Toxoplasma gondii is a single-celled parasite that infects nearly all warm-blooded animals,including humans(Montoya and Liesenfeld,2004).It occurs worldwide and can persist for a lifetime in mammals.Humans get infecte...Toxoplasma gondii is a single-celled parasite that infects nearly all warm-blooded animals,including humans(Montoya and Liesenfeld,2004).It occurs worldwide and can persist for a lifetime in mammals.Humans get infected by eating undercooked meat of animals containing the tissue cysts of this parasite.In immune-competent individuals,T.展开更多
Toxoplasma gondii(T.gondii)is a globally distributed parasite that can infect a diversity of warm-blooded animals,including swine and humans.Infection in swine poses a considerable threat to food safety and public hea...Toxoplasma gondii(T.gondii)is a globally distributed parasite that can infect a diversity of warm-blooded animals,including swine and humans.Infection in swine poses a considerable threat to food safety and public health.The aim of this meta-analysis was to estimate the seroprevalence of T.gondii infection in the swine population in China from 2000 to 2023 and to examine potential factors associated with infection.A total of 112 studies were included,collectively involving 145,152 swine samples originating from 26 provinces.The pooled seroprevalence was 26.0%(95%CI:23.3%–28.7%).Stratified analysis based on diagnostic methods revealed that studies using the indirect hemagglutination assay(IHA)reported a seroprevalence of 19.7%(95%CI:17.2%–22.2%),whereas those utilizing the enzyme-linked immunosorbent assay(ELISA)reported a higher seroprevalence of 35.5%(95%CI:29.1%–41.8%).Geographical analysis indicated higher seroprevalence in the South Central and Southwest regions,whereas the East and Northwest areas reported the lowest seroprevalence.Chongqing Province reported the highest seroprevalence,reaching 44.9%(95%CI:43.4%–46.0%),followed by Xinjiang,Hainan,and Guizhou,whereas the lowest was observed in Shandong Province(3.5%,95%CI:1.7%–6.1%).These findings provide important epidemiological evidence that can inform strategies for the prevention and control of T.gondii infection in swine populations,with a focus on high-risk populations and geographical areas.This imperative contributes substantially to the improvement of both food safety and public health.展开更多
Toxoplasma gondii is an important zoonotic parasite which has over 200 genotypes worldwide.N^(6)-methyladenosine(m^(6)A)methylation is a common epigenetic modification in messenger RNAs(mRNAs),and has been implicated ...Toxoplasma gondii is an important zoonotic parasite which has over 200 genotypes worldwide.N^(6)-methyladenosine(m^(6)A)methylation is a common epigenetic modification in messenger RNAs(mRNAs),and has been implicated in many aspects of mRNA biology.However,little is known about the difference in m^(6)A methylation among different genotypes of T.gondii.In the present study,we employed methylated RNA immunoprecipitation sequencing(MeRIP-seq)technology to identify key genes exhibiting m^(6)A methylation in the three major clonal lineages(Types I,II and III)of T.gondii tachyzoites.A total of 7,650,8,359 and 7,264 m^(6)A peaks were identified in 5,211,5,607 and 4,974 genes in tachyzoites of RH(Type I),ME49(Type II)and VEG strain(Type III),respectively.By comparing RH vs.ME49,RH vs.VEG,and ME49 vs.VEG,735,192 and 615 differentially methylated peaks(DMPs)were identified in 676,168 and 553 genes,respectively.A combined MeRIP-seq and RNA-seq analysis revealed 172,41 and 153 differentially methylated genes(DMGs)at both the m^(6)A methylation and transcriptional level.Gene Ontology term enrichment analysis of the DMPs identified differences related to Golgi apparatus,plasma membrane,signal transduction,RNA processing and catalytic step 2 spliceosome.KEGG pathway enrichment analysis showed that the DMGs are mainly involved in endocytosis,systemic lupus erythematosus and mTOR signaling pathway.These findings reveal genotype-specific differences in m^(6)A methylation,which provide new resources for further investigations of the role of m^(6)A in the pathobiology of T.gondii.展开更多
The most common medications for the treatment of zoonotic toxoplasmosis are pyrimethamine and sulfadiazine,which may cause serious undesirable side effects.Thus,there is an urgent need to develop novel therapeutics.Ba...The most common medications for the treatment of zoonotic toxoplasmosis are pyrimethamine and sulfadiazine,which may cause serious undesirable side effects.Thus,there is an urgent need to develop novel therapeutics.Baicalein(BAI,C_(15)H_(10)O_(5))has been shown to perform well against protozoan parasites including Leishmania and Cryptosporidium.In this study,the inhibition efficacy of BAI on Toxoplasma gondii was evaluated using plaque,invasion,and intracellular proliferation assays.BAI effectively inhibited T.gondii(half-maximum inhibitory concentration(IC_(50))=6.457×10^(−5)mol/L),with a reduced invasion rate(33.56%)and intracellular proliferation,and exhibited low cytotoxicity(half-maximum toxicity concentration(TC_(50))=5.929×10^(−4)mol/L).Further investigation using a mouse model shed light on the inhibitory efficacy of BAI against T.gondii,as well as the potential mechanisms underlying its anti-parasitic effects.The survival time of T.gondii-infected ICR mice treated with BAI was remarkably extended,and their parasite burdens in the liver and spleen were greatly reduced compared with those of the negative control group.Histopathological examination of live sections revealed effective therapeutic outcomes in the treatment groups,with no notable pathological alterations observed.Furthermore,alterations in cytokine levels indicated that BAI not only effectively suppressed the growth of T.gondii but also prevented excessive inflammation in mice.Collectively,these findings underscore the significant inhibitory efficacy of BAI against T.gondii,positioning it as a promising alternative therapeutic agent for toxoplasmosis.展开更多
Background: Toxoplasma gondii (T. gondii) is an intracellular parasite mainly found in the central nervous system CNS, however, it can persist in multiple tissues in the body. Moreover, T. gondii is the commonest prot...Background: Toxoplasma gondii (T. gondii) is an intracellular parasite mainly found in the central nervous system CNS, however, it can persist in multiple tissues in the body. Moreover, T. gondii is the commonest protozoans causing infections among individuals with acquired immunodeficiency syndrome (AIDS). Thus, the aim of this study was to investigate the frequency of T. gondii infection among AIDS patients in Makkah at Saudi Arabia. Methods: Fifty patients with AIDS proved to be positive by ULTRA HIV Ag-Ab Enzyme Immunoassay, and thirty healthy volunteers negative for AIDS by ULTRA HIV Ag-Ab Enzyme Immunoassay were subjected to determination of anti T. gondii immunoglobulin M (IgM) antibody seropositivity and anti T. gondii immunoglobulin G (IgG) antibody seropositivity using commercially available enzyme-linked immunosorbent assay kits. Results: The results showed that the seropositivity rate of anti T. gondii IgM antibodies among AIDS patients (18%) was significantly higher than in the healthy volunteers group (3.33%). Regarding the serum level of anti T. gondii IgG antibodies among AIDS patients, it was 30% significantly higher compared with those of the seropositive healthy volunteers (6.67%). Conclusions: These statistically significant results support the association between T. gondii infection and AIDS and suggest the usefulness of providing data for an educational program that will be designed to prevent T. gondii infection among AIDS patients.展开更多
Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA...Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA.Methods:The analytical sensitivity of LAMP and ncstcd-PCR was obtained against 10-fold serial dilutions of T.gondii DNA ranging from 1 ng to 0.01 fg.DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays.Results:After testing LAMP and nesled-PCR in duplicate,the detection limit of RE-LAMP.B1-LAMP,RE-nested PCR and B1-nested PCR assays was one fg.100 fg,1 pg and 10 pg of T.gondii DNA respectively.All the LAMP assays and nested PCRs were 100% specific.The RE-LAMP assay revealed the most sensitivity for the detection of T.gondii DNA.Conclusions:The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T.gondii.Furthermore,these findings indicate that primers based on the RE are more suitable than those based on the B1 gene.However,the B1-LAMP assay has potential as a diagnostic tool for detection of T.gondii.展开更多
The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CS...The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CSFV) and porcine circovirus type 2(PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay(ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14%(34/372), 50.00%(186/372), 37.10%(138/372) and 3.23%(12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61%(6/372), 4.03%(15/372), 0.27%(1/372), 0.27%(1/372) and 0.81%(3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.展开更多
Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10...Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10~4 alive tachyzoites of Toxoplasma gondii RH strain.After 1,2,3 days post infection and the last day(before death),different tissues of mice including blood,brain,eye,liver,spleen,kidney,heart and muscle were harvested.Following tissues DNA extraction,the parasite burden was quantified using real time QPCR targeting the B1 gene(451 bp).Results:It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in24 hours.Parasite burden was high in all tissues but the most number of parasites were observed in kidney,heart and liver,respectively.Conclusions:These data provide significant baseline information about Toxoplasma pathogenesis,vaccine monitoring and drug efficiency.展开更多
Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collec...Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.展开更多
The dense granule protein 4 （GRA4） is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3, 1-GRA4 （pGRA4）, encoding for the GRA4 a...The dense granule protein 4 （GRA4） is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3, 1-GRA4 （pGRA4）, encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine （PC）, 8 mmol/L dioleoyl phosphatidylethanolamine （DOPE）, and 4 mmol/L 1,2-diodeoyl-3-（trimethylammonium） propane （DOTAP）. C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay （ELISA） of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon （IFN）-7 and interleukin （IL）-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th 1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii.展开更多
Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients.Apoptosis is one of the principal strategies of host cells to clear pat...Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients.Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis,but the mechanism of cell apoptosis induced by T.gondii remains obscure.To explore the apoptosis influenced by T.gondii,Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing(RNA-seq).Using high-throughput Illumina sequencing and bioinformatics analysis,we found that pro-apoptosis genes such as DNA damage-inducible transcript 3(DDIT3),growth arrest and DNA damage-inducibleα(GADD45 A),caspase-3(CASP3),and high-temperature requirement protease A2(Htr A2)were upregulated,and anti-apoptosis genes such as poly(adenosine diphosphate(ADP)-ribose)polymerase family member 3(PARP3),B-cell lymphoma 2(Bcl-2),and baculoviral inhibitor of apoptosis protein(IAP)repeat containing 5(BIRC5)were downregulated.Besides,tumor necrosis factor(TNF)receptor-associated factor 1(TRAF1),TRAF2,TNF receptor superfamily member 10 b(TNFRSF10 b),disabled homolog2(DAB2)-interacting protein(DAB2 IP),and inositol 1,4,5-trisphosphate receptor type 3(ITPR3)were enriched in the upstream of TNF,TNF-related apoptosis-inducing ligand(TRAIL),and endoplasmic reticulum(ER)stress pathways,and TRAIL-receptor2(TRAIL-R2)was regarded as an important membrane receptor influenced by T.gondii that had not been previously considered.In conclusion,the T.gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells.Our findings improve the understanding of the T.gondii infection process through providing new insights into the related cellular apoptosis mechanisms.展开更多
AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of t...AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS： The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION： SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.展开更多
One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a r...One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 （4.76%） chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5′-SAG2, 3′-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.展开更多
Objective:To determine the detection rate of anti-Toxoplasma gondii(T.gondii) IgG and IgM in chronic HCV patients attending the Department of Tropical Medicine Mansoura University hospital in Egypt.Methods:This study ...Objective:To determine the detection rate of anti-Toxoplasma gondii(T.gondii) IgG and IgM in chronic HCV patients attending the Department of Tropical Medicine Mansoura University hospital in Egypt.Methods:This study included 120 adult chronic HCV patients.81 decompensate cirrhosis(late-stage)and 39 chronic HCV non cirrhotic patients(early-stage) and40 healthy blood donors as controls.Serum samples uere examined for anti-Toxoplasma IgM and anti-Toxoplasma IgG antibodies by ELISA.Real-time RT-polymerase chain reaction assay was done for quantitation of hepatitis C virus.Results:Anti-T.gondii IgG antibodies were detected in 75(92.6%) of 81 late-stage cirrhotic patients.30(76.9%) of the 39 chronic HCV non cirrhotic patients(early-Stage) and in 6(15ft) of 40 controls with statistically significant difference(P<0.001).Anti-T.gondii IgM antibodies were found in 11(13.6%) in late stage patients,5(12.8%)in early stage and in 3(7.5%) of controls with no statistical significant difference(P=0.610).There was no correlation between stage of fibrosis and IgM or IgG antibodies positivity in our studied groups(P=0.526).High IgG levels significantly correlated with high viral load(P=0.026).Conclusions:Our findings suggest that the serious opportunistic T.gondii infection represent a potential significant risk for chronic HCV patients.So.toxoplasmosis should be considered in their investigations and follow-up.展开更多
The normal fine structures of toxoplasma gondii tachyzoite and the erfect of usnic acid on the ultrastructure of the tachyzoites were observed by transmission electron microscope (TEM).The studies indicate that the pa...The normal fine structures of toxoplasma gondii tachyzoite and the erfect of usnic acid on the ultrastructure of the tachyzoites were observed by transmission electron microscope (TEM).The studies indicate that the pathological changes or the ultrastructure of the parasite took place under the effect of the 10 mg/L usnic acid for 30 min.These changes can be illustrated as folio'vs; 1)The posterior portion of the rhopties were destroyed.2)The membrane of the daughter cell fractured. 3)The membranate organellae or the organisms were demaged.展开更多
Objective:Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii(T.gondii),which can lead to complications such as encephalitis and ocular toxoplasmosis.The disease becomes more severe when the host...Objective:Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii(T.gondii),which can lead to complications such as encephalitis and ocular toxoplasmosis.The disease becomes more severe when the host’s immune system is compromised.Rhoptry proteins are major virulence factors that enable T.gondii to invade host cells.This study aims to construct a T.gondii rhoptry protein 41(rop41/ROP41)gene knockout strain and preliminarily investigate the biological function of rop41.Methods:Using CRISPR/Cas9 technology,a specific single-guide RNA(sgRNA)for the target gene was designed and linked to a recombinant plasmid.Homologous fragments were fused with a pyrimethamine resistance gene for selection purposes.The recombinant plasmid and the homologous fragments were electroporated into T.gondii,and PCR identification was performed after drug selection and monoclonal screening.Plaque assays were used to comprehensively assess whether rop41 affected the growth and proliferation of T.gondii in host cells.Invasion and proliferation assays were conducted to evaluate the invasion ability of the knockout strain into host cells and its intracellular proliferation capacity.The STRING database was utilized to construct a protein-protein interaction(PPI)network,and functional enrichment analysis was performed to predict the signaling pathways in which ROP41 might be involved.Results:The T.gondii rop41 gene knockout strain(RHΔku80Δrop41)was successfully constructed and stably inherited.Plaque assays showed that compared with the parental strain,the number of plaques formed by the rop41 gene knockout strain did not significantly decrease,but the reduction in plaque size was statistically significant(P<0.05).After the rop41 gene was knocked out,the invasion ability of T.gondii was reduced,but there was no statistically significant difference in its proliferation ability(P>0.05).The PPI network revealed that ROP41 was associated with other protein kinases and autophagy related proteins.Enrichment analysis indicated that proteins interacting with ROP41 may be involved in signal transduction,biosynthesis,metabolism,and autophagy-related pathways and could be components of various kinase complexes and phagocytic vesicles.Conclusion:The T.gondii RHΔku80Δrop41 strain has been successfully constructed.ROP41 primarily affects the ability of T.gondii to invade host cells and may play a role in signal transduction and autophagy-related pathways between T.gondii and the host.展开更多
Introduction: Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect any warm blood vertebrae, and if first trimester pregnant woman infected, it may cause abortion. The objective is to prov...Introduction: Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect any warm blood vertebrae, and if first trimester pregnant woman infected, it may cause abortion. The objective is to prove the effect of the Toxoplasma gondii concentration in anti-toxoplasma IgG-IgM antibody levels, and the outcomes of Balb/c mice pregnancies. Materials and Methods: The study was conducted in Balb/c mice with inclusion criteria, and was conditioned pregnant. The pathogen strains of Toxoplasma gondii tachyzoite injected intraperitoneally. The blood samples were taken serially to be tested for anti-toxoplasma IgG-IgM antibody levels. After the mice were injected with tachyzoite, they are assessed every day to observe their body weight, vaginal bleeding, and labor. Anti-toxoplasma IgG-IgM antibody levels examined using qualitative mouse IgG-IgM antibody ELISA KIT. Results: Anti-toxoplasma IgM antibody levels increased significantly after 24 hours of injection tachyzoites in all dose groups, and remained high through day 21. Anti-toxoplasma antibody IgG levels increased significantly after 72 hours post injection and remained elevated until day 21. The incidence of abortion is 100% in mice which injected tachyzoite levels 1 × 103 and 1 × 104, and the incidence of abortion approximately 2 - 4 days post injection. 100% of mice that were injected with tachyzoites 1 × 101 and 1 × 102 have labor at term. Physical anomaly was found in baby mice from mice that were injected with tachyzoite 1 × 102. Conclusion: There is a significant correlation between the concentrations of Toxoplasma gondii tachyzoite with anti-toxoplasma IgG-IgM antibody levels, and there is a significant relationship between the concentrations of tachyzoite with abortion.展开更多
Toxoplasma gondii is an intracellular, zoonotic protozoan parasite that causes toxoplasmosis. It can potentially infect almost all mammalian and avian hosts including one-third of the human population world-wide. The ...Toxoplasma gondii is an intracellular, zoonotic protozoan parasite that causes toxoplasmosis. It can potentially infect almost all mammalian and avian hosts including one-third of the human population world-wide. The major target group of the parasite includes immunocompromised patients (e.g. AIDS, cancer, organ transplantation) and fetus bearing pregnant women where it develops toxoplasmic encephalitis, myocarditis, chorioretinitis and abnormal fetal brain development or stillbirths respectively. In this review, we have presented the current status of T. gondii infection in livestock animals and human population in Bangladesh to assess the country-wide relative risk. Although exact prevalence is difficult to predict due to the scarcity of data, nevertheless existing literature suggests that 16% - 39% humans and 8% - 70% domestic animals are infected with T. gondii, which implies Bangladeshi population is at high risk of toxoplasmosis. Furthermore, we have proposed a potential area of research to decipher the genetic diversity and transmission routes of T. gondii infection into Bangladeshi population.展开更多
Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its...Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its life cycle.The current study aimed to create animal and in vitro models for production of the tachyzoites of the Prugniaud(PRU)genotype II strain.Methods:To develop an immunocompromised model and obtain tachyzoites of the PRU strain,BALB/c mice were orally treated with dexamethasone(10 mg/kg),cyclo-phosphamide(36 mg/kg),and cyclosporine(18 mg/kg)from 5 days prior to inocula-tion.Then,10-15 tissue cysts of PRU strain were inoculated intraperitoneally into the mice.The tachyzoites obtained from mice were then cultivated in a HeLa cell culture.The resulting yield of tachyzoites was cryopreserved in 92%fetal calf serum,8%dimethyl sulfoxide.The infectivity of these tachyzoites was evaluated using in vivo and in vitro examinations.Results:Numerous tachyzoites were observed in the peritoneal fluid of the immuno-suppressed mice within 10-15 days after inoculation,and many tachyzoites were har-vested from the HeLa cell culture.Trypan Blue staining showed 80%viability of the tachyzoites recovered from cryopreservation and this was confirmed by HeLa cell culture.In addition,mice infected intraperitoneally with the recovered tachyzoites presented with cysts in the brain after 2 months.Conclusion:We have developed an animal model for mass production of T.gondii tachyzoites of the PRU strain.This method can provide fresh viable tachyzoites of Toxoplasma gondii for use as and when required in future investigations.展开更多
基金supported by the National Natural Sci ence Foundation of China(No.31672543)the Zhejiang Province“Sannongliufang”Science and Technology Coopera tion Project(No.2020SNLF007),China.
文摘Toxoplasma gondii is a single-celled parasite that infects nearly all warm-blooded animals,including humans(Montoya and Liesenfeld,2004).It occurs worldwide and can persist for a lifetime in mammals.Humans get infected by eating undercooked meat of animals containing the tissue cysts of this parasite.In immune-competent individuals,T.
基金supported by the National Key Research and Development Program of China(2022YFE0114400).
文摘Toxoplasma gondii(T.gondii)is a globally distributed parasite that can infect a diversity of warm-blooded animals,including swine and humans.Infection in swine poses a considerable threat to food safety and public health.The aim of this meta-analysis was to estimate the seroprevalence of T.gondii infection in the swine population in China from 2000 to 2023 and to examine potential factors associated with infection.A total of 112 studies were included,collectively involving 145,152 swine samples originating from 26 provinces.The pooled seroprevalence was 26.0%(95%CI:23.3%–28.7%).Stratified analysis based on diagnostic methods revealed that studies using the indirect hemagglutination assay(IHA)reported a seroprevalence of 19.7%(95%CI:17.2%–22.2%),whereas those utilizing the enzyme-linked immunosorbent assay(ELISA)reported a higher seroprevalence of 35.5%(95%CI:29.1%–41.8%).Geographical analysis indicated higher seroprevalence in the South Central and Southwest regions,whereas the East and Northwest areas reported the lowest seroprevalence.Chongqing Province reported the highest seroprevalence,reaching 44.9%(95%CI:43.4%–46.0%),followed by Xinjiang,Hainan,and Guizhou,whereas the lowest was observed in Shandong Province(3.5%,95%CI:1.7%–6.1%).These findings provide important epidemiological evidence that can inform strategies for the prevention and control of T.gondii infection in swine populations,with a focus on high-risk populations and geographical areas.This imperative contributes substantially to the improvement of both food safety and public health.
基金supported by the National Key Research and Development Program of China(2021YFC2300800,2021YFC2300802 and 2021YFC2300804)the NSFC-Yunnan Joint Fund,China(U2202201)+2 种基金the Research Fund of Shanxi Province for Introduced High-level Leading Talents,China(RFSXIHLT202101)the Special Research Fund of Shanxi Agricultural University for Highlevel Talents,China(2021XG001)the Veterinary Public Health Innovation Team of Yunnan Province,China(202105AE160014)。
文摘Toxoplasma gondii is an important zoonotic parasite which has over 200 genotypes worldwide.N^(6)-methyladenosine(m^(6)A)methylation is a common epigenetic modification in messenger RNAs(mRNAs),and has been implicated in many aspects of mRNA biology.However,little is known about the difference in m^(6)A methylation among different genotypes of T.gondii.In the present study,we employed methylated RNA immunoprecipitation sequencing(MeRIP-seq)technology to identify key genes exhibiting m^(6)A methylation in the three major clonal lineages(Types I,II and III)of T.gondii tachyzoites.A total of 7,650,8,359 and 7,264 m^(6)A peaks were identified in 5,211,5,607 and 4,974 genes in tachyzoites of RH(Type I),ME49(Type II)and VEG strain(Type III),respectively.By comparing RH vs.ME49,RH vs.VEG,and ME49 vs.VEG,735,192 and 615 differentially methylated peaks(DMPs)were identified in 676,168 and 553 genes,respectively.A combined MeRIP-seq and RNA-seq analysis revealed 172,41 and 153 differentially methylated genes(DMGs)at both the m^(6)A methylation and transcriptional level.Gene Ontology term enrichment analysis of the DMPs identified differences related to Golgi apparatus,plasma membrane,signal transduction,RNA processing and catalytic step 2 spliceosome.KEGG pathway enrichment analysis showed that the DMGs are mainly involved in endocytosis,systemic lupus erythematosus and mTOR signaling pathway.These findings reveal genotype-specific differences in m^(6)A methylation,which provide new resources for further investigations of the role of m^(6)A in the pathobiology of T.gondii.
基金supported by the National Natural Science Foundation of China(No.32370997)the Key Projects Jointly Constructed by the Ministry and the Province of Zhejiang Medical and Health Science and Technology Project(No.WKJ-ZJ-2545)+2 种基金the Chinese Medicine Science and Technology Program of Zhejiang Province(No.2024ZL367)the Health Commission of Zhejiang Province(No.2024KY923)the Foundation of GuoTai(Taizhou)Center of Technology Innovation for Veterinary Biologicals(No.GTKF(23)001),China.
文摘The most common medications for the treatment of zoonotic toxoplasmosis are pyrimethamine and sulfadiazine,which may cause serious undesirable side effects.Thus,there is an urgent need to develop novel therapeutics.Baicalein(BAI,C_(15)H_(10)O_(5))has been shown to perform well against protozoan parasites including Leishmania and Cryptosporidium.In this study,the inhibition efficacy of BAI on Toxoplasma gondii was evaluated using plaque,invasion,and intracellular proliferation assays.BAI effectively inhibited T.gondii(half-maximum inhibitory concentration(IC_(50))=6.457×10^(−5)mol/L),with a reduced invasion rate(33.56%)and intracellular proliferation,and exhibited low cytotoxicity(half-maximum toxicity concentration(TC_(50))=5.929×10^(−4)mol/L).Further investigation using a mouse model shed light on the inhibitory efficacy of BAI against T.gondii,as well as the potential mechanisms underlying its anti-parasitic effects.The survival time of T.gondii-infected ICR mice treated with BAI was remarkably extended,and their parasite burdens in the liver and spleen were greatly reduced compared with those of the negative control group.Histopathological examination of live sections revealed effective therapeutic outcomes in the treatment groups,with no notable pathological alterations observed.Furthermore,alterations in cytokine levels indicated that BAI not only effectively suppressed the growth of T.gondii but also prevented excessive inflammation in mice.Collectively,these findings underscore the significant inhibitory efficacy of BAI against T.gondii,positioning it as a promising alternative therapeutic agent for toxoplasmosis.
文摘Background: Toxoplasma gondii (T. gondii) is an intracellular parasite mainly found in the central nervous system CNS, however, it can persist in multiple tissues in the body. Moreover, T. gondii is the commonest protozoans causing infections among individuals with acquired immunodeficiency syndrome (AIDS). Thus, the aim of this study was to investigate the frequency of T. gondii infection among AIDS patients in Makkah at Saudi Arabia. Methods: Fifty patients with AIDS proved to be positive by ULTRA HIV Ag-Ab Enzyme Immunoassay, and thirty healthy volunteers negative for AIDS by ULTRA HIV Ag-Ab Enzyme Immunoassay were subjected to determination of anti T. gondii immunoglobulin M (IgM) antibody seropositivity and anti T. gondii immunoglobulin G (IgG) antibody seropositivity using commercially available enzyme-linked immunosorbent assay kits. Results: The results showed that the seropositivity rate of anti T. gondii IgM antibodies among AIDS patients (18%) was significantly higher than in the healthy volunteers group (3.33%). Regarding the serum level of anti T. gondii IgG antibodies among AIDS patients, it was 30% significantly higher compared with those of the seropositive healthy volunteers (6.67%). Conclusions: These statistically significant results support the association between T. gondii infection and AIDS and suggest the usefulness of providing data for an educational program that will be designed to prevent T. gondii infection among AIDS patients.
基金supported financially by grant of Lorestan University of Medical Sciences,Khorramabad,Iran
文摘Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA.Methods:The analytical sensitivity of LAMP and ncstcd-PCR was obtained against 10-fold serial dilutions of T.gondii DNA ranging from 1 ng to 0.01 fg.DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays.Results:After testing LAMP and nesled-PCR in duplicate,the detection limit of RE-LAMP.B1-LAMP,RE-nested PCR and B1-nested PCR assays was one fg.100 fg,1 pg and 10 pg of T.gondii DNA respectively.All the LAMP assays and nested PCRs were 100% specific.The RE-LAMP assay revealed the most sensitivity for the detection of T.gondii DNA.Conclusions:The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T.gondii.Furthermore,these findings indicate that primers based on the RE are more suitable than those based on the B1 gene.However,the B1-LAMP assay has potential as a diagnostic tool for detection of T.gondii.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Agriculture of China (20090303604)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CSFV) and porcine circovirus type 2(PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay(ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14%(34/372), 50.00%(186/372), 37.10%(138/372) and 3.23%(12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61%(6/372), 4.03%(15/372), 0.27%(1/372), 0.27%(1/372) and 0.81%(3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.
基金prepared from Yousef Dadimoghaddam's MScthesis and supported by grant(no.90-31) from Deputy of Research,Mazandaran University of Medical Sciences.Sari,IranThe spousor or Junding organization had norole in the design or conduct of this research
文摘Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10~4 alive tachyzoites of Toxoplasma gondii RH strain.After 1,2,3 days post infection and the last day(before death),different tissues of mice including blood,brain,eye,liver,spleen,kidney,heart and muscle were harvested.Following tissues DNA extraction,the parasite burden was quantified using real time QPCR targeting the B1 gene(451 bp).Results:It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in24 hours.Parasite burden was high in all tissues but the most number of parasites were observed in kidney,heart and liver,respectively.Conclusions:These data provide significant baseline information about Toxoplasma pathogenesis,vaccine monitoring and drug efficiency.
基金supported by Infectious and Tropical Disease Research Center,Tabriz University of Medical Sciences,Tabriz,Iran(Grant No.94/2-5/17)
文摘Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.
基金supported by the Science Foundation of the Health Bureau of Zhejiang Province, China (Nos. 2003QN003 and 2005A001)the Science Foundation of the Science and Technology Department of Zhejiang Province, China (No. 2006C13022)
文摘The dense granule protein 4 （GRA4） is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3, 1-GRA4 （pGRA4）, encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine （PC）, 8 mmol/L dioleoyl phosphatidylethanolamine （DOPE）, and 4 mmol/L 1,2-diodeoyl-3-（trimethylammonium） propane （DOTAP）. C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay （ELISA） of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon （IFN）-7 and interleukin （IL）-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th 1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii.
基金supported by the National Natural Science Foundation of China(Nos.81802037,81871684)the Qingshan Lake United Fund of Zhejiang Province(No.LQY19H190002)+2 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LY22H190003)the Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talentsthe Basic Scientific Research Funds of Department of Education of Zhejiang Province(Nos.KYZD202104 and KYYB202101),China。
文摘Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients.Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis,but the mechanism of cell apoptosis induced by T.gondii remains obscure.To explore the apoptosis influenced by T.gondii,Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing(RNA-seq).Using high-throughput Illumina sequencing and bioinformatics analysis,we found that pro-apoptosis genes such as DNA damage-inducible transcript 3(DDIT3),growth arrest and DNA damage-inducibleα(GADD45 A),caspase-3(CASP3),and high-temperature requirement protease A2(Htr A2)were upregulated,and anti-apoptosis genes such as poly(adenosine diphosphate(ADP)-ribose)polymerase family member 3(PARP3),B-cell lymphoma 2(Bcl-2),and baculoviral inhibitor of apoptosis protein(IAP)repeat containing 5(BIRC5)were downregulated.Besides,tumor necrosis factor(TNF)receptor-associated factor 1(TRAF1),TRAF2,TNF receptor superfamily member 10 b(TNFRSF10 b),disabled homolog2(DAB2)-interacting protein(DAB2 IP),and inositol 1,4,5-trisphosphate receptor type 3(ITPR3)were enriched in the upstream of TNF,TNF-related apoptosis-inducing ligand(TRAIL),and endoplasmic reticulum(ER)stress pathways,and TRAIL-receptor2(TRAIL-R2)was regarded as an important membrane receptor influenced by T.gondii that had not been previously considered.In conclusion,the T.gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells.Our findings improve the understanding of the T.gondii infection process through providing new insights into the related cellular apoptosis mechanisms.
基金Supported by China Ministry of Human Affairs and Department of Science and Technology of Shandong Province, No. 031050115
文摘AIM： To analyze the biological role of the surface antigen of Toxoplasma gondii（Tgondii） in development of vaccine. METHODS： The surface antigen of Tgondii （SAG1） was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS： The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION： SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.
基金supported by the Special Fund for Public Welfare Industry of Chinese Ministry of Agriculture(200903036-04)
文摘One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 （4.76%） chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5′-SAG2, 3′-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.
文摘Objective:To determine the detection rate of anti-Toxoplasma gondii(T.gondii) IgG and IgM in chronic HCV patients attending the Department of Tropical Medicine Mansoura University hospital in Egypt.Methods:This study included 120 adult chronic HCV patients.81 decompensate cirrhosis(late-stage)and 39 chronic HCV non cirrhotic patients(early-stage) and40 healthy blood donors as controls.Serum samples uere examined for anti-Toxoplasma IgM and anti-Toxoplasma IgG antibodies by ELISA.Real-time RT-polymerase chain reaction assay was done for quantitation of hepatitis C virus.Results:Anti-T.gondii IgG antibodies were detected in 75(92.6%) of 81 late-stage cirrhotic patients.30(76.9%) of the 39 chronic HCV non cirrhotic patients(early-Stage) and in 6(15ft) of 40 controls with statistically significant difference(P<0.001).Anti-T.gondii IgM antibodies were found in 11(13.6%) in late stage patients,5(12.8%)in early stage and in 3(7.5%) of controls with no statistical significant difference(P=0.610).There was no correlation between stage of fibrosis and IgM or IgG antibodies positivity in our studied groups(P=0.526).High IgG levels significantly correlated with high viral load(P=0.026).Conclusions:Our findings suggest that the serious opportunistic T.gondii infection represent a potential significant risk for chronic HCV patients.So.toxoplasmosis should be considered in their investigations and follow-up.
文摘The normal fine structures of toxoplasma gondii tachyzoite and the erfect of usnic acid on the ultrastructure of the tachyzoites were observed by transmission electron microscope (TEM).The studies indicate that the pathological changes or the ultrastructure of the parasite took place under the effect of the 10 mg/L usnic acid for 30 min.These changes can be illustrated as folio'vs; 1)The posterior portion of the rhopties were destroyed.2)The membrane of the daughter cell fractured. 3)The membranate organellae or the organisms were demaged.
基金supported by the National Natural Science Foundation of China(32170510)the Innovation Training Program of Central South University(20240026020055),China.
文摘Objective:Toxoplasmosis is a zoonotic parasitic disease caused by Toxoplasma gondii(T.gondii),which can lead to complications such as encephalitis and ocular toxoplasmosis.The disease becomes more severe when the host’s immune system is compromised.Rhoptry proteins are major virulence factors that enable T.gondii to invade host cells.This study aims to construct a T.gondii rhoptry protein 41(rop41/ROP41)gene knockout strain and preliminarily investigate the biological function of rop41.Methods:Using CRISPR/Cas9 technology,a specific single-guide RNA(sgRNA)for the target gene was designed and linked to a recombinant plasmid.Homologous fragments were fused with a pyrimethamine resistance gene for selection purposes.The recombinant plasmid and the homologous fragments were electroporated into T.gondii,and PCR identification was performed after drug selection and monoclonal screening.Plaque assays were used to comprehensively assess whether rop41 affected the growth and proliferation of T.gondii in host cells.Invasion and proliferation assays were conducted to evaluate the invasion ability of the knockout strain into host cells and its intracellular proliferation capacity.The STRING database was utilized to construct a protein-protein interaction(PPI)network,and functional enrichment analysis was performed to predict the signaling pathways in which ROP41 might be involved.Results:The T.gondii rop41 gene knockout strain(RHΔku80Δrop41)was successfully constructed and stably inherited.Plaque assays showed that compared with the parental strain,the number of plaques formed by the rop41 gene knockout strain did not significantly decrease,but the reduction in plaque size was statistically significant(P<0.05).After the rop41 gene was knocked out,the invasion ability of T.gondii was reduced,but there was no statistically significant difference in its proliferation ability(P>0.05).The PPI network revealed that ROP41 was associated with other protein kinases and autophagy related proteins.Enrichment analysis indicated that proteins interacting with ROP41 may be involved in signal transduction,biosynthesis,metabolism,and autophagy-related pathways and could be components of various kinase complexes and phagocytic vesicles.Conclusion:The T.gondii RHΔku80Δrop41 strain has been successfully constructed.ROP41 primarily affects the ability of T.gondii to invade host cells and may play a role in signal transduction and autophagy-related pathways between T.gondii and the host.
文摘Introduction: Toxoplasma gondii is an obligate intracellular protozoan parasite that can infect any warm blood vertebrae, and if first trimester pregnant woman infected, it may cause abortion. The objective is to prove the effect of the Toxoplasma gondii concentration in anti-toxoplasma IgG-IgM antibody levels, and the outcomes of Balb/c mice pregnancies. Materials and Methods: The study was conducted in Balb/c mice with inclusion criteria, and was conditioned pregnant. The pathogen strains of Toxoplasma gondii tachyzoite injected intraperitoneally. The blood samples were taken serially to be tested for anti-toxoplasma IgG-IgM antibody levels. After the mice were injected with tachyzoite, they are assessed every day to observe their body weight, vaginal bleeding, and labor. Anti-toxoplasma IgG-IgM antibody levels examined using qualitative mouse IgG-IgM antibody ELISA KIT. Results: Anti-toxoplasma IgM antibody levels increased significantly after 24 hours of injection tachyzoites in all dose groups, and remained high through day 21. Anti-toxoplasma antibody IgG levels increased significantly after 72 hours post injection and remained elevated until day 21. The incidence of abortion is 100% in mice which injected tachyzoite levels 1 × 103 and 1 × 104, and the incidence of abortion approximately 2 - 4 days post injection. 100% of mice that were injected with tachyzoites 1 × 101 and 1 × 102 have labor at term. Physical anomaly was found in baby mice from mice that were injected with tachyzoite 1 × 102. Conclusion: There is a significant correlation between the concentrations of Toxoplasma gondii tachyzoite with anti-toxoplasma IgG-IgM antibody levels, and there is a significant relationship between the concentrations of tachyzoite with abortion.
文摘Toxoplasma gondii is an intracellular, zoonotic protozoan parasite that causes toxoplasmosis. It can potentially infect almost all mammalian and avian hosts including one-third of the human population world-wide. The major target group of the parasite includes immunocompromised patients (e.g. AIDS, cancer, organ transplantation) and fetus bearing pregnant women where it develops toxoplasmic encephalitis, myocarditis, chorioretinitis and abnormal fetal brain development or stillbirths respectively. In this review, we have presented the current status of T. gondii infection in livestock animals and human population in Bangladesh to assess the country-wide relative risk. Although exact prevalence is difficult to predict due to the scarcity of data, nevertheless existing literature suggests that 16% - 39% humans and 8% - 70% domestic animals are infected with T. gondii, which implies Bangladeshi population is at high risk of toxoplasmosis. Furthermore, we have proposed a potential area of research to decipher the genetic diversity and transmission routes of T. gondii infection into Bangladeshi population.
基金This research was funded by the project 97-01-01-18897 from Shiraz University of Medical Sciences,Shiraz,Iran.
文摘Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its life cycle.The current study aimed to create animal and in vitro models for production of the tachyzoites of the Prugniaud(PRU)genotype II strain.Methods:To develop an immunocompromised model and obtain tachyzoites of the PRU strain,BALB/c mice were orally treated with dexamethasone(10 mg/kg),cyclo-phosphamide(36 mg/kg),and cyclosporine(18 mg/kg)from 5 days prior to inocula-tion.Then,10-15 tissue cysts of PRU strain were inoculated intraperitoneally into the mice.The tachyzoites obtained from mice were then cultivated in a HeLa cell culture.The resulting yield of tachyzoites was cryopreserved in 92%fetal calf serum,8%dimethyl sulfoxide.The infectivity of these tachyzoites was evaluated using in vivo and in vitro examinations.Results:Numerous tachyzoites were observed in the peritoneal fluid of the immuno-suppressed mice within 10-15 days after inoculation,and many tachyzoites were har-vested from the HeLa cell culture.Trypan Blue staining showed 80%viability of the tachyzoites recovered from cryopreservation and this was confirmed by HeLa cell culture.In addition,mice infected intraperitoneally with the recovered tachyzoites presented with cysts in the brain after 2 months.Conclusion:We have developed an animal model for mass production of T.gondii tachyzoites of the PRU strain.This method can provide fresh viable tachyzoites of Toxoplasma gondii for use as and when required in future investigations.
