Genetic characterization of Toxoplasma gondii isolates and toxoplasmosis seroprevalence in stray cats of İzmir, Turkey

Gastrointestinal parasites of cats in the Middle East (2000-2023): A literature review

BACKGROUND/OBJECTIVE

Gastrointestinal parasites in stray cats are of significant clinical and zoonotic importance and pose a potential threat to public health. Hence, the current review has practical implications as it aims to present the diversity and the prevalence of cat parasites in Middle Eastern countries.

METHODS

The research process was rigorous and thorough, spanning from 2000 to 2023. Data collection and analysis were conducted utilizing multiple international and national databases, including Google Scholar, Scopus, PubMed, and Irandoc. This meticulous approach ensures the reliability and validity of the findings, providing a solid foundation for further research and preventive measures.

RESULTS

A total of 159 articles were collected and comprehensively reviewed. Among these, 85 articles were from Iran, 25 from Türkiye, 20 from Iraq, 11 from Egypt, five from Qatar, three from Cyprus, three from Kuwait, and one each from the UAE, Saudi Arabia, Syria, Lebanon, Jordan, Israel, and Palestine. Toxocara cati was the most prevalent nematode, exhibiting the highest prevalence in Iran, ranging from 8% to 90%, followed by Egypt, with a range of 8.23% to 58.7%. In comparison, the lowest prevalence was recorded in Qatar at 8%. Hydatigera taeniaeformis, a common cestode in the feline, showed the highest prevalence in Qatar, with a range of 73.6% to 75.8%, while the lowest was in Kuwait at 0.8%. In Iran, the prevalence ranged from 0.9% to 64.7%. Toxoplasma gondii, a cosmopolitan protozoan, showcased the highest prevalence in Lebanon at 78.1% and the lowest in the UAE at 0.8%. In Iran, the prevalence ranged between 1.2% and 90%. Additionally, noteworthy patterns regarding the distribution and potential risk factors associated with these parasites were observed. While gender variations were not significant, environmental conditions such as high humidity and absence of sunlight exposure, along with the age and behavior of cats, were among the risk factors associated with the prevalence of parasites.

CONCLUSION

The prevalence of parasites among stray cats in Iran and other Middle Eastern countries remains notably high. This emphasizes the urgent need for a series of control and preventive measures. Implementing effective anti-parasitic strategies and emphasizing the development of multiple diagnostic methods are essential.

Toxoplasma gondii genotypes and frequency in domestic cats from Romania

BACKGROUND

Toxoplasma gondii is a zoonotic protozoan parasite with a heteroxenus life cycle that involves felids as the definitive hosts and any warm-blooded animal, including humans, as intermediate hosts. Cats are key players in parasite transmission as they are capable of shedding high numbers of oocysts in their feces that contaminate the environment.

METHODS

The study was performed on 31 domestic cats (31.23 ± 27.18 months old) originating from rural and urban areas (5.17:1) in the center and north-west Romania. Feces (n = 31), blood (n = 28), and heart samples (n = 27) were collected. Fecal samples were analyzed by flotation technique, and PCR (529 bp repetitive element). Fecal samples with T. gondii oocysts were bioassayed in mice. Serum samples were analyzed by modified agglutination test and ImmunoComb for the detection of specific anti-T. gondii IgG antibodies. Heart samples were bioassayed in mice, and analyzed by PCR. Toxoplasma gondii positive samples were genotyped by nPCR-RFLP targeting eleven genetic loci (SAG1, SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico).

RESULTS

Toxoplasma gondii oocysts were found in 2 out of 31 fecal samples collected from a 3-months old stray kitten, and a 4-years old female. In total, 17 out of 27 sera were positive for T. gondii IgG antibodies. The antibody titers in MAT ranged from 1:6 to 1:384. Toxoplasma gondii DNA was detected in 7 out of 27 heart samples, and four of them were positive also by bioassay. Six T. gondii DNA samples from bioassayed mice could be assigned to ToxoDB PCR-RFLP genotype #1 or #3 (Type II) and one T. gondii DNA from heart digest to genotype #2 (Type III). Both of these genotypes are common in Europe.

CONCLUSIONS

Our results revealed that the infection with T. gondii is still high in cats from Romania. The oocysts shedded by these cats represent an important source of infection for intermediate hosts, including humans. Further studies on a wider range of cases are necessary for a more exhaustive definition of the T. gondii genotypes circulating in Romania.

Genetic characterization of Toxoplasma gondii strains isolated from humans living in İzmir, Türkiye

PURPOSE

Toxoplasma gondii is an obligate intracellular zoonotic parasite that can infect all warm-blooded animals, including humans. Currently, clinical findings of toxoplasmosis are being related to T. gondii strains such as Type I genotype may cause high pathogenicity and Type II genotype causes a milder clinical presentation. We have showed in our previous that Type II genotype is the most frequent strain detected in stray cats and wild birds living in natural life of İzmir. The aim of this study was to assess toxoplasmosis seroprevalence in immunocompromised patients, investigate the presence of T. gondii DNA in their blood samples, and genotype the PCR positive ones.

METHODS

The 42 buffy-coat and serum samples were collected from immunocompromised patients who were from various clinics. Thereafter, Real-Time PCR targeting RE gene of T. gondii was performed with DNA samples obtained from buffy-coat samples. Genotyping was performed by sequencing of GRA6 and GRA7 gene regions of positive DNA samples obtained from tissues of bioassay and PCR positive samples.

RESULTS

According to Real-Time PCR results, T. gondii DNA was detected in 23.8% (10/42) samples. Among these 10 samples, two samples were determined as T. gondii Type II genotype. Anti-Toxoplasma IgG antibodies were detected in 28.57% (12/42) samples.

CONCLUSIONS

Overall, the detection of Type II genotype in humans in İzmir province suggested that T. gondii infection in humans, stray cats, and wild animals may be associated to each other in terms of transmission.

A preliminary study to develop a lateral flow assay using recombinant GRA1 protein for the diagnosis of toxoplasmosis in stray cats

Toxoplasma gondii is a protozoan parasite that may infect many mammals including humans. Cats are one of the main sources of infection for humans. Therefore, routine screening of cats with tests that are inexpensive, rapid, and do not require sophisticated laboratory equipment is important. In this study, a lateral flow assay (LFA) was designed to rapidly diagnose toxoplasmosis in cats. For this purpose, we selected GRA1 protein of T. gondii due to its high antigenicity in diagnostic and vaccine studies. We further analyzed the immunological properties of GRA1 protein using in silico tools. Then, we expressed and purified recombinant GRA1 (rGRA1) protein and used it during the development of LFA to detect toxoplasmosis in serum samples (n = 40) of cats. According to the results, rGRA1 protein has negative GRAVY value, high aliphatic index, alpha helix, random coil and 12 B cell epitopes. The in silico data supported the high antigenic properties of rGRA1 protein and showed that it can be a good antigen candidate for LFA. Among 30 cat positive serum samples, 27 were found positive by the LFA while seronegative sera (n = 10) were negative by the LFA. The preliminary data showed that the LFA has high sensitivity (90 %) and specificity (100 %). When we used high responsive cat sera (i.e. sera that have optical density > 0.5 with ELISA) the sensitivity value reached 100 %. These results showed that rGRA1 protein is a good candidate to develop a LFA for rapid diagnosis of toxoplasmosis in cats.

Molecular prevalence and genetic diversity of Hepatozoon spp. in stray cats of İzmir, Türkiye

Hepatozoon spp. are an apicomplexan protozoan parasites that infect vertebrates including mammals, marsupials, birds, reptiles, and amphibians. Among Hepatozoon species, H. canis and H. felis are causative agents of hepatozoonosis in dogs and cats, respectively and have veterinary importance. This study aimed to determine the prevalence of Hepatozoon spp. in stray cats living in İzmir and investigate genetic diversity among positive samples. To achieve this aim, the prevalence of Hepatozoon spp. 18S rRNA gene was screened by PCR in DNA samples extracted from blood samples of stray cats (n = 1012). Then, Hepatozoon-positive samples were sequenced and the generated data were used for species identification, phylogenetic and haplotype analyses. According to the results, among the samples screened, 2.37 % (24/1012) of them were found to be Hepatozoon-positive, and of these positive samples, 18 (18/24; 75 %) were successfully sequenced. BLAST and phylogenetic analyses revealed that all of these samples were H. felis. Also, phylogenetic analysis showed that H. felis samples were genotype I. Within H. felis samples isolated from cats living in different countries/regions, 9 haplotypes were detected and among these haplotypes, H-1 was found to be prevalent (n = 20 H. felis isolates). In conclusion, this study showed that the prevalence of Hepatozoon spp. was low in stray cats analyzed. Also, H. felis genotype I was predominant in comparison to other Hepatozoon species.

Molecular prevalence of Enterocytozoon bieneusi in stray cats of İzmir, Türkiye

The phylum Microsporidia contains obligate single celled parasites that can infect many vertebrate hosts including humans. Enterocytozoon bieneusi is considered as the most diagnosed species in humans. E. bieneusi has also been detected in many animals such as cats, dogs and cattle. Among these animals, cats are carriers of type D and IV which are the most common human pathogenic genotypes of E. bieneusi. In Türkiye, the prevalence of E. bieneusi in stray cats is not well known. Therefore, in this study, the molecular prevalence of E. bieneusi in stray cats (n = 339) was determined by Real-Time PCR targeting ribosomal DNA ITS (internal transcribed spacer) region of E. bieneusi. Initially, the analytical sensitivity of Real-Time PCR was determined by a plasmid control and then E. bieneusi DNA was investigated in fecal samples of stray cats. The results showed that the analytical sensitivity of Real-Time PCR targeting ITS region of E. bieneusi was ≤1 copy plasmid/reaction. Analysis of fecal samples revealed that the molecular prevalence of E. bieneusi was 50.15% (170/339). Overall, these results showed that the Real-Time PCR successfully detected E. bieneusi in cat's fecal samples and stray cats can be an important source for transmission of E. bieneusi to humans and other animals.

Feline Toxoplasmosis in Greece: A Countrywide Seroprevalence Study and Associated Risk Factors

Toxoplasma gondii is a ubiquitous zoonotic parasite, with felines being the only definitive hosts. Cats shed oocysts with their faeces, and seroprevalence studies can be used to indirectly assess the environmental contamination. The current study aimed to evaluate T. gondii seroprevalence in Greek cats and identify possible risk factors. In total, 1554 blood samples were analyzed from different cats across all nine geographic regions of Greece, and a short questionnaire was completed for each cat. A rapid immunochromatographic test was used to detect anti-T. gondii antibodies, IgG type, and 21.8% of cats were seropositive. Regarding risk factors, when chi-square tests were applied, seropositivity was significantly higher (p < 0.05) in rural cats, cats with outdoor access, and hunting cats. Gender, age, ownership, and raw feeding were not significant risk factors, although female, adult, stray, and raw-feeding cats had a higher seroprevalence than their counterparts. Binary logistic regression models were developed to adjust for the confounding effects of the initially recognized risk factors, and only hunting in urban areas remained a significant risk factor. Greek cats had lower seropositivity than the average European value, and the present research highlights the importance of updated seroprevalence and risk factor studies within the context of One-Health.

Role of landscape context in Toxoplasma gondii infection of invasive definitive and intermediate hosts on a World Heritage Island

Free-ranging cats are invasive species threatening biodiversity worldwide. They may also impose an environmental risk to humans and livestock through the transmission of zoonotic diseases. We investigated antibody levels against Toxoplasma gondii in free-ranging cats and black rats (definitive and representative intermediate hosts) by ELISA and determined their relationships with landscape environmental factors on Tokunoshima Island, Japan, the Natural World Heritage site. We found a higher seroprevalence (>70%) in both cats and black rats in landscapes where the cattle barn density was high. This was consistent with higher density of rats revealed in our trapping survey. The spatial scale of landscape factors affecting infection was broader in cats (1 km buffer radius) than in black rats (100 m buffer radius). Both cats and rats showed an increasing trend in optical density (OD) values with increasing body weight and landscape cattle barn density, suggesting that the antibody concentration increases as the chance of exposure to T. gondii in the environment increases. Thus, management actions to stop humans from feeding cats and to control rat populations without using cats are both necessary to reduce the human health risk as well as to conserve endangered species on the island.

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High seroprevalence of T. gondii was found in cats and black rats on an island.

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Seroprevalence was high (>70%) in landscapes where there were many cattle barns.

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Antibody level in cats was lower in forests and higher around residential areas.

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Spatial scale of environmental factors affecting infection was broader in cats.

Molecular characterization and genotyping of Toxoplasma gondii in free-living animals in Iran: Effect of One Health

To understand the transmission of Toxoplasma gondii, this parasite's genetic diversity distribution in free-living hosts is essential. This research's objective is the molecular genotyping of T. gondii isolates from the brain and muscles of Columbidae, Corvidae, Rattus, and Felidae of Mianeh County, East-Azerbaijan Province, Northwest Iran. Three hundred fifty samples were taken. For the genotyping of T. gondii, the GRA6 gene was amplified and digested by the Tru1I (MseI) enzyme. Results of RFLP were confirmed by sequencing and phylogenetic analysis. In total, 52%, 34%, 24%, and 50% of Columbidae, Corvidae, Rattus, and Felidae were positive for T. gondii DNA, respectively. All isolated Columbidae were identified as genotype III (100%). Also, 94.1% and 5.9% of Corvidae isolates, 84.4% and 15.6% of the Rattus isolates, and 51.7% and 48.3% of the Felidae isolates belonged to genotypes III and II, respectively. This study is the first to evaluate genetic similarity and phylogenetic analysis between many definitive and intermediated hosts in northwestern Iran. The finding indicates that the T. gondii cycle is maintained among these hosts. As a result, their presence in the environment can be a risk factor for transmitting the infection to humans. Due to demographic and geographic differences in various regions, further studies are required to determine the genetic population structure.

Genetic diversity of Toxoplasma gondii isolates from rodents in the world: A systematic review

Toxoplasmosis is one of the most frequent food-borne infections in humans caused by an obligate intracellular protozoan parasite, Toxoplasma gondii. Rodents, as intermediate and reservoir hosts, play key role in the epidemiology of toxoplasmosis; because they are the main source of infection for the Felidae family members and establish the parasite life cycle. Hence, the infectious isolates of T. gondii in rodents may be the main genotypes infecting the environment, humans and animals. Our review aimed to present the population structure of T. gondii in these mammals. To access the relevant studies, six English language databases were systematically searched from 1990 to 2019. Finally, 3,395 samples of rodents were analysed for the genotyping data and 118 isolates were separated from the samples. The results of the present study showed that atypical genotypes were dominant with a frequency of 65.2% of the total isolates (77 out of 118). Clonal Types II, III and I had less frequency, respectively. Type I clonal isolates were identified only from Asia. The examination of genotypes circulating in rodents around the world revealed that ToxoDB #1 or #3 (Type II) were the most common, followed by ToxoDB #9 and #2, respectively. Overall, our data showed low genetic diversity of T. gondii with circulating clonal strains in rodents compare to the isolates from Europe, North America and Africa, while non-clonal parasites with high genetic diversity were dominant in South America and Asia.

Molecular prevalence and subtyping of Cryptosporidium spp. in fecal samples collected from stray cats in İzmir, Turkey

Background

Cryptosporidium spp. are obligate intracellular apicomplexan parasites transmitted to humans and other animals by contaminated water, food, or direct contact. They mainly cause gastrointestinal symptoms, although subclinical infections are also common. Cats are primarily infected by host-adapted Cryptosporidium felis while C. parvum and C. muris have also been detected in some cases. In this study, the molecular prevalence of Cryptosporidium spp. was investigated by screening 399 fecal samples collected from stray cats using nested PCR targeting the 18S rRNA gene for the first time in Turkey. Additionally, Cryptosporidium PCR-positive samples were genotyped by nested PCR- restriction fragment length polymorphism (RFLP), and subsequently, amplicons of 18S SSU rRNA were sequenced. They were further subtyped by amplification and sequencing of the gp60 gene.

Results

Among fecal samples screened, 12 of them (3%) were found to be Cryptosporidium-positive, and according to RFLP and sequencing of 18S rRNA gene, all positive samples were identified as C. felis. Subtyping analyses at the gp60 gene showed that C. felis isolates belonged to the XIXa subtype family, which are closely related to human subtypes of the parasite.

Conclusions

The results of this study are important in terms of indicating the potential role of stray cats for transmission of Cryptosporidium spp. to humans or other animals. Also, the presence of XIXa, which is the dominant subtype family of C. felis in cats and humans was shown for the first time in stray cats of İzmir, Turkey.

Development of a new serotyping ELISA for Toxoplasma gondii type II, type III and Africa 1 lineages using in silico peptide discovery methods, well categorized feline and human outbreak serum samples

BACKGROUND

Discovery of new Toxoplasma gondii serotyping epitopes is important due to reports showing the influence of genotype on the severity of toxoplasmosis. In Turkey, genotypes belonging to type II, type III and Africa 1 lineages were mainly detected. The present study focused on to find out epitopes with high discriminative capacity to serotype these genotypes using well characterized strains isolated from Turkey.

METHODS

To meet this objective, GRA6 and GRA7 genes were sequenced from strains belonging to the type II, III and Africa 1 lineages, and B cell epitopes inside these sequences were predicted by Bcepred and additional docking analysis was performed with B cell receptor. Based on these analyses, 22 peptides harboring lineage specific epitopes were synthesized. Then, the serotyping potency of these peptides was tested using peptide ELISA and well categorized serum samples collected from stray cats infected with genotypes of the different lineages type II (n:9), III (n:1) and Africa 1 (n:1). As a result of peptide-ELISA, a serotyping schema was constructed with peptides that show high discriminative capacity and this assay was validated by sera collected from humans after an outbreak (n:30) and mother/newborn pair sera (n:3). Later, the validated serotyping schema was used to serotype a larger group of human (n:38) and cat (n:24) sera.

RESULTS

Among 22 peptides, GRA6II/c, GRA7III/d, and GRA6 Africa 1/b epitopes have shown discriminative capacity. During the validation of peptide-ELISA, the serotype of toxoplasmosis outbreak and mother/newborn cases were detected to be serotype II. Moreover, the analyses in a larger group showed that serotype II was prevalent in humans and stray cats.

CONCLUSIONS

Overall, the results showed that the serotyping schema could be successfully used to serotype T. gondii infections caused by type II, III and Africa 1 genotype.

Prevalence of Toxoplasma gondii Measured by Western Blot, ELISA and DNA Analysis, by PCR, in Cats of Western Mexico

Toxoplasma gondii is the causative agent of toxoplasmosis in humans and animals. The sexual reproductive cycle of Toxoplasma takes place in the small intestine of felines, the definitive hosts. In the final part of the sexual cycle, T. gondii forms oocysts in infected cats. Oocysts transferred via the faeces to the environment are highly infectious to both animals and humans. This study aimed to determine the prevalence and risk factors associated with T. gondii infection in cats from the metropolitan region of Guadalajara in western Mexico. Western blotting and ELISA for anti-Toxoplasma IgG antibodies was performed, and Toxoplasma DNA was identified using polymerase chain reaction. Prevalence of anti-T. gondii antibodies was 14.8% (44/297), and only 2/297 cases were positive for PCR. Cats older than one year were at an increased risk of infection (OR = 3.9, 95% CI 1.844-8.362). Sex, raw meat feeding, hunting habits, vaccination status, and body condition were not associated with positivity. The prevalence of T. gondii infection determined with Western blot in cats in the metropolitan area of Guadalajara, Jalisco, Mexico, was lower than that reported in previous studies.

Rapid detection of Toxoplasma gondii DNA in cat feces using colorimetric loop-mediated isothermal amplification (LAMP) assays targeting RE and B1 genes

Toxoplasma gondii is an obligate protozoan parasite that can infect mammals and birds. Cats are the definitive host of T. gondii and have a very important role in transmission of toxoplasmosis due to the shedding of millions of unsporulated oocysts, that become infective in the environment. Since cats play a major key role in the epidemiology of toxoplasmosis, rapid and accurate diagnosis of infected cats has utmost importance. In this study, we developed a novel colorimetric loop mediated isothermal amplification (LAMP) assay detecting T. gondii RE gene and modified a previously developed colorimetric LAMP assay targeting B1 gene to detect T. gondii DNA in cat feces for the first time. The analytical sensitivity of colorimetric LAMP assays was determined using plasmid controls. The clinical sensitivities of both colorimetric LAMPs were determined using cat fecal DNA samples that were confirmed to be positive by two different real-time PCRs in our previous study. According to the results, analytical sensitivities of both assays were 1 copy plasmid/reaction. Using real-time PCR as a reference method, sensitivities of colorimetric LAMP assays targeting RE and B1 genes were 100% and 97.56% whereas specificities of both assays were 100%. Overall, the colorimetric LAMP RE assay developed in this study brings an advantage in the diagnosis of T. gondii in cat fecal samples since it has higher sensitivity, does not need for experienced personnel, and can be applied in basic laboratories or in the field.

Toxoplasma gondii Genotypes Circulating in Serbia-Insight into the Population Structure and Diversity of the Species in Southeastern Europe, a Region of Intercontinental Strain Exchange

In Europe, Toxoplasma gondii lineage II is dominant, and ToxoDB#1 the most frequently occurring genotype. The abundance of lineage III genotypes varies geographically and lineage I are rare, yet present in several regions of the continent. Data on the T. gondii population structure in southeastern Europe (SEE) are scarce, yet necessary to appreciate the diversity of the species in Europe. To help fill this gap, we genotyped 67 strains from nine species of intermediate hosts in Serbia by MnPCR-RFLP, determined the population structure, and identified the genotypes using ToxoDB. A neighbor-joining tree was also constructed from the isolates genotyped on nine loci. While 42% of the total genotype population consisted of ToxoDB#1 and ToxoDB#2, variant genotypes of both lineages comprised 46% of the population in wildlife and 28% in domestic animals and humans. One genotype of Africa 4 lineage was detected in a human sample. Interestingly, the findings include one lineage III variant and one II/III recombinant isolate with intercontinental distribution, which appear to be moderately related to South American genotypes. Based on these findings, SEE is a region of underappreciated T. gondii genetic diversity and possible strain exchange between Europe and Africa.

Presence of atypical genotypes of Toxoplasma gondii isolated from cats in the state of Bahia, Northeast of Brazil

In this study, 20 blood, heart, and brain samples were collected from euthanized cats at the Zoonosis Control Centers and Veterinary Clinics in the state of Bahia, Brazil. The sera were examined for anti-T. gondii antibodies using the indirect hemagglutination test. The brains and hearts of seven seropositive cats were ground, and peptide digestion was performed for bioassay in mice. Toxoplasma gondii was isolated in 5/7 (71.42%) of seropositive cats. In these isolates, the parasite was genotyped using the Polymerase chain reaction, associated with the DNA fragment polymorphism obtained by restriction enzyme PCR-RFLP technique with 11 markers (SAG1, 5’-SAG2, 3’-SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3) and 15 microsatellite markers (TUB-2, W35, TgM-A, B18, B17, M33, IV.1, XI.1, M48, M102, N60, N82, AA, N61, N83). The analysis of the isolates by PCR-RFLP revealed five distinct genotypes. Three of these genotypes have never been reported before; one corresponded to the TgDgCo13 genotype, and one incomplete genotype. In genotyping analysis using microsatellite markers, it was observed that the isolates showed atypical alleles in the typing and fingerprint markers. This revealed five atypical genotypes. The typing marker B17 showed the highest degree of atypia. This study is the first to report the genotyping of T. gondii obtained from naturally infected cats in Bahia, Northeast Brazil. The genotypes found in this study were different from those found in other studies conducted in Bahia, which included different species of animals. None of the clonal lineages I, II, or III were found. This study demonstrates the diversity of T. gondii in the study region, with the presence of unusual genotypes, reaffirming the genetic variability of the parasite in Brazil.

The molecular and serological investigation of Feline immunodeficiency virus and Feline leukemia virus in stray cats of Western Turkey

This study aimed to investigate the Feline immunodeficiency virus (FIV) / Feline leukemia virus (FeLV) infection prevalence among looking healthy stray cats in Western Turkey by serologic and molecular-based tests. A total of 1008 blood samples from the stray cats were used in this study. All samples were tested for FIV antibodies / proviral DNA and FeLV antibodies / antigens / proviral DNA. The genetic characterization and phylogenetic analysis of FeLV and FIV were carried out in this study. These cats also tested for Leishmaniasis and Toxoplasmosis previously. FIV Ab and proviral DNA detected in 25.2 % and 25.5 % of samples, respectively. FeLV Ab, Ag, proviral DNA positivity was in 45.2 %, in 3.3 %, in 69.7 %, respectively. The molecular detection and phylogenetic analysis of the current FeLV pol gene and FIV gag gene performed. The molecular characterization for the pol gene of FeLV (enFeLV and exFeLV) among Turkey's cat population was reported for the first time. The exFeLV pol sequences closer to the FeLV-A genotype, and the enFeLV pol sequences overlapped with other enFeLV. The current FIV gag sequences were clustered within the subtypes A, B, and C. The findings revealed FeLV subtype A and FIV subtype-A, subtype-B, subtype-C circulate among Turkish stray cats. Single and multiple co-infection positivity was found higher compared to previous reports.

GRA8 DNA vaccine formulations protect against chronic toxoplasmosis

Toxoplasma gondii has a very wide host range and infects all warm-blooded animals including humans. The disease causes great economic losses both in animals and humans. Vaccination is the most effective approach to fight against toxoplasmosis however an effective vaccine has not been developed yet. In the present study, GRA8 protein of T. gondii that showed high immunogenicity in our previous microarray screening study was used to develop a DNA vaccine using pcDNA 3.3 vector for the first time. In order to increase the potency of the DNA vaccine, 10 times lower amount of GRA8 DNA vaccine was combined with molecular adjuvant CpG and formulated into a commercial liposome (pcDNA3.3-GRA8+CpG+Escort). Mice were vaccinated intramuscularly two times at three-week intervals and challenged orally with the T. gondii PRU strain tissue cysts. The humoral immune response was determined by Western Blot and ELISA. The cellular immune response was analyzed by flow cytometry, cytokine ELISA and MTT assay. Among the vaccine groups, pcDNA3.3-GRA8 and pcDNA3.3-GRA8+CpG+Escort induced strong IgG response compared to controls (P < 0.001). The IgG1 and IgG2a responses showed a balanced Th1-Th2 polarization. The ratio of CD4⁺ and CD8⁺ T lymphocytes secreting IFN-γ increased, and significantly higher extracellular IFN-γ secretion was achieved compared to the controls (P < 0.01). The amount of tissue cysts in the group of mice vaccinated with pcDNA3.3-GRA8 decreased significantly compared to control groups (P < 0.0001). In the group vaccinated with pcDNA3.3-GRA8+CpG+Escort, the amount of tissue cysts also decreased significantly compared to PBS (P = 0.0086) and Empty plasmid+CpG+Escort (P = 0.0007) groups. This study showed for the first time that pcDNA 3.3. vector encoding GRA8 with or without CpG and Liposome can induce strong cellular and humoral immune responses and confer strong protection against mouse model of chronic toxoplasmosis.

First isolation and genotyping of Toxoplasma gondii strains from domestic animals in Tunisia

The isolation and molecular typing of Toxoplasma gondii strains provide an essential basis for a better understanding of the parasite’s genetic diversity, determinants of its geographical distribution and associated risks to human health. In this study, we isolated and genetically characterized T. gondii strains from domestic animals in Southern and coastal area of Tunisia. Blood, hearts and/or brains were collected from 766 domestic animals (630 sheep and 136 free-range chickens). Strain isolation from these samples was performed using mouse bioassay and genotyping was carried out with a multiplex PCR technique using 15 microsatellite markers. Thirty viable strains of T. gondii were successfully isolated from tissues of sheep (19/142) and chickens (11/33). In addition, 3 strains could be successfully genotyped from animal tissues for which mouse bioassay was unsuccessful. A large predominance of type II strains (n = 29) was found in the sampled regions, followed by type III (n = 3) and, for the first time in Tunisia, a single isolate of Africa 4 lineage from a sheep. Analyses of population genetics showed the presence of a divergent population of type II lineage in Tunisia, supporting limited recent migrations of strains between Tunisia and other countries of the world.

Prevalence of serum antibodies to Toxoplasma gondii in free-ranging cats on Tokunoshima Island, Japan

The prevalence of Toxoplasma gondii infection in free-ranging cats on Tokunoshima Island was assessed by testing 125 serum samples using anti-T. gondii IgG indirect enzyme-linked immunosorbent assay. The overall seropositivity rate was 47.2% (59/125). Seropositivity rates in cats with body weight >2.0 kg (57.4%) were significantly higher than in those with body weight ≤2.0 kg (12.5%, P<0.01). Analysis of the number of seropositive cats by settlement revealed the presence of possibly-infected cats in 17 of 23 settlements, indicating the widespread prevalence of T. gondii on the island. This is the first study to show the seroprevalence of T. gondii in free-ranging cats on Tokunoshima Island. The information revealed in this paper will help to prevent the transmission of T. gondii among cats and also in both wild and domestic animals and humans on the island.

All about toxoplasmosis in cats: the last decade

Toxoplasma gondii infections are common in humans and animals worldwide. Toxoplasmosis continues to be of public health concern. Cats (domestic and wild felids) are the most important host in the epidemiology of toxoplasmosis because they are the only species that can excrete the environmentally resistant oocysts in feces. Cats can excrete millions of oocysts and a single cat can spread infection to many hosts. The present paper summarizes information on prevalence, persistence of infection, clinical signs, and diagnosis of T. gondii infections in domestic and wild cats for the past decade. Special emphasis is paid to genetic diversity of T. gondii isolates from cats. Review of literature indicates that a unique genotype (ToxoDB genotype #9 or Chinese 1) is widely prevalent in cats in China and it has been epidemiologically linked to outbreaks of clinical toxoplasmosis in pigs and deaths in humans in China; this genotype has rarely been detected in other countries. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Toxoplasma gondii Seropositivity and Associated Risk Factors in Cats (Felis catus) in Three Provinces in Northeastern China from 2013 to 2019

Toxoplasma gondii is an important protozoan parasite that can infect a range of animals. Cats are the most important definitive hosts for T. gondii. Therefore, an assessment of the level of T. gondii infection in cats is of public health importance. As limited information about seroprevalence of T. gondii infection in cats in northeastern China was available, 854 serum samples, including 235 cats in Jilin province, 267 cats in Liaoning province, and 352 cats in Heilongjiang province, were examined by an indirect hemagglutination assay (IHA) test, between September 2013 and July 2019. The overall seroprevalence of T. gondii was 19.09% (163/854) at the cutoff 1:64, with 19.60% (69/352), 18.29% (43/235), and 19.10% (51/267) in Heilongjiang, Jilin and Liaoning, respectively. Logistic regression analysis showed that mode of life was highly related to T. gondii infection in cats at the investigation areas. These results could provide foundation data for prevention and control of T. gondii prevalence in these regions. Moreover, the results also suggested that the effective control strategies should continue to be performed.

Comparison of an in house and a commercial real-time polymerase chain reaction targeting Toxoplasma gondii RE gene using various samples collected from patients in Turkey

Background

Toxoplasma gondii is an opportunistic protozoan parasite that can infect all warm-blooded animals including humans and cause serious clinical manifestations. Toxoplasmosis can be diagnosed using histological, serological, and molecular methods. In this study, we aimed to detect T. gondii RE gene in various human samples by in house and commercial real time polymerase chain reactions.

Methods

A total of 38 suspected cases of toxoplasmosis [peripheral blood (n:12), amnion fluid (n:11), tissue (n:9), cerebrospinal fluid (n:5), and intraocular fluid (n:1)] were included to the study. An in house and a commercial RT-PCR were applied to investigate the T. gondii RE gene in these samples.

Results

The compatibility rate of the two tests was 94.7% (37/38). When the commercial RT-PCR kit was taken as reference, the sensitivity and specificity of in house RT-PCR test was 87.5 and 100%. When the in house RT-PCR test was taken as reference, the commercial RT-PCR kit has 100% sensitivity and 96.8% specificity. Incompatibility was detected in only in a buffy coat sample with high protein content.

Conclusions

Both the commercial and in house RT-PCR tests can be used to investigate T. gondii RE gene in various clinical specimens with their high sensitivity and specificity. In house RT-PCR assay can be favorable due to cost savings compared to using the commercial test.

A review of toxoplasmosis in humans and animals in Turkey

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Turkey but little is known of the burden of their clinical toxoplasmosis. Many early papers on toxoplasmosis in Turkey were published in Turkish and often not available widely. Here, we review prevalence, clinical spectrum, epidemiology and diagnosis of T. gondii in humans and animals in Turkey. This knowledge should be useful to biologists, public health workers, veterinarians and physicians. Although one-third of the human population in Turkey is seropositive, the rate of congenital toxoplasmosis is unknown and no information is available in children 12 years old or younger. One large outbreak of acute toxoplasmosis has been reported in 14–18-year old school children in Turkey. An alarming rate (36%) of T. gondii tissue cysts were reported in tissues of sheep and water buffalo meats destined for human consumption; these reports require verification. Genetically, T. gondii strains from domestic cats and wild birds in Turkey were generally classical type II and III, like those prevalent in Europe. A separate genotype, Type 1 Africa, was isolated from two congenitally infected children and a domestic cat in Turkey.

A systematic review of Toxoplasma gondii genotypes and feline: Geographical distribution trends

Toxoplasma gondii (T. gondii) is well known for its ability to virtually infect all warm-blooded vertebrates. Although felines as the definitive hosts have an important role in the epidemiology of toxoplasmosis, there are few descriptions of genetic diversity in the world. The present review study aimed to describe the population structure of T. gondii in these animal species. For the purpose of the study, five English language databases reporting data on T. gondii genotyping in cats were searched within March-June 2019. This study is registered on the site of CAMARADES-NC3Rs (15-Jan-2018). The searching process resulted in the inclusion of 50 reports published from 1992 to June 2019. The data revealed that 47,390 samples were genotyped into 662 T. gondii DNA/isolates. Globally, atypical genotypes were predominant (47.7%, n = 316); in addition, Type II clonal strains were the second most common genotype (37%, n = 244). These results suggested an epidemic population structure in America and Asia, and a clonal population structure in Europe and Africa. Genotype #3 was found to be dominant in Africa, Europe and Oceania continents. Furthermore, genotypes #9 and #5 were prevalent in Asia and America, respectively. Additionally, genotypes #2, #3, #5 and #20 were common genotypes in domestic and sylvatic cycles from family Felidae. Collectively, this systematic review indicated a large degree of genetic diversity and circulation of mouse-virulent T. gondii strains in this family. However, further studies are necessary to better understand the population structure of T. gondii in these animal species and determine the significance of their features.

A serological and parasitological study of Toxoplasma gondii infection in stray cats of Mashhad, Khorasan Razavi province, Iran

The aim of the present study was to determine seroprevalence of Toxoplasma gondii infection in stray cats and correlation with oocyst shedding and IFN-γ concentration. From April to August 2016, one hundred fifty-nine stray cats were captured from various localities in Mashhad area. The blood and fecal samples were collected from each cat. The serum samples were examined to detect antibodies against T. gondii infection by ELISA assay and the fecal samples were microscopically examined for T. gondii oocyst detection. The concentration changes of IFN-γ in serum samples of seropositive and seronegative cats were measured using ELISA kit. The results showed that 59.12% (94/159) of cats had antibodies against T. gondii infection. The seroprevalence of T. gondii infection in the adult cats above three years olds was higher than other groups. Regarding gender, month and region factors, the difference of seroprevalence of T. gondii infection was not significant. In this study, the Toxoplasma/Hammondia like oocyst (THLO) were detected in 2.56% (4/156) in fecal samples of one seropositive and three seronegative cats. Results also showed that the mean value for IFN-γ concentration in the seropositive cats was significantly higher than that of the seronegative cats. Based on the results, the high percentages of stray cats were infected with T. gondii in this area. The IFN-γ concentration of seropositive cats was higher than that of the seronegative cats.

Diversity of Toxoplasma gondii strains at the global level and its determinants

The population structure of Toxoplasma gondii is characterized by contrasting geographic patterns of strain diversity at different spatial scales: global, regional and even local scales in some regions. The determinants of this diversity pattern and its possible evolutionary mechanisms are still largely unexplored. This review will focus on three main dichotomies observed in the population structure of the parasite: (1) domestic versus wild, (2) South America versus the rest of the world and (3) intercontinental clonal lineages versus regional or local clonal lineages. Here, the impact in terms of public health of this remarkably contrasting geographic diversity of T. gondii populations is discussed, with emphasis on the role of globalization of exchanges that could lead to rapid evolution of T. gondii population spatial structure and new challenges in a One Health context.

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Recombination events drive the evolution of population structure of Toxoplasma gondii.

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The population structure of Toxoplasma is different in wild and domestic environments.

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Virulence of Toxoplasma strains in reservoir hosts influences selection of local strains.

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Globalization of exchanges will impact the population structure of the parasite.

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Clinicians should be aware of more pathogenic strains imported from the wild environment or from South America.

Prevalence of toxoplasmosis and genetic characterization of Toxoplasma gondii strains isolated in wild birds of prey and their relation with previously isolated strains from Turkey

Toxoplasma gondii is a protozoon parasite that causes congenital toxoplasmosis, as well as other serious clinical presentations, in immune compromised humans. Analyses of the prevalence and genotyping of strains from the definitive host and intermediate hosts will help to understanding the circulation of the different strains and elucidating the role of the genotype(s) in human toxoplasmosis. Turkey has a specific geographic location bridging Africa, Europe, and Asia. We hypothesized that T. gondii strains may have been transferred to Turkey from these continents via migratory birds or vice versa. The present study aimed to assess the prevalence of toxoplasmosis in wild birds of prey of İzmir and Manisa provinces as well as genetically characterize T. gondii strains from these wild birds to show the relation between bird strains and neighboring stray cats as well as human strains previously isolated in Turkey. Tissues obtained from 48 wild birds were investigated for the presence of T. gondii DNA and then bioassayed in mouse. Isolated strains were genotyped using 15 microsatellite markers. The prevalence of T. gondii DNA was found to be 89.6% (n: 43/48) in wild birds. Out of 43 positive samples, a total of 14 strains were genotyped by 15 microsatellite markers. Among them, eight were type II, three were type III and three were mixture of genotypes (two type II/II and one was II/III). These are the first data that showed the presence of T. gondii and types II and III genotypes in wild birds of Turkey. Moreover, Africa 1 was not detected. In addition, cluster analysis showed that T. gondii strains within type II and III lineage have close relation with strains previously isolated from stray cats in İzmir. Further studies are required to isolate more strains from human cases, other intermediate hosts, and water sources to reveal this relation.

Direct genetic characterization of Toxoplasma gondii from clinical samples from Denmark: not only genotypes II and III

Genetic variation within Toxoplasma gondii can have both clinical and epidemiological significance, while the genotypes circulating in many parts of the world, including the Nordic country Denmark, are still unknown. We genetically characterized T. gondii strains that had been detected in human clinical samples in Denmark in 2011-2016. Samples that had tested positive for T. gondii DNA and had a quantification cycle value <33 were included in this study and subjected to direct genetic characterization of T. gondii based on length-polymorphism of 15 microsatellite markers. A total of 23 DNA samples from 22 individual patients were analyzed. The results were consistent with genotype II with 15/15 markers amplified from seven samples from the central nervous system (CNS) including two samples from one patient, four ocular samples, and one unspecified sample; with genotype III with 15/15 markers amplified from two ocular samples; with genotype Africa 1 with 15/15 markers amplified from one amniotic fluid sample and from one CNS-sample; with atypical genotype with 15/15 markers amplified from one CNS-sample and with 11/15 markers amplified from one CNS-sample; and with HG12-like genotype with 9/15 markers amplified from one CNS-sample. Genotype II, which is endemic in Europe, was predominant, but more than a third of the successfully genotyped strains were non-type-II. The possibility that clinical toxoplasmosis is caused by a strain that is not considered endemic to the region is definitely not negligible.

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.

Toxoplasma gondii Type I, predominant genotype isolated from sheep in South of Iran

Aim:

This study was performed to determine the genetic diversity of Toxoplasma gondii in sheep using nested-polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in Southern Iran.

Materials and Methods:

The tissue samples of diaphragm and heart from 125 sheep were collected from the main slaughterhouses of Jahrom district in South of Fars province, Iran, between Aprils and June 2013. The DNA were extracted and analyzed by nested-PCR using specific primers for SAG2 and GRA6 loci. RFLP was used to classify strains into one of the three major lineages of T. gondii.

Results:

T. gondii Type I was predominant in this area. The data obtained from both loci demonstrated that the frequency of each genotype was 72% Type I, 2.4% Type III, 7.2% mixed Type I and II, 16.8% mixed Type I and III, 0.8% mixed Type II and III, and 0.8% mixed Type I, II and III.

Conclusions:

Although the previously published data indicated that Type II is the predominant T. gondii genotype in sheep in the other parts of the world, this study showed that genotype I is the dominant genotype of T. gondii in the southern Iran; however, other genotypes were detected. High diversity of T. gondii genotypes including mix genotypes in lambs is of importance for the public health. These studies depict a new mapping of T. gondii genotypes pattern which could be very helpful in toxoplasmosis control and prevention.

A survey study on gastrointestinal parasites of stray cats in Azarshahr, (East Azerbaijan province, Iran)

Gastrointestinal parasites are among the most common parasitic infections found in stray cats, which might act potential helminthic parasites to domestic cats. The objective of this study was to determine the prevalence of gastrointestinal parasites in stray cats in the city of Azarshahr, which is located in East Azerbaijan province, Iran. A cross-sectional study was conducted on 50 necropsied stray cats, trapped and collected from different geographic regions of Azarshahr. From a total 50 stray cats examined, 15 (30 %) were female and 35 (70 %) were male. Overall 47 cats (94 %) were identified as infected with at least one of the endoparasites. The prevalence of parasites found were: Taenia taeniaeformis (60 %), Dipylidium caninum (58 %), Taenia hydatigera (24 %), Mesocestoides lineatus (78 %), Ancylostoma tubaeforme (14 %), Toxascaris leonina (30 %), Toxocara cati (78 %), Physaloptera praeputialis (10 %), and Syphacia obvelata (10 %). Contamination rate for zoonotic parasites of cat was greater than expected in AzarShahr region. Therefore, appropriate control measures should be taken and preventive methods should be applied.

Identification of Toxoplasma gondii antigens associated with different types of infection by serum antibody profiling

Acquisition of acute toxoplasmosis during the first trimester of pregnancy can have catastrophic consequences for the foetus. Diagnosis is routinely based on the detection of maternal Toxoplasma gondii--antibodies using whole parasite extracts as detection antigen. While such assays are sensitive, they show no specificity for the stage of infection. We hypothesized diagnosis might be improved using recombinant antigens for detection, particularly if antibodies to certain antigen(s) were associated with early or late stages of infection. To address this, protein microarrays comprising 1513 T. gondii exon products were probed with well-characterized sera from seronegative ('N') controls, and acute ('A'), chronic/IgM-persisting ('C/M') and chronic ('C') toxoplasmosis cases from Turkey. Three reactive exon products recognized preferentially in A infections, and three recognized preferentially in C/M infections, were expressed in Escherichia coli and tested for discrimination in IgG ELISAs. The best discriminators were exon 1 of TGME49_086450 (GRA5) which detected C/M infections with 70.6% sensitivity and 81.8% specificity, and exon 6 of TGME49_095700 (ubiquitin transferase domain-containing protein) which detected A infections with 84.8% sensitivity and 82.4% specificity. Overall, the data support a recombinant protein approach for the development of improved serodiagnostic tests for toxoplasmosis.