selected dogs of Ambo, Bako, and Gojo towns of West Shewa Zone, Oromia regional state, Ethiopia. A questionnaire survey was administered to households to collect data on potential risk factors. Dog sera samples were assayed for T. gondii IgG antibodies using the direct agglutination test while Leishmania spp. specific antibodies tested using an indirect enzyme-linked immunosorbent assay (ELISA). Logistic regression was used for data analysis.

RESULTS

Overall, T. gondii and Leishmania spp. infection seroprevalence was found to be 82.86% (95% confidence interval (CI): 78.71-86.49%) and 92.47% (95% CI: 89.36-94.90%), respectively. Seropositivity for both T. gondii and Leishmania spp. was found in 82.58% of the dogs. None of the investigated factors were associated with Leishmania spp. seropositivity (p > 0.05). The seroprevalence of T. gondii was significantly different among the study towns (p = 0.003). The risk of T. gondii infection was 2.71 times higher in adult dogs than juvenile dogs (p = 0.043). Dogs kept simultaneously with other domestic animals had increased odds of T. gondii seropositivity compared to those with no other domestic animals (Adjusted Odds ratio: 1.96, p = 0.021). However, altitude, sex, breed, housing, feeding, educational level of head of the household, and dog's living area were not significantly associated with T. gondii seropositivity (p > 0.05).

CONCLUSIONS

The high seropositivity and the simultaneous presence of antibodies of T. gondii and Leishmania spp. in dogs suggest the widespread nature of these parasites in the environment and the high potential of transmission to other animals and humans. Further epidemiological studies, isolation and molecular characterization of the parasites, and educational campaigns are suggested.

Detection and genetic characterisation of Toxoplasma gondii circulating in free-range chickens, pigs and seropositive pregnant women in Benue state, Nigeria

Toxoplasma gondii parasites present strong but geographically varied signatures of population structure. Populations sampled from Europe and North America have commonly been defined by over-representation of a small number of clonal types, in contrast to greater diversity in South America. The occurrence and extent of genetic diversity in African T. gondii populations remains understudied, undermining assessments of risk and transmission. The present study was designed to establish the occurrence, genotype and phylogeny of T. gondii in meat samples collected from livestock produced for human consumption (free-range chickens, n = 173; pigs, n = 211), comparing with T. gondii detected in blood samples collected from seropositive pregnant women (n = 91) in Benue state, Nigeria. The presence of T. gondii DNA was determined using a published nested polymerase chain reaction, targeting the 529 bp multicopy gene element. Samples with the highest parasite load (assessed using quantitative PCR) were selected for PCR-restriction fragment length polymorphism (PCR-RFLP) targeting the surface antigen 3 (SAG3), SAG2 (5’ and 3’), beta-tubulin (BTUB) and dense granule protein 6 (GRA6) loci, and the apicoplast genome (Apico). Toxoplasma gondii DNA was detected in all three of the populations sampled, presenting 30.6, 31.3 and 25.3% occurrence in free-range chickens, pigs and seropositive pregnant women, respectively. Quantitative-PCR indicated low parasite occurrence in most positive samples, limiting some further molecular analyses. PCR-RFLP results suggested that T. gondii circulating in the sampled populations presented with a type II genetic background, although all included a hybrid type I/II or II/III haplotype. Concatenation of aligned RFLP amplicon sequences revealed limited diversity with nine haplotypes and little indication of host species-specific or spatially distributed sub-populations. Samples collected from humans shared haplotypes with free-range chickens and/or pigs. Africa remains under-explored for T. gondii genetic diversity and this study provides the first detailed definition of haplotypes circulating in human and animal populations in Nigeria.

Toxoplasma gondii is a parasite that infects most warm-blooded animals and can be transmitted from animals to humans. Three dominant genetic types have been described from a larger pool of around 16, and it has been suggested that the severity of disease may be influenced by genetic type. Little is known of T. gondii in Africa. The burden of disease is unclear, while lack of knowledge around genetic diversity and population structure undermines effective risk assessment and control. We sought to determine if T. gondii was prevalent in pigs and poultry produced for human consumption in Nigeria, comparing with genetic types detected in the overlapping human population. Using meat samples from free-range chickens and pigs, and blood samples from seropositive pregnant women in Benue state, Nigeria, we found that T. gondii with a type II genetic background were most common with limited genetic diversity. Detection of comparable genetic types in the free-range chicken, pig and human populations indicate an overlapping parasite population and can be used to inform assessments of risk to human health, most notably pregnant women. The information reported here informs on the occurrence and population structure of T. gondii in Nigeria, contributing to improved understanding in Africa.

Seroprevalence of Toxoplasma gondii in outdoor dogs and cats in Bangkok, Thailand

The aim of this study was to estimate the seroprevalence and risk factors associated with Toxoplasma gondii exposure in dogs and cats from Bangkok, Thailand. Blood samples from 318 dogs and 321 cats were tested for T. gondii antibodies by modified agglutination test (cut-off 1:25). Additionally, 18 dogs and 20 cats were longitudinally sampled for T. gondii antibodies during the same study period, between June and July 2019. The overall seroprevalence in dogs and cats was 7.9% (25/318; 95% CI 4.9–10.8%) and 18.7% (95% CI 14.4–23.0%), respectively. For dogs, risk factors identified were being a mixed-breed animal and living totally outdoors, while increasing age was shown to be a risk factor for cats. Seroconversion was not detected and titres from positive animals remained constant over longitudinal study. The present study indicates that there is a prominent presence of T. gondii in urban and peri-urban areas of Bangkok, suggesting that outdoor dogs and cats should be considered as a possible risk factor for humans.

A hotspot of Toxoplasma gondii Africa 1 lineage in Benin: How new genotypes from West Africa contribute to understand the parasite genetic diversity worldwide

Through international trades, Europe, Africa and South America share a long history of exchanges, potentially of pathogens. We used the worldwide parasite Toxoplasma gondii to test the hypothesis of a historical influence on pathogen genetic diversity in Benin, a West African country with a longstanding sea trade history. In Africa, T. gondii spatial structure is still non-uniformly studied and very few articles have reported strain genetic diversity in fauna and clinical forms of human toxoplasmosis so far, even in African diaspora. Sera from 758 domestic animals (mainly poultry) in two coastal areas (Cotonou and Ouidah) and two inland areas (Parakou and Natitingou) were tested for T. gondii antibodies using a Modified Agglutination Test (MAT). The hearts and brains of 69 seropositive animals were collected for parasite isolation in a mouse bioassay. Forty-five strains were obtained and 39 genotypes could be described via 15-microsatellite genotyping, with a predominance of the autochthonous African lineage Africa 1 (36/39). The remaining genotypes were Africa 4 variant TUB2 (1/39) and two identical isolates (clone) of Type III (2/39). No difference in terms of genotype distribution between inland and coastal sampling sites was found. In particular, contrarily to what has been described in Senegal, no type II (mostly present in Europe) was isolated in poultry from coastal cities. This result seems to refute a possible role of European maritime trade in Benin despite it was one of the most important hubs during the slave trade period. However, the presence of the Africa 1 genotype in Brazil, predominant in Benin, and genetic analyses suggest that the triangular trade was a route for the intercontinental dissemination of genetic strains from Africa to South America. This supports the possibility of contamination in humans and animals with potentially imported virulent strains.

The parasite Toxoplasma gondii is a worldwide-distributed pathogen, able to infect all warm-blooded animals. There are important differences in the clinical expression of the infection in direct relation with the parasite genetic profile. In some regions, the geographical structuration of its genetic diversity points towards a crucial role of human activities in some lineages introduction or sorting. Benin is a West African country with a history of extensive transcontinental exchanges. Our genetic study of Toxoplasma in Benin shows a surprisingly homogeneous and autochthonous diversity, which contrasts with previous studies from other West and Central African countries. In Benin, the absence of European Toxoplasma lineages may be explained by the extreme rarity of the house mouse (Mus musculus), a host species that was previously described as highly susceptible to the mouse-virulent African strains. Might Benin be the origin region for the Africa 1 lineage, our results suggest that Guinean Gulf coasts may be a starting point of this lineage towards South America, especially Brazil, during the slave trade. As a whole, the present study provides further insights into the recent evolutionary history of Toxoplasma gondii and its consequences on human and animal health.

Detection of antibodies to Toxoplasma gondii among owned dogs in Cambodia

Toxoplasma gondii is a protozoan parasite belonging to the phylum Apicomplexa, which has a two-host life cycle and an extensive global distribution. The presence of antibodies to T. gondii was examined in owned dogs in Cambodia. In total, 103 dog serum samples from 37 households in northern Cambodia were collected and examined for evidence of T. gondii infection using an indirect immunofluorescent antibody test. In total, 52 of 103 (50.5%) samples were serologically positive for T. gondii in this study. No significant risk factor associated with T. gondii infection was found. To the best of our knowledge, this is the first report of the seroprevalence of T. gondii in dogs from Cambodia, which revealed a considerable risk of infection for humans. Therefore, consuming undercooked dog meat or contacting feces with contaminated cat feces should be restricted to avoid the possibility of zoonosis. Further studies are needed to determine the epidemiology of T. gondii in populations of larger dogs and other animals to improve our understanding of the situation of the pathogen in this country.

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First report of T. gondii infection in dogs from Cambodia

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Adult dogs are more likely to be infected with the pathogen (T. gondii) at higher antibody concentration.

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Consumption of undercooked dog meat or contact with cat feces maybe potential risks for human T. gondii infection in Cambodia.

Toxoplasma gondii infections in dogs: 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 dogs (Canis familiaris) from 2009-2020. Seroprevalence estimates of T. gondii worldwide were tabulated. Reports of high seroprevalence in canine population and high congenital transmission of T. gondii in dogs in Brazil are reviewed. Most reports from China were published in Chinese, and these reports are now summarized here. Dogs have an additional importance in some countries such as China, Vietnam, and Nigeria; whereas in many cities dog meat is sold commercially for human consumption and given to felids, and transmission of T. gondii could occur if meat is not cooked properly. Dogs can ingest T. gondii-infected cat feces and these oocysts remain viable after passage through the digestive tract of the dog; T. gondii DNA was found in feces of dogs from New York City parks in USA. Most clinical canine cases of toxoplasmosis were in immunosuppressed dogs, and ulcerative dermatitis was one of the main presentations. Genetic diversity based on PCR-RFLP markers using DNA derived from 133 viable T. gondii isolates from dogs from several countries is discussed. T. gondii strains from Asia and Americas were more genetically diverse than those from Africa. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

A review on toxoplasmosis in humans and animals from Egypt

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

The introduction of new hosts with human trade shapes the extant distribution of Toxoplasma gondii lineages

Toxoplasma gondii is a zoonotic protozoan with a worldwide occurrence, but the determinants of the current pattern in the geographical distribution of T. gondii lineages and strains remain poorly understood. To test the influence of human trade on T. gondii populations, we conducted a population genetic study of 72 T. gondii animal isolates from Senegal, a West African country in which the ongoing inland progress of invasive murine hosts (introduced in port cities of Senegal since the 16th century by European sailors) is well described. Isolates were mainly collected on free-range poultry, which are considered as relevant bioindicators of T. gondii strain diversity in the domestic environment. Sampling was conducted in two port cities of Senegal (Dakar and Saint-Louis) and in one inland region (Kedougou). Population genetic analyses using 15 microsatellite markers revealed different patterns between port cities where lineages non-virulent for mice (type II, type III, and Africa 4) were predominant, and Kedougou where the mouse-virulent Africa 1 lineage was the most common. By considering the current spatial pattern in the inland progress of invasive rodents in Senegal, our results suggest that the invasive house mouse Mus musculus domesticus counter-selects the Africa 1 lineage in the invaded areas. The comparison of the microsatellite alleles of type II strains from Senegal to type II strains from other areas in Africa and Western Europe, using discriminant analysis of principal components and Network analysis, point to a mainly Western European origin of the type II lineage in Senegal. Collectively, these findings suggest that human-mediated intercontinental migrations of murine hosts are important vectors of T. gondii strains. Differential susceptibility of endemic and introduced murine hosts to various T. gondii strains probably determines the persistence of these strains in the environment, and therefore their availability for human and animal infection.

Molecular Detection and Genotyping of Toxoplasma gondii in Edward's Long-Tailed Rats (Leopoldamys edwardsi)

Toxoplasma gondii is an important zoonotic parasite infecting humans and various animals with a worldwide distribution. However, limited information is available on T. gondii infection in wild rats. The present study aimed to examine the prevalence and characterize the genotypes of T. gondii in wild rats in two regions of China. Brain tissues were collected from 111 Edward's long-tailed rats (Leopoldamys edwardsi) and 117 Bower's white-toothed rats (Berylmys bowersi) between November 2017 and January 2018. Genomic DNA was extracted and amplified by PCR targeting the T. gondii B1 gene. B1 gene-positive samples were genotyped at 10 genetic markers (SAG1, SAG2 [5', 3'] and [alternative], SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) using multilocus nested polymerase chain reaction/restriction fragment length polymorphism. Six (5.41%, 6/111) Edward's long-tailed rats from Chongqing Municipality were positive for T. gondii B1 gene, whereas no T. gondii infection was detected in Bower's white-toothed rats (n = 117) from Guangdong province. T. gondii prevalence in female and male rats was 1.77% (2/113) and 3.48 (4/115), respectively. Four of the six positive DNA samples were completely genotyped at 10 genetic loci and were identified as ToxoDB#20. The present study revealed the occurrence of T. gondii infection in Edward's long-tailed rats. These findings raised public health concerning about T. gondii infection in wild rats. These results provide reference data for understanding the distribution of T. gondii genotypes in wild rats in China.

Isolation, genotyping and pathogenicity of a Toxoplasma gondii strain isolated from a Serval (Leptailurus serval) in China

Toxoplasma gondii typically causes lifelong chronic infection and has been identified in a variety of intermediate and definitive hosts. Felids are capable of serving as both intermediate and definite hosts for T. gondii infection. However, there is no direct evidence to prove that servals are the intermediate host of T. gondii. In this study, T. gondii antibodies were detected in a serval by a modified agglutination test (titer, 1:200). Viable T. gondii was isolated from the striated muscles of the serval. This strain was further propagated in cell culture and designated as TgServalCHn1. Genetic characterization of DNA derived from cell culture was performed by RFLP-PCR of 10 markers, as well as polymorphic ROP5 and ROP18 genes. Results showed that this strain of T. gondii belonged to the genotype ToxoDB#20. The ROP5 allele 4 and ROP18 allele 3 suggested that this strain was avirulent, which was further supported by infection in mice. Encephalitis, immune organ necrosis and focal mononuclear cell infiltration in multiple organs were the main pathology characteristics observed in BALB/C mice infected with the TgServalCHn1 strain. To our knowledge, the present study is the first to report the isolation of T. gondii from a serval, which gives direct evidence for servals serving as an intermediate host of T. gondii. The genotyping results revealed the presence of genotype ToxoDB#20 in central China, enriching the scope of the distribution of T. gondii genotypes in Asia.

Evidence of red panda as an intermediate host of Toxoplasma gondii and Sarcocystis species

Toxoplasma gondii has been found to infect almost all warm-blooded animals; however, some hosts lack direct evidence of T. gondii infection. The red panda (Ailurus fulgens) is an endangered species that mainly lives in temperate forests of South Asia. Here, T. gondii infection in red pandas from zoos in China were reported. Antibodies to T. gondii were found in 14.3% (2/14) of red pandas via the modified agglutination test (MAT) with a cut-off titer of 1:25. One viable T. gondii strain was isolated from tissues of red panda and designated as TgRedpandaCHn1. DNA from tachyzoites obtained from cell culture was characterized by PCR-RFLP with 10 markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and virulence genes of ROP5 and ROP18. The results indicate that this isolate belonged to ToxoDB genotype #20. The ROP18/ROP5 genotype combination predicated that this strain is non-lethal to mice, which is supported by the infection in mice. T. gondii tissue cysts were readily formed and mice survived. Tissue cysts observed in the histopathological sections of the tongue and diaphragm of one red panda were speculated as sarcocysts, but not T. gondii base on morphological characteristics. To our knowledge, this study is the first to report on the isolation of T. gondii from red panda. Additionally, this report provides direct evidence of red panda as an intermediate host of T. gondii and Sarcocystis species.

Toxoplasma gondii infection and toxoplasmosis in North Africa: a review

Toxoplasmosis is an important zoonosis caused by an obligate intracellular parasitic protozoan, Toxoplasma gondii. The disease is distributed worldwide and can affect all warm-blooded vertebrates, including humans. The present review aimed to collect, compile and summarize the data on the prevalence of T. gondii infection in humans and animals in the five North African countries (Morocco, Algeria, Tunisia, Libya and Egypt). Published data from national and international databases were used. Distribution patterns and risk factors for T. gondii infection are discussed, focusing on biotic and abiotic factors. This review is a comprehensive epidemiological analysis of T. gondii infection in North Africa and will therefore be a useful tool for researchers. It can also be used to propose or enhance appropriate national toxoplasmosis control programs.

Toxoplasma and Africa: One Parasite, Two Opposite Population Structures

Exploring the genetic diversity of Toxoplasma gondii is essential for an understanding of its worldwide distribution and the determinants of its evolution. Africa remains one of the least studied areas of the world regarding T. gondii genetic diversity. This review has compiled published data on T. gondii strains from Africa to generate a comprehensive map of their continent-wide geographical distribution. The emerging picture about T. gondii strain distribution in Africa suggests a geographical separation of the parasite populations across the continent. We discuss the potential role of a number of factors in shaping this structure. We finally suggest the next steps towards a better understanding of Toxoplasma epidemiology in Africa in light of the strains circulating on this continent.

A rare case of acute toxoplasmosis in a stray dog due to infection of T. gondii clonal type I: public health concern in urban settings with stray animals?

Background

Typing of Toxoplasma gondii strains is important in epidemiological surveys, to understand the distribution and virulence of different clones of the parasite among human and animal populations. Stray dogs can be consider sentinel animals for contaminated environments playing an important but probably under- evaluated role in the epidemiology of T. gondii. We reported a rare case of acute toxoplasmosis in a stray dog due to clonal type I infection. The clonal type I, sporadic in Europe, is frequently associated with severe toxoplasmosis in humans and the control of its circulation is particularly relevant for public health. The symptomatology suggested a potential infection with the high similar parasite Neospora caninum but differential diagnosis showed that only T. gondii was involved highlighting the importance of multiple diagnostic methods beyond the clinical signs.

Case presentation

A female stray dog approximately six-month of age presented muscular atrophy of the femoral region and hyperextension of hind limbs. Body condition score (BCS) was 20% below ideal weight, ribs had almost no fat and the sensor state was depressed. Haematological values were normal and the dog did not show any neurological abnormalities. Serological analysis showed a positive response for T. gondii immunoglobulin G (IgG) antibodies and exclude N. caninum infection.

To confirm T. gondii infection, a muscle biopsy was performed and genomic DNA was extracted. PCR analysis resulted positive to T. gondii and strain genotyping reveals clonal type I infection. The dog recovered after 4 weeks of treatment with clindamycin hydrochloride and aquatic physiotherapy.

Conclusions

Our study reports a rare and severe case of T. gondii clonal type I infection in a stray dog feeding in garbage containers. The data confirm the importance of an in vivo early diagnosis for toxoplasmosis in dog. Clinical signs are often related to specific T. gondii genotype and parasite genotyping is important in the epidemiological survey of toxoplasmosis in public health. The detection of parasitic DNA in the tissue could be an useful diagnostic method in facilitating early treatment of the disease, which is important for a timely clinical recovery.

Isolation and Genotyping of Toxoplasma gondii in Brazilian Dogs

Strains of Toxoplasma gondii in Brazil are highly genetically diverse compared to strains from North America and Europe. Dogs are epidemiologically important because they act as sentinels for T. gondii infections in humans and are good indicators of environmental contamination. The aim of this study was to isolate and genetically characterize T. gondii strains from tissues of naturally infected Brazilian dogs. For this study, 21 blood samples were collected from dogs at the Zoonosis Control Centers of Ilhéus and Itabuna cities, Bahia, Brazil. The sera were examined for T. gondii antibodies using the indirect hemagglutination test. Brains and hearts of seropositive dogs were bioassayed in mice to isolate and characterize T. gondii parasites by PCR-RFLP using 10 genetic markers (SAG1, newSAG2, SAG3, BTUB, c22-8, c29-2, GRA6, PK1, APICO, and L358). However, T. gondii was isolated from only 4 (57.1%) dogs, designated TgDgBr6, 13, 17, and 21. All strains were virulent, causing clinical changes (rough hair coat, lethargy, and abdominal distention) and the death of all mice within 8-20 days after inoculation. Genetic analysis of these 4 T. gondii isolates revealed 4 distinct genotypes with different clonal lineage combinations (types I, II, and III) and 2 atypical alleles. Using PCR-RFLP with several markers, this study contributes to evaluations of the genetic diversity of strains circulating in Brazil.

Geographical distribution of Toxoplasma gondii genotypes in Asia: A link with neighboring continents

Defining the pattern of genetic diversity of Toxoplasma gondii is important to understand its worldwide distribution. During the last decades, a large number of studies have been published on Toxoplasma genotypes circulating in Europe, in North and South America. Two continents are still largely unexplored, Africa and, to a less extent, Asia. In this last continent, an increasing number of publications reported genotypes circulating in diverse provinces of China, but very few data are available for other Asian countries. After a systematic database search, 47 papers related to T. gondii genotypes in Asia were analyzed. Genetic characterization of DNA was performed by microsatellite markers, or more usually by a multiplex PCR using 11 PCR-RFLP markers, allowing data comparison to draw a first global picture of the population structure of this parasite throughout Asia. Overall, 390 isolates or DNA extracts were completely typed by PCR-RFLP and/or microsatellite marker methods, revealing 36 different PCR-RFLP or equivalent microsatellite genotypes: 15 genotypes identified by a ToxoDB number and 21 atypical or unique genotypes. The most common genotype found in Asia is the genotype ToxoDB#9 (Chinese 1). The clonal types I, II and II variant, and III were also commonly found in Asia. The geographical distribution of these genotypes across Asia may reflect either a continuum with Europe for the western part of Asia (presence of Type II), or the circulation of strains through animal migration or human activities between Africa and the Southwestern part of Asia (Africa 1 genotype in Turkey or ToxoDB#20 both I Sri-Lanka and in Ethiopia or Egypt). Although there are some indications of a genetic population structure in Southeast Asian countries different from the rest of Asia, more studies in this tropical part of Asia will be necessary for a region which represent as well as Africa one of the missing links of the T. gondii genetic diversity.

Seroprevalence and genotype of Toxoplasma gondii in pigs, dogs and cats from Guizhou province, Southwest China

BACKGROUND

Toxoplasma gondii is an obligate, intracellular protozoan that infects almost all warm-blooded animals, including humans, domesticated and wild animals. Recent studies of Toxoplasma gondii isolates from animals in different regions of China have shown a limited genetic diversity with the dominance of the ToxoDB PCR-RFLP genotype #9 named as "Chinese 1". However, there is not much published information regarding its prevalence in domestic animals from Guizhou province, a subtropical region in Southwest China. The objectives of this study were to determine seroprevalence and genetic diversity of T .gondii in pigs, dogs and cats in Guizhou province, Southwest China.

FINDINGS

The anti-T. gondii IgG were detected in 70.0%(49/70) pigs, 20.56%(22/107) dogs and 63.16(12/19) cats. The anti-T. gondii IgM were found in 0.93%(1/107) dogs, 21.53%(4/19) cats, but not in pigs. In addition, the toxoplasma circulating antigen (CAG) were detected in 16.9%18/70)pigs, 13.1% (14/107) dogs and 10.5%(2/19) cats. The T. gondii DNA were detected in 31.5%(22/70) pigs, 3.7%(4/107) dogs and 52.63%(10/19) cats. Five T. gondii isolates were obtained(3 from pigs and 2 from cats). The genotype of these five isolates belonged to the predominant genotype "Chinese 1".

CONCLUSIONS

The high prevalence of T. gondii infection in pigs,cats and dogs indicated that the T. gondii infection is common in Guizhou province. Additionally, the T. gondii genotype "Chinese 1" was dominant in Southwest China.

Low prevalence of Neospora caninum and Toxoplasma gondii antibodies in dogs in Jilin, Henan and Anhui Provinces of the People's Republic of China

BACKGROUND

Neospora caninum and Toxoplasma gondii are important pathogens of worldwide distribution. N. caninum is a major cause of abortion in cattle and dogs are main reservoirs because they excrete the environmentally resistant oocysts. Toxoplasmosis is a worldwide zoonosis and dogs are considered as sentinels for this parasite because of their close contact with people and cats; additionally dog meat is also used for human consumption in China. The aim of the present study was to assess the prevalence of N. caninum and T. gondii infection in dogs from China. A total of 425 countryside dog hearts in Jilin, Henan and Anhui provinces of the People's Republic of China were collected from slaughter houses in two batches; the first batch of 96 in October 2013, and the second batch of 329 in April 2014. Serum samples extracted from 96 dog hearts were tested for antibodies to N. caninum and from 425 dog hearts were tested for T. gondii antibodies in the modified agglutination tests (cut-off 1:25 for both), using respective antigens.

RESULTS

Antibodies to N. caninum were 6 of 96 (6.25%) of dogs with titers of 1:25 in 2, 1:50 in 3, and 1:100 in 1. All seropositive dogs were more than 1 year old. Antibodies to T. gondii were found in 35 of 425 (8.24%) dogs with titers of 1:25 in 15, 1:50 in 14; and 1:100 in 6.

CONCLUSION

The results of the present study indicated low prevalence of N. caninum and T. gondii antibodies in dogs of China, compared with Europe and America. Identification of the risk factors that underlie these differences may help prevention of neosporosis and toxoplasmosis. This is the first report of N. caninum infection in dogs from China.

Toxoplasmosis in dogs: first report of Toxoplasma gondii infection in any animal species in Angola

Despite the worldwide importance of zoonotic parasite Toxoplasma gondii, nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also at assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a veterinary clinic in the city of Luanda were investigated. Serum samples were tested for antibodies to T. gondii with a modified agglutination test (MAT) commercial kit, at serial dilutions of 1∶20 to 1∶160. In accordance with the established cutoff value (MAT ≧20), 16 dogs [15·5%; 95% confidence interval (CI): 9·2-24·0%] had antibodies to T. gondii: 10 had a titer of 20, two had a titer of 40, and four had a titer of 80. Age (≧12 months) was found to be a risk factor for infection [odds ratio (OR) = 9·23; 95% CI: 1·16-73·27). For each 1-year increase in age, the risk of a dog being found seropositive significantly increased by an OR of 1·18 (95% CI: 1·02-1·36). The present study, which represents the first serological survey of T. gondii in any animal species from Angola, reveals a 15·5% seroprevalence of infection in pet dogs in Luanda. Further studies are needed to better understand the epidemiology of zoonotic T. gondii infection in Luanda and also in Angola.

High prevalence of Toxoplasma gondii antibodies in dogs in Veracruz, Mexico

BACKGROUND

Little is known concerning the prevalence of Toxoplasma gondii infection in dogs in Mexico. Here, we investigated antibodies to T. gondii and associated risk factors in 101 dogs from an animal shelter in Veracruz State, Mexico. Canine sera were assayed for T. gondii IgG antibodies by using the modified agglutination test (MAT, cut off 1:25).

RESULTS

Sixty eight (67.3%) of 101 dogs were seropositive with titers of 1:25 in 16, 1:50 in 8, 1:100 in 9, 1:200 in 10, 1:400 in 10, 1:800 in 10, 1:1600 in 3, and 1:3200 or higher in 2. None of the dogs' characteristics studied including age, sex, breed, and history of deworming, rabies vaccination and contact with cats was associated with seroprevalence of T. gondii infection.

CONCLUSION

Using the dogs as sentinel animals, the results indicate high contamination with T. gondii of the environment in Veracruz, Mexico. Results have public health implications, and further studies in Veracruz should be conducted to establish the sources of environmental contamination with T. gondii and to determine optimal preventive measures against T. gondii infection in humans.

Genetic characterization of Toxoplasma gondii from cats in Yunnan Province, Southwestern China

Background

Cats are the definitive hosts of Toxoplasma gondii. The distribution of genetic diversity of T. gondii in cats is of importance to understand the transmission of this parasite. The objective of this study was to genetically characterize T. gondii isolates from cats in Yunnan province, southwestern China.

Methods

Genomic DNA was extracted from 5–10 g cat tissue samples (brain, tongue, heart, and liver). Using multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology, we determined genetic diversity of T. gondii isolates from cats in Yunnan province.

Result

In total, 175 stray cats were tested for T. gondii DNA, respectively, 44 (25.14%) of which were found to be positive for the T. gondii B1 gene by PCR amplification. The positive DNA samples were typed at 11 genetic markers, including 10 nuclear markers, namely, SAG1, 5'-3'SAG2, alternative SAG2, SAG3, GRA6, L358, PK1, BTUB, c22-8, c29-2 and an apicoplast locus Apico. Of these, 16 isolates from cats were genotyped with data for more than 9 loci, revealed 5 genotypes in total, of which 11 of 16 samples were identified as ToxoDB#9, two samples may belong to genotye #225, one was Type II, one was ToxoDB#3, and one was ToxoDB#20 (http://toxodb.org/toxo/).

Conclusions

The results of the present study indicated a wide distribution of T. gondii infection in cats in Yunnan province, which may pose significant public health concerns. To our knowledge, the present study is the first report of T. gondii prevalence and genotypes in cats in southwestern China, and the first report of Type II T. gondii from cats in China.

Seroprevalence and genetic characterization of Toxoplasma gondii in three species of pet birds in China

Background

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China.

Methods

A total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies were determined using the modified agglutination test (MAT). Genomic DNA was extracted from the brain tissues of seropositive pet birds and T. gondii B1 gene was amplified using a semi-nested PCR.DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP.

Results

The overall T. gondii seroprevalence was 11.21% (77/687). C. spinus had the highest T. gondii seroprevalence (11.65%), followed by A. arvensis (11.39%) and C. migratorlus (5.26%), these differences were not statistically significant (P > 0.05). Of 77 DNA samples, 8 were positive for the T. gondii B1 gene, four showed complete genotyping results. Only one genotype (the Type II variant: ToxoDB genotype #3) was identified.

Conclusions

The results of the present survey indicated the presence of T. gondii infection in pet birds in Gansu province, China. These data provide base-line information for the execution of control strategies against T. gondii infection in pet birds. To our knowledge, this is the first report documenting the occurrence of T. gondii prevalence and genotype in pet birds in China.

Toxoplasma gondii prevalence in food animals and rodents in different regions of China: isolation, genotyping and mouse pathogenicity

BACKGROUND

Recent studies of Toxoplasma gondii isolates from animals in different regions of China have shown a limited genetic diversity and type China 1 was the dominant genotype of T. gondii prevalent in Chinese animals. However, little has been known concerning the isolation and genotyping of T. gondii circulating in chickens, pigs and rodents in China. The aim of the study was to characterize samples of T. gondii isolates obtained from naturally infected cats, pigs and free-range chickens slaughtered for human consumption in China.

METHODS

In the present study, brain tissues of 77 animals collected from different areas of China, including 24 free-range chickens (Gallus domesticus) , 13 voles (Rattus flavipectus), 23 pigs and 17 cats, were bioassayed in mice and viable T. gondii were isolated from the brains of eleven. These eleven T. gondii isolates were maintained in Kunming (KM) outbred mice and DNA isolated from tissues of infected mice was characterized using 11 PCR-restriction fragment length polymorphism (PCR-RFLP) markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3. Moreover, to determine mouse virulence of China 1 lineage of parasites, a TgCtgy5 genotype isolate was selected randomly and assessed in KM mice with different inoculation doses.

RESULTS

Results of genotyping revealed that ten isolates were type China 1 (ToxoDB PCR-RFLP genotype #9), and TgCksz1 was a new genotype that was reported for the first time designated here as ToxoDB PCR-RFLP #225. No clonal types I, II and III lineages were found. DNA sequencing of four introns (EF1, HP2, UPRT1 and UPRT7) and two genes (GRA6 and GRA7) from representative isolates confirmed the results of PCR-RFLP genotyping. The TgCtgy5 isolate was highly virulent in KM mice; all infected mice died of acute toxoplasmosis, irrespective of the inoculation dose. The results indicate that mouse virulent isolates of T. gondii are predominantly circulating in cats in China.

CONCLUSIONS

T. gondii isolated from chickens, pigs, cats and rodents in different locations in China were genotyped and the results reconfirmed the limited diversity of T. gondii in China and showed that type China 1 lineage was dominant in this country.