Prevalence of Ecto and Gastrointestinal Parasites of Rattus rattus in Mazandaran Province, North of Iran

Objective: Rodents act as reservoir hosts and are an important potential source for many zoonotic pathogens such as parasites, which pose a public health risk to humans. Therefore, it is necessary to investigate the prevalence of parasites among rodents. Methods: A total of 118 Rattus rattus were captured in Mazandaran province, north of Iran, using snap live traps. Various samples were collected from feces and each rat was combed with a fine-tooth comb to extricate any ectoparasite. Fecal specimens were examined by direct wet mounting, formalin-ether concentration, modified acid-fast, and trichrome staining methods. Results: The overall prevalence of gastrointestinal parasites in the examined rats was 75.4%. Cryptosporidium spp. (30.5%) were the most prevalent protozoan, followed by Giardia spp. (20.3%), Entamoeba muris (13.5%), Trichomonas muris (10.1%), and Spironucleus muris (3.3%). Regarding helminths' eggs, Syphacia obvelata (24.5%), Hymenolepis diminuta (10.1%), and Trichuris muris (9.3%) had the highest prevalence, respectively. Furthermore, 3060 ectoparasites collected from 102 rodents were infested with lice (40% Polyplax spp.), mites (33.3%), and flea (16.1% Xenopsylla cheopis and 10.6% Xenopsylla astia). Conclusion: According to the results of this study, the prevalence of ecto and gastrointestinal parasites in the collected rats in the area being studied was remarkably high. Additionally, Rattus rattus can be considered a potential risk to human health.

Biodegradable chitosan-graphene oxide as an affective green filler for improving of properties in epoxy nanocomposites.

In this work, we investigated the effect of biodegradable Chitosan-encapsulated Graphene Oxide (CGO) on the morphology and properties of epoxy composites prepared using solution mixing with different filler loadings. The microstructures and properties of chitosan-GO and composites were studied using FTIR, XRD, SEM, TEM, tensile, impact, bending analysis, DMTA and TG tests. Microstructural observations confirmed that the CGO composition and its content in the matrix affected the distribution of fillers in the epoxy matrix. Mechanical and thermal tests indicated that the loading level of CGO and the ratio of chitosan to GO were the main factors that changed the strength of epoxy/CGOs composites. The tensile analysis confirmed that nanocomposites containing CGO exhibited a 65 % increase in elastic modulus due to the improved load transfer as a result of interfacial interactions between CGO and the matrix. DMTA analysis showed that the presence of CGO in the epoxy matrix increased Tg of the composite by ~30 °C. In the TGA test, although the introduction of CGO caused higher decomposition temperature of the CGO filled resins. CGO enhanced the final properties of epoxy-based nanocomposites as a result of the synergistic effect of chitosan and GO and the formation of 3-D CGO structures in the epoxy matrix.

Identification and multilocus genotyping of Toxoplasma gondii isolates from congenital infection in north of Iran.

Congenital toxoplasmosis can cause severe consequences in the fetus, such as spontaneous abortion which is affected by parasite strain. Also, recent studies revealed the high genetic diversity of Toxoplasma gondii. This study aims to investigate the serological status of T. gondii in pregnant women, multilocus genotyping in aborted fetuses' tissue, and archived formalin-fixed paraffin-embedded placenta. This study was performed on 100 pregnant women with spontaneous abortion and their aborted fetuses, and 250 of the archived placentae in Iran. The blood and tissue were examined for seroprevalence and genotype determination of T. gondii using ELISA and multilocus nested-PCR-RFLP, respectively. Anti-T. gondii IgG and IgM were detected in 68 samples (68%) and 1 (1%) out of 100 serums. Toxoplasma DNA was identified in 1 (1%) aborted fetuses' tissue and 32 (12.8%) placenta samples. Overall, ten positive DNA samples were successfully genotyped, and five genotypes were recognized (ToxoDB#1, #2, #10, #27, and #48). The obtained results indicated congenital toxoplasmosis is a severe risk in this region. As type I is highly pathogen and can lead to severe complications, the prevention of the infection should be considered in seronegative pregnant women.

More Than Seventy Years of Research (1948-November 2021) on Toxoplasma gondii in Iran: A Narrative Review.

In this review, we intend to provide a summary of the activities of researchers in the field of Toxoplasma gondii in Iran, during the past 70 years. Most studies have been limited to epidemiological studies (mostly using ELISA and IFA methods). Designing a standard and reliable method using the specific antigens of this parasite is essential. So far, studies in the field of drug effects have not been able to introduce an effective drug with few side effects. Various types of vaccines have been developed, such as recombinant and DNA vaccines. However, none of them had a good efficacy. The use of multi-epitope vaccines as potential vaccines against toxoplasmosis is recommended. At present, limited studies have been conducted on the patterns of transmission and genetic diversity of isolated isolates in Iran. Future research to determine the genotype of T. gondii could play an important role in the study of population structure, and biological characteristics of this parasite. It is hoped that the results of this study will help control, prevent, and reduce the burden of disease caused by this parasite.

Diagnosis of Toxoplasmosis in Ruminants Aborted Fetuses in Northern Iran Using Molecular and Bioassay Techniques.

BACKGROUND: Toxoplasma gondii is a zoonotic obligatory intracellular protozoan parasite that infects a wide range of warm-blooded species. This study aimed to obtain further information on the role of T. gondii infection in ruminant abortion (sheep, goats and cattle) using bioassay and PCR methods in Mazandaran province, northern Iran. METHODS: Overall, 104 aborted fetuses (52 bovine, 48 ovine, 4 caprine) were collected at different stages of gestation during the lambing seasons in various parts of Mazandaran Province from Mar 2016 to May 2017. Brains of 104 aborted fetuses were bioassayed in female BALB/c mice. DNA was extracted from all brain samples using phenol-chloroform-isoamyl Alcohol instructions. RE gene was used for detection all of T. gondii DNA by conventional PCR assay. RESULTS: The results of the bioassayed samples were negative because no tachyzoites or cyst were observed in the peritoneal and brain specimens of the mice. The detection of T. gondii DNA was confirmed by observation of a 529 bp band in 15 out of 104 fetuses (14.4%). The highest prevalence rate of T. gondii detected from sheep (16.6%) followed by cattle (13.4%) and goats (0%). The highest prevalence of the infection was observed in east area, while the lowest prevalence of the infection was observed in west area. CONCLUSION: T. gondii infection may partly be responsible for abortion and economic losses in livestock husbandry in this region. Therefore, further additional researches such as genotyping T. gondii and designing control strategies for improving management in livestock flocks are necessary.

Seroprevalence of Toxoplasma gondii in Wild Rats (Rattus rattus) in Northern Iran.

Rodents are considered as reservoir hosts for various pathogens (such as Toxoplasma gondii) and have been revealed to play an important role in the spread of several infectious diseases to humans and other animals. The aim of this investigation was to survey the prevalence of anti-T. gondii IgG antibodies in wild rats in Northern Iran. One hundred rats were caught using rat traps set in different areas in Northern Iran (September 2017). The thoracic cavity of each rat was opened, and then the blood sample was collected from the heart. IgG anti-Toxoplasma gondii antibodies were detected using the modified agglutination test (MAT) with a cutoff value equal to 1 : 40. Overall, 56% of rats were infected by T. gondii. Considering the sex of rats, 45% of male and 55% of female rats were seropositive, but the differences were not statistically significant. There was a significant difference between seropositivity and habitat types and age of rodents. Our findings have public health implications and confirm the high seroprevalence of T. gondii infection in northern Iran. The study established that wild rats represent an important and persistent wildlife intermediate host reservoir for T. gondii.

Toxoplasma gondii: A possible etiologic agent for Alzheimer's disease.

Toxoplasma gondii (T. gondii) is one of the most pervasive neurotropic pathogens causing different lesions in a wide variety of mammals as intermediate hosts, including humans. It is estimated that one-third of the world population is infected with T. gondii; however, for a long time, there has been much interest in the examination of the possible role of this parasite in the development of mental disorders, such as Alzheimer's disease (AD). T. gondii may play a role in the progression of AD using mechanisms, such as the induction of the host's immune responses, inflammation of the central nervous system (CNS), alteration in the levels of neurotransmitters, and activation of indoleamine-2,3-dyoxigenase. This paper presents an appraisal of the literature, reports, and studies that seek to the possible role of T. gondii in the development of AD. For achieving the purpose of the current study, a search of six English databases (PubMed, ScienceDirect, Web of Science, Scopus, ProQuest, and Google Scholar) was performed. The results support the involvement of T. gondii in the induction and development of AD. Indeed, T. gondii can be considered a risk factor for the development of AD and requires the special attention of specialists and patients. Furthermore, the results of this study may contribute to prevent or delay the progress of AD worldwide. Therefore, it is required to carry out further studies in order to better perceive the parasitic mechanisms in the progression of AD.

The global seroprevalence of Toxoplasma gondii infection in bovines: a systematic review and meta-analysis.

Bovines, especially cattle, are considered as one of the main sources of Toxoplasma gondii infection for humans. A more comprehensive understanding of the occurrence of T. gondii is needed to provide a global perspective on the prevalence of T. gondii in bovines. Here, we present the results of the first systematic review and meta-analysis on the global T. gondii seroprevalence in bovines. Six databases (PubMed, ScienceDirect, Web of Science, Scopus, ProQuest and Google Scholar) were comprehensively searched for relevant studies published between 1 January 1967 and 30 May 2019. Among 7691 publications searched, 178 studies (from 50 countries) with 193 datasets were included in the meta-analysis. The global pooled and weighted seroprevalence of T. gondii among bovines was 17.91% [95% confidence interval (CI): 15.32­20.6]. Weighted prevalence based on the host was as follows: cattle 16.94% (95% CI: 14.25­19.81), buffalo 22.26% (95% CI: 16.8­29), yak 23% (95% CI: 14­33) and bison 8.1% (95% CI: 3.9­13.7). Continued monitoring on the status of T. gondii seroprevalence in bovines is essential. Study on the prevalence of T. gondii in the products of bovines such as milk, meat, etc., which are considered as the source of transmission of infection to humans, is recommended.

Global seroprevalence of Toxoplasma gondii in Camelidae: A systematic review and meta-analysis.

PURPOSE: The present study aimed to analyze data available of the seroprevalence of Toxoplasma gondii (T. gondii) among camelids around the world. METHODS: The search was performed using seven international databases including Scopus, PubMed, Google Scholar, ProQuest, ScienceDirect, Web of Science, and EMBASE up to 11 October 2018. Random effects model was used to determine the pooled seroprevalence of T. gondii infection with 95% confidence intervals (CI) and analyzed data from four continents. Subgroup and meta-regression analyses were also performed according to continent and gender. RESULTS: In total, 42 studies out of 3517 published articles involving 14,542 camels from 17 countries were included for the final analyses. The global pooled seroprevalence of T. gondii infection in the Camelidae family was 28.16% (95% CI 23.64-32.68%). Besides, the highest seroprevalence rate was in Europe (49.64%) followed by Africa (37.63%), America (21.76%), and Asia (17.58%). Moreover, the overall seroprevalence rates of T. gondii infection were 22% (95% CI 10-33%) and 15% (95% CI 9-22%) for the females and males, respectively. CONCLUSION: This meta-analysis showed a high seroprevalence of T. gondii infection in camelids as these animals play an important role in the transmission cycle of this zoonotic disease.

High Parasitic Contamination of Soil Samples in the North of Iran: A Potential Risk of Parasitic Infection for Tourists.

BACKGROUND: Soil-transmitted parasites (STPs) are significant intestinal parasites that infect humans and animals and impose considerable burdens on human society and animal husbandry industries. Therefore, the present study aimed to determine the prevalence of parasitic elements of soil samples collected from the north of Iran. METHODS: A total of 256 soil samples were collected from public parks, public places, vegetable gardens, sand heaps, and shadow areas near houses in the north of Iran and examined using the sucrose flotation method. RESULTS: Out of 256 examined samples, 131 (51.2%) showed parasitic contamination, including larvae (43%), oocysts (14.1%), and different eggs (6.6%). According to the results, the most and least common parasites observed in the samples were larvae (43%), as well as Toxascaris leonina, and Trichuris trichiura (0.4%), respectively. Moreover, the most and least contaminated locations were sand heaps (62.5%) and shadow areas near houses (45.6%), respectively. Regarding cities, Behshahr (68.3%) and Sari (67.5%) had the highest contaminated soil samples, whereas Chalus (37.5%) showed the lowest contamination. On the other hand, rural samples showed more contamination compared to urban areas (P< 0.05). CONCLUSION: The findings of the present study indicate that the overall prevalence of STPs in examined areas and highly contaminated soil samples can be considered as a potential source of human contamination particularly tourists with STPs.

Toxoplasmosis among cancer patients undergoing chemotherapy: a population study based on the serological, molecular and epidemiological aspects.

BACKGROUND: Toxoplasmosis is highly prevalent in northern Iran and immunocompromised individuals are more susceptible to this infection. The present study aimed to determine the seroprevalence, parasitism and genetic diversity of Toxoplasma gondii among patients with cancer undergoing chemotherapy in northern Iran. METHODS: A total of 350 serum samples obtained from cancer patients were collected from laboratory centers in northern Iran. Immunodiagnosis and DNA detection were accomplished by ELISA and PCR. Thereafter, multiplex-nested PCR-restriction fragment length polymorphism was used for the genotyping of T. gondii. RESULTS: In general, out of 350 patients, 264 (75.4%) and 9 (2.57%) cases were positive for anti-T. gondii IgG and IgM, respectively. Moreover, 19 (5.43%) samples contained T. gondii DNA. From 19 positive samples, 10 high-quality samples with sharp and non-smear bands were selected to determine the genotypes of T. gondii. Accordingly, the samples were classified as genotype #1 (type II clonal; n=4, 40%), genotype #2 (type III clonal; n=3, 30%), genotype #10 (type I clonal; n=2, 20%) and genotype #27 (type I variant; n=1, 10%). CONCLUSIONS: As evidenced by the results, due to the high prevalence of T. gondii, cancer patients in northern Iran are at serious risk of severe toxoplasmosis and its complications. Therefore, oncologists need to regard this critical health problem as a matter requiring urgent attention.

Copro-molecular diagnosis of the Toxoplasmatinae subfamily in dog and cat populations in northern Iran.

OBJECTIVES: The oocysts of the Toxoplasmatinae subfamily (Neospora caninum, Hammondia hammondi and H. heydorni, and Besnoitia besnoiti) are morphologically similar to Toxoplasma gondii, and indistinguishable from each other. This study investigated the prevalence of the Toxoplasmatinae subfamily in dog and cat fecal samples using a nested polymerase chain reaction method. METHODS: Overall, 200 fecal samples from domestic dogs (n=120) and cats (n=80) were collected from 15 farms in northern Iran. The samples were homogenized in 2.5% potassium dichromate solution and subsequently concentrated with sucrose solution. DNA was extracted from samples using a genomic DNA kit. Specific primers and the 18S rDNA gene were used to screen and detect all Toxoplasmatinae oocysts. RESULTS: Overall, 2.5% (3 of 120) and 22.5% (18 of 80) of the fecal samples collected from dogs and cats were infected with Toxoplasmatinae. In dogs, 2 samples were positive for N. caninum and 1 sample was positive for T. gondii. In cats, all 18 positive samples belonged to T. gondii. No contamination with H. heydorni was observed in dog fecal samples or H. hammondi and B. besnoiti in cat fecal samples. A phylogenetic analysis revealed that the T. gondii (cat) and N. caninum (dog) found had similarities with parasites reported from other regions of the world. CONCLUSIONS: This is the first study to provide data on the epidemiology of Toxoplasmatinae oocysts in Iran. The findings suggest that public-health monitoring for the effective control of feces from cats and dogs and improved pet hygiene habits are needed.

Relationship between toxoplasmosis and autism: A systematic review and meta-analysis.

Toxoplasma gondii (T. gondii) is a foodborne parasite that is investigated in many psychiatric diseases, such as autism spectrum disorders (ASD). Therefore, a systematic literature review was conducted searching seven electronic databases on the prevalence of T. gondii antibodies among autism patients. The current study involved sensitivity analysis, meta-regression, subgroup analysis, publication bias test, and quality assessment of studies. On the basis of the findings, the odds ratio (OR) of latent Toxoplasma infection 1.93 (95% confidence intervals (CI): 1.01-3.66) was associated with ASD risk. However, there was no relationship between acute infection and ASD 0.39 (95% CI: 0.18-0.87). The obtained results of Begg's and Egger's tests showed no publication bias (P = 0.851 and P = 0.297, respectively). The sensitivity analysis confirmed robust and stable estimates with a significant level of heterogeneity (I2 = 78.1%, P < 0.000). Of the investigated patients' characteristics, only the gender variable was analyzed, indicating the combined ORs of 2.63 (95% CI: 0.29-23.63) in females and 2.62 (95% CI: 0.94-7.30) in male participants. This study showed that toxoplasmosis plays an important role as a risk factor for autism. However, further prospective investigations are highly recommended to illuminate the developmental pathways to this disorder and provide new strategies for the prevention and treatment of this disease.

Isolation and Genotypic Characterization of Toxoplasma gondii Based on GRA6 Gene from Environmental Soil Samples in Mazandaran Province, North of Iran.

BACKGROUND: Soil is one of the environmental sources of Toxoplasma gondii oocysts. The other hand, genotype of the parasite is one of the important factors for its pathogenicity. Due to the importance of toxoplasmosis on public health, this study aimed to isolation and genotyping of T. gondii in environmental soil samples of Mazandaran Province, north of Iran. METHODS: Overall, 192 soil samples were collected from different areas in Mazandaran Province from Apr to Sep 2014. The flotation method was used for recovering oocysts. Then, soil samples were investigated for DNA detection of T. gondii using nested PCR of RE gene, genotyping with Semi-nested PCR of GRA6 gene and restriction fragment length polymorphism (RFLP) analysis. Results were analyzed using Chi-squared test. A significant difference was considered with a P<0.05. RESULTS: From 192 soil samples, T. gondii DNA was detected in 150 samples (78.1%). Then genotype of 23 samples was determined (91.3% type I and 8.7% type II). CONCLUSION: Prevalence of T. gondii in soil samples of Mazandaran province, north of Iran is high and T. gondii GRA6 type I is predominant. Soil can be the most important source of severe toxoplasmosis in this province.

The global serological prevalence of Toxoplasma gondii in felids during the last five decades (1967-2017): a systematic review and meta-analysis.

BACKGROUND: Felids (domestic and wild cats) are important in the epidemiology of the parasite Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts. We conducted a systematic review and meta-analysis to estimate the global prevalence of T. gondii in species of the family Felidae. METHODS: We searched seven databases (PubMed, Embase, Google Scholar, ScienceDirect, Scopus, Proquest and Web of Science) for studies reporting seroprevalence of T. gondii in felids from 1967 to 31 December 2017. A total of 217 published papers, containing 223 datasets were eligible for inclusion in the meta-analysis, comprised 59,517 domestic and 2733 wild cats from 1967 to 2017. RESULTS: The pooled global T. gondii seroprevalence was estimated to be 35% (95% CI: 32-38%) and 59% (95% CI: 56-63%) in domestic cats and wild felids, respectively, using random effects model. The seroprevalence was higher in Australia and Africa where the T. gondii seropositivity in domestic cats was 52% (95% CI: 15-89%) and 51% (95% CI: 20-81%), respectively. The lowest seroprevalence was estimated in Asia 27% (95% CI: 24-30%). The seroprevalence values for T. gondii in wild felids were 74% (95% CI: 62-83%) in Africa, 67% (95% CI: 23-111%) in Asia, 67% (95% CI: 58-75%) in Europe and 66% (95% CI: 41-91%) in South America. CONCLUSIONS: Our study provides the global prevalence of T. gondii in species of the family Felidae and is a source of information to aid public health workers in developing prevention plans.

The Mixed AII and BIII Genotypes of Human Giardia lamblia Isolate Circulating in Mazandaran Province, Northern Iran.

OBJECTIVES: Giardiasis is one of the human parasitic diseases by a flagellate protozoan named Giardia lamblia. This parasite is one of the most common organisms causing diarrhea in humans and a common gastrointestinal parasite in vertebrates. The purpose of this investigation was to determine the molecular epidemiology of Giardia lamblia (G. lamblia) by PCR-RFLP method in the Mazandaran Province and to investigate the possible relationship between parasite genotype and clinical symptoms. METHODS: In this study, 50 stool samples were collected from human cases of G. lamblia. referred to health centers in Sari, Babol, Nowshahr cities. The samples were examined by formalin-ether concentration procedure. DNA extraction was carried out on samples containing adequate Giardia cysts, and then PCR-RFLP was done on glutamate dehydrogenase (gdh) marker. RESULTS: In these patients, the most common signs were abdominal pain (42.9%), and diarrhea (47.6%); and least marked common sign was malaise (4.7%). Of all 21 isolates, 9 samples (42.8%) were found as genotype mixed AII and BIII, 6 samples (28.6%) belonged to genotype BIII and 6 (28.6%) were of genotype AII. Additionally, there was a significant correlation between AII genotype and clinical symptoms (P <0.05). According to the statistical tests, there was a significant relationship between abdominal pain and the intensity of infection (P<0.05). CONCLUSION: However, genotype AII and mixed AII and BIII genotypes were more common, respectively. The relatively high prevalence of mixed infection of these genotypes indicated the potential of zoonotic source of giardiasis among patients in Mazandaran Province.

The effect of edelfosine on GRA1 and MIC3 expressions in acute toxoplasmosis.

Phosphoinositide-dependent phospholipase-C (PI-PLC) triggers the calcium signaling pathway which plays an important role in dense granule and microneme secretion and pathogenesis of Toxoplasma gondii (T. gondii). There are limited data about the effects of phospholipid analogues against T. gondii. The current study assessed the effect of edelfosine, as a phospholipid analogue, on GRA1 and MIC3 expressions using in vitro and in vivo models of acute toxoplasmosis. Infected Vero cells were treated by edelfosine in two subgroups: 24 h following the cell infection and treatment at the same time of cell infection. Animal study was performed on forty mice in four groups including non-infected, infected untreated, infected edelfosine-treated, and infected pyrimethamine-treated. Gene and protein expression analyses were done using quantitative real-time PCR and western blot, respectively. Edelfosine significantly reduced the GRA1 (P < 0.01) and MIC3 (P < 0.01) mRNA and protein expressions in 24 h following the cell infection and at the same time of cell infection groups. In vivo study showed that the edelfosine significantly reduced the GRA1 expression in eye, and MIC3 expression in brain and liver. Moreover, the edelfosine-treated infected mice had significant higher survival rate compared with uninfected mice. The reducing effect of edelfosine on GRA1 and MIC3 mRNA and protein levels 24 h following the cell infection was more than treatment at the same time of cell infection group. Moreover, the effect of edelfosine on GRA1 and MIC3 expression in animal tissues was variable. These data showed that the edelfosine may decrease the T. gondii excretory/secretory antigens through inhibition of PI-PLC.

A serological investigation and genotyping of Toxoplasma gondii among Iranian blood donors indicates threat to health of blood recipients.

BACKGROUND: Toxoplasmosis is a zoonotic disease in animals and human caused by the intracellular obligatory protozoan named Toxoplasma gondii. The purpose of this study was to evaluate the sero-molecular prevalence and genotyping T. gondii among healthy blood donors in north of Iran. METHODS: In this cross-sectional study, 400 blood donors participated from all Blood Transfusion Organization (BTO) in Mazandaran province during October and November 2014. The blood samples were investigated for seroprevalence, DNA detection and genotyping of T. gondii using ELISA, nested-PCR, and Multilocus nested-PCR-RFLP methods respectively. RESULTS: Among all of blood donors, 294 (73.5 %) and 9 (2.2 %) cases were seropositive for anti-T. gondii IgG and IgM antibodies. T. gondii DNA was detected in 7 samples. Four genotype of T. gondii were identified in blood donors samples (Genotype ToxoDB#1, #2, #10 and #27), which 50 % of T. gondii strains were highly pathogenic. CONCLUSIONS: Taking into account survive T. gondii in blood transfusion bag, the high prevalence of T. gondii and existence of pathogenic genotypes in Iranian blood donors, it seems that T. gondii screening should be performed at the BTO to prevent complications of toxoplasmosis in blood recipients.

Toxoplasma gondii surface antigen 1 (SAG1) as a potential candidate to develop vaccine against toxoplasmosis: A systematic review.

Toxoplasma gondii is an intracellular parasite that infects a broad range of animal species and humans. As the main surface antigen of the tachyzoite, SAG1 is involved in the process of recognition, adhesion and invasion of host cells. The aim of the current systematic review study is to clarify the latest status of studies in the literature regarding SAG1-associated recombinant proteins or SAG1-associated recombinant DNAs as potential vaccines against toxoplasmosis. Data were systematically collected from six databases including PubMed, Science Direct, Web of Science, Google Scholar, EBSCO and Scopus, up to 1st of January 2019. A total of 87 articles were eligible for inclusion criteria in the current systematic review. The most common antigens used for experimental cocktail vaccines together with SAG1 were ROP2 and SAG2. In addition, the most parasite strains used were RH and ME49. Freund's adjuvant and cholera toxin have been predominantly utilized. Furthermore, regarding the animal models, route and dose of vaccination, challenge methods, measurement of immune responses and cyst burden have been discussed in the text. Most of these experimental vaccines induce immune responses and have a high degree of protection against parasite infections, increase survival rates and duration and reduce cyst burdens. The data demonstrated that SAG1 antigen has a high potential for use as a vaccine and provided a promising approach for protecting humans and animals against toxoplasmosis.

Seroprevalence of Neospora caninum Infection in Dog Population Worldwide: A Systematic Review and Meta-analysis.

PURPOSE: Neospora caninum is an obligate intracellular apicomplexan protozoan that causes neurological disorders in dogs. This systematic review and meta-analysis targeted at evaluating the worldwide seroprevalence rate of N. caninum in dogs. METHODS: Five electronic databases, including PubMed, Scopus, Web of Science, Science Direct, and Google Scholar, until December 2018 were thoroughly searched for relevant English language articles. Papers were selected based on inclusion criteria. Data were analyzed in StatsDirect statistical software (version 2.7.9). RESULTS: The searching process yielded a total number of 156 papers. The total prevalence (95% confidence intervals) of N. caninum infection in dog population worldwide was measured as 17.14% in data analyses (15.25-19.10). In addition, a significant association was also detected between neosporosis infection in dogs and continent, country, year, WHO regions, sample size and diagnostic method (P < 0.001). CONCLUSION: Dogs are a matter of concern to public health officials as a source of N. caninum infection. Therefore, it is of paramount importance to provide comprehensive data and systematically analyze the prevalence of N. caninum infection in dogs. Accordingly, it is recommended that researchers carry out further studies to prevent and control neosporosis among dog population worldwide.